JP2006109042A - Image processor and image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly reflect wishes on the side which utilizes a distributed image on the distributed image from an image processor and to obtain image quality which a user desires at a distribution destination. <P>SOLUTION: A data form conversion device 10 which performs a conversion processing to the distributed image into data compatible with a receiving side device (such as a client PC), image quality adjustment which a client requests is performed. The image quality adjustment is performed by setting results of γ (density) adjustment and color balance adjustment performed on the client PC side in a client request correction γ processing part 103 and a client request color correction processing part 104. Information used for the γ (density) adjustment and the color balance adjustment is obtained by the density read by an image processor and the adjusting operation of the client PC to image data of a reference patch of each color. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus capable of distributing color image data, such as a color MFP having a distribution function (a color copying machine combining multiple functions such as a copy function, a facsimile function, and a scanner function). More specifically, the present invention relates to an image processing apparatus provided with a means for converting to image data suitable for use of an external information processing apparatus that makes a distribution request, and an image processing system including the image processing apparatus and the external information processing apparatus.

In recent years, MFPs that have become digital copiers and have functions such as scanners, printers, and facsimiles in addition to copy functions are becoming more and more common. Due to the network technology that supports these functions, A network distribution / capture function for transmitting and receiving image data read by a scanner unit to / from an external information device such as a computer connected to a network has also been installed.
In addition, as technologies necessary for realizing such functions, related technologies such as storage of image data in a storage medium, conversion / processing of image data for using shared images, output to various destination devices, etc. The field is also expanding.
For example, the following Patent Documents 1 to 3 can be shown as conventional techniques for configuring a system that uses an image shared between devices connected to a network using such a technique.
Patent Document 1 relates to a digital color copying machine that allows a workstation to be connected via a network. The RGB color system image data read from the scanner and the image converted from the RGB color system to the CMYK color system. Data is stored in the HDD in the machine. By storing image data in the RGB color system and CMYK color system, the image data is properly used for transmission to the workstation and printing processing in the copier to prevent image quality deterioration and processing delay. I have to.
Patent Document 2 relates to an image information processing apparatus in which a facsimile apparatus, a printer, or the like can be connected via a network. This image information processing apparatus has a density conversion table and a standard density conversion table suitable for recording by the own apparatus. When the transmission destination recording characteristics are unknown, the image data to be transmitted is processed using a standard density conversion table so that there is no significant difference between the recording results of the own apparatus and the transmission destination.
Patent Document 3 discloses a resolution, standard color space (sRGB, etc.) that can be used at a distribution destination when distributing an image stored in an HDD as CMYK data that is convenient for print output performed in the apparatus. ) And a file format (a general-purpose file format such as JPEG or TIFF).
JP 2002-36750 A Japanese Patent Laid-Open No. 10-308772 JP 2004-159035 A

By the way, in recent years, user demands for a system that uses document image data input by an MFP or the like in an external information processing apparatus connected to a network have been diversified.
The above-mentioned Patent Documents 1 to 3 all relate to a system in which document image data input by a scanner in an image processing apparatus such as an MFP is used in an external information processing apparatus as a distribution destination. In Patent Documents 1 to 3, in any case, an image processing apparatus such as a copying machine that is a distribution source performs data conversion in consideration of adaptation to a distribution destination, thereby supporting the use side.
However, Patent Document 1 prepares two image data of an RGB color system and a CMYK color system converted from RGB. Patent Document 2 performs conversion using a standard density conversion table. Japanese Patent Application Laid-Open No. 2004-228561 performs conversion to resolution, standard color space (sRGB, etc.), and a general-purpose file format. That is, the data conversion performed on the distribution image in Patent Documents 1 to 3 is limited to the data conversion considering the conformity to the device characteristics of the distribution destination.
Therefore, by this data conversion, for example, the user's request for an individual image, such as adjusting the appearance of the shade of the image as desired by the user or making the color such as yellow or black darker. I cannot respond directly. In other words, according to the user's request, the image to be distributed is not adjusted by changing the gamma correction characteristics or adjusting the color balance by changing the color conversion characteristics.
The present invention has been made in view of the above-described problems in the conventional image processing system in which the document image data input in the image processing apparatus can be used in the external information processing apparatus as the distribution destination. An object to be solved is to make the image distributed from the image processing apparatus directly reflect the demand of the side using the distribution image and obtain the image quality desired by the user at the distribution destination.

According to the first aspect of the present invention, the image input means for inputting the original image, the first image processing means for processing the input original image as data of a predetermined format according to the variable setting condition, and the first image processing means Between the image processing means for storing the processed image, the second image processing means for processing the image stored in the image storing means as print output data according to variable setting conditions, and the external information processing apparatus An image processing apparatus having a communication interface that enables data transmission and reception, and data format conversion means for converting image data in a predetermined format stored in the image storage means into data in another format according to variable setting conditions. The data format conversion means is an external information processing apparatus serving as a conversion means for converting images to be transmitted to the external information processing apparatus via the communication interface. The image processing apparatus having a means for applying the target image gamma correction processing according to the processing conditions indicated in al the distribution request as a conversion element, attempt to resolve the problem.
According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the data format conversion means is the external information processing apparatus as conversion means for converting an image to be transmitted to the external information processing apparatus via the communication interface. Means for performing color correction processing on the target image in accordance with the processing conditions indicated in the distribution request from as a conversion element.

  According to the third aspect of the present invention, the image input means for inputting the document image, the first image processing means for processing the input document image as data of a predetermined format according to the variable setting condition, and the first image processing means Between the image processing means for storing the processed image, the second image processing means for processing the image stored in the image storing means as print output data according to variable setting conditions, and the external information processing apparatus An image processing apparatus having a communication interface that enables data transmission and reception, and data format conversion means for converting image data in a predetermined format stored in the image storage means into data in another format according to variable setting conditions. The data format conversion means is an external information processing apparatus serving as a conversion means for converting images to be transmitted to the external information processing apparatus via the communication interface. The image processing apparatus having a means for applying to the target image color correction processing according to the processing conditions indicated in al the distribution request as a conversion element, attempt to resolve the problem.

  The invention of claim 4 is an image processing system comprising the image processing device according to any one of claims 1 to 3 and an external information processing device connected to the image processing device via a communication interface, The problem is solved by a system in which an external information processing apparatus is provided with means for making a delivery request indicating processing conditions set in the data format conversion means to the image processing apparatus.

According to the first, second, and fourth aspects of the invention, when the document image data input by the image processing apparatus is distributed to the external information processing apparatus (client), the target image conforms to the processing conditions indicated in the client distribution request. By applying the gamma correction process, it is possible to distribute the image data adjusted to the image quality of the user's desired density to the client, in addition to the data format that can be processed by the client. An efficient system can be configured. In addition, it can be distributed as image data adjusted to the image quality of the color balance desired by the user (claim 2).
(2) According to the third and fourth aspects of the invention, when the document image data input by the image processing apparatus is distributed to the external information processing apparatus (client), the processing conditions indicated in the distribution request of the client are applied to the target image. By performing color correction processing according to the above, it is possible to deliver image data adjusted to the color balance desired by the user to the client in addition to a data format that can be processed by the client. An efficient system can be configured.

Embodiments relating to an image processing apparatus and an image processing system of the present invention will be described below.
In the embodiment described below, the image processing apparatus is a color MFP. In addition, a system that uses a distribution image is configured with an external information processing apparatus that inputs a scanner input from a color MFP machine and requests distribution of stored image data as a PC (client).
In the present embodiment, when the distribution function is used, an image requested to be distributed is converted into a data format according to the request of the client PC. In this conversion, the data format that can be processed on the client side is used, and the adjustment to the image quality desired by the client can be performed on the target image data.
In this way, it is possible to receive distribution in the form of image data that meets the client's request, and an efficient system can be configured.

FIG. 1 is a block diagram schematically showing the configuration of an image processing system according to this embodiment including a color MFP and an external client PC.
First, referring to FIG. 1, the configuration of each part of the color MFP machine and the process at the time of copying performed in the process of reading a document image, accumulating the read image, and printing output using the accumulated image are shown in the flow (same as above). This will be described along the broken line in the figure.
When using the copy function, first, a document set on the document table is R, G, B (R: Red, G: Green, B: Blue) by the scanner of the reading unit 1 under the control of the engine controller 12. ) Is read out as 8-bit image data of each color.
The read image data is sent to the scanner correction unit 2 and subjected to various corrections and conversions. FIG. 2 is a diagram showing a configuration example of scanner correction. As shown in FIG. 2, the scanner γ21, the processing of the filter 22 corresponding to the image quality mode, and the scaling 24 processing are performed. These processes are suitable for the target image by referring to bibliographic information (managed and associated with the image) indicating functions and operating conditions set from an operation panel (not shown) on which the user performs an input operation. Processing is performed.

The 8-bit color data of each RGB color after scaling is converted into color data of each color nbit (n ≦ 8) by a fixed-length compressor. The output of the fixed length compressor 3 is connected to the general-purpose bus I / F 15, and the compressed RGB 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 (R, G, B) for each color in the semiconductor memory 11, temporarily stores the data sent thereto, and then stores an image storage device such as an HDD (Hard Disc Drive) 5 or the like. To accumulate.
The HDD 5 stores bibliographic information set from an operation panel (not shown) together with image data. The image is stored in the HDD 5 in order to avoid re-reading the original even when the paper is printed, that is, when the printing is not completed normally when printing out the data, or to operate the image data such as electronic sorting. To do. In addition, it supports a re-output function such as printing out the read original image when necessary, or distributing it to an information processing apparatus such as an external PC 19 via a network.

When printing out, 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. The image data is again restored to RGB 8-bit image data by the fixed length expander 6 of the engine unit. This data is sent to the printer correction 7. FIG. 3 is a diagram showing a configuration example of the printer correction 7. As shown in the figure, here, each of the color correction processing 75, the printer γ correction 71, and the halftone processing 72 is performed.
The printer correction 7 is performed according to the bibliographic information stored together with the image data in the HDD 5 in accordance with the target image. First, the RGB color signals are converted into CMYK color signals by the color correction processing 75. Next, after performing printer γ correction 71 for each color of CMYK, halftone processing 72 according to GAVD (writing unit) 8 and image forming unit 9 is performed. The print output data converted and processed in this way is output to a transfer sheet through a writing unit (GAVD) 8 and an image forming unit 9.
According to such a flow, the color MFP realizes a copy operation, and after the image data is output from the image forming unit 9, the image data passing through the scanner input path is stored in the HDD 5. In addition to the copy operation, the stored image is used as data shared between networks, as will be described later, from an information processing apparatus such as an external PC 19 such as the PC 19.

In addition, a process when distributing the image data stored in the HDD 5 to the external PC 19 via the network will be described along the flow.
FIG. 4 is a diagram for explaining processing during distribution. This figure shows the same image processing system as that in FIG. 1, and the flow of image data at the time of distribution is indicated by a one-dot chain line in the figure.
At the time of distribution, as shown in FIG. 4, first, the image data stored in the HDD 5 is temporarily developed in the semiconductor memory 11, and then sent to the data format conversion device 10 through the general-purpose bus 15. At that time, the bibliographic information is also sent to the data format converter 10 together with the image data to be transmitted.
The data format conversion apparatus 10 performs processing suitable for the target image based on the bibliographic information. In addition, image format processing is performed to make the format suitable for the delivery destination. The image data converted by the data format conversion device 10 is distributed to an external PC 19 through a NIC (network interface controller) 14.
In the processing flow during the copying operation described above, image data read by the color MFP is stored in the HDD 5 as RGB data. However, it is desirable to be able to cope with other color space image data. For this purpose, as a color space converter provided in the data format conversion device 10, it is necessary to adopt means (detailed later) capable of dealing with different color space systems.
The other color space system may be, for example, device-dependent “Yuv” or “CMYK”, or may be a standard color space such as device-independent “sRGB”.

Here, the basic configuration and operation of the data format conversion apparatus 10 will be described with reference to FIG. 5 showing the internal configuration of the apparatus.
Since the image data stored in the HDD 5 has been compressed through the input path from the previous reading unit 1, the image data from the HDD 5 input through the input port 101 is first changed to the first data. Is decompressed and restored by the decompressor 102 of the following format.
Thereafter, the resolution conversion is performed by the resolution converter 105 based on the bibliographic information. Next, the color space is converted by the color space converter 106 based on the bibliographic information. These image processes are all performed according to the conditions set by the bibliographic information.
After that, it is compressed to the second format by the compressor 108 to the second format for output again through the output port 109.
As an embodiment, for example, it is assumed that input image data is multi-value data, and is data compressed to a general-purpose data format by a multi-value data compression method. The output image data is multi-value data compressed into a general-purpose data format by a multi-value data compression method. That is, both the input of the data format conversion device 10 and the output from the data format conversion device 10 are multi-value data compressed into a general-purpose data format.

FIG. 6 is a block diagram showing the data format conversion apparatus 10 of this embodiment.
FIG. 6 shows an example in which the first format decompressor 102 and the second format compressor 108 are general data formats in the data format conversion apparatus 10 shown in FIG. As shown in the figure, both the first format decompressor 102 and the second format compressor 108 are JPEG decompressors that are compatible with a compression / decompression method conforming to JPEG (Joint Photographic Experts Group). 102j and a JPEG compressor 108j are used. FIG. 6 shows the data format conversion apparatus 10 in a simplified manner, and the image processing 107 corresponds to the resolution converter 105 and the color space converter 106 in the example of FIG.
Multi-value data input to the data format conversion apparatus 10 shown in FIG. 6 is data compressed by JPEG. In the data format conversion apparatus 10, in order to perform predetermined image processing based on bibliographic information, the compressed data is decompressed by the JPEG decompressor 102j and restored to multivalued data, and then the resolution is converted by the image processing 107 based on the bibliographic information. It is configured to perform processing such as color space conversion. After performing predetermined image processing, compression is performed again when output to the outside. At this time, the data is output in a general data format by passing through the JPEG compressor 108j.

In this way, by transmitting and receiving data in a standardized general-purpose data format such as JPEG, it is possible to unify the data format between the units to be transmitted and received, and further improve the data quality and data transmission and reception efficiency. A data format conversion system that maintains both can be constructed. In this embodiment, the conversion to the JPEG format is performed, but the conversion of the image format is a general-purpose format other than this, for example, the TIFF (Tagged Image File Format) format or the BMP (bitmap). ) The format may be converted to another format desired by the receiving side.
When the data is binary data, a standard compression / decompression method such as the MHMR / MMR method is adopted, and the data format conversion apparatus 10 also uses a compression / decompression device corresponding to this method.
In this embodiment, the system is such that both the input image data and the output image data are in a general-purpose data format. However, the input image data is in a dedicated image data format, and the output image A system in which the data format is a general-purpose image data format may be used. Also, a system in which both input image data and output image data are in a dedicated image data format may be used.

Next, the resolution conversion process performed in the data format conversion apparatus 10 (FIG. 5) will be described in more detail.
FIG. 7 is a block diagram showing an internal configuration of the resolution converter.
In the present embodiment, the pixel data of the target image is multi-valued data, and an example of a method that can be converted to an arbitrary resolution in both main scanning and sub-scanning is illustrated. Therefore, as shown in FIG. 7A, the resolution converter 105 converts the input multi-value data into a main scanning resolution conversion block 1051 that performs resolution conversion in the main scanning direction, and in the main scanning direction. It comprises a sub-scanning resolution conversion block 1052 that performs resolution conversion in the sub-scanning direction on the converted multi-value data.
The main scanning resolution conversion block 1051 performs pixel interpolation in the main scanning direction in order to convert the input multi-value data to the resolution specified by the bibliographic information. For this purpose, the main scanning resolution conversion block 1051 includes a register 105f that shifts pixel data in the main scanning direction and an interpolation pixel calculation block 105a that calculates pixel data values to be interpolated. The interpolation pixel calculation block 105a is a data to be interpolated based on the pixel data string held in the register 105f by using a calculation method such as the nearest pixel replacement method, the adjacent two-pixel weighted average method, and the cubic function convolution method. Calculate the value. The above calculation methods are all known methods.
The data after the resolution conversion in the main scanning direction is held in the sub-scanning line accumulation memory 105m in the sub-scanning resolution conversion block 1052. The sub-scanning line storage memory 105m has a plurality of line memories that can store data for one line. The interpolation pixel calculation block 105c calculates the data value of the line to be interpolated based on the reference pixel data in the sub-scanning direction held in the line memory for a plurality of lines. As the calculation method, the known nearest pixel replacement method, the adjacent two-pixel weighted average method, the cubic function convolution method, and the like can be applied as in the main scanning direction.

Next, color space conversion processing performed in the data format conversion apparatus 10 (FIG. 5) will be described in more detail. It is assumed that the color space converter 106 used in this embodiment converts a color space for multi-value image data.
This color space conversion can be performed by applying a known table interpolation method. The LUT used for the table interpolation method is a system in which each axis of the input space is divided into 8 parts, the input color space is divided into upper and lower parts, the LUT is referred to in the upper part, and three-dimensional interpolation is performed in the lower part to obtain a precise output. is there. There are many kinds of three-dimensional interpolation methods, but the simplest tetrahedral interpolation method among linear interpolations is taken as an example.
FIG. 8 is a diagram for explaining this tetrahedral interpolation method. 8A shows an input color space on the xyz solid coordinate axis, FIG. 8B shows a method of dividing the input color space into interpolation unit solids (tetrahedrons), and FIG. 8C shows a divided tetrahedron. Show.
The tetrahedral interpolation method divides the input color space into a plurality of unit cubes as shown in FIG. 8A, and further shares the symmetry axis of the unit cube as shown in FIG. 8B. Divide into tetrahedrons. 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, as shown in FIG. 8C, this is a method of obtaining an output value by performing a linear operation from the lattice point parameters of the unit tetrahedron selected by the lower coordinates.
The color conversion processing procedure by this table interpolation method is as follows.
(1) Select a unit cube containing the input color signal X (x, y, z).
(2) The lower coordinates (□ x, □ y, □ z) of the coordinate P in the selected unit cube are obtained.
(3) Select the unit tetrahedron by comparing the subordinate size and perform linear interpolation for each unit tetrahedron.
An output value Pout at the coordinate P is obtained. The linear interpolation value of each unit tetrahedron is given by the following equation (1). Note that □: the length of one side of the unit cube.
(□ x <□ y <□ z) P _out = P2 + (P5-P7) × □ x / □ + (P7-P8) × □ y / □ + (P8−P2) × □ z / □
(□ y ≦ □ x <□ z) P _out = P2 + (P6-P8) × □ x / □ + (P5-P6) × □ y / □ + (P8−P2) × □ z / □
(□ y <□ z ≦ □ x) P _out = P2 + (P4-P2) × □ x / □ + (P5-P6) × □ y / □ + (P6−P4) × □ z / □
(□ z ≦ □ y ≦ □ x) P _out = P2 + (P4-P2) × □ x / □ + (P3-P4) × □ y / □ + (P5−P3) × □ z / □
(□ z ≦ □ x <□ y) P _out = P2 + (P3-P1) × □ x / □ + (P1-P2) × □ y / □ + (P5−P3) × □ z / □
(□ x <□ z ≦ □ y) P _out = P2 + (P5-P7) × □ x / □ + (P1-P1) × □ y / □ + (P7−P1) × □ z / □
... Formula (1)

Up to this point, the basic configuration and operation of the data format conversion apparatus 10 have been described with reference to FIG. As described above, the conversion / processing applied to the distribution image by the data format conversion apparatus 10 in FIG. 5 can be processed by an external information processing apparatus such as the PC 19 that is the distribution destination, that is, data that considers the adaptation to the distribution destination device Based on conversion to format. Therefore, it is possible to directly reflect the request of the client PC or the like that uses the distributed image on the target image data so that the desired image quality can be obtained at the distribution destination. 10 is unexpected and no guarantee is made.
Therefore, in this embodiment, an instruction on the image quality required by the client is issued in response to a distribution request from the client, and it is possible to perform conversion / processing on the image data to be distributed on the MFP machine that responds to the distribution request in accordance with this instruction. The image data requested by the client can be provided.
Specifically, on the basis of the above-described embodiment (see FIGS. 1 to 8), the image format adjustment requested by the client is performed by the data format conversion apparatus 10 to achieve the implementation. In this embodiment, image quality adjustment is performed by using two correction processes, γ (gamma) correction and color correction, as additional elements. Hereinafter, each form of “γ correction processing”, “color correction processing”, and “(γ correction + color correction) processing” will be described.

“Γ correction processing”
FIG. 9 is a block diagram showing an internal configuration of the data format conversion apparatus 10 to which “γ correction processing” is added. As shown in the figure, a client request γ correction processing unit 103 is added to the data format conversion apparatus 10 (see FIG. 5) described above.
The configuration and operation related to the newly added client request γ correction processing unit 103 will be described with reference to FIG.
First, the image data compressed when stored in the HDD 5 is decompressed and restored by the decompressor 102 of the first format. Thereafter, the restored image data is subjected to γ correction processing by the client request γ correction processing unit 103 in accordance with the correction condition based on the request from the client.
Thereafter, the image data after γ correction is converted by the resolution converter 105 and the color space converter 106, respectively. Thereafter, data compression for delivery output is applied by the compressor 108 to the second format. This process is the same as that of the data format conversion apparatus 10 (FIG. 5) described above except that it is a process for image data after γ correction.

The correction conditions set in the client request γ correction processing unit 103 will be described.
Here, an image read from a document is set as a distribution target, and the client sets conditions for γ correction for this target image. An example of a form applied to this case will be described below.
A processing method known as “read correction γ processing” is one of γ correction processing methods for image data input by a scanner. In this process, the density gradient and density characteristics of the image are made variable, and a desired output can be obtained with respect to the input by changing the curve (γ characteristic curve) of the conversion table. In the present embodiment, a mechanism is provided for changing this γ characteristic curve in response to a client request.
FIG. 10 is a diagram for explaining the “read correction γ processing” method. (A) in the figure shows a density γ correction patch, and (B) and (C) in the figure show patch image data in the process of “read correction γ processing”. Further, (D) in the figure shows a γ characteristic curve drawn on a graph in which the horizontal axis is an input and the vertical axis is an output (“255” is a maximum value).
In the “read correction γ process”, first, a density γ correction process patch serving as a density reference is read by the MFP (FIG. 1). As shown in FIG. 10A, the density γ correction processing patch is composed of a patch showing a plurality of reference densities in which the density is changed with a linear gradient from white to the maximum density black. The scanner of the reading unit 1 of the MFP that reads the patch has a characteristic unique to the device. Accordingly, although the image data of the patch for density γ correction processing read by the scanner actually varies, it is possible to obtain image data for reproducing the density shown in FIG. The target is to have the device characteristics shown in the γ characteristic curve (A) of 10 (D).

The read image data of the density γ correction processing patch is sent to the client PC 19 through the NIC 14 in order to set a γ correction condition according to the client's request. The client PC 19 changes the γ characteristic curve based on the received image data of the density γ correction processing patch and performs desired γ correction from the client side.
In this process, the client PC 19 outputs the received image data of the density γ correction processing patch as a visible image, for example, to a display, and performs a desired density adjustment operation. At the time of adjustment, the image output to the display is affected by the device characteristics in the process of the MFP. For example, the patch image shown in FIG. 10A has a density as shown in FIG. The image shows the change. The density shown in FIG. 10B is biased toward the darker side than that shown in FIG. 10A, and has the characteristics shown in the γ characteristic curve (B) in FIG.
The client performs a density adjustment operation so as to obtain a desired density while viewing the image showing the density change shown in FIG. In this adjustment operation, for example, the image data of the density γ correction processing patch shown in FIG. 10B is opened with a tool such as Photoshop (registered trademark) so that the image data becomes as intended by the client. The tone curve (γ characteristic curve) correction function is used to change. When using the tone curve correction function, an intended γ characteristic is set while monitoring an image obtained by changing the γ characteristic. FIG. 10C shows an image monitored at the time of adjustment based on the image data of the density γ correction processing patch shown in FIG. (C) in FIG. 10 shows a case where adjustment is performed so that the γ characteristic is biased toward the dark side, and the characteristic shown in the γ characteristic curve (C) in FIG. 10 (D) is set.
After performing the γ adjustment operation in this way, the client PC 19 sends information on the γ characteristics set via the NIC 14 to the data format conversion apparatus 10.
The data format conversion apparatus 10 that receives the information on the γ characteristic performs a γ correction process requested by the client in the client request γ correction processing unit 103 so that the data output conforms to the set characteristic. That is, the difference is calculated so that the data having the characteristic indicated by the curve (B) in FIG. 10D becomes the data having the characteristic indicated by the curve (C) in FIG. For example, the γ characteristic curve of curve (B) in FIG. 10D has an output of 180 when the input is 150. In contrast, the γ characteristic curve of curve (C) in FIG. 10D has an output of 200 when the input is 150. Therefore, the γ characteristic curve used for the γ correction processing of the client request γ correction processing unit 103 is set to a γ characteristic curve that becomes 200 when the input is 180.

“Color correction”
FIG. 11 is a block diagram showing an internal configuration of the data format conversion apparatus 10 to which “color correction processing” is added. As shown in the figure, a client request color correction processing unit 104 is added to the data format conversion apparatus 10 (see FIG. 5) described above.
The configuration and operation related to the newly added client request color correction processing unit 104 will be described with reference to FIG.
First, the image data compressed when stored in the HDD 5 is decompressed and restored by the decompressor 102 of the first format. Thereafter, the client-requested color correction processing unit 104 performs color correction processing on the restored image data according to the correction condition based on the request from the client.
Thereafter, the image data after color correction is converted by the resolution converter 105 and the color space converter 106, respectively. Thereafter, data compression for delivery output is applied by the compressor 108 to the second format. This process is the same as the data format conversion apparatus 10 (FIG. 5) described above except that it is a process for color-corrected image data.

Correction conditions set in the client request color correction processing unit 104 will be described.
Since the present embodiment enables the client to instruct desired color correction for an image read from a document to be distributed, an example of an embodiment applied in this case will be described below. Here, an example is shown in which the color correction processing for the image data input by the scanner is performed by the “color correction patch reading method”.
FIG. 12 is a diagram for explaining the “color correction patch reading method”. (A) in the figure shows a color correction patch, and (B) and (C) in the figure show patch image data in the process of color correction in the “color correction patch reading method”.
In the color correction processing of the “color correction patch reading method”, first, a color correction patch serving as a color reference is read by the MFP (FIG. 1). The color correction patch is a representative color as shown in FIG. 12A, for example, color A ₀ (red), color B ₀ (pink), color C ₀ (yellow), color D _0. It is composed of patches indicating a plurality of reference colors of (sky blue), color E ₀ (green), and color F ₀ (indigo). The scanner of the reading unit 1 of the MFP that reads the patch has a characteristic unique to the device. Accordingly, the color correction patch image data read by the scanner actually varies in color, but the goal is to obtain image data that reproduces the color of the patch shown in FIG. Become.

The read image data of the color correction patch is sent to the client PC 19 through the NIC 14 in order to set the color correction condition according to the request of the client. The client PC 19 changes the color balance based on the received color correction patch image data, and performs desired color correction from the client side.
In this process, the client PC 19 outputs the transmitted color correction patch image data as a visible image to, for example, a display, and performs a desired color balance adjustment operation. At the time of adjustment, the image output to the display is affected by device characteristics in the process of the MFP. That is, in the patch shown in FIG. 12A, as shown in FIG. 12B, the color of each patch is color A ₀ → color A ₁ (red), color B ₀ → color B ₁ ( Pink), color C ₀ → color C ₁ (yellow), color D ₀ → color D ₁ (sky blue), color E ₀ → color E ₁ (green), color F ₀ → color F ₁ (blue) , Changes to a deeper color.
The client performs a color balance adjustment operation so as to obtain a desired color while viewing the image of the color correction patch shown in FIG. In this adjustment operation, for example, the image data of the color correction patch shown in FIG. 12B is opened with a tool such as Photoshop (registered trademark) so that the image has a color as intended by the client. Change using the color balance correction function. When using the color balance correction function, an intended color balance is set while monitoring an image obtained by changing the color balance. FIG. 12C shows an image monitored during adjustment based on the image data of the color correction patch shown in FIG. FIG. 12C shows the color of each patch as color A ₁ → color A ₂ (red), color B ₁ → color B ₂ (pink), color C ₁ → color C ₂ (yellow), color D _1. → Color D ₂ (sky blue), Color E ₁ → Color E ₂ (Green), Color F ₁ → Color F ₂ (Indigo) is adjusted to change the color according to the client's request. .
After performing the adjustment operation in this way, the client PC 19 sends the color balance information set via the NIC 14 to the data format conversion apparatus 10.
The data format conversion apparatus 10 that receives the color balance information performs color correction processing requested by the client in the client request color correction processing unit 104 so that the data output conforms to the set correction conditions. The color correction performed by the client request color correction processing unit 104 can be performed by applying a table interpolation method similar to that employed by the color space conversion unit 106 described above.

“(Γ correction + color correction) processing”
In the following embodiment, the above-described “γ correction processing” and “color correction processing” can be processed together.
FIG. 13 is a block diagram showing an internal configuration of the data format conversion apparatus 10 to which “(γ correction + color correction) processing” is added. As shown in the figure, a client request correction γ processing unit 103 and a client request color correction processing unit 104 are added to the data format conversion apparatus 10 (see FIG. 5) described above.
The configuration and operation of the newly added client request correction γ processing unit 103 and client request color correction processing unit 104 will be described with reference to FIG.
First, the image data compressed when stored in the HDD 5 is decompressed and restored by the decompressor 102 of the first format. Thereafter, the restored image data is first subjected to γ conversion by the client request correction γ processing unit 103 so as to obtain density characteristics according to the client's request. Next, the client request color correction processing unit 104 performs color correction processing according to the correction condition based on the request from the client.
Thereafter, the image data after γ correction and color correction is converted by the resolution converter 105 and the color space converter 106 based on the bibliographic information. After these processes, data compression for distribution output is applied by the compressor 108 for the second format, and the process in the data format conversion apparatus 10 is finished and output.
The configuration and operation of each part of the client request correction γ processing unit 103, the client request color correction processing unit 104, the resolution converter 105, and the color space converter 106 are basically the same as described above. The description is omitted here by referring to the above description.

1 schematically shows a configuration of an image processing system including an image processing apparatus (MFP machine) and a client PC according to an embodiment of the present invention. The internal structure of the scanner correction | amendment part in FIG. 1 is shown. The internal structure of the printer correction | amendment part in FIG. 1 is shown. It is a figure which shows the same image processing system as FIG. 1, and is a figure explaining the flow of the image data at the time of delivery. An example of the internal configuration of the data format conversion device in FIG. 1 is shown. The other example of the internal structure of the data format converter in FIG. 1 is shown. The internal structure of the resolution converter in FIG. 1 is shown. The figure for demonstrating the tetrahedral interpolation method in the color space conversion in a data format conversion apparatus is shown. An internal configuration of a data format conversion apparatus to which “γ correction processing” is added is shown. It is a figure explaining the "read correction gamma process" method. An internal configuration of a data format conversion apparatus to which “color correction processing” is added is shown. It is a figure for demonstrating the "color correction process" by the "color correction patch reading system". An internal configuration of a data format conversion apparatus to which “(γ correction + color correction) processing” is added is shown.

Explanation of symbols

1 .... Reading unit, 2 .... Scanner correction unit,
4. ・ Printer controller, 5. ・ HDD (Hard Disc Drive),
10. Data format conversion device,
14. NIC (network interface controller),
19..External PC, 103..Client request correction gamma processing unit,
104. Client request color correction processing unit.

Claims (4)

  An image input means for inputting a document image, a first image processing means for processing the input document image as data in a predetermined format according to variable setting conditions, and an image processed by the first image processing means are stored. Data can be transmitted and received between the image storage unit, the second image processing unit that processes the image stored in the image storage unit according to variable setting conditions as print output data, and the external information processing apparatus. And a data format conversion means for converting image data of a predetermined format stored in the image storage means into data of another format in accordance with variable setting conditions, the data format conversion means Is shown in the distribution request from the external information processing apparatus as means for converting the image to be transmitted to the external information processing apparatus via the communication interface. The image processing apparatus, characterized in that the means for applying the target image gamma correction processing according to the processing conditions are those having as a conversion element.   The image processing apparatus according to claim 1, wherein the data format conversion unit is indicated in a distribution request from the external information processing apparatus as a conversion unit to an image to be transmitted to the external information processing apparatus via the communication interface. An image processing apparatus comprising, as a conversion element, means for performing color correction processing on a target image in accordance with the processing conditions.   An image input means for inputting a document image, a first image processing means for processing the input document image as data in a predetermined format according to variable setting conditions, and an image processed by the first image processing means are stored. Data can be transmitted and received between the image storage unit, the second image processing unit that processes the image stored in the image storage unit according to variable setting conditions as print output data, and the external information processing apparatus. And a data format conversion means for converting image data of a predetermined format stored in the image storage means into data of another format in accordance with variable setting conditions, the data format conversion means Is shown in the distribution request from the external information processing apparatus as means for converting the image to be transmitted to the external information processing apparatus via the communication interface. The image processing apparatus, characterized in that the means for applying the target image color correction processing according to the processing conditions are those having as a conversion element.   An image processing system comprising: the image processing device according to any one of claims 1 to 3; and an external information processing device connected to the image processing device via a communication interface. An image processing system comprising: means for making a distribution request indicating processing conditions set in the data format conversion means to an image processing apparatus.

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