JP2006033320A - Image processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration in image quality for the image of any function and to enable data processing thereof without requiring special hardware in using various functions of MFP and using accumulated image data for reprinting. <P>SOLUTION: In any case of a scanner input system or an input system via a network, image data to be accumulated as image data to be reprinted are subjected to conversion of sRGB (general use) to RGB to CMYK, as general-purpose RGB data (or original scanner output) in color correction 26 in scanner correction 2 doubly used with scanner input in reprinting without adding an independent color conversion circuit as in a precedent example. In reprinting even for the contents of color conversion or filter processing 22 of the scanner 2, image paths (I)-(III) are selected in accordance with attribute information added to the accumulated images and correction processing is executed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides an image input through various paths, such as a digital copier having a distribution function and a capture function, for example, a composite type (combining a copy function, a scanner function, a facsimile function, a printer function, etc.). More specific about image processing devices (systems) that store data and output data that forms images on recording media based on the stored image data, and that can be delivered to external devices (computers, etc.) Then, the present invention relates to the image processing apparatus including a processing unit that can output image data from any input path that does not cause deterioration in image quality.

In recent years, multi-function machines (MFPs) equipped with scanner functions, printer functions, facsimile functions, etc., in addition to copy functions, are becoming common in copiers, and network technologies that support these functions have been introduced accordingly. Is progressing. Networking enables image data acquired and stored between image devices including a copying machine to be exchanged and realized as a distribution function and a capture function.
In an MFP, input image data is usually stored in a storage device such as an HDD (Hard Disc Drive), and is used to expand image processing functions such as electronic sorting, and to use it for backup data or re-copying. In addition, the stored image data is targeted for image data that is input and output using the distribution function and the capture function. Therefore, the target image is input via the network using the image data input by scanning the scanner, the printer function, the facsimile reception function, etc., when using the copy function, scanner function, facsimile transmission function, etc. Various image data such as coming image data are included.
The following Patent Document 1 can be cited as a conventional example of the distribution function of a digital multi-function peripheral that handles such various image data. In this example, in order to efficiently use a distribution function that handles various image data, the file storage unit classifies the image data and provides a folder in which attribute information related to the image data is registered. When new image data is stored, the image data is managed by a method of notifying predetermined information to each registered delivery destination. The attribute information registered in the folder is mainly information for searching image data.
In addition, in the case of a scanner-read image, the accumulated image to be distributed is subjected to image processing under different processing conditions depending on the original or the function used, and processing appropriate for each is performed. Will increase further. The following Patent Document 2 can be cited as a conventional example relating to a multifunctional image processing apparatus that aims to obtain an output with an appropriate image quality in accordance with the diversity of distribution image data and eliminate the complexity of operation. In this example, when transmitting scanner document data and print data to another multi-function image processing apparatus via a network, image data and attribute data (compression attribute data, etc.) of the image data are transmitted, and the transmission destination It is supposed that processing using attribute data is enabled.
JP 2001-268328 A JP 2001-223828 A

Incidentally, in the MFP, conventionally, the data format of image data stored in a storage device such as an HDD is not constant, and is stored in a different format depending on the function used.
For example, when using a copy function or a printer function, processing is performed in a format suitable for MFP for printing out, and when using a scanner function, it may be in a format dedicated for MFP, but it is considered as a distribution destination. It is stored in a general-purpose format convenient for use as image data to be displayed on a PC display. In the case of a color MFP, for printer application and copy application data, CMYK (C: Cyan, M: Magenta, Y: Yellow, K: Black) data for print output is stored in the memory. For scanner application data, general-purpose RGB (R: Red, G: Green, B: Blue) data is stored in a memory if the distribution destination is a PC.
The RGB data stored in this way may then be reused and used as print output data. If the stored scanner application data is RGB data in a general-purpose format, a normal result can be obtained even if print output is performed via a network. However, when a dedicated format unique to the MFP is selected as the accumulated RGB data, it is possible to print out via a network system by converting the dedicated format into a general-purpose format. In this case, image quality degradation occurs.

Both of the above-mentioned Patent Documents 1 and 2 only show the matter of transmitting the folder or image data in which attribute information is registered and the attribute data of the image data in the MFP that distributes the accumulated image data via the network. There is no article about image degradation due to incompatibility of the data format in image data, and recognition as a solution to this problem is not shown.
As a method for making it possible to solve the problem of image degradation that occurs when scanner application data is stored in a dedicated format unique to the MFP, a data format conversion device is provided to convert the dedicated format RGB to the dedicated format CMYK. Proposals to be made (description and reference regarding the data format conversion device 10 in FIG. 1 below, referred to as “prior art”) are being studied. However, since the prior art prepares the data format conversion device as special hardware, the circuit scale becomes large and the cost increases.
SUMMARY OF THE INVENTION In order to solve the above-described problems in the prior art and the prior art in an image processing apparatus having a function of accumulating various input image data by an MFP and transmitting the accumulated image data to a network. The problem to be solved is that, when the stored image data is reused and used as print output data, image degradation for any application of the MFP is minimized. An object of the present invention is to provide an image processing apparatus that can be limited to a limited amount and does not require special hardware.

According to the first aspect of the present invention, document image data input means, first image processing means for processing image data in accordance with variable setting conditions whose image characteristics can be changed, image storage means for storing image data, An image processing apparatus comprising: a communication unit that transmits image data stored in the image storage unit to a network; and a second image processing unit that processes the image data as print output image data according to variable setting conditions. The first image processing unit processes the document image data from the input unit as image data to be stored in the image storage unit, and at the time of print output by the image data stored in the image storage unit, the image characteristics By setting the image data to be input as image data to be input to the second image processing means under the corresponding setting conditions, the problem can be solved.
According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the image processing apparatus includes a communication unit that receives image data stored in the image storage unit from a network.
According to a third aspect of the present invention, in the image processing apparatus according to the first or second aspect, the setting condition set in the first image processing means at the time of print output uses data added as attribute information to the image data. It is characterized by this.

According to a fourth aspect of the present invention, in the image processing apparatus according to the third aspect, the first image processing means includes processing means for changing the format of color image data when the image to be processed is color. The attribute information includes information indicating whether the format of the color image data is general-purpose or dedicated to the device.
According to a fifth aspect of the present invention, in the image processing apparatus according to the third or fourth aspect, the first image processing unit includes a filter processing unit for image data, and the attribute information includes data after filtering. Or information indicating whether the data is before filtering.

  According to the first to third aspects of the present invention, it has a function of accumulating various input image data by the MFP, transmitting the accumulated image data to the network, or receiving and accumulating the image data received from the network. (Claim 2) In an image processing apparatus for performing print output image data processing on accumulated image data, image processing required when scanner input data is accumulated and reused and used as print output data; That is, as a means for performing processing for converting data stored in different data formats depending on the application into data having the optimum format using data added as attribute information to the data (claim 3), the scanner input data The image processing means (first image processing means) at the time of storage of the image data can also be used. Print output without quality deterioration becomes possible, and this processing can be realized without requiring special hardware.

  According to the fourth and fifth aspects of the present invention, when the image to be processed is a color, the scanner RGB image data is a format dedicated to a color MFP machine or a general format such as sRGB as attribute information in the stored image data Can be switched to a process suitable for the copy image processing function of the color MFP machine, and the stored scanner RGB image data is the data obtained by applying the filter process of the color MFP machine, or the filter Since the attribute information indicates whether the data is not subjected to processing, it is possible to switch to processing that satisfies the same conditions, so that it is possible to obtain a desired image without image quality degradation even when reprinting is performed.

In the following, as an embodiment relating to the image processing apparatus of the present invention, a copy function, a facsimile (FAX) function, a printer function, and an input image stored therein (read original image or image input by a printer or FAX function) An example implemented in a digital color copier equipped with a combination of a distribution function and a capture function is shown.
FIG. 1 is a block diagram schematically showing the configuration of an image data processing system according to the digital color copying machine of the present embodiment.
As elements used for the copy function, a reading unit 1 that reads color image data from a document, a scanner correction unit 2 that performs image processing on image data read by the reading unit 1, and a color / monochrome multivalue output from the scanner correction unit 2 A color / monochrome multi-value data fixed length compressor 3 for compressing data and an HDD 5 for storing the compressed data are provided. In a configuration that can handle only monochrome, the reading unit 1 reads an image with a monochrome signal, and the multi-value data fixed length compressor 3 also supports monochrome.
The printer controller 4 operates as a controller that controls the operation of the entire composite function, including a copy function such as reading a document, storing read image data, and printing output using the stored image data. Therefore, the semiconductor memory 11 for storing data necessary for the operation is under control. In the semiconductor memory 11, as shown in the figure, a processing area is secured independently for each color when processing color image data. An operation unit 17 is connected to the memory printer controller 4 for performing input operations such as function selection and operation condition setting by the user.

As an element used for the FAX function, in this example, a FAX controller 13 having a binary variable length lossless compression data decompressor connected to the PSTN for transmitting and receiving FAX signals and returning compressed received FAX data to the original data is provided. . When the FAX image is monochrome, the binary variable length lossless compression data decompressor is monochrome compatible.
As an element used for the printer function, in this example, raster image processing (RIP) is performed in accordance with a print command from the external PC 19 via a NIC (network interface controller) 14 for performing communication with the external PC 19 connected to the network. In addition, the printer controller 4 performs compression dedicated to data after RIP.
As an element used for the distribution function of the accumulated input image data, the data generated when using the above-described functions of the copy / fax / printer and accumulated in the HDD 5 is transferred to the external device of the transmission destination (in this example, the external PC 19). The image format conversion unit 10 performs conversion into a general-purpose data format that can be used in (1) and processing of image data according to instructed settings.
In addition, when print output (image forming processing) is performed using image data generated using the above functions, in this example, data stored in the HDD 5 is used. For this purpose, in order to restore the stored compressed data to the original data, a decompressor corresponding to the image data type is used. In the case of a copy function, a multi-value data fixed length expander 6 that expands multi-value color / monochrome data is added to the printer controller 4 in the case of each function of FAX and printer. A lossless compression data decompressor is provided. Further, as means for performing image forming processing, a printer correction unit 7 that corrects the expanded data, an engine unit including a GAVD (writing unit) 8 and an image forming unit 9 are provided. The engine unit is controlled by the engine controller 12.

With reference to FIG. 1, the image data processing of this embodiment will be described in detail along the flow.
First, the processing flow when using the copy function will be described. In FIG. 1, the flow of image data at the time of copying is indicated by a one-dot chain line.
When reading a document, the document set on the document table is read by a reading device such as a scanner of the reading unit 1. The read image data is sent to the scanner correction unit 2 as data separated into R, G, and B colors. The scanner correction 2 performs various corrections and conversions. FIG. 2 is a diagram showing a configuration example of scanner correction. As shown in FIG. 2, a scanner gamma process 21, a filter process 22, a scaling process 24, and a color correction process 26 in the case of a color machine are performed. Is called. These processes are performed according to the mode information set from the operation panel (not shown). The 8-bit color data of RGB after the scaling process 24 or the 8-bit color data of CMYK after the color correction process 26 is converted into color data of n bits (n ≦ 8) for each color by the color / monochrome multi-value data fixed length compressor 3. Converted.
The compressed RGB image data or CMYK image data is sent to the printer controller 4 through the general-purpose bus I / F 15. The printer controller 4 has an independent memory area for each color in the semiconductor memory 11, temporarily stores the transmitted data, and then stores the data in the HDD 5.

The data stored in the HDD 5 stores mode information set from an operation panel (not shown) together with image data. This is to avoid rereading the original again or to perform electronic sorting even when the paper is clogged at the time of printout, that is, when the printing has not ended normally. In addition to the above, in recent years, image data input through various input paths (scanner input, input from an external device such as a PC, FAX, etc.) has been accumulated, and the HDD 5 can be used when necessary. A function of re-outputting or re-printing using the accumulated image data (detailed later) is added.
In the case of print output when using the copy function, the image data in the HDD 5 is temporarily developed in the semiconductor memory 11 and then sent to the engine unit through the general-purpose bus 15. In the engine unit, the color / multi-value data fixed length decompressor 6 decompresses the image data to CMYK 8-bit image data again. This data is sent to the printer correction 7 for correction. FIG. 3 is a diagram showing a configuration example of the printer correction 7. As shown in FIG. 3, a printer gamma 71, halftone processing 72, and the like are performed here. These processes are set on the operation panel (not shown), and the process suitable for the operation mode is performed based on the mode information stored in the HDD 5 together with the image data. The data output from the printer correction 7 is converted into LD (laser diode) data by the GAVD 8, and is output to the transfer paper through the latent image, development, transfer and fixing by the image forming unit 9. The above-mentioned operation mode refers to an image quality mode that can be selected by a user from an operation panel (not shown). For example, a character mode, a character photo mode, a photo mode, a notch such as making a document darker or thinner. There is information.

Next, an embodiment relating to reprint output by accumulated image data in a digital copying machine constituted by the above-described elements will be described.
In this type of MFP, when reprinting with image data stored in the HDD 5, the data format handled by each application is different, so the data types are diversified, and image quality may be deteriorated in the print output. In addition, it has been a problem of the prior art to bring about disadvantages such as separately providing a data conversion device for avoiding this (see the above section [Problems to be solved by the invention]). This embodiment shows an embodiment for solving such a problem, and any application can minimize image quality degradation, and print output that does not require special hardware. It is intended to be able to be processed as image data for use.
In the following, each embodiment will be described by dividing into the stored image data of the scanner input system input by the scanner equipped in the multifunction digital color copying machine and the stored image data of the input system via the network.

"Processing of scanner input system"
FIG. 4 is a block diagram schematically showing the configuration of the image data processing system according to the present embodiment. The system configuration shown in FIG. 4 is the same as that shown in FIG. 1, but is shown in FIG. 4 as (1) the flow of image data during storage and (2) the flow of image data during reprinting. The processing operation of the image data is controlled by the printer controller 4 in accordance with an appropriate processing flow (particularly, the operations characteristic of this embodiment relating to the scanner correction 2 will be described in detail in FIGS. 6, 7, and 9). It is possible to process image data for print output.
Referring to FIG. 4, first, the process of accumulating scanner input image data in HDD 5 will be described along (1) the flow of image data during accumulation shown in FIG. The image data input to the scanner correction 2 is RGB data, and various correction / conversion processes are performed by the scanner correction 2 as described above (description of FIG. 1). In this embodiment, the scanner correction is performed. The image data output through 2 is RGB data in a general format. Note that if you are not thinking about storing data for reprinting or reprinting, you can output it as data in the dedicated format of your own machine, but for input images that can be reprinted, Either RGB data in a general format or scanner correction 2 is passed through and passed to the HDD 5 as scanner raw data.
Therefore, as described above (description of FIG. 1), the HDD 5 stores the RGB image data in the general-purpose format subjected to the scanner correction and the attribute information selected from the operation panel for the image.

A process for reprinting by itself using the image data stored in the HDD 5 will be described along (2) the flow of image data at the time of reprinting shown in FIG. When the printing process is performed, the image data to be passed to the engine unit is CMYK data, and is usually CMYK data in a dedicated format. Therefore, the image accumulated through the scanner input path as described above is RGB data in the general format. In some cases, conversion needs to be done.
In such a case, in the prior art, a circuit for converting RGB data in a general format into CMYK data in a dedicated format is separately mounted as an additional circuit in the data format conversion device 105, and the converted image data is passed to the engine unit. It was. For this reason, the circuit scale of the data format converter 105 is large and complicated.
Therefore, in this embodiment, in order to simplify the circuit, the scanner correction 2 provided in the scanner input path is passed again to perform the processing. Since the scanner correction 2 includes a conversion circuit for converting RGB data in a general-purpose format into CMYK data in a dedicated format, it is not necessary to add a circuit for this to the data format conversion device 105.
However, the scanner correction 2 is controlled so that only necessary processing including format conversion is performed. For this purpose, the attribute information stored in the HDD 5 together with the image data is read out, necessary processing is determined, and a control command is issued. After performing the scanner correction 2, the data is transferred to the engine unit and subjected to a printer correction process. The process flow is performed in the same manner as the above copy process (see FIG. 1).

"Processing the input system via the network"
FIG. 5 is a block diagram schematically showing the configuration of the image data processing system according to the present embodiment. Although the system configuration itself shown in FIG. 5 is the same as that shown in FIG. 1, it is shown in FIG. 5 as (1) the flow of image data during storage and (2) the flow of image data during reprinting. The processing operation of the image data is controlled by the printer controller 4 in accordance with an appropriate processing flow (particularly, the operations characteristic of this embodiment relating to the scanner correction 2 will be described in detail in FIGS. 6, 7, and 9). It is possible to process image data for print output.
Referring to FIG. 5, first, a process for storing image data input via a network in HDD 5 will be described along (1) the flow of image data during storage shown in FIG. As shown in the figure, this example shows a case where image data is input as a print request via the network so that the external PC 19 uses the printer function of the MFP.
When the printer controller 4 receives a print command from the external PC 19 via a NIC (network interface controller) 14 for performing communication with the external PC 19 connected to the network, the printer controller 4 decodes the print command and is instructed there. Raster image processing (RIP) is performed in accordance with the conditions, and the attribute information transferred as a print command and the image data after RIP are subjected to dedicated compression and stored in the HDD 5. The image data stored at this time is RGB image data in a general format.

  A process for reprinting by itself using the image data stored in the HDD 5 will be described along (2) the flow of image data at the time of reprinting shown in FIG. Since the image data to be passed to the engine unit when performing the printing process is CMYK data, it is provided in the scanner input path in the same manner as in the RGB data of the general format accumulated through the scanner input path described above (see FIG. 4). The stored image data is converted through the scanner correction 2. That is, since the scanner correction 2 includes a conversion circuit for converting RGB data in the general-purpose format into CMYK data in the dedicated format, the attribute information stored in the HDD 5 together with the image data is read, and necessary processing is determined. The control command is issued. After performing the scanner correction 2, it is passed to the engine unit and output after being subjected to a printer correction process.

"Scanner correction section"
FIG. 6 exemplifies scanner correction 2 applicable to the above-described embodiment (see FIGS. 4 and 5).
Referring to FIG. 6, in the scanner correction 2, the RGB data output from the reading unit 1 is first synchronized in the line direction by the CCD line correction 18.
The color CCD that outputs the read image signal of each color component signal has a three-line configuration with RGB filters, and scaling in the sub-scanning direction is achieved by changing the carriage traveling speed (mechanical scaling). Therefore, it is necessary to switch the correction amount between lines for each magnification. Therefore, the shading correction 19 is performed at the subsequent stage.
For the data after shading correction, scanner gamma correction (characteristic conversion from reflectance linear to density linear) 21, filter processing (smoothing & enhancement, smoothing filter processing will be described in detail later) 22, color correction ( RGB → CMYK conversion, sRGB → RGB conversion, and color space conversion are described in detail later) 26 and main scanning scaling (electric convolution interpolation) 24 are executed.
In this embodiment, in either case of the scanner input system or the input system via the network, the image data accumulated as image data to be reprinted is general-purpose RGB data (or raw scanner output). At the time of printing, color correction of scanner correction 2 requires conversion of sRGB → RGB → CMYK, and execution of other processes of scanner correction 2 is selected according to attribute information added to the stored image.

"Image path control in the scanner correction unit"
In the scanner correction 2, an embodiment relating to image path control in which an image path is switched and processing is selected according to attribute information added to an accumulated image at the time of reprinting will be described.
In this example, an embodiment in which the scanner input data is stored in the HDD 5 and used for reprinting is shown. In the case of scanner input data, it may be possible to store it as image data having different image characteristics depending on the application. For example, the following image characteristics (I) to (III):
(I) Use the raw data of the scanner output.
(II) Leave the smoothing filter for removing moire in the filter processing to the setting of the MFP.
(III) Convert RGB data into a general-purpose format so that it can be edited using general-purpose software.
Etc. In this example, when the image characteristic information of the above (I) to (III) is stored in the HDD together with the scanner RGB image data as attribute information of the image data and reprinted, the image characteristics of (I) to (III) are obtained. In order to perform the corresponding scanner correction, each processing is executed while switching the image path in the scanner correction 2.

FIG. 7 is a diagram for explaining the configuration of the implementation circuit of scanner correction 2 that enables control of the image path and the operation at the time of control. FIG. 9 shows the image in the color correction 26 of scanner correction 2 shown in FIG. It is a figure explaining the structure of the implementation circuit which enabled path | pass control, and the operation | movement at the time of control. In FIG. 7, selectors 20 a to 20 c are provided on the input side of processes that can be selected so that the image path can be controlled (note that FIG. 6 shows an example in which the image path is not controlled and has a selector. However, the selector selects an input line and switches the image path. Note that (I) to (III) given to each image path in FIGS. 7 and 8 correspond to the image characteristic information (I) to (III). The selector 20d is for selecting an output in the operation at the time of scanner input.
The control operation will be described with reference to FIGS. 7 and 9. When information indicating that (I) the raw data of the scanner output is used as the attribute of the image data, the printer controller 4 performs the shading correction 19. And the scanner gamma correction 21 return the scanner RGB image data (raw data) stored in the HDD 5 to perform all of the subsequent correction / conversion processing as shown in the image path (I) shown in the figure. .
Further, if the information that the smoothing filter for removing the moire in the filter processing is left to the setting of the MFP is added as the attribute of the image data, the printer controller 4 performs the filter processing 22 and the color correction. 26, the scanner RGB image data that has been subjected to the scanner gamma correction and the filter processing accumulated in the HDD 5 is returned, and as shown in the image path (II) in the figure, the subsequent color correction 26 and the variable magnification 24 To do. The color correction 26 at this time only performs RGB → CMYK conversion.
Further, as the attribute of the image data, (III) information that converts RGB data into a general-purpose format and enables editing using general-purpose software is added. The scanner RGB image data that has been subjected to the scanner gamma correction and filter processing stored in the HDD 5 is returned between the color correction 26 and the subsequent color correction 26 and the change as shown in the image path (III) shown in the figure. Double 24. At this time, the color correction 26 performs conversion from general-purpose sRGB to dedicated RGB as format conversion, and then executes dedicated RGB to dedicated CMYK conversion.

"Smoothing filter"
In the filter process 22, image data is adjusted according to the image type.
FIG. 8 shows an example of a moire removal smoothing filter used in the filter processing 22. (A) of FIG. 8 shows the coefficient value of the filter used for strong smoothing, and (B) shows the coefficient value of the filter used for weak smoothing. The coefficient values shown in the figure are fixed coefficients of “main scanning direction 7 × sub-scanning direction 5”.
In this way, a plurality of types of filters that can give different characteristics are prepared, and a filter process that adjusts the image quality is performed by using a filter that suits each image type. At the time of application, the image type of the input image is discriminated and a filter suitable for the image area of the discriminated image type is used. For example, an image area determined to have a halftone dot is subjected to processing by a strong smoothing filter having a coefficient value as shown in FIG. 8A in order to remove the generated moire, On the other hand, processing by a weak smoothing filter having a coefficient value as shown in FIG.
In the above description, moire removal has been described. However, image quality adjustment for a character image may be performed using an edge enhancement filter.

"Color correction (format conversion)"
In the color correction 26, the engine unit converts the image data stored in the HDD 5 into a format (general-purpose sRGB or dedicated CMYK) in the scanner input path, or uses the image data format stored in the HDD 5 for reprinting. Is converted into a format (general sRGB → dedicated RGB → dedicated CMYK) required for the image data to be passed to.
The color correction is performed by conversion of a color space, and an example in which the color correction is performed by a table interpolation method which is a known technique is shown below.
A look-up table (hereinafter referred to as “LUT”) used in the table interpolation method divides each axis of the input space into eight parts, divides the input color space into upper and lower parts, refers to the LUT in the upper part, and performs three-dimensional interpolation in the lower part This is a method to obtain a precise output. There are many kinds of three-dimensional interpolation methods, but the simplest tetrahedral interpolation method among linear interpolations is taken as an example.
FIG. 10 is a diagram for explaining this tetrahedral interpolation method. 10A shows an input color space on the xyz solid coordinate axis, FIG. 10B shows a method of dividing the input color space into interpolation unit solids (tetrahedrons), and FIG. 10C shows a divided tetrahedron. Show.
In the tetrahedral interpolation method, as shown in FIG. 10, the input color space is divided into a plurality of unit cubes (FIG. 10A), and further divided into six tetrahedrons that share the symmetry axis of the unit cube ( FIG. 10B). Thereby, the input color signal refers to the parameters (hereinafter referred to as “lattice point parameters”) of the division boundary points (= lattice points P1 to P8) of the unit tetrahedron selected by the upper coordinates of the input color signal from the LUT. Next, there is a method of obtaining an output value by performing a linear operation from the lattice point parameters of the unit tetrahedron (FIG. 10C) selected by the lower coordinates.

The color conversion processing procedure by this table interpolation method is as follows.
(1) One CMY cube is determined from Bk data among input color signals.
However, there is no procedure (1) in the case of sRGB → RGB conversion.
(2) A unit cube containing the input color signal X (c, m, y) is selected.
(3) The lower coordinates (□ c, □ m, □ y) of the coordinate P in the selected unit cube are obtained.
(4) Select the unit tetrahedron by comparing the lower coordinates and perform linear interpolation for each unit tetrahedron to obtain the output value Pout (c ', m', y ', k') at the coordinate P . The linear interpolation value of each unit tetrahedron is given by the following equation (1). □: the length of one side of the unit cube,
It is.
(□ c <□ m <□ y):
Pout = P2 + (P5-P7) × □ c / □ + (P7-P8) × □ m / □ + (P8-P2) × □ y / □
(□ m ≦ □ c <□ y):
Pout = P2 + (P6-P8) × □ c / □ + (P5-P6) × □ m / □ + (P8-P2) × □ y / □
(□ m <□ y ≦ □ c):
Pout = P2 + (P4-P2) × □ c / □ + (P5-P6) × □ m / □ + (P6-P4) × □ y / □
(□ y ≦ □ m ≦ □ c):
Pout = P2 + (P4-P2) × □ c / □ + (P3-P4) × □ m / □ + (P5-P3) × □ y / □
(□ y ≦ □ c <□ m):
Pout = P2 + (P3-P1) × □ c / □ + (P1-P2) × □ m / □ + (P5-P3) × □ y / □
(□ c <□ y ≦ □ m):
Pout = P2 + (P5-P7) × □ c / □ + (P1-P1) × □ m / □ + (P7-P1) × □ y / □
... Formula (1)

1 shows a block configuration of an image data processing system related to a color digital copying machine according to an embodiment of the present invention, and an image data path during copying. 2 shows an example of the internal configuration of scanner correction in FIG. 2 shows an example of the internal configuration of printer correction in FIG. FIG. 2 shows image data paths at the time of scanner input accumulation and reprinting in an image data processing system similar to FIG. FIG. 3 shows an image data path when storing and reprinting input via a network in the same image data processing system as FIG. An example of scanner correction applicable to the image data processing system shown in FIGS. 4 and 5 will be described. It is a figure explaining the structure of the implementation circuit of the scanner correction | amendment which enabled control of an image path, and the operation | movement at the time of control. An example of a moire removal smoothing filter used in filter processing is shown. FIG. 8 is a diagram for explaining the configuration of an implementation circuit that enables image path control in the color correction of the scanner correction shown in FIG. 7 and the operation during control. The figure for demonstrating the tetrahedral interpolation method in color space conversion is shown.

Explanation of symbols

1 .... reading unit, 2 .... scanner correction,
4. ・ Printer controller, 5. ・ HDD,
7. ・ Printer correction, 9. ・ Print image forming unit,
14. ・ NIC (Network Interface Controller),
19. ・ External PC, 26 ・ ・ Color correction.

Claims (5)

  Document image data input means, first image processing means for processing image data in accordance with variable setting conditions whose image characteristics can be changed, image storage means for storing image data, and stored in the image storage means An image processing apparatus comprising: communication means for transmitting image data over a network; and second image processing means for processing the image data as print output image data in accordance with variable setting conditions, wherein the first image processing means The document image data from the input means is processed as image data to be stored in the image storage means, and at the time of print output by the image data stored in the image storage means, the setting conditions according to the image characteristics are used. An image processing apparatus which is a means for processing as image data input to the second image processing means.   2. The image processing apparatus according to claim 1, further comprising a communication unit that receives image data stored in the image storage unit from a network.   3. The image processing apparatus according to claim 1, wherein the setting condition set in the first image processing means at the time of print output uses data added as attribute information to the image data. apparatus.   4. The image processing apparatus according to claim 3, wherein the first image processing means includes processing means for changing a format of color image data when the image to be processed is color, and the attribute information is An image processing apparatus comprising information indicating whether the color image data format is general-purpose or dedicated to equipment.   5. The image processing apparatus according to claim 3, wherein the first image processing unit includes a filter processing unit for image data, and the attribute information includes data after filtering or data before filtering. An image processing apparatus including information indicating the above.

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