Apparatus and method for using feedback and feedforward in the generation of ...

1

APPARATUS AND METHOD FOR USING
FEEDBACK AND FEEDFORWARD IN THE
GENERATION OF PRESENTATION IMAGES
IN A DISTRIBUTED DIGITAL IMAGE

PROCESSING SYSTEM 5

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the generation of presentation images in a distributed digital image processing system. In 10 particular, this invention is directed to the use of feedback and feedforward in generating predictable, reproducible and aesthetically pleasing images in a distributed digital image processing system.

2. Description of the Related Art

Distributed digital image processing systems provide a method for generating an image from an image originating device and distributing the image to output devices in both proximal and remote locatings. However, in conventional 20 distributed digital image processing systems, problems arising with remote output devices, such as unsatisfactory image and/or color quality, output device inoperability, and output device resource deficiencies, are not readily detectable or correctable by a customer situated at the image originating 25 device. For example, a customer generating an image (usually a digital image) at an image originating device is not immediately aware of the quality of that image as rendered on a remotely located display or printer. Due to the different configurations between various output devices, an 30 image that appears pleasing at the image origination device or its associated local output device may not be accurately replicated by the desired remote output device. Such problems are quite common and cause significant inconvenience and dissatisfaction. 35

Unsatisfactory image and/or color quality can result from various system limitations. For example, discrepancies can arise when an image is converted from red, green and blue (RGB) components to cyan, magenta, yellow and black (CMYK) components. The system is also limited by the 40 gamut of colors that can be produced by an given output device, which is often different than the gamut available on the image originating device. Further, the system is limited by the characteristics of each particular output device that cause it to output an unsatisfactory image. For example, the 45 actual output colors may depend on the color of ink or toner, a low ink or toner state, and the like. Additionally, over time, the actual output of the output device may drift, i.e., deviate from predetermined optimum standards, due to various factors. These factors include environmental conditions, 50 such as temperature, relative humidity, and the like, use patterns, the type of media used (such as different paper types, transparencies, and the like), variations in media, variations from original models used in initializing the hard copy output device, general wear, and the like. Thus, even 55 though the output device may be capable of producing a presentation image that matches the original image, the desired image may still not be achieved due to the current status of the particular output device.

FIG. 1 shows an example of the connectivity of a sim- 60 plified global distributed digital image processing system. As shown in FIG. 1, the distributed digital image processing system 10 includes an image originating device 20 having a display device (not shown), located, for example, in Webster, N.Y A proximally located printer 25 is connected 65 to the image originating device 20. The image originating device 20 is connected to a server, or set of connected

2

servers, 30 that may or may not be located proximal the image originating device 20. Alternatively, a proximally located printer 26 could be connected to the image originating device 20 by way of the server, or set of connected servers, 30. Three remote printers 40 are connected to the central server, or set of connected servers, 30, and are located, for example, in Chicago, Tokyo and Budapest.

After a customer creates pleasing documents on the image originating device 20, the customer prints them on the local printer 25. The documents printed on the local printer 25 are usually satisfactory because, for example, the image originating device and/or the display device are calibrated for the local printer 25. The customer may then need to print the documents on one ore more of the remote printers 40. However, the actual image printed on the remote printers 40 may not appear as the customer expected. This may be due to, for example, poor color transformations between the work station, central server and remote printers, the requested colors being out of the gamut of the remote printers, the remote printers having different screening or halftoning, or the like.

In general, although not shown in FIG. 1, the conventional distributed digital image processing systems may include a large number of work stations 20 connected to the server 30. Although not shown in FIG. 1, a distributed digital image processing system may include a plurality of servers connected together to share the workload in performing requested operations. Similarly, although not shown in FIG. 1, a large number of output devices 40 are usually connected to the server, or set of connected servers, 30 are located at widely distributed locations. Each of the output devices 40 is a physical device, or hardware, that is capable of rendering images of documents and/or producing hard copy output of the print jobs received from the server, or set of connected servers, 30. The output devices include, but are not limited to video display, direct markers (i.e., direct marking devices, which include printers and other similar devices), and indirect markets (where the image is developed on an imaging member and subsequently transferred to an output substrate). The customers of the work station 20 include any end user.

SUMMARY OF THE INVENTION

There is the need for a distributed digital image processing system that dynamically monitors each aspect of an image processing operation to ensure that a desired remote output device will produce a presentation image substantially the same as an image created and viewed by a customer at an image originating device or its proximal local output device. Presently, the only reliable way to monitor the presentation images of remote output device is to travel to the location of each output device printer and observe the printed output or the displayed image, or to have a printed output delivered back to the customer at the image originating device. Thus, monitoring the presentation images output by the remotely located output devices is nearly impossible in a distributed digital image processing system, because traveling to the plurality of locations remote from the originating workstation is impractical, and delivering a printed output from a remote location to the customer requires some delay time to allow for courier or postal delivery.

This invention provides a method and apparatus for using feedback and feedforward in generating predictable, reproducible and pleasing images in a distributed digital image processing system.