CA2016642C - Accurate detection of a drastical change between successive pictures - Google Patents
Accurate detection of a drastical change between successive picturesInfo
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- CA2016642C CA2016642C CA 2016642 CA2016642A CA2016642C CA 2016642 C CA2016642 C CA 2016642C CA 2016642 CA2016642 CA 2016642 CA 2016642 A CA2016642 A CA 2016642A CA 2016642 C CA2016642 C CA 2016642C
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Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/147—Scene change detection
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T7/00—Image analysis
- G06T7/20—Analysis of motion
- G06T7/277—Analysis of motion involving stochastic approaches, e.g. using Kalman filters
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
- H04N19/142—Detection of scene cut or scene change
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
- H04N19/179—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a scene or a shot
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/85—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression
- H04N19/87—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using pre-processing or post-processing specially adapted for video compression involving scene cut or scene change detection in combination with video compression
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/14—Picture signal circuitry for video frequency region
- H04N5/144—Movement detection
Abstract
Abstract of the Disclosure:
On detecting a drastical change, such as a scene change, between current and previous ones of successive pictures which are represented by a digital video signal and each of which comprises a predetermined number of picture elements, the digital video signal is processed by using correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures. A statistical distribution of the processed results is calculated from the processed signal. The statistical distribution of the processed results in the current picture is collated with the statistical distribution of the processed results in the previous picture to be produced as a change detection signal representative of the drastical change with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the processed results in the previous picture. The processed signal may be obtained by producing a difference signal between the digital video signal and a prediction signal predictive of the digital video signal by using the correlations. Alternatively, an orthogonal transform is carried out for the digital video signal to produce the processed signal.
On detecting a drastical change, such as a scene change, between current and previous ones of successive pictures which are represented by a digital video signal and each of which comprises a predetermined number of picture elements, the digital video signal is processed by using correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures. A statistical distribution of the processed results is calculated from the processed signal. The statistical distribution of the processed results in the current picture is collated with the statistical distribution of the processed results in the previous picture to be produced as a change detection signal representative of the drastical change with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the processed results in the previous picture. The processed signal may be obtained by producing a difference signal between the digital video signal and a prediction signal predictive of the digital video signal by using the correlations. Alternatively, an orthogonal transform is carried out for the digital video signal to produce the processed signal.
Description
~016fi4Z
ACCURATE DETECTION OF A DRASTICAL CHANGE
BETWEEN SUCCESSIVE PICTURES
Background of the Invention:
_, This invention relates to a method of detecting a drastical change between two adjacent ones o~
successive pictures represented by an input digital 5 video signal. This invention relates also to a detecting device for use in carrying out the method.
The input digital video signal is, for example, a television s:ignal. Each of the successive pictures comprises a predetermined number of picture elements and 10 corresponds to a frame of the input digital video signal.
As will later be described, a conventional detecting method makes use of a correlation between two successive pictures in order to detect the drastical or 15 large change, such as a scene change, between two adjacent ones of successive pictures. More specifically, a frame memory delays the input digital video signal into a delayed digital video signal having 2 ;~01~i4~
a delay which is e~ual to one frame of the input digital video signal. A subtracter produces a difference signal representative of a difference between the input digital video signal and the delayed digital video signal.
5 Responsive to the 'difference signal, a first comparator compares an absolute value of the difference with a first threshold value for each picture element to produce first and second comparison result signals when the absolute value is greater than the first threshold 10 value and when the absolute value is not greater than the first threshold value, respectively. A counter counts the first comparison result signals for each picture to produce a count signal. A second comparator compares the count signal with a second threshold value 15 to produce a change detection signal representative of the drastical change when the count signal is greater than the second threshold value.
The conventional method is, however, defective in that the change detection signal is produced even 20 when a large object body moves so that the large object body has different positions in a current picture and in a previous picture which are two adjacent ones of the successive pictures. The conventional method is therefore incapable of accuratel~ detecting a drastical 25 change.
ACCURATE DETECTION OF A DRASTICAL CHANGE
BETWEEN SUCCESSIVE PICTURES
Background of the Invention:
_, This invention relates to a method of detecting a drastical change between two adjacent ones o~
successive pictures represented by an input digital 5 video signal. This invention relates also to a detecting device for use in carrying out the method.
The input digital video signal is, for example, a television s:ignal. Each of the successive pictures comprises a predetermined number of picture elements and 10 corresponds to a frame of the input digital video signal.
As will later be described, a conventional detecting method makes use of a correlation between two successive pictures in order to detect the drastical or 15 large change, such as a scene change, between two adjacent ones of successive pictures. More specifically, a frame memory delays the input digital video signal into a delayed digital video signal having 2 ;~01~i4~
a delay which is e~ual to one frame of the input digital video signal. A subtracter produces a difference signal representative of a difference between the input digital video signal and the delayed digital video signal.
5 Responsive to the 'difference signal, a first comparator compares an absolute value of the difference with a first threshold value for each picture element to produce first and second comparison result signals when the absolute value is greater than the first threshold 10 value and when the absolute value is not greater than the first threshold value, respectively. A counter counts the first comparison result signals for each picture to produce a count signal. A second comparator compares the count signal with a second threshold value 15 to produce a change detection signal representative of the drastical change when the count signal is greater than the second threshold value.
The conventional method is, however, defective in that the change detection signal is produced even 20 when a large object body moves so that the large object body has different positions in a current picture and in a previous picture which are two adjacent ones of the successive pictures. The conventional method is therefore incapable of accuratel~ detecting a drastical 25 change.
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Summary of the Invention:
It is therefore a general object of this invention to provide a method of accurately detecting a drastical change between two successive pictures.
S It is a specific object of this invention to provide a detecting device for accurately detecting a drastical change between two successive pictures.
Other objects of this invention will become clear as the description proceeds.
On describing the gist of this invention, it is possible to understand that a method is for detecting a change between current and previous pictures which are two adjacent ones of successive pictures represented by an input digital video signal. Each of the successive 15 pictures comprises a predetermined number of picture elements.
According to this invention, the above-understood method comprises the steps of:
processing the input digital video signal by using 20 correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures; calculating a statistical distribution of the processed results in response to the 25 processed signal; and collating the statistical distribution of the processed results in the current picture with the statistical distribution of the processed results in the previous picture to produce a 4 ~01664~
change detection signal representative of the change with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the 5 processed results in the previous picture.
On describing the gist of this invention, it is furthermore possible to understand that a detecting device is for detecting a change between current and previous pictures which are two adjacent ones of 10 successive pictures represented by an input digital video signal. Each of the successive pictures comprises a predetermined number of picture elements.
According to this invention, the above-understood detecting device comprises: processing means 15 for processing the input digital video signal by using correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures; statistical distribution 20 calculating means connected to the processing means and supplied with the processed signal for calculating a statistical distribution of said processed results; and collating means connected to the statistical distribution calculating means for collating the 25 statistical distribution of the processed results in the current picture with the statistical dis-tribution of the processed results in the previous picture to produce a change detection signal representative of said change 201664'~, with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the processed results in the previous picture.
Brief_Description of the Drawing:
Fig. 1 is a block diagram of a detecting device for use in describing a conventional method;
Figs. 2(A) and 2(B) are graphs for use in describing a demerit of the detecting device illustrated 10 in Fig. l;
Figs. 3(A) and 3(B) are graphs for use in describing another demerit of the detecting device illustrated in Fig. l;
Fig. 4 is a block diagram of a detecting device 15 for use in carrying out a method according to an embodiment of this invention;
Fig. 5 is a block diagram of a processing circuit of the detecting device illustrated in Fig. 4;
Fig. 6 is a diagram for use in describing 20 operation of the processing circuit illustrated in Fig. S;
Fig. 7 is a block diagram of another processing circuit which may be used in the detecting device illustrated in Fig. 4; and Figs. 8(A), 8(B), 8(C), and 8(D) are graphs for use in describing operation of a statistical distribution calculating circuit of the detecting device illustrated in Fig. 4.
Summary of the Invention:
It is therefore a general object of this invention to provide a method of accurately detecting a drastical change between two successive pictures.
S It is a specific object of this invention to provide a detecting device for accurately detecting a drastical change between two successive pictures.
Other objects of this invention will become clear as the description proceeds.
On describing the gist of this invention, it is possible to understand that a method is for detecting a change between current and previous pictures which are two adjacent ones of successive pictures represented by an input digital video signal. Each of the successive 15 pictures comprises a predetermined number of picture elements.
According to this invention, the above-understood method comprises the steps of:
processing the input digital video signal by using 20 correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures; calculating a statistical distribution of the processed results in response to the 25 processed signal; and collating the statistical distribution of the processed results in the current picture with the statistical distribution of the processed results in the previous picture to produce a 4 ~01664~
change detection signal representative of the change with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the 5 processed results in the previous picture.
On describing the gist of this invention, it is furthermore possible to understand that a detecting device is for detecting a change between current and previous pictures which are two adjacent ones of 10 successive pictures represented by an input digital video signal. Each of the successive pictures comprises a predetermined number of picture elements.
According to this invention, the above-understood detecting device comprises: processing means 15 for processing the input digital video signal by using correlations between the picture elements within each of the successive pictures to produce a processed signal which represents processed results for each of the successive pictures; statistical distribution 20 calculating means connected to the processing means and supplied with the processed signal for calculating a statistical distribution of said processed results; and collating means connected to the statistical distribution calculating means for collating the 25 statistical distribution of the processed results in the current picture with the statistical dis-tribution of the processed results in the previous picture to produce a change detection signal representative of said change 201664'~, with reference to a relationship between the statistical distribution of the processed results in the current picture and the statistical distribution of the processed results in the previous picture.
Brief_Description of the Drawing:
Fig. 1 is a block diagram of a detecting device for use in describing a conventional method;
Figs. 2(A) and 2(B) are graphs for use in describing a demerit of the detecting device illustrated 10 in Fig. l;
Figs. 3(A) and 3(B) are graphs for use in describing another demerit of the detecting device illustrated in Fig. l;
Fig. 4 is a block diagram of a detecting device 15 for use in carrying out a method according to an embodiment of this invention;
Fig. 5 is a block diagram of a processing circuit of the detecting device illustrated in Fig. 4;
Fig. 6 is a diagram for use in describing 20 operation of the processing circuit illustrated in Fig. S;
Fig. 7 is a block diagram of another processing circuit which may be used in the detecting device illustrated in Fig. 4; and Figs. 8(A), 8(B), 8(C), and 8(D) are graphs for use in describing operation of a statistical distribution calculating circuit of the detecting device illustrated in Fig. 4.
6 2()1664~
Description of the Preferred Embodiment:
.
Referring to Fig. 1, description will now be made at first as regards a conventional detecting device for use in carrying out a conventional method which is 5 equivalent to that described in the preamble of the instant specification. The conventional detecting device is for detecting a drastical change, such as a scene change, between two adjacent ones of successive pictures represented by an input digital video signal 10 10.
The conventional detecting device comprises a frame memory 11 which delays the input digital video signal 10 into a delayed digital video signal having a delay which. is equal to one frame of the input digital 15 video signal. A subtracter 12 produces a difference signal representative of a difference (namely, an interframe difference) between the input digital video signal 10 and the delayed digital video signal.
Responsive to the difference signal, a first 20 comparator 13 compares an absolute value of the difference with a first threshold value 14 for each picture element. The first comparator 13 thereby produces first and second comparison result signals when the absolute value is greater than the first threshold 25 value 14 and when the absolute value is not greater than the first threshold value 14, respectively.
A counter 15 counts the first comparison result signals for each picture to produce a count signal. A
Description of the Preferred Embodiment:
.
Referring to Fig. 1, description will now be made at first as regards a conventional detecting device for use in carrying out a conventional method which is 5 equivalent to that described in the preamble of the instant specification. The conventional detecting device is for detecting a drastical change, such as a scene change, between two adjacent ones of successive pictures represented by an input digital video signal 10 10.
The conventional detecting device comprises a frame memory 11 which delays the input digital video signal 10 into a delayed digital video signal having a delay which. is equal to one frame of the input digital 15 video signal. A subtracter 12 produces a difference signal representative of a difference (namely, an interframe difference) between the input digital video signal 10 and the delayed digital video signal.
Responsive to the difference signal, a first 20 comparator 13 compares an absolute value of the difference with a first threshold value 14 for each picture element. The first comparator 13 thereby produces first and second comparison result signals when the absolute value is greater than the first threshold 25 value 14 and when the absolute value is not greater than the first threshold value 14, respectively.
A counter 15 counts the first comparison result signals for each picture to produce a count signal. A
7 20~6fi4~
second comparator lh compares the count signal with a second threshold value 17 to produce a change detection signal representative of the drastical change when the count signal is greater than the second threshold value 5 17~
Inasmuch as the conventional method makes use of a correlation between two successive pictures in order to detect the drastical change between two adjacent ones of the successive pictures, the conventional method is 10 defective in that the change detection signal is incorrectly produced in a case where a large image of, for example, an object body has different positions in current and previous pictures which are two adjacent ones of the successive pi,ctures. The change detection 15 signal is also incorrectly produced when a background surrounding the object body changes in brightness in the current and the previous pictures.
Turning to Figs. 2(A) and 2(B) with reference to Fig. 1 continued, the reason will be described why the 20 change detection signal is produced even when a large image has different positions in the current and the previous pictures. In Fig. 2(A), a solid-line curve 20 shows a frequency distribution of the interframe differences which are produced by the subtracter 12 for 25 an i-th picture of the input digital video signal 10~
The first comparator 13 compares each of the interframe differences with the first threshold value 14 for each picture element. The first threshold value 14 has plus 8 ~016fi~
and minus threshold values + ~ shown in Fig. 2. The first comparator 13 thereby produces the first comparison result signal when an absolute value of each of the interframe differences is greater than another 5 absolute value of each of the plus and minus threshold value + ~ . The counter 15 counts the first comparison result signals for each picture and produces a count signal. The second comparator 16 compares the count signal with the second threshold value 17 to produce the 10 chanqe detection signal when the count signal is greater than the second threshold value 17. For the frequency distribution of the interframe differences illustrated in Fig. 2(A), the second comparator 16 produces no change detection signal.
It is assumed that a large image moves so that the large image has different positions in the i-th picture and an (i+l)-th picture which next succeeds the i-th picture in the input digital video signal 10. In Fig. 2(B), another solid-line curve 21 shows another 20 frequency distribution of the interframe differences which are produced by the subtracter 12 for the (i+l)-th picture. For the frequency distribution of the interframe differences illustrated in Fig. 2(B), the second comparator 16 inevitably produces the change 25 detection si~nal although the drastical change, such as the scene change, does not actually occur.
Turning to Figs. 3(A) and 3(B) with reference to Fig. 1 continued, description will be made as regards g Z01664;2 another case where the change detection signal is incorrectly produced. In Fig. 3(A), a solid-line curve 22 shows a frequency distribution of the interframe differences which are produced by the subtracter 12 for 5 an n-th picture of the input digital video signal 10.
The frequency distribution of the interframe differences has an average level which is substantially equal to zero. For the frequency distribution of the interframe differences illustrated in Fig. 3(A), the second 10 comparator 16 produces no change detection signal like for the frequency distribution illustrated in Fig. 2(A).
In Fig. 3(B), another solid-line curve 23 shows a different frequency distribution of the interframe differences which are produced for an (n+l)-th picture 15 which next succeeds the n-th picture in the input digital video signal 10. The different frequency distribution of the interframe differences has another average level which is substantially equal to a positive value + L. The positive value + L is greater than the 20 plus threshold value +a . That is, an offset is generated in an entire area of the (n+l)-th picture.
For the different frequency distribution of the interframe differences illustrated in Fig. 3(B), the second comparator 16 unavoidably produces the change 25 detection signal although the drastical change, such as the scene change, does not occur in fact.
Such a frequency distribution illustrated in Fig. 3(B) may be produced when operation is started for 20~66~.~
an automatic iris diaphragm unit of a television camera connected to the detecting device. When either a fluctuation of illumination or a flicker occurs in light sources illuminating the object body, the frequency 5 distribution illustrated in Fig. 3~B) may also be produced .
Turning to Fig. 4, description will proceed to a detecting device for use in carrying out a method according to a preferred embodiment of this invention.
10 The detecting device is for detecting a drastical change, such as a scene change, between current and previous pictures which are two adjacent ones of successive pictures represented by the input digital video signal 10. Each of the successive pictures 15 comprises a predetermined number of picture elements.
A processing circuit 30 processes the input digital video signal 10 by using correlations between the picture elements within each of the successive pictures. The processing circuit 30 thereby produces a 20 processed siqnal 31 which represents processed results for each of the successive pictures. Use of the correlations within each picture can reduce an influence of a movement of the large body from the previous picture to the current picture. It is also possible to 25 reduce another influence of the offset generated in an entire area of the current picture by either the fluctuation of illumination or the flicker which occurs in the light sources surrounding the object body. The 20~66~:
processing circuit 30 will later be described more in detail.
A statistical distribution calculating circuit 32 is connected to the processing circuit 30. Supplied 5 with the processed signal 31, the statistical distribution calculating circuit 32 calculates a statistical distribution of the processed results. The statistical distribution calculating circuit 32 will ]ater be described.
A collating circuit 33 is connected to the statistical dist~ribution calculating circuit 32. The collating circuit 33 collates the statistical distribution of the processed results in the current picture with the statistical distribution of the 15 processed results in the previous picture and produces a change detection signal representative of the drastical change, such as the scene change, with reference to a relationship between the statistical distribution of the processed results in the current picture and the 20 statistical distribution of the processed results in the previous picture.
The collating circuit 33 comprises a distribution difference calculating circuit 34 connected to the statistical distribution calculating circuit 32.
25 The distribution difference calculating circuit 34 calculates distribution differences between the statistical distribution of the processed results in the 12 201664~
current picture and the statistical distribution of the processed results in the previous picture.
More specifically, a frame memory (namely, a temporary memory) 35 is connected to the statistical 5 distribution calculating circuit 32. The frame memory 35 temporarily memorizes the statistical distribution of the processed results in the current picture during one frame of the input digital video signal 10 and produces a delayed distribution having a delay which is equal to 10 one frame.
A subtracter 36 is connected to the statistical distribution calculating circuit 32 and the frame memory 35. The subtracter 36 calculates differences between the statistical distribution of the processed results in 15 the current picture and the delayed distribution as the distribution differences.
A comparator 37 is connected to the distribution difference calculating circuit 34. The comparator 37 compares each of the distribution differences with a 20 predetermined threshold value 38. The comparator 37 thereby produces the change detection signal with reference to a relationship between each of the distribution differences and the predetermined threshold value 38.
The distribution difference calculating circuit 34 may calculate a sum of absolute values of the distribution differences. In this case, the comparator 37 compares the sum of the absolute values of the 13 201~6~
distribution differences with the predetermined threshold value 38 and produces the change detection signal when the sum of the absolute values of the distribution differences is greater than the S predetermined threshold value 38~
As an alternative, the distribution difference calculating circuit 34 may calculate another sum of frequencies or times when the distribution differences have absolute values each of which is greater than a 10 preselected level. In this case, the other sum is compared with the predetermined threshold value 38 in the comparator 37. As a further alternative, the distribution difference calculating circuit 34 may calculate a product of the preselected level and the 15 frequencies.
As a still further alternative, the distribution difference calculating circuit 34 may calculate a pattern of the distribution differences. In this case, the comparator 37 may compare the pattern of the 20 distribution differences with a reference pattern.
Turning to Fig. 5, the processing circuit 30 comprises a predictor ~namely, a prediction signal producing circuit) 38'. Responsive to the input digital video signal 10, the predictor 38' produces a prediction 25 signal predictive of the input digital video signal 10 by using correlations between the picture elements within each of the successive pictures in the manner which will presently be described. Connected to the 201664~
predictor 38, another subtracter (namely, a difference signal producing circuit) 39 produces, as the processed signal 31, a difference signal which represents, as the processed results, differences between the input digital 5 video signal 10 and the prediction signal for each of the successive pictures.
The predictor 38' has a predictive fu~nction so that prediction of a particular element of the picture elements of the current picture is carried out by the 10 use of a previous element of the picture elements of the current picture. The particular element next succeeds the previous element in the input digital video signal 10 .
Supposing in Fig. 6 that the particular element 15 is designated by c, the previous element corresponds to an element designated by d. In Fig. 6, three of scanning lines of the input digital video signal 10 are depicted b~ parallel lines.
As an alternative, the predictor 38' illustrated 20 in Fig. 5 may have another predictive function in which prediction of a particular element of a specific line of the scanning lines of the current picture is carried out by the use of a corresponding element of a previous line of the scanning lines of the current picture. The 25 specific line next succeeds the previous line in the input digital video signal 10. The corresponding element corresponds to the particular element.
Supposing in Fig. 6 again that the particular element is 201664~
designated by c, the corresponding element is an element designated by e.
As a further alternative, prediction of the particular element c illustrated in Fig. 6 may be 5 carried out by the use of either a combination of the pre~ious element d and the corresponding element e or another combination of picture elements a, b, d, and e which surround the particular element c. In the latter case, the processing circuit 30 (Fig. 4) produces the 10 processed signal 31 (Fig. 4) representative of a result of a calculation of c - (a + b + d ~ e)/4, where a, b, c, d, and e represent amplitude values of the picture elements a, b, c, d, and e, respectively. Such a processing circuit will be exemplified in the following.
Referring to Fig. 7, the processing circuit comprises a first delay circuit 41 for delaying the input digital video signal 10 by a first delay which is equal to a period of each scanning line minus another period of each picture element. The first delay circuit 20 41 thereby produces a first delayed signal. A second delay circuit 42 delays the first delayed signal by a second delay which is equal to the other period of each picture element. The second delay circuit 42 thereby produces a second delayed signal. A third delay circuit 25 43 delays the second delayed signal by the second delay and produces a third delayed signal. A fourth delay circuit 44 delays the third delayed signal by the first delay and produces a fourth delayed signal.
~U1~64~
With this arrangement of the first through the fourth delay circuits 41 to 44, the first through the fourth delayed signals represent the picture elements b, c, d, and e (Fig. 6), respectively, at a time instant 5 when the input digital video signal 10 represents the picture element a (Fig. 6).
Responsive to the input digital video signal 10, and the first through the fourth delayed signals, an arithmetic circuit 45 produces the processed signal 31 10 representative of a result of the calculation of c - (a + b + d + e)/4 at the time instant when the input digital video signal 10 represents the picture element a (Fig. 6).
Turning to Figs. 8(A), 8(B), 8~C), and 8(D)I the 15 statistical distribution calculating circuit 32 illustrated in Fig 4 will be described more in detail.
As described with reference to Figs. 5 and 6, the processing circuit 30 produces, as the processed signal 31, a difference signal representative of a difference 20 between one of the picture elements of the current picture and a previous element which is followed by the above-mentioned one of the picture elements of the current picture.
The statistical distribution calculating circuit 25 32 produces, as the statistical distribution, a fre~uency distribution of the differences between picture elements within each picture. The statistical 17 20~664;?~
distribution calculating circuit 32 may be constituted by a combination of a comparator and a counter.
In each of Figs. 8(A), 8(B), 8(C), and 8(D), a frequency distribution of the differences is exemplified 5 for each of (i-l)-th, i-th, (i+l)-th, and (i+2)-th pictures which are four successive pictures. Almost no change occurs in the statistical distribution between the (i-l)-th picture and the i-th picture. A large change appears in the statistical distribution between 10 the i-th picture and the (i+l)-th picture. Almost no change appears in the statistical distribution between the (i+l)-th picture and the (i+2~-th picture. It may be understood that each of the (i-l)-th and the i-th pictures has a small amount of comparatively complicated 15 patterns and that each of the (i+l)-th and the (i+2)-th pictures has a lot of the comparatively complicated patterns.
The collating circuit 33 (Fig. 4) produces the change detection signal when a large change appears in 20 the statistical distribution, namely, when the collating circuit 33 processes the (i+l)-th picture.
The detecting device illustrated in Fig. 4 may be used in, for example, a coding device for carrying out predictive coding of a digital video signal by using 25 correlation between two successive pictures. Such a coding device is disclosed, for example, in United States Patent No. 4,689,672 issued to Akihiro Furukawa et al and assigned to the present assignee. In the 18 ~0166~
Furukawa et al device, a change detection signal is produced as a result of a drastical change, such as a scene change, from a previous picture to a current picture. The digital video signal is separated, in 5 response to the change detection signal, into a preceding part ending at the previous picture and a succeeding part which begins at the current picture.
Furthermore, the change detection signal controls the predictive coding so that the succeeding part be coded 10 with an area of predictive coding of each picture gradually widened with time. According to Furukawa et al, pictures can be reproduced with a high quality even when the drastical change occurs.
While this invention has thus far been described 15 in conjunction with a single preferred embodiment thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, an orthogonal transform circuit may be used as the processing circuit 20 30 illustrated in Fig. 4. The orthogonal transform circuit is for carrying out either of a one-dimensional and a two-dimensional orthogonal transform of the input digital video signal 10 to produce, as the processed signal 31, a resul`t signal which represents, as the 25 processed results, transform results of the orthogonal transform for each of the successive pictures.
When the orthogonal transform circuit is used, the statistical distribution calculating circuit 32 19 20~664?, calculates a statistical distribution of coefficient values of transform coefficients which are produced as the transform results of the orthogonal transform.
Inasmuch as the coeff cient values represent discrete 5 frequency components, respectively, which belong to a frequency range from a direct current component to a high frequency component, it is possible to elevate an accuracy of detecting the drastical change by calculating the statistical distribution of the 10 coefficient values for the discrete frequency components in each picture and by collating the statistical distribution of the coefficient values in the current picture with the statistical distribution of the coefficient values in the previous picture. The 15 collating circuit 33 collates the statistical distribution of the coefficient values in the current picture with the statistical distribution of the coefficient values in the previous picture in the manner described in conjunction with Fig. 4. When the 20 two-dimensional orthogonal transform is carried out for each block comprising a predetermined number N of samples (namely, picture elements) and the same number N
of the scanning lines, the number N x N of the discrete frequency components are obtained from each block. It 25 is possible to remove the offset by subtracting from each of the coefficient values a lowest one of the coefficient values that represents the direct current component.
second comparator lh compares the count signal with a second threshold value 17 to produce a change detection signal representative of the drastical change when the count signal is greater than the second threshold value 5 17~
Inasmuch as the conventional method makes use of a correlation between two successive pictures in order to detect the drastical change between two adjacent ones of the successive pictures, the conventional method is 10 defective in that the change detection signal is incorrectly produced in a case where a large image of, for example, an object body has different positions in current and previous pictures which are two adjacent ones of the successive pi,ctures. The change detection 15 signal is also incorrectly produced when a background surrounding the object body changes in brightness in the current and the previous pictures.
Turning to Figs. 2(A) and 2(B) with reference to Fig. 1 continued, the reason will be described why the 20 change detection signal is produced even when a large image has different positions in the current and the previous pictures. In Fig. 2(A), a solid-line curve 20 shows a frequency distribution of the interframe differences which are produced by the subtracter 12 for 25 an i-th picture of the input digital video signal 10~
The first comparator 13 compares each of the interframe differences with the first threshold value 14 for each picture element. The first threshold value 14 has plus 8 ~016fi~
and minus threshold values + ~ shown in Fig. 2. The first comparator 13 thereby produces the first comparison result signal when an absolute value of each of the interframe differences is greater than another 5 absolute value of each of the plus and minus threshold value + ~ . The counter 15 counts the first comparison result signals for each picture and produces a count signal. The second comparator 16 compares the count signal with the second threshold value 17 to produce the 10 chanqe detection signal when the count signal is greater than the second threshold value 17. For the frequency distribution of the interframe differences illustrated in Fig. 2(A), the second comparator 16 produces no change detection signal.
It is assumed that a large image moves so that the large image has different positions in the i-th picture and an (i+l)-th picture which next succeeds the i-th picture in the input digital video signal 10. In Fig. 2(B), another solid-line curve 21 shows another 20 frequency distribution of the interframe differences which are produced by the subtracter 12 for the (i+l)-th picture. For the frequency distribution of the interframe differences illustrated in Fig. 2(B), the second comparator 16 inevitably produces the change 25 detection si~nal although the drastical change, such as the scene change, does not actually occur.
Turning to Figs. 3(A) and 3(B) with reference to Fig. 1 continued, description will be made as regards g Z01664;2 another case where the change detection signal is incorrectly produced. In Fig. 3(A), a solid-line curve 22 shows a frequency distribution of the interframe differences which are produced by the subtracter 12 for 5 an n-th picture of the input digital video signal 10.
The frequency distribution of the interframe differences has an average level which is substantially equal to zero. For the frequency distribution of the interframe differences illustrated in Fig. 3(A), the second 10 comparator 16 produces no change detection signal like for the frequency distribution illustrated in Fig. 2(A).
In Fig. 3(B), another solid-line curve 23 shows a different frequency distribution of the interframe differences which are produced for an (n+l)-th picture 15 which next succeeds the n-th picture in the input digital video signal 10. The different frequency distribution of the interframe differences has another average level which is substantially equal to a positive value + L. The positive value + L is greater than the 20 plus threshold value +a . That is, an offset is generated in an entire area of the (n+l)-th picture.
For the different frequency distribution of the interframe differences illustrated in Fig. 3(B), the second comparator 16 unavoidably produces the change 25 detection signal although the drastical change, such as the scene change, does not occur in fact.
Such a frequency distribution illustrated in Fig. 3(B) may be produced when operation is started for 20~66~.~
an automatic iris diaphragm unit of a television camera connected to the detecting device. When either a fluctuation of illumination or a flicker occurs in light sources illuminating the object body, the frequency 5 distribution illustrated in Fig. 3~B) may also be produced .
Turning to Fig. 4, description will proceed to a detecting device for use in carrying out a method according to a preferred embodiment of this invention.
10 The detecting device is for detecting a drastical change, such as a scene change, between current and previous pictures which are two adjacent ones of successive pictures represented by the input digital video signal 10. Each of the successive pictures 15 comprises a predetermined number of picture elements.
A processing circuit 30 processes the input digital video signal 10 by using correlations between the picture elements within each of the successive pictures. The processing circuit 30 thereby produces a 20 processed siqnal 31 which represents processed results for each of the successive pictures. Use of the correlations within each picture can reduce an influence of a movement of the large body from the previous picture to the current picture. It is also possible to 25 reduce another influence of the offset generated in an entire area of the current picture by either the fluctuation of illumination or the flicker which occurs in the light sources surrounding the object body. The 20~66~:
processing circuit 30 will later be described more in detail.
A statistical distribution calculating circuit 32 is connected to the processing circuit 30. Supplied 5 with the processed signal 31, the statistical distribution calculating circuit 32 calculates a statistical distribution of the processed results. The statistical distribution calculating circuit 32 will ]ater be described.
A collating circuit 33 is connected to the statistical dist~ribution calculating circuit 32. The collating circuit 33 collates the statistical distribution of the processed results in the current picture with the statistical distribution of the 15 processed results in the previous picture and produces a change detection signal representative of the drastical change, such as the scene change, with reference to a relationship between the statistical distribution of the processed results in the current picture and the 20 statistical distribution of the processed results in the previous picture.
The collating circuit 33 comprises a distribution difference calculating circuit 34 connected to the statistical distribution calculating circuit 32.
25 The distribution difference calculating circuit 34 calculates distribution differences between the statistical distribution of the processed results in the 12 201664~
current picture and the statistical distribution of the processed results in the previous picture.
More specifically, a frame memory (namely, a temporary memory) 35 is connected to the statistical 5 distribution calculating circuit 32. The frame memory 35 temporarily memorizes the statistical distribution of the processed results in the current picture during one frame of the input digital video signal 10 and produces a delayed distribution having a delay which is equal to 10 one frame.
A subtracter 36 is connected to the statistical distribution calculating circuit 32 and the frame memory 35. The subtracter 36 calculates differences between the statistical distribution of the processed results in 15 the current picture and the delayed distribution as the distribution differences.
A comparator 37 is connected to the distribution difference calculating circuit 34. The comparator 37 compares each of the distribution differences with a 20 predetermined threshold value 38. The comparator 37 thereby produces the change detection signal with reference to a relationship between each of the distribution differences and the predetermined threshold value 38.
The distribution difference calculating circuit 34 may calculate a sum of absolute values of the distribution differences. In this case, the comparator 37 compares the sum of the absolute values of the 13 201~6~
distribution differences with the predetermined threshold value 38 and produces the change detection signal when the sum of the absolute values of the distribution differences is greater than the S predetermined threshold value 38~
As an alternative, the distribution difference calculating circuit 34 may calculate another sum of frequencies or times when the distribution differences have absolute values each of which is greater than a 10 preselected level. In this case, the other sum is compared with the predetermined threshold value 38 in the comparator 37. As a further alternative, the distribution difference calculating circuit 34 may calculate a product of the preselected level and the 15 frequencies.
As a still further alternative, the distribution difference calculating circuit 34 may calculate a pattern of the distribution differences. In this case, the comparator 37 may compare the pattern of the 20 distribution differences with a reference pattern.
Turning to Fig. 5, the processing circuit 30 comprises a predictor ~namely, a prediction signal producing circuit) 38'. Responsive to the input digital video signal 10, the predictor 38' produces a prediction 25 signal predictive of the input digital video signal 10 by using correlations between the picture elements within each of the successive pictures in the manner which will presently be described. Connected to the 201664~
predictor 38, another subtracter (namely, a difference signal producing circuit) 39 produces, as the processed signal 31, a difference signal which represents, as the processed results, differences between the input digital 5 video signal 10 and the prediction signal for each of the successive pictures.
The predictor 38' has a predictive fu~nction so that prediction of a particular element of the picture elements of the current picture is carried out by the 10 use of a previous element of the picture elements of the current picture. The particular element next succeeds the previous element in the input digital video signal 10 .
Supposing in Fig. 6 that the particular element 15 is designated by c, the previous element corresponds to an element designated by d. In Fig. 6, three of scanning lines of the input digital video signal 10 are depicted b~ parallel lines.
As an alternative, the predictor 38' illustrated 20 in Fig. 5 may have another predictive function in which prediction of a particular element of a specific line of the scanning lines of the current picture is carried out by the use of a corresponding element of a previous line of the scanning lines of the current picture. The 25 specific line next succeeds the previous line in the input digital video signal 10. The corresponding element corresponds to the particular element.
Supposing in Fig. 6 again that the particular element is 201664~
designated by c, the corresponding element is an element designated by e.
As a further alternative, prediction of the particular element c illustrated in Fig. 6 may be 5 carried out by the use of either a combination of the pre~ious element d and the corresponding element e or another combination of picture elements a, b, d, and e which surround the particular element c. In the latter case, the processing circuit 30 (Fig. 4) produces the 10 processed signal 31 (Fig. 4) representative of a result of a calculation of c - (a + b + d ~ e)/4, where a, b, c, d, and e represent amplitude values of the picture elements a, b, c, d, and e, respectively. Such a processing circuit will be exemplified in the following.
Referring to Fig. 7, the processing circuit comprises a first delay circuit 41 for delaying the input digital video signal 10 by a first delay which is equal to a period of each scanning line minus another period of each picture element. The first delay circuit 20 41 thereby produces a first delayed signal. A second delay circuit 42 delays the first delayed signal by a second delay which is equal to the other period of each picture element. The second delay circuit 42 thereby produces a second delayed signal. A third delay circuit 25 43 delays the second delayed signal by the second delay and produces a third delayed signal. A fourth delay circuit 44 delays the third delayed signal by the first delay and produces a fourth delayed signal.
~U1~64~
With this arrangement of the first through the fourth delay circuits 41 to 44, the first through the fourth delayed signals represent the picture elements b, c, d, and e (Fig. 6), respectively, at a time instant 5 when the input digital video signal 10 represents the picture element a (Fig. 6).
Responsive to the input digital video signal 10, and the first through the fourth delayed signals, an arithmetic circuit 45 produces the processed signal 31 10 representative of a result of the calculation of c - (a + b + d + e)/4 at the time instant when the input digital video signal 10 represents the picture element a (Fig. 6).
Turning to Figs. 8(A), 8(B), 8~C), and 8(D)I the 15 statistical distribution calculating circuit 32 illustrated in Fig 4 will be described more in detail.
As described with reference to Figs. 5 and 6, the processing circuit 30 produces, as the processed signal 31, a difference signal representative of a difference 20 between one of the picture elements of the current picture and a previous element which is followed by the above-mentioned one of the picture elements of the current picture.
The statistical distribution calculating circuit 25 32 produces, as the statistical distribution, a fre~uency distribution of the differences between picture elements within each picture. The statistical 17 20~664;?~
distribution calculating circuit 32 may be constituted by a combination of a comparator and a counter.
In each of Figs. 8(A), 8(B), 8(C), and 8(D), a frequency distribution of the differences is exemplified 5 for each of (i-l)-th, i-th, (i+l)-th, and (i+2)-th pictures which are four successive pictures. Almost no change occurs in the statistical distribution between the (i-l)-th picture and the i-th picture. A large change appears in the statistical distribution between 10 the i-th picture and the (i+l)-th picture. Almost no change appears in the statistical distribution between the (i+l)-th picture and the (i+2~-th picture. It may be understood that each of the (i-l)-th and the i-th pictures has a small amount of comparatively complicated 15 patterns and that each of the (i+l)-th and the (i+2)-th pictures has a lot of the comparatively complicated patterns.
The collating circuit 33 (Fig. 4) produces the change detection signal when a large change appears in 20 the statistical distribution, namely, when the collating circuit 33 processes the (i+l)-th picture.
The detecting device illustrated in Fig. 4 may be used in, for example, a coding device for carrying out predictive coding of a digital video signal by using 25 correlation between two successive pictures. Such a coding device is disclosed, for example, in United States Patent No. 4,689,672 issued to Akihiro Furukawa et al and assigned to the present assignee. In the 18 ~0166~
Furukawa et al device, a change detection signal is produced as a result of a drastical change, such as a scene change, from a previous picture to a current picture. The digital video signal is separated, in 5 response to the change detection signal, into a preceding part ending at the previous picture and a succeeding part which begins at the current picture.
Furthermore, the change detection signal controls the predictive coding so that the succeeding part be coded 10 with an area of predictive coding of each picture gradually widened with time. According to Furukawa et al, pictures can be reproduced with a high quality even when the drastical change occurs.
While this invention has thus far been described 15 in conjunction with a single preferred embodiment thereof, it will readily be possible for those skilled in the art to put this invention into practice in various other manners. For example, an orthogonal transform circuit may be used as the processing circuit 20 30 illustrated in Fig. 4. The orthogonal transform circuit is for carrying out either of a one-dimensional and a two-dimensional orthogonal transform of the input digital video signal 10 to produce, as the processed signal 31, a resul`t signal which represents, as the 25 processed results, transform results of the orthogonal transform for each of the successive pictures.
When the orthogonal transform circuit is used, the statistical distribution calculating circuit 32 19 20~664?, calculates a statistical distribution of coefficient values of transform coefficients which are produced as the transform results of the orthogonal transform.
Inasmuch as the coeff cient values represent discrete 5 frequency components, respectively, which belong to a frequency range from a direct current component to a high frequency component, it is possible to elevate an accuracy of detecting the drastical change by calculating the statistical distribution of the 10 coefficient values for the discrete frequency components in each picture and by collating the statistical distribution of the coefficient values in the current picture with the statistical distribution of the coefficient values in the previous picture. The 15 collating circuit 33 collates the statistical distribution of the coefficient values in the current picture with the statistical distribution of the coefficient values in the previous picture in the manner described in conjunction with Fig. 4. When the 20 two-dimensional orthogonal transform is carried out for each block comprising a predetermined number N of samples (namely, picture elements) and the same number N
of the scanning lines, the number N x N of the discrete frequency components are obtained from each block. It 25 is possible to remove the offset by subtracting from each of the coefficient values a lowest one of the coefficient values that represents the direct current component.
Claims (12)
1. A method of detecting a change between current and previous pictures which are two adjacent ones of successive pictures represented by an input digital video signal, each of said successive pictures comprising a predetermined number of picture elements, said method comprising the steps of:
processing said input digital video signal by using correlations between the picture elements within each of said successive pictures to produce a processed signal which represents processed results for each of said successive pictures;
calculating a statistical distribution of said processed results in response to said processed signal;
and collating the statistical distribution of said processed results in said current picture with the statistical distribution of said processed results in said previous picture to produce a change detection signal representative of said change with reference to a relationship between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture.
processing said input digital video signal by using correlations between the picture elements within each of said successive pictures to produce a processed signal which represents processed results for each of said successive pictures;
calculating a statistical distribution of said processed results in response to said processed signal;
and collating the statistical distribution of said processed results in said current picture with the statistical distribution of said processed results in said previous picture to produce a change detection signal representative of said change with reference to a relationship between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture.
2. A method as claimed in Claim 1, wherein said processing step comprises the steps of:
(Claim 2 continued) predictively producing, in response to said input digital video signal, a prediction signal predictive of said input digital video signal by using correlations between the picture elements within each of said successive pictures; and producing, as said processed signal, a difference signal which represents, as said processed results, differences between said input digital video signal and said prediction signal for each of said successive pictures.
(Claim 2 continued) predictively producing, in response to said input digital video signal, a prediction signal predictive of said input digital video signal by using correlations between the picture elements within each of said successive pictures; and producing, as said processed signal, a difference signal which represents, as said processed results, differences between said input digital video signal and said prediction signal for each of said successive pictures.
3. A method as claimed in Claim 1, wherein said processing step is for carrying out an orthogonal transform of said input digital video signal to produce, as said processed signal, a result signal which represents, as said processed results, transform results of said orthogonal transform for each of said successive pictures.
4. A method as claimed in Claim 1, wherein said collating step comprises the steps of:
calculating distribution differences between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture; and comparing each of said distribution differences with a predetermined threshold value to produce said change detection signal with reference to a relationship (Claim 4 continued) between each of said distribution differences and said predetermined threshold value.
calculating distribution differences between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture; and comparing each of said distribution differences with a predetermined threshold value to produce said change detection signal with reference to a relationship (Claim 4 continued) between each of said distribution differences and said predetermined threshold value.
5. A method as claimed in Claim 4, wherein said distribution difference calculating step comprises the steps of:
temporarily memorizing the statistical distribu-tion of said processed results in said current picture during one frame of said input digital video signal to produce a delayed distribution having a delay which is equal to said one frame; and producing differences between the statistical distribution of said processed results in said current picture and said delayed distribution as said distribution differences.
temporarily memorizing the statistical distribu-tion of said processed results in said current picture during one frame of said input digital video signal to produce a delayed distribution having a delay which is equal to said one frame; and producing differences between the statistical distribution of said processed results in said current picture and said delayed distribution as said distribution differences.
6. A method as claimed in Claim 4, wherein:
said distribution difference calculating step is for calculating a sum of absolute values of said distribution differences;
said comparing step being for comparing said sum with said predetermined threshold value to produce said change detection signal when said sum is greater than said predetermined threshold value.
said distribution difference calculating step is for calculating a sum of absolute values of said distribution differences;
said comparing step being for comparing said sum with said predetermined threshold value to produce said change detection signal when said sum is greater than said predetermined threshold value.
7. A detecting device for detecting a change between current and previous pictures which are two adjacent ones of successive pictures represented by an input digital video signal, each of said successive (Claim 7 continued) pictures comprising a predetermined number of picture elements, said device comprising:
processing means for processing said input digital video signal by using correlations between the picture elements within each of said successive pictures to produce a processed signal which represents processed results for each of said successive pictures;
statistical distribution calculating means connected to said processing means and supplied with said processed signal for calculating a statistical distribution of said processed results; and collating means connected to said statistical distribution calculating means for collating the statistical distribution of said processed results in said current picture with the statistical distribution of said processed results in said previous picture to produce a change detection signal representative of said change with reference to a relationship between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture.
processing means for processing said input digital video signal by using correlations between the picture elements within each of said successive pictures to produce a processed signal which represents processed results for each of said successive pictures;
statistical distribution calculating means connected to said processing means and supplied with said processed signal for calculating a statistical distribution of said processed results; and collating means connected to said statistical distribution calculating means for collating the statistical distribution of said processed results in said current picture with the statistical distribution of said processed results in said previous picture to produce a change detection signal representative of said change with reference to a relationship between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture.
8. A detecting device as claimed in Claim 7, wherein said processing means comprises:
prediction signal producing means responsive to said input digital video signal for predictively producing a prediction signal predictive of said input digital video signal by using correlations between the (Claim 8 continued) picture elements within each of said successive pictures; and difference signal producing means connected to said prediction signal producing means for producing, as said processed signal, a difference signal which represents, as said processed results, differences between said input digital video signal and said prediction signal for each of said successive pictures.
prediction signal producing means responsive to said input digital video signal for predictively producing a prediction signal predictive of said input digital video signal by using correlations between the (Claim 8 continued) picture elements within each of said successive pictures; and difference signal producing means connected to said prediction signal producing means for producing, as said processed signal, a difference signal which represents, as said processed results, differences between said input digital video signal and said prediction signal for each of said successive pictures.
9. A detecting device as claimed in Claim 7, wherein said processing means is for carrying out an orthogonal transform of said input digital video signal to produce, as said processed signal, a result signal which represents, as said processed results, transform results of said orthogonal transform for each of said successive pictures.
10. A detecting device as claimed in Claim 7, wherein said collating means comprises:
distribution difference calculating means connected to said statistical distribution calculating means for calculating distribution differences between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture; and comparing means connected to said distribution difference calculating means for comparing each of said distribution differences with a predetermined threshold value to produce said change detection signal with (Claim 10 continued) reference to a relationship between each of said distribution differences and said predetermined threshold value.
distribution difference calculating means connected to said statistical distribution calculating means for calculating distribution differences between the statistical distribution of said processed results in said current picture and the statistical distribution of said processed results in said previous picture; and comparing means connected to said distribution difference calculating means for comparing each of said distribution differences with a predetermined threshold value to produce said change detection signal with (Claim 10 continued) reference to a relationship between each of said distribution differences and said predetermined threshold value.
11. A detecting device as claimed in Claim 10, wherein said distribution difference calculating means comprises:
temporary memorizing means connected to said statistical distribution calculating means for temporarily memorizing the statistical distribution of said processed results in said current picture during one frame of said input digital video signal to produce a delayed distribution having a delay which is equal to said one frame; and means connected to said statistical distribution calculating means and to said temporary memorizing means for producing differences between the statistical distribution of said processed results in said current picture and said delayed distribution as said distribution differences.
temporary memorizing means connected to said statistical distribution calculating means for temporarily memorizing the statistical distribution of said processed results in said current picture during one frame of said input digital video signal to produce a delayed distribution having a delay which is equal to said one frame; and means connected to said statistical distribution calculating means and to said temporary memorizing means for producing differences between the statistical distribution of said processed results in said current picture and said delayed distribution as said distribution differences.
12. A detecting device as claimed in Claim 10, wherein:
said distribution difference calculating means is for calculating a sum of absolute values of said distribution differences;
said comparing means being for comparing said sum with said predetermined threshold value to produce (Claim 12 continued) said change detection signal when said sum is greater than said predetermined threshold value.
said distribution difference calculating means is for calculating a sum of absolute values of said distribution differences;
said comparing means being for comparing said sum with said predetermined threshold value to produce (Claim 12 continued) said change detection signal when said sum is greater than said predetermined threshold value.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP116121/1989 | 1989-05-11 | ||
| JP11612189 | 1989-05-11 |
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| CA2016642C true CA2016642C (en) | 1995-01-17 |
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| CA 2016642 Expired - Fee Related CA2016642C (en) | 1989-05-11 | 1990-05-11 | Accurate detection of a drastical change between successive pictures |
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| US (1) | US5032905A (en) |
| JP (1) | JP2861249B2 (en) |
| CA (1) | CA2016642C (en) |
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|---|---|---|---|---|
| JP2863818B2 (en) * | 1990-08-31 | 1999-03-03 | 工業技術院長 | Moving image change point detection method |
| JPH04271669A (en) * | 1991-02-27 | 1992-09-28 | Matsushita Electric Ind Co Ltd | Gradation corrector |
| GB9206651D0 (en) * | 1992-03-26 | 1992-05-06 | Solid State Logic Ltd | Video processing |
| US5500904A (en) * | 1992-04-22 | 1996-03-19 | Texas Instruments Incorporated | System and method for indicating a change between images |
| EP0590759B1 (en) * | 1992-08-12 | 1998-12-09 | International Business Machines Corporation | System and method for locating video segment boundaries |
| KR100215586B1 (en) * | 1992-11-09 | 1999-08-16 | 모리시타 요이찌 | Digest image auto-generating apparatus and digest image auto-generating method |
| JP3036287B2 (en) * | 1992-12-15 | 2000-04-24 | 富士ゼロックス株式会社 | Video scene detector |
| JP2518503B2 (en) * | 1993-03-08 | 1996-07-24 | 日本電気株式会社 | Screen switching detection method |
| US5555193A (en) * | 1993-05-25 | 1996-09-10 | Kabushiki Kaisha Toshiba | Video compression system with editing flag |
| US5719643A (en) * | 1993-08-10 | 1998-02-17 | Kokusai Denshin Denwa Kabushiki Kaisha | Scene cut frame detector and scene cut frame group detector |
| DE4327779C1 (en) * | 1993-08-18 | 1994-12-08 | Siemens Ag | Method and circuit arrangement for a television set for the purpose of reducing flicker |
| KR100333223B1 (en) * | 1993-08-18 | 2002-11-22 | 지멘스 악티엔게젤샤프트 | Method and apparatus for reducing flicker in TV sets |
| US5396284A (en) * | 1993-08-20 | 1995-03-07 | Burle Technologies, Inc. | Motion detection system |
| DE4332753C2 (en) * | 1993-09-25 | 1997-01-30 | Bosch Gmbh Robert | Process for the detection of moving objects |
| US5614945A (en) * | 1993-10-19 | 1997-03-25 | Canon Kabushiki Kaisha | Image processing system modifying image shake correction based on superimposed images |
| JP2765674B2 (en) * | 1993-12-16 | 1998-06-18 | インターナショナル・ビジネス・マシーンズ・コーポレイション | Data supply device |
| US6055025A (en) * | 1993-12-21 | 2000-04-25 | Lucent Technologies, Inc. | Method and apparatus for detecting abrupt and gradual scene changes in image sequences |
| US6211912B1 (en) * | 1994-02-04 | 2001-04-03 | Lucent Technologies Inc. | Method for detecting camera-motion induced scene changes |
| US6271892B1 (en) | 1994-06-02 | 2001-08-07 | Lucent Technologies Inc. | Method and apparatus for compressing a sequence of information-bearing frames having at least two media |
| US5835163A (en) | 1995-12-21 | 1998-11-10 | Siemens Corporate Research, Inc. | Apparatus for detecting a cut in a video |
| EP0780844A3 (en) | 1995-12-21 | 2002-03-20 | Siemens Corporate Research, Inc. | Cut browsing and editing apparatus |
| JPH09261648A (en) * | 1996-03-21 | 1997-10-03 | Fujitsu Ltd | Scene change detector |
| TW361046B (en) * | 1996-10-31 | 1999-06-11 | Matsushita Electric Ind Co Ltd | Dynamic picture image decoding apparatus and method of decoding dynamic picture image |
| JP2983509B2 (en) * | 1998-02-10 | 1999-11-29 | 日本放送協会 | Method and apparatus for detecting flicker of television image |
| JP3724956B2 (en) * | 1998-08-06 | 2005-12-07 | パイオニア株式会社 | Image signal fade detection method and fade detection apparatus |
| US7233696B2 (en) * | 2002-07-12 | 2007-06-19 | Hill Richard K | Apparatus and method for characterizing digital images using a two axis image sorting technique |
| US7046729B2 (en) | 2002-08-27 | 2006-05-16 | Ess Technology, Inc. | Bit rate control for motion compensated video compression system |
| WO2010098105A1 (en) * | 2009-02-26 | 2010-09-02 | 国立大学法人名古屋大学 | Incubated state evaluating device, incubated state evaluating method, incubator, and program |
| JP5949559B2 (en) * | 2011-01-06 | 2016-07-06 | 株式会社ニコン | Image processing apparatus, imaging apparatus, and image processing program |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1252569A (en) * | 1985-09-13 | 1989-04-11 | Akihiro Furukawa | Method and device of coding a digital video signal for reproduction of pictures with a high quality even upon occurrence of a drastical change between the pictures |
| DE3682068D1 (en) * | 1986-03-19 | 1991-11-21 | British Broadcasting Corp | TELEVISION MOTION MEASUREMENT. |
| FR2613892A1 (en) * | 1987-04-10 | 1988-10-14 | Labo Electronique Physique | METHOD AND DEVICE FOR MOTION ESTIMATING IN AN IMAGE SEQUENCE |
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- 1990-05-10 JP JP11866790A patent/JP2861249B2/en not_active Expired - Lifetime
- 1990-05-11 CA CA 2016642 patent/CA2016642C/en not_active Expired - Fee Related
- 1990-05-11 US US07/522,026 patent/US5032905A/en not_active Expired - Fee Related
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| JPH0373076A (en) | 1991-03-28 |
| JP2861249B2 (en) | 1999-02-24 |
| CA2016642A1 (en) | 1990-11-11 |
| US5032905A (en) | 1991-07-16 |
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