MXPA99002903A - Method and a system for the selective interpretation of data from co space - Google Patents

Abstract

A method and system for processing color space data to be interpreted by a visual display device to selectively overload color space data when overloaded data, or data overload, is compatible with satisfactory output of the visual representation device. If the color space data is compatible, an overload process occurs. If the data of the original color space is incompatible to interpret the overload, the data of the original color space is passed through without processing the overload. Compatibility is generally determined when it is possible to trace the map of the color space or the general shape again and the ranges of allowable values for each channel are the same as for the original color space and the overloaded color space. If incompatibility is determined, the data from the original color space is passed through the interpretation process without overloading

Description

METHOD AND A SYSTEM FOR SELECTIVE INTERPRETATION OF COLOR SPACE DATA The present invention relates to the processing and interpretation of image data specified by the work unit in a digital color printing or reproduction system. More specifically, the present invention relates to the processing and interpretation of the original color space data, specified by the unit of work, based on a determination that the original color space data may be overloaded to be converted to a preferred form of color space data. In other words, if the overload of the color space is an optimal and compatible color space, the overload process occurs. On the other hand, if the determination is made that the overload of the original color space with a compatible color space can not be effected, the original color space data is not processed and is simply passed through the visual representation device.

BACKGROUND OF THE PRESENT INVENTION The variety of different emission systems in computing devices that generate graphics invariably REF: 29618 will specify the color space data that is not always optimal for a particular printer or display device. The colors of graphic objects produced by such desktop publishing programs will vary between different types of visual representation devices. The interpretation of the color space data specified by the unit of work in the color space data of the display device will often require assumptions that the display device may produce unsatisfactory results for the system operator. The object of the invention will minimize the problems engendered by such assumptions. Graphic colors can be described in any variety of color systems or color spaces. PostScript Language Reference Manual, 2nd edition, Section 4.8, "Color Spaces", pages 176-200, 1990, Addison-Wesley Publishing Co. Most desktop publishing systems will attempt to specify abstract colors in a separate device, but the Color values that originate from an application that generates a source page description language file can be defined in a number of different color spaces. Some color spaces are related to the representation of the color of the device (grayscale, RGB and CMYK), or they can be related to independent representations of the device, for example, XYZ, CIELAB. However, some independent color spaces still have a derivation of the device that will cause the generation of unsatisfactory results if they only pass through the visual representation device. The problem of whether and how to overload such independent color spaces but diverted by the device is the object of the invention addressed. Conventional interpretation aids of a printing system or visual representation will use a set of transformations to convert the input color spaces according to what is specified by the unit of work to a color space of the device for such systems, in an effort by being adaptable to different input color spaces and achieving a consistent color output or the intended interpretation of the output. It is common to have several paths through the interpretation system with different capacities, such as a path of the device or a calibrated path. The path of the device communicates the colors of the input device and converts them into colors of the output device. The calibrated path is a more powerful path and generally has more sophisticated processing associated with it than the path of the device. The calibrated path facilitates the calibration by the system of the input color space to obtain a more consistent output. The Xerox Intelligent Color ™ interpretation system (application Serial No. 08/664, 297, pending, presented on May 19, 1976) takes advantage of the processing color of a calibrated path to force the calibrated path through a mapping again of some of the originally fed color spaces. Again mapping the color space can also take place on a calibrated path, to ensure that a particular output device is optimized. The compatibility between the original color space and the overload of the color space of the Xerox Intelligent ColorMR interpretation system must be ensured to avoid certain interpretation defects, such as images that are interpreted as black. Consequently, there is a first problem with systems that force overload through an interpretation processor in the printer limitation to require compatibility between the original input color space and the color space overload that, of course , limits the adaptability of the printing system. A second problem is that, although there are some colors, such as the colors of the device, which are desirable to process through the calibrated path, there are other colors that are processed on the calibrated path that are formed in a slightly freer way and that they must be passed through the interpretation system without being processed due to overload. In particular, in a Postscript system, the CIÉ based on the ABC is an abstract color space, which, depending on the parameters of the color space, can be implemented to implement a number of color spaces, including CIELAB and others. color spaces deflected by the device. If the original input color space is CIELAB, it is desirable to make such color space pass through the interpretation system. On the other hand, if the input color space is a calibrated RGB space that is fixed for a particular monitor, it is usually desirable that the color space be overloaded with a printer's interpretation system. Another problem occurs when a calibrated RGB color space has an incompatible gamma by a selected printer. Unsatisfactory outputs, such as dark impressions, may result if the RGB color space calibrated with gammas that are incompatible with the interpretation system is processed in the usual way. The present invention contemplates a new and improved system and method for interpreting an input color space specified by the unit of work that overcome the above problems and provide a system of selective color space overload, which is easily adapted to a plurality of original input color spaces that can provide improved consistency and satisfactory results in graphic outputs presented or presented and printed.

BRIEF DESCRIPTION OF THE INVENTION According to the present invention, there is provided a method for processing color space data to be interpreted by a visual representation device having the steps of receiving a color space deflected by the device, independently, which define an object to be presented by the visual representation device, determine if the color space data are compatible to interpret the overload; if the color space is compatible, then process the color space data to generate the overloaded color space data; if the color space data is not compatible with the interpretation of the overload, pass the color space data through without processing the overload; and, processing the overloaded color space data to generate the visual representation; wherein, if overloaded color space data is not generated, then processing the original color space data to generate the visual representation on the visual representation device. According to another aspect of the present invention, a condition determining compatibility includes identifying whether the data of the original color space falls within a limiting range of a potential overload color space. If in a range of allowable values, each channel of the data of the original color space has a compatibility condition to redraw the map of a preselected preferred color space. Other defined compatibility conditions may exist, depending on the nature of the color spaces involved. According to another aspect of the present invention, a printing system or visual representation is provided for selectively processing color space data to interpret the original color space specified by the unit of work "in an optimal device color space if The original color space and the color space of the device are compatible A color space generator specifies the data of the original color space An interpretation processor determines whether the data of the original color space is of an independent color space , diverted by a device, which are incompatible with the overload to generate the data of the preferred color space, if so, the processor overloads the data of the original color space to form the data of the preferred color space. the data of the original color space is passed through the interpretation processor if it is determined not to They can be overloaded. A benefit obtained by the use of the present invention is an interpretation processing system, which allows the intelligent selection of input color spaces to route them through a calibrated path of an interpretation process. Another benefit of the object of the invention is that the data of a space of the original color can be restored after an overload execution of the interpretation system. The present state relationship specified by the unit of work through the interpretation system provides greater robustness, since the unit of work could make certain assumptions about the parameters that it has previously set and it is desired to preserve the integrity of the environment of the original work unit.

Other benefits and advantages of the new method and object system will be apparent to those skilled in the art after reading and understanding this specification.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention was able to take physical form in certain parts and steps and arrangements of parts and steps, the preferred embodiments of which are described in detail in the specification and are illustrated in the accompanying drawings, and wherein : Figure 1 is a block diagram of a typical xerographic color interpretation system; Figure 2 is a block diagram illustrating a system for interpreting the group of the original input color space according to the concepts of the present invention; Figure 3 is a detail of a portion of the interpretation path block block of Figure 2; Figure 4 is a flowchart illustrating processes for interpreting particular input color space data in accordance with the present invention; and Figure 5 is a state diagram specifying the possible states of the color space data processed in accordance with the present invention, as identified in Table 1 of the following specification.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings in which the views have the purpose of illustrating the preferred embodiments of the invention only and not the purpose of limiting the same, the FIGURES show a method and a system for the selective interpretation of data of the invention. color space, wherein the interpretation comprises selecting the overload of the data from the original color space to a preferred way to print them or in other circumstances presenting them, or it can simply pass the data from the original color space through interpretation paths without overload In this description, as well as in the drawings, similar numerical references represent similar equivalent devices, circuits or circuits which perform equivalent functions. The actual interpretation process can be carried out in conjunction with a variety of devices, such as laser xerography, ink jet, etc. and may be applicable, in addition, to electronic visual representation devices. For the purpose of abbreviating, a laser xerographic printing system will be described below with respect to the present invention, the invention does not depend on any particular visual representation device (for example a printer or copier) and can be implemented in any of several systems.

Figure 1 is a schematic elevation view of a typical electrostatic digital color copier. An ESS (electronic subsystem) or the image processing station (both referred to as IPS), indicated generally by the reference numeral 12, contains electronic data processing devices and controllers which prepare and manage the flow of image data to a frame output browser (ROS) generally indicated by the reference numeral 16. A network of one or more personal computers (PCs), indicated generally by the reference number 5, is shown interconnected or in communication with the IPS 12 The user interface (UI), indicated generally by the reference number 14, is also in communication with the IPS 12. The UI 14 allows an operator. control and verify several functions adjustable by the operator and maintain their activity. The operator operates the appropriate keys of the UI 14 to adjust the parameters of the copy. The UI 14 can be a touch-sensitive screen, or any other suitable control board, that provides an operator with interconnection with the system. The output signal from the UI 14 is transmitted to the IPS 12. The UI 14 can also present electronic documents on a display screen (not shown in Figure 1), as well as stop the image interpretation selections.

As shown, moreover, in Figure 1, an original multi-color document 38 can be placed on (optionally) the frame input browser (RIS), generally indicated by the reference number 10. The RIS contains document lighting lamps, optical devices, a mechanical scanning controller, and a charge-coupled device (CCD array) or a full-color color scanning array. The RIS 10 captures the entire image of the original document 38 and converts it to a series of frame scan lines and, in addition, measures a set of primary color densities, ie densities of red, green and blue, at each point of the original document. The RIS 10 can provide data on the scanned image to the IPS 12, directly to PC 5 and / or directly to PC 5. Can be created, selected, modified, stored and / or otherwise processed in digital or other form. type by PC 5 before transmission / referral to IPS 12 for printing on the printer 18. The device for visual representation of the PC 5 can display electronic documents on a screen (not shown - shown in Figure 1). The IPS 12 may include the processors and controllers (not shown in Figure 1) required for the operation of the adaptive image interpretation system of the present invention. The IPS 12 can also transmit signals that correspond to the desired electronic devices or the scanned image to the ROS 16, which creates the image of the output copy. The ROS will expose the photoconductor band to record the latent images corresponding to the signals transmitted from the IPS 12. A latent image is revealed with cyan developer material. Another latent image is revealed with the magenta developer material, and the third latent image is revealed with the yellow developer material. A black latent image can be revealed instead of or in addition to the other latent (colored) images. These revealed images are transferred to one copy sheet in register superimposed with another to form a multiple color image on the copy sheet. This image of multiple colors is then fused to the copy sheet forming a color copy. Continuing with reference to Figure 1, the printer or marking machine 18 is an electrophotographic printing machine. Cerno noted earlier, the interpretation systems in the printers will use the mapping again of the color space of the original color-fed spaces to force the interpretation through a path that is expected to be optimized for a particular printer. The Xerox Intelligent ColorMR has previously noted one such system. With reference to Figure 2, the data of the original input color space or graphics 20 inputted by the scanner 16 are received in a receiving block of the printer 22 and communicated to an interpretation path circuit 24. In a conventional system, the interpretation path circuit 24 will include a path of the device and a calibrated path. The Xerox system Intelügent Color takes advantage of the processing power of the calibrated path and in some cases forces the data of the original color space through the calibrated path for a mapping of maps again of the color spaces. It pretends that such mapping again obtains an optimized interpretation of a particular output device. Unfortunately, compatibility between the original color space and the overburdened color space must be maintained to prevent serious defects of interpretation from occurring as a result of mapping again. Independent color spaces, even those with a device deviation (for example, SMPTE RGB, NTSC RGB and SRGB which define monitor standards) were usually passed through interpretation paths 24, without mapping again . The incompatibility between the color spaces deflected by the device and the interpretation system can result in an unsatisfactory interpretation such as dark interpretations. An example of incompatibility is the significant gamma mismatch between the color space deflected by the device and the interpretation system. With particular reference to Figure 3, the circuit of interpretation paths is identified more particularly as that which comprises a portion that can identify the color space specified by the unit of work as one that is susceptible to overload in accordance with the present invention. More particularly, the data of the work unit specified in the original color spaces comprised of the color space of the work unit 30, the color data of the work unit 32 and other data of the work unit 34 (for example, a type of object). The system will then determine whether the color space of work 30 is susceptible to overload of one or more candidate color spaces according to that indicated by block 36. If one or more col de spaces are determined. "&Rt; r candidates, then the optimal color spaces selected in block 37 are selected for the overload process in block 39.

The overloaded, processed color data is sent from the process block 39 to be communicated through the rest of the system along with the rest of the interpretation paths 40. A feature of the subject invention is that a method and a system are provided. to automatically retain the data of the original color space if there is no appropriate overload of the color space or can not be generated by the circuit of the interpretation path 24. Thus, if there are no candidate color spaces in block 36, then the color space of the work unit 30 is passed through the processing of the color space 39. More particularly, the invention is a method and system for ensuring compatibility between the original color space and the color space. overloaded. Overloading by the circuit of the interpretation path 24 is only performed selectively if the compatibility conditions are the same for the data of the original color space and the data of the overloaded color space. The visual display device 26 will then be able to provide more satisfactory results to an operator of the work unit. Figure 4 represents a preferred process used by the system illustrated in Figure 2. In this example, a page description language file passed between PC 5 to IPS 12 is processed by the interpretation path circuit 24 to determine if the data for each 'channel of any of a number of color spaces in the file has a range of between 0 and 1. In this particular example, it is assumed that there is a compatible color space to overload it with the original color space when it is within this range. More particularly, the method of the invention comprises determining whether the color space of the work unit is an independent color space 42, which in most systems of the prior art would have been passed through without the overload process. If so, a check is made to determine if this is also a color space deflected by the device 44 that is compatible with the overload process. The compatibility verification step 46 may comprise a plurality of checks. The specifically shown 48 considers whether the data in each channel of the color spaces has a range of between 0 and 1. Other potential commutability checks could include an examination of matrix transformations or other color space parameters, such as gamma. Verifications or compatibility steps can be arranged in different orders.

If the data of the original color space has been left out of the range in step 48, then the original color space could not be overloaded through the interpretation path 24 and would pass through 50 to the display device 26. ability to pass color space data through the interpretation path 24 without overload, when it was determined that the original color space is incompatible with the overload process of the particular device at the same time, is a special benefit of the invention. For some color spaces originally fed it is very clear that an overload can occur. For example, when the original color space is a RGB color space of the device, the interpretation path circuit 24 will always overload it in a compatible color space. Similarly, when the powered device is CMYK, it will be overloaded with a particular DEFG color space. Determining when the original color-fed space is incompatible with the overload when the interpretation path 24 may have some uncertainty about the compatibility between the overloaded color space and the printing device is the most complex determination. Other steps in Figure 4 are after having found the compatibility through the verification of step 46, then an optimal color space overload is selected in step 52 and a real overload occurs at 54.

Table 1 Table 1 (continued) With reference to Table 1 above and Figure 5, each time a painting operator was executed, the status control determines a new game based on the overloaded color space, the manual compensation state and the current state. If necessary, the original color space is restored after the operator executes the painting. This preservation of the graphic state through painting operators is necessary for reasons of robustness; for example, in printing applications the printing work units can make certain assumptions about the color space based on the adjustment of the color space in the work unit itself. The state control for a selective color space compensation is shown in Table 1 and Figure 5. In Table 1, it is determined whether or not there is a compatible and optimum color space. Based on this determination, and the current state there are four permissible states: overloaded (which means that the original color space is overloaded), already overloaded (which means that the original color space has already been overloaded), not overloaded (which means that the original color space is not overloaded) and not overloaded yet (which means that the original color space has not been previously overloaded). Note that the actions are only associated with the "overloaded" and "not overloaded" states. Activation of the application color space feature disables the overload feature of the selective color space when an overload of the original color space does not occur (see cases 1 and 2 in Table 1). Manual compensation (cases 1 and 2) implies an overload. The invention has been described with reference to preferred embodiments. Obviously, modifications and alterations will occur to others after reading and understanding the specification. It is my intention to include all such modifications and alterations so that they fall within the scope of the appended or equivalent claims thereto.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (12)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A method for processing color space data to be interpreted by a visual representation device, characterized in that it comprises the steps of: (a) receiving the data from the original color space including the independent color space data defining a representation by the visual representation device; (b) determining whether the data of the independent color space is data of the color space deflected by the device; s (c) determining whether the data of the color space diverted by the device is compatible to interpret the overload by the visual representation device; (d) if the independent color space data, diverted by the device are compatible, process the data of the original color space to generate data from the overloaded color space; (d) if the data of the independent color space, deviated by the device, are incompatible, the interpretation of the overload, make pass the data of the original color space through processing, without overload, where the data of the space of original color define the representation; and, (e) processing the overloaded color space data to generate the representation, or if the overloaded color space data was not generated, then processing the data from the original color space to generate the representation on the visual representation device .

2. The method of compliance with the claim 1, characterized in that the compatibility determination includes identifying whether one or more compatible color spaces exist to interpret the overload.

3. The method of compliance with the claim 2, characterized in that the processing of the overload includes selecting an optimum color space between one or more compatible color spaces.

The method according to claim 1, characterized in that the determination of compatibility includes identifying whether the data of the additional color space falls within a limiting range of the data of the overburdened color space.

5. The method in accordance with the claim 4, characterized in that the identification comprises evaluating whether a form and range of permissible values for each channel for the data of the original color space are compatible for redrawing the map of a preselected preferred color space of the visual representation device.

6. The method of compliance with the claim 5, characterized in that if the data of the original color space is data from the CIELAB space, then it is determined that the data of the original color space is incompatible to interpret the overload.

The method according to claim 1, characterized in that it includes manually compensating the overload process to pass the data of the original color space to generate the visual representation.

The method according to claim 1, characterized in that it includes resetting the data of the original color space after processing to generate data from the overloaded color space.

9. A printing system for selectively processing color space data to interpret an original color space specified by a unit of work in an overloaded color space if the "original" color space is compatible for overloading, characterized in that comprises: a generator of color spaces to specify an original color space, an interpretation processor to identify whether the original color space is an independent color space, deflected by the device that is compatible for overloading with a color space overloaded and referred to include means for generating the preferred color space, and means for passing the original color space through the interpretation process based on the determination that the original color space can not be overloaded with a space of compatible color; and a display processor for presenting a visual representation comprising the preferred overloaded color space or the original color space.

10. The printing system according to claim 9, characterized in that the interpretation processor includes a manual compensation to prevent the generation of the preferred overloaded color space.

11.The printing system according to claim 9, characterized in that the interpretation processor includes means for identifying a plurality of compatible, possible overloaded color spaces and means for selecting the optimum of a plurality to generate the preferred color space.

12. The printing system according to claim 9, characterized by if the original color space is incompatible with gamma with a set of potential overloaded color spaces, then the rendering processor passes the original color space through it. without overload