JP2006094425A - Image processing apparatus, image processing method and image processing program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deterioration of quality of image data, when outputting read image data to other externally connected output equipment. <P>SOLUTION: The image processing apparatus comprises a reading unit 111 for reading an image of a document and converting it into image data; a scanner correction section 112 for applying predetermined image processing to the image data generated by the reading unit 111; a hard disk 118 for storing image data outputted by the scanner correction section 112; a data format converting section 125 for converting the format of image data stored on the hard disk 118 in matching with the output characteristics of external output equipment; and an NIC 124 for outputting the image data converted by the data format converting section 125, to an external output device 126. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image processing apparatus, an image processing method, and an image processing program that print out image data stored in a storage medium in the apparatus to an output device connected to a network.

  For example, there is an image processing apparatus having a memory for storing image data in a host computer having a color conversion function and connected to a plurality of color image input apparatuses and color image output apparatuses. The image processing apparatus generates an intermediate signal independent of the color image input apparatus or the color image output apparatus when determining an optimum color conversion coefficient by a combination of the color image input apparatus and the color image output apparatus. Also, the process of converting the input signal to the intermediate signal and the process of converting the intermediate signal to the output signal are separated, and the color is adjusted according to the device characteristic information of the color image input device and the color image output device. This is a configuration for determining a conversion coefficient (see, for example, Patent Document 1 below).

Japanese Patent Application Laid-Open No. 08-102865

  However, in the prior art, in order to obtain the color conversion coefficient, the device characteristic information of each of the color image input device and the color image output device is necessary, and when the color conversion coefficient is determined, the color image input device or the color image output Since the intermediate signal independent of the apparatus is generated, there is a problem that faithful color reproduction cannot be realized and the image quality of the image data is deteriorated.

  In order to solve the above-described problems caused by the prior art, the present invention provides an image processing apparatus and image processing capable of suppressing deterioration in image quality of image data when the read image data is output to an externally connected output device. It is an object to provide a method and an image processing program.

  In order to solve the above-described problems and achieve the object, an image processing apparatus according to a first aspect of the present invention is generated by an image reading unit that reads an image of a document and converts it into image data, and the image reading unit. A scanner correction unit for performing predetermined image processing on the image data, a storage unit for storing the image data output by the scanner correction unit, and a format of the image data stored in the storage unit for the external output device. Data format conversion means for converting in accordance with output characteristics, and output means for outputting the image data converted by the data format conversion means to an external output device are provided.

  According to the first aspect of the present invention, since the format of the image data can be converted in accordance with the output characteristics of the external output device, deterioration of image quality can be suppressed when outputting the image data stored in the storage means. Can do.

  According to a second aspect of the present invention, in the image processing apparatus according to the first aspect, the scanner correction unit converts the image data into CMYK dedicated format data.

  According to the second aspect of the present invention, when image data is output, the format of the image data can be converted into a CMYK-dedicated format that matches the output characteristics of the output device. be able to.

  According to a third aspect of the present invention, in the image processing apparatus according to the first aspect, the data format conversion unit converts the image data stored in the storage unit into color conversion characteristics of an output device. It is characterized by comprising color conversion means for conversion according to the above.

  According to the third aspect of the present invention, since the format of the image data can be converted in accordance with the color conversion characteristics of the output device, the color of the image data is output when the image data stored in the storage means is output. Deterioration can be suppressed.

  According to a fourth aspect of the present invention, in the image processing apparatus according to the first aspect, the data format conversion means converts the image data stored in the storage means into resolution conversion characteristics of an output device. And a resolution conversion means for performing conversion according to the above.

  According to the fourth aspect of the present invention, since the format of the image data can be converted according to the resolution conversion characteristics of the output device, the resolution of the image data stored in the storage means can be output. Deterioration can be suppressed.

  According to a fifth aspect of the present invention, in the image processing apparatus according to the first aspect, the data format conversion unit converts the image data stored in the storage unit into a γ conversion characteristic of an output device. Γ conversion means for converting according to the above.

  According to the fifth aspect of the present invention, since the format of the image data can be converted in accordance with the γ conversion characteristics of the output device, the density characteristics are output when outputting the image data stored in the storage means. Can be prevented.

  According to a sixth aspect of the present invention, in the image processing apparatus according to the first aspect, the data format conversion unit converts the image data stored in the storage unit into halftone processing of an output device. It is characterized by comprising halftone processing means for converting in accordance with the characteristics.

  According to the sixth aspect of the present invention, since the format of the image data can be converted in accordance with the halftone processing characteristics of the output device, when the image data stored in the storage means is output, It is possible to suppress deterioration in image quality related to the tone.

  An image processing method according to a seventh aspect of the invention includes an image reading step of reading an image of a document and converting the image into image data, and performing predetermined image processing on the image data generated by the image reading step. A scanner correction step to be performed, a storage step for storing image data output by the scanner correction step, and a data format conversion step for converting the format of the image data stored in the storage step in accordance with the output characteristics of the external output device And an output step of outputting the image data converted by the data format conversion step to an external output device.

  According to the seventh aspect of the present invention, since the format of the image data can be converted in accordance with the output characteristics of the external output device, the image quality can be reduced when outputting the image data stored in the storage process. Deterioration can be suppressed.

  An image processing method according to an eighth aspect of the present invention is the image processing method according to the seventh aspect, wherein the scanner correction step converts the image data into CMYK dedicated format data.

  According to the eighth aspect of the present invention, when image data is output, the format of the image data can be converted in accordance with the output characteristics of the output device, so that deterioration in image quality can be suppressed.

  An image processing method according to a ninth aspect of the present invention is the image processing method according to the seventh aspect, wherein the data format conversion step converts the image data stored in the storage step into color conversion characteristics of an output device. And a color conversion step of converting according to the above.

  According to the ninth aspect of the present invention, since the format of the image data can be converted in accordance with the color conversion characteristics of the output device, the color of the image data is output when the image data stored in the storage process is output. Deterioration can be suppressed.

  An image processing method according to a tenth aspect of the present invention is the image processing method according to the seventh aspect, wherein the data format conversion step converts the image data stored in the storage step into a resolution conversion characteristic of an output device. And a resolution conversion step of converting according to the above.

  According to the tenth aspect of the present invention, since the format of the image data can be converted in accordance with the resolution conversion characteristics of the output device, the resolution of the image data stored in the storing step can be output. Deterioration can be suppressed.

  An image processing method according to an eleventh aspect of the present invention is the image processing method according to the seventh aspect, wherein the data format conversion step converts the image data stored in the storage step into a γ conversion characteristic of an output device. It is characterized by comprising a γ conversion step for converting according to the above.

  According to the eleventh aspect of the present invention, since the format of the image data can be converted in accordance with the γ conversion characteristics of the output device, it is related to the density when outputting the image data accumulated in the storing step. Degradation of image quality can be suppressed.

  An image processing method according to a twelfth aspect of the present invention is the image processing method according to the seventh aspect of the present invention, wherein the data format conversion step converts the image data stored in the storage step into halftone processing of an output device. A halftone processing step of converting according to characteristics is provided.

  According to the twelfth aspect of the present invention, since the format of the image data can be converted in accordance with the halftone processing characteristics of the output device, when the image data stored in the storing process is output, It is possible to suppress deterioration in image quality related to the tone.

  According to a thirteenth aspect of the present invention, an image processing program causes a computer to execute the image processing method according to any one of the seventh to twelfth aspects.

  According to the thirteenth aspect, the image processing method according to any one of the seventh to twelfth aspects can be executed.

  According to the image processing apparatus, the image processing method, and the image processing program of the present invention, when the read image data is printed on an externally connected output device, the image data stored in the storage means is output characteristics of the output device. Therefore, the image data can be output while suppressing deterioration of the image quality.

  Exemplary embodiments of an image processing apparatus, an image processing method, and an image processing program according to the present invention are explained in detail below with reference to the accompanying drawings.

(Embodiment)
FIG. 1 is a diagram showing a configuration of an image processing apparatus according to an embodiment of the present invention. The image processing apparatus 100 is assumed to be a so-called multi-function machine having a copying function, a printing function, and the like. Hereinafter, with reference to FIG. 1, a schematic configuration of each unit of the image processing apparatus 100 and contents of a series of processes from reading an image of a document to printing out when the document is copied will be described. In addition, the arrow shown in the figure has shown the flow of image data.

  The functions of the image processing apparatus 100 are roughly divided into an engine unit 101 and a printer controller unit 102.

  First, the entire engine unit 101 is controlled by the engine controller 110. In the engine unit 101, a reading unit 111 is an image reading unit that reads an image of a document, and the image of the document is read as image data separated into R, G, and B (hereinafter referred to as RGB data), and scanner correction is performed. Sent to the unit 112.

  FIG. 2 is a diagram illustrating the configuration of the scanner correction unit 112. As shown in FIG. 2, the scanner correction unit 112 performs scanner γ processing by the scanner γ correction unit 201, filter processing by the filter processing unit 202, and scaling processing by the scaling unit 203 for RGB data. In the case of color image data, the color correction processing unit 204 performs color correction. These processes are performed in a manner reflecting a preset processing mode.

  FIG. 3 is a diagram illustrating an operation panel provided outside the housing of the image processing apparatus. For example, the processing mode is set by a user input from an operation panel 300 provided outside the housing of the image processing apparatus as shown in FIG. Here, the processing mode that can be selected by the user is the image quality mode. Specifically, there are a character mode, a character photo mode, and a photo mode. In addition, there is notch information such as making a document darker or thinner.

  The RGB color 8-bit data processed by the scanner correction unit 112 or the CMYK color 8-bit data after color correction is converted to data of each color nbit (n ≦ 8) by the color / monochrome multi-value data fixed length compression unit 113. . The compressed image data is sent to the printer controller 115 via the general-purpose bus 114.

  The printer controller 115 includes an independent semiconductor memory 116 (116a to 116d) for each color of CMYK. The semiconductor memory 116 stores the transmitted image data under the control of the main controller 117. The main controller 117 includes a microcomputer and centrally controls the entire image processing apparatus 100. The hard disk (HDD) 118 stores image data stored in the semiconductor memory 116 and processing mode information input from the operation panel 300. This is for avoiding rereading of the original again even when the paper is printed at the time of printout by the image processing apparatus 100, that is, when printing is not normally completed, and for performing electronic sorting. In recent years, not only this, but also a function has been added to store scanned originals and re-output them when necessary.

  When outputting image data, the image data in the hard disk 118 serving as storage means is once expanded in the semiconductor memory 116 of the printer controller 115 and then sent to the engine unit 101 via the general-purpose bus 114. The color / monochrome multi-value data fixed length expansion unit 119 of the engine unit 101 converts the transmitted image data into RGB data of 8 bits or CMYK data of 8 bits. The converted image data is sent to the printer correction unit 120.

  FIG. 4 is a diagram illustrating the configuration of the printer correction unit 120. As shown in FIG. 4, in the printer correction unit 120, the printer γ correction unit 401 performs printer γ correction, the halftone processing unit 402 performs halftone processing, and color correction in the case of color image data. Output to the video driver (GAVD) 121 (see FIG. 1).

  The GAVD 121 outputs a signal for controlling the LD (laser diode) of the image forming unit 122 to the image forming unit 122 based on the image data output from the printer correction unit 120. The image forming unit 122 outputs an image of the image data to transfer paper by an optical scanning device using an LD controlled by an LD control signal output from the GAVD 121. As the printing method of the image forming unit 122, various methods such as an inkjet method, a sublimation type thermal transfer method, a silver salt photography method, a direct thermal recording method, and a melt type thermal transfer method can be used in addition to the electrophotographic method.

  FIG. 5 is a diagram for explaining transmission of image data stored in the hard disk 118 of the image processing apparatus to an external output device. With reference to FIG. 5, an example of transmitting data stored in hard disk 118 to external output device 126 is shown. A network interface controller (NIC) 124 is an interface for connecting the image processing apparatus 100 to a network such as a LAN. Details of the data format conversion unit 125 will be described later.

  As described above, the hard disk 118 stores image data that has been subjected to scanner correction, that is, that has been subjected to image processing for copying, and processing mode information input from the operation panel 300. The image data stored in the hard disk 118 is once expanded in the semiconductor memory 116 of the printer controller 115 and then sent to the data format conversion unit 125 via the general-purpose bus 114. At this time, processing mode information is also sent to the data format conversion unit 125 together. The data format conversion unit 125 performs image processing suitable for the mode depending on the processing mode. In addition, image processing or image format processing appropriate for output to the external output device 126 is performed, and the image is distributed to the external output device 126 through the NIC 124. Note that the processing mode of image data desired to be acquired can also be designated from the external output device 126 to the image processing apparatus 100. In this case, the main controller 117 detects the processing mode sent from the external output device 126, transmits this to the data format conversion unit 125, and the data format conversion unit 125 adapts to the processing mode desired by the external output device 126. The format of the image data is converted as follows.

  FIG. 6 is a diagram illustrating a configuration example of the data conversion format unit 125 provided in the image processing apparatus according to the embodiment. As shown in FIG. 6, the input port 601 receives image data and processing mode information stored in the hard disk 118 via the general-purpose bus 114. Next, the decompressor 602 decompresses the compressed image data. The decompressed image data is subjected to the following conversion according to the mode information stored in the hard disk 118 or the output characteristics and format characteristics of the external output device 126.

  The resolution converter 603 converts the resolution to a CMYK dedicated format that matches the output characteristics of the external output device 126, and the color space converter 604 converts the color space to a CMYK dedicated format that matches the output characteristics of the external output device 126. The γ converter 605 performs γ conversion to a CMYK dedicated format that matches the output characteristics of the external output device 126, and the halftone processor 606 performs gradation processing conversion to a CMYK dedicated format that matches the output characteristics of the external output device 126. , Each done.

  Thereafter, the data is compressed and encoded in a predetermined compression encoding format by the compressor 607, output to the general-purpose bus 114 via the output port 608, and transmitted to the external output device 126 and the like. As a result, the image data in the first format stored in the hard disk 118 is output as image data in the second format after the data format is changed.

  Next, the color space conversion function by the color space converter 604 will be described. Hereinafter, an example in which color space conversion is performed by table interpolation will be described as an example of color space conversion.

  In this process, a predetermined lookup table (LUT) is used.

  FIG. 7 is a diagram for explaining the table interpolation method. As shown in FIG. 7, each axis in the xyz direction is divided into eight 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.

  There are many kinds of three-dimensional interpolation methods, but here, the simplest tetrahedral interpolation method among linear interpolations is taken as an example.

  FIG. 8 is a diagram for explaining the tetrahedral interpolation method. In the tetrahedral interpolation method, as shown in FIG. 7, the input color space is divided into a plurality of unit cubes, and further divided into six tetrahedrons that share the symmetry axis of the unit cube.

  FIG. 9 is a diagram for explaining the tetrahedral interpolation method. As shown in FIG. 9, the input color signal refers to a parameter (hereinafter referred to as a “lattice point parameter”) of the division boundary point (grid point) of the unit tetrahedron selected by the upper coordinates of the input color signal from the LUT. Next, an output value can be obtained by performing a linear operation from the lattice point parameters of the unit tetrahedron selected by the lower coordinates.

The actual processing procedure is as follows.
1. One CMY cube is completed from the Bk data of the input signals.
2. A unit cube containing the input signal X (c, m, y) is selected.
3. The subordinate coordinates (.c, .m, .y) of the coordinate P in the selected unit cube are obtained. (Here, the symbol “·” indicates the length of one side of the unit cube.)

  A unit tetrahedron is selected by comparing the magnitudes of the lower coordinates, linear interpolation is performed for each unit tetrahedron, and an output value Pout at the coordinate P is obtained. An arithmetic expression for linear interpolation of each unit tetrahedron is expressed by the following expression (1).

(.C <.m <.y) Pout = P2 + (P5-P7) .times.c /.+ (P7-P8) .times.m /.+ (P8-P2) .times.y /.
(.M ≦ .c <.y) Pout = P2 + (P6-P8) .times.c /.+ (P5-P6) .times.m /.+ (P8-P2) .times.y /.
(.M <.y.ltoreq..c) Pout = P2 + (P4-P2) .times.c /.+ (P5-P6) .times..m /.+ (P6-P4) .times.y /.
(· Y ≦ · m ≦ · c) Pout = P2 + (P4−P2) × • c / • + (P3−P4) × • m / • + (P5−P3) × • y / •
(.Y ≦ .c <.m) Pout = P2 + (P3-P1) .times.c /.+ (P1-P2) .times.m /.+ (P5-P3) .times.y /.
(.C <.y.ltoreq..multidot.m) Pout = P2 + (P5-P7) .times.c /.+ (P1-P1) .times.m /.+ (P7-P1) .times.y / .... (1)

  Next, processing for resolution conversion will be described with reference to FIGS.

  FIG. 10 is a diagram illustrating a configuration of the resolution conversion unit 1000. The resolution conversion unit 1000 performs resolution conversion on the image data. Here, a case will be described in which the target pixel data is multi-value data and conversion to an arbitrary resolution is performed for both main scanning and sub-scanning. The resolution conversion unit 1000 includes a main scanning direction resolution conversion unit 1001 and a sub-scanning direction resolution conversion unit 1002.

  The main scanning direction resolution conversion unit 1001 performs resolution conversion on the input image data in the main scanning direction, and outputs the converted data to the sub-scanning direction resolution conversion unit 1002. The sub-scanning direction resolution conversion unit 1002 performs resolution conversion in the sub-scanning direction on the data output from the main scanning direction resolution conversion unit 1001 and outputs the data to the outside of the resolution conversion unit 1000.

  FIG. 11 is a diagram illustrating a configuration of the main scanning direction resolution conversion unit 1001. An FF (flip-flop circuit) 1101 and a pixel interpolation unit 1102 perform pixel interpolation in the main scanning direction on the input multivalued data, and convert the number of data to a designated resolution. The converted data is output to the sub-scanning direction resolution conversion unit 1002. As a calculation method of the pixel data value to be interpolated, the nearest pixel replacement method, the adjacent two-pixel weighted average method, the cubic function convolution method, and the like are known.

  FIG. 12 is a diagram illustrating a configuration of the sub-scanning direction resolution conversion unit 1002. The sub-scanning line storage memory 1201 has a plurality of one-line memories 1202 (1202a to 1202d). The 1-line memory 1202 can store data for one line after resolution conversion in the main scanning direction. A pixel interpolation unit 1204 calculates an interpolation pixel value based on reference pixel data in the sub-scanning direction, and performs pixel interpolation. As a calculation method of the pixel interpolation value, the nearest pixel replacement method, the adjacent two-pixel weighted average method, the cubic function convolution method, and the like are used as in the main scanning direction.

  With the configuration as described above, the resolution conversion unit 1000 converts multi-value data input to the image processing apparatus 100 into an arbitrary resolution (magnification) in the main scanning and sub-scanning directions. Furthermore, when calculating interpolation pixels in the main scanning direction and sub-scanning direction, it is also possible to determine the interpolation pixels using a predetermined calculation method with reference to surrounding multi-value pixel data, and to perform resolution conversion with reduced texture It is.

  Next, the γ conversion process will be described with reference to FIGS. The γ conversion process converts the density gradient and density characteristics of an image according to a predetermined γ table (γ conversion characteristics).

  FIG. 13 is a graph showing an example of the γ conversion table. The horizontal axis represents the dynamic range of the base image data, and the vertical axis represents the dynamic range after γ conversion processing. A solid line and a dotted line indicate γ conversion tables, respectively.

  If the solid line in FIG. 13 is used as the γ conversion table, the value of the base image data (horizontal axis a) is converted into the corresponding value after γ conversion (vertical axis b) according to the γ conversion table. Further, it is possible to change to image data having an arbitrary density distribution by changing the curve of the conversion table. For example, if the linear γ conversion table indicated by the solid line in FIG. 13 is changed to a γ conversion table indicated by the dotted line, the image data after γ conversion is an image having a smooth density gradient compared to the γ conversion table indicated by the solid line. Can be converted to data.

  FIG. 14 is a graph illustrating an example of the γ conversion table. The horizontal axis represents the dynamic range of the base image data, and the vertical axis represents the dynamic range after γ conversion processing. A solid line indicates a linear γ conversion table, a dotted line indicates a γ conversion table in which the density gradient is changed, and a one-dot chain line indicates a γ conversion table in which the overall density is changed.

  A linear γ conversion table indicated by a solid line extends in a 45 ° direction from the origin. If it is desired to change the overall density of the image without changing the density characteristics of this table, the γ conversion table may be translated in the horizontal axis direction of the graph as shown by the alternate long and short dash line. Further, when it is desired to change the density gradient of the image, the slope of the γ conversion table may be changed as indicated by the dotted line.

  If it is desired to change the density characteristic, an arbitrary density characteristic can be obtained by changing the curve of the γ conversion table as shown by a continuous curve as shown in FIG. Thus, by changing the γ conversion table, it is possible to convert the image data into an arbitrary density gradient and density characteristic.

  Next, halftone processing will be described with reference to FIGS. Halftone processing is processing for quantizing multi-valued image data into binary or a small number of gradations close to it, and various methods have been proposed. Here, generally used simple quantization method, dither method, and error diffusion method will be described. For convenience of explanation, the number of quantized gradations is assumed to be binary.

  The simple quantization method is a method of converting image data into two gradations using an arbitrary value in the dynamic range of multivalued image data as a threshold value. For example, when multi-valued image data having 256 gradations with a dynamic range of 0 to 255 is quantized to 0 or 1, assuming that the threshold is 128, the quantized value is 0 if the image data is 100, If it is 200, the quantized value is 1.

  FIG. 15 is a diagram for explaining quantization by the dither method. A region surrounded by a thick line as in A in the figure is a threshold matrix, and one threshold matrix represents one threshold. Then, one threshold value one pixel, that is, one threshold value matrix for each pixel is applied to the image data, and two gradations are performed for each pixel. If the threshold value in the matrix is a threshold value that varies within the range of the dynamic range of the image data, there is a trade-off with the resolution of the image, but intermediate density can be expressed even in image data with two gradations.

  FIG. 16 is a diagram for explaining quantization by the error diffusion method. In the error diffusion method, as in the simple quantization method, two gradations are performed with an arbitrary threshold value. Quantization errors that occur during quantization are stored, and for the pixel of interest 1601, the quantization process has already been completed in the raster format order, and the error of surrounding pixels (shaded portions in the figure) for which errors have been determined Quantization is performed with As a result, errors due to quantization of the entire image data can be minimized.

  The error due to quantization is, for example, when quantizing multi-value image data having 256 gradations with a dynamic range of 0 to 255 into values of 0 and 1, and if the image data is 100, the quantization value is 0. Become. Although the image data has the intermediate density information of 100, the minimum value of 0 is lost, so the intermediate density information of the image data is lost. Therefore, the quantization error of this image data is 100 (= 100-0, 0 is the lowest value of the dynamic range). Also, if the image data is 200, the quantization value is 1. In this case, the maximum value is 1 even though there is intermediate density information of 200. The error is -55 (= 200-255, 255 is the maximum value of the dynamic range).

  These quantization error values are stored as data different from image data for each pixel after the quantization processing is completed. As shown in FIG. 16, since the image data is sequentially processed in the raster format, the quantization error of the shaded pixels has been determined and stored as separate data. In the quantization process for the pixel of interest 1601, the average of error values around the pixel of interest for which an error has been determined is added to the pixel value of interest before quantization. As a result, it is possible to alleviate the lack of intermediate density information due to the quantization error of the entire image data.

  As described above, according to the image processing apparatus according to the embodiment, when the read image data is output to an externally connected output device, it is possible to suppress deterioration in image quality of the image data.

  As described above, the image processing apparatus, the image processing method, and the image processing program according to the present invention are useful when printing out image data read by a copying machine to an output device connected to a network. It is suitable for a digital multi-function peripheral having a plurality of functions such as FAX.

It is a figure which shows the structure of the image processing apparatus concerning embodiment of this invention. 2 is a diagram illustrating a configuration of a scanner correction unit 112. FIG. It is a figure which shows the operation panel provided outside the housing | casing of an image processing apparatus. 2 is a diagram illustrating a configuration of a printer correction unit 120. FIG. It is a figure for demonstrating transmission to the external output apparatus of the image data accumulate | stored in the hard disk 118 of an image processing apparatus. It is a figure which shows the example of 1 structure of the data conversion format part 125 provided in the image processing apparatus concerning Embodiment. It is a figure for demonstrating a table interpolation method. It is a figure for demonstrating the tetrahedral interpolation method. It is a figure for demonstrating the tetrahedral interpolation method. 2 is a diagram illustrating a configuration of a resolution conversion unit 1000. FIG. 2 is a diagram illustrating a configuration of a main scanning direction resolution conversion unit 1001. FIG. 2 is a diagram illustrating a configuration of a sub-scanning direction resolution conversion unit 1002. FIG. It is a graph which shows an example of a gamma conversion table. It is a graph which shows an example of a gamma conversion table. It is a figure for demonstrating the quantization by a dither method. It is a figure for demonstrating the quantization by an error diffusion method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image processing apparatus 101 Engine part 102 Printer controller part 110 Engine controller 111 Reading unit 112 Scanner correction part 113 Color / monochrome multi-value data fixed length compression part 114 General-purpose bus 115 Printer controller 116a-116d Semiconductor memory 117 Main controller 118 Hard disk 119 Color・ Monochrome multi-value data fixed length expansion unit 120 Printer correction unit 121 GAVD
122 Image forming unit 124 NIC
125 Data format converter 126 External output device

Claims (13)

Image reading means for reading an image of a document and converting it into image data;
Scanner correction means for performing predetermined image processing on the image data generated by the image reading means;
Storage means for storing image data output by the scanner correction means;
Data format conversion means for converting the format of the image data stored in the storage means according to the output characteristics of the external output device;
Output means for outputting the image data converted by the data format conversion means to an external output device;
An image processing apparatus comprising:   The image processing apparatus according to claim 1, wherein the scanner correction unit converts the image data into format data dedicated to CMYK.   2. The image processing according to claim 1, wherein the data format conversion means includes color conversion means for converting the image data stored in the storage means in accordance with a color conversion characteristic of an output device. apparatus.   The image processing according to claim 1, wherein the data format conversion unit includes a resolution conversion unit that converts the image data stored in the storage unit in accordance with a resolution conversion characteristic of an output device. apparatus.   2. The image processing according to claim 1, wherein the data format conversion means includes γ conversion means for converting the image data stored in the storage means in accordance with γ conversion characteristics of an output device. apparatus.   The said data format conversion means is provided with the halftone processing means which converts the image data accumulate | stored in the said memory | storage means according to the halftone processing characteristic of an output device. Image processing device. An image reading process for reading an image of a document and converting it into image data;
A scanner correction step for performing predetermined image processing on the image data generated by the image reading step;
A storage step of storing image data output by the scanner correction step;
A data format conversion step for converting the format of the image data stored in the storage step according to the output characteristics of the external output device; and
An output step of outputting the image data converted by the data format conversion step to an external output device;
An image processing method comprising:   8. The image processing method according to claim 7, wherein the scanner correction step converts the image data into CMYK dedicated format data.   The image processing according to claim 7, wherein the data format conversion step includes a color conversion step of converting the image data stored in the storage step in accordance with a color conversion characteristic of an output device. Method.   The image processing according to claim 7, wherein the data format conversion step includes a resolution conversion step of converting the image data stored in the storage step in accordance with a resolution conversion characteristic of an output device. Method.   The image processing according to claim 7, wherein the data format conversion step includes a γ conversion step of converting the image data stored in the storage step in accordance with a γ conversion characteristic of an output device. Method.   The said data format conversion process is provided with the halftone process process of converting the image data accumulate | stored in the said memory | storage process according to the halftone process characteristic of an output device. Image processing method. An image processing program for causing a computer to execute the image processing method according to any one of claims 7 to 12.

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