JP2001211316A - Device and method for image processing, storage medium, and image processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that an image of high quality could not be outputted on condition that it is made easy to handle the image when the image is processed and enlarged or reduced while features of the image are taken into consideration. SOLUTION: This device has an input means which inputs color image data, a storage means which stores the color image data, a generating means which generates flag data showing features of an image corresponding to the color image data from the color image data, a flag data storage means which stores the generated flag data, a 1st pixel density converting means which converts the pixel density of the color image data read out of the storage means into specified magnification, a 2nd pixel density converting means which converts the pixel density of the flag data read out of the flag data storage means into the same magnification as the above specified magnification, and an output means which outputs the pixel-density converted image data and pixel-density converted flag data to a printer part while making them correspond to each other, pixel by pixel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image processing apparatus, an image processing method, a storage medium, and an image processing system.

[0002]

2. Description of the Related Art Conventionally, a so-called color original copying apparatus as shown in FIG. 10 is known as a system for digitally reading a color original image to generate a copied image.

In FIG. 10, reference numeral 1001 denotes an image scanner which reads an original and performs digital signal processing. Reference numeral 1002 denotes a printer unit which prints out an image corresponding to the document image read by the image scanner 1001 on paper in full color. In the image scanner 1001, reference numeral 1000 denotes a mirror surface pressure plate, and a document 1004 on a platen glass (hereinafter, platen) 1003 is a lamp 100.
5, and is guided to mirrors 1006, 1007, 1008, and forms an image on a three-line solid-state image sensor (hereinafter referred to as CCD) 1010 by a lens 1009. Red (R) and green (G) as full-color information , Blue (B) are sent to the signal processing unit 1011. 1005 and 1006 are speeds v, 100
Reference numerals 7 and 1008 scan the entire surface of the document (sub-scanning) by mechanically moving the line sensor in the direction perpendicular to the electrical scanning (main scanning) direction at a speed of 1/2 v. Here, the original 1004 is 600 dpi in both the main scanning and the sub-scanning.
(Dots / inch) resolution.

In a signal processing unit 1011, the read image signal is electrically processed, decomposed into magenta (M), cyan (C), yellow (Y), and black (Bk) components. Send to 1002. Further, M, M
One component of C, Y, and Bk is the printer unit 1002
And one printout is completed by a total of four document scans.

The M, C, Y, and Bk pixel signals sent from the image scanner unit 1001 are sent to a laser driver 1012. Laser driver 1012
Is a semiconductor laser 10 according to the transmitted image signal.
13 is driven by modulation. Laser light is polygon mirror 1
014, scans on the photosensitive drum 1017 via the f-θ lens 1015 and the mirror 1016. Here, as in the case of reading, both the main scanning and the sub-scanning are performed at 600 dpi (dot).
s / inch).

[0006] Reference numeral 1018 denotes a rotary developing unit, which comprises a magenta developing unit 1019, a cyan developing unit 1020, a yellow developing unit 1021, and a black developing unit 1022. The four developing units alternately contact the photosensitive drum 1017, and Is developed with toner.

Reference numeral 1023 denotes a transfer drum which winds a sheet supplied from a sheet cassette 1024 or 1025 around the transfer drum 1023 and transfers an image developed on the photosensitive drum to the sheet.

After the four colors of M, C, Y, and Bk are sequentially transferred in this manner, the sheet passes through the fixing unit 1026, and is discharged after the toner is fixed on the sheet.

[0009]

In the prior art described above, it is basically necessary that the image scanner section for reading a document and the printer section for outputting a copied image operate synchronously. That is, the R, G, and B image signals read by the CCD sensor are processed by the signal processing unit for each pixel, converted into M, C, Y, and Bk, and sequentially sent to the printer unit to be transferred onto the photosensitive drum. It is written with a laser to form a copied image.

However, in this conventional example, the image is formed on any one of M, C, Y, and Bk, and the image forming process is repeated for each of them, so that the original is read four times in succession.

The reading operation of the document need not always be performed four times in a row, but the image data read only once is stored in the temporary storage means and synchronized with the image formation of each of M, C, Y and Bk. A configuration for reading and outputting the stored image data is also conceivable.

However, in the former configuration, it is not necessary to store the image data in the storage means. However, since the scanner unit and the printer unit need to operate at the same time, for example, the fixing unit of the printer unit (normal heating and fixing) If the heater unit is not sufficiently heated, the printer unit is in the standby state, so that the copying operation and the original reading operation cannot be performed.

When a plurality of originals are copied in a plurality,
It is necessary to carry out the operation of reading one original multiple times corresponding to the output of multiple copies, and this operation must be performed for each of the multiple originals, and the time that the user has to spend for it is enormous. Become.

In the latter configuration, the scanner unit can perform the original reading operation without synchronizing with the printer unit.
Also, in the case of a copy output of a plurality of copies, the document reading operation may be performed once for one document. However, since the capacity of image data to be stored in the storage means is extremely large, it is difficult to store a plurality of document images simultaneously. Therefore, if a plurality of document images are read in a batch and replacement of pages or combined output of a plurality of document images is realized after the reading is completed, a huge storage device is required, which is not practical. Also, layout synthesis or the like by enlarging or reducing stored image data cannot be performed.

[0015] When an optimum process is to be performed in consideration of the characteristics of the image data, it is necessary to detect the characteristics of the image. When performing layout synthesis by enlarging or reducing processing using this feature data, it is easy to handle images,
High-quality image output has not been sufficiently studied.

An object of the present invention is to solve the above problems.

[0017]

Therefore, according to the present invention, there is provided means for separating an original image into colors and reading as color digital signals for each pixel, and temporarily storing the read R, G, B color image signals. Means, at the same time as reading the original, means for detecting a feature amount for each pixel of the original image,
An image processing system comprising: means for generating flag data for identifying a feature of the pixel from the detected feature amount; and means for storing the flag data. A first pixel density converter for converting the pixel data and a second pixel density converter for converting the flag data at the same magnification as the designated magnification, and storing the stored image data and flag data; The first and second pixel density conversion means read out the pixel density from each means, convert the pixel density by the first and second pixel density conversion means, and transfer the pixel density to the printer unit in association with each pixel to form an output color image. Was canceled.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of the first embodiment.

(Reading Unit) A document to be copied is placed on a document table glass (not shown) of the scanner unit 101 and read. As in the case of FIG. 10, the scanner section digitally reads a document image for each pixel using a color 3-line CCD and transfers a color image signal to the input image processing section 102. The input image processing unit 102 performs known image processing such as shading correction, CCD line-to-line correction, and color correction on the RGB color image signal sent from the scanner unit.

Reference numeral 103 denotes a block for performing image area separation processing on the input image-processed color image signal output from the image processing unit 102. Image features such as a photograph area, a character area, and a halftone area are provided for each pixel of the input image. And an image area separation processing unit that generates flag data representing an attribute of each image area.

(Image Area Separation Processing) Here, the image area separation processing section will be described. The image area separation process is to extract a characteristic of an original image and generate a signal indicating an image area attribute (hereinafter, referred to as flag data) in order to perform optimal image processing according to the characteristic of an image included in the original image. Done in For example, in a manuscript, a continuous tone full-color photograph area, a solid black character area, or a halftone print area such as newspaper printing,
Usually, various image areas are mixed. If these are uniformly processed and output in the same image processing procedure, the output image generally does not often have a desirable image quality. Therefore, in the first embodiment, a specific procedure for detecting an attribute of image data included in a document image using a color image signal input from 102 and generating flag data for identifying the attribute is described below. As shown in FIG.

FIG. 2 shows an example of a document image.
This shows a state in which a silver halide photograph area 202, a black character area 203, a halftone dot printing area 204, and a color graphic area 205 are mixed in one page 201. Here, the scanner section scans the original image by a color CCD sensor and outputs color digital signals (R,
G, B). The read RGB signals have characteristics determined by attributes of each area of the image.
The signal value (R,
When the G signal of G and B) is plotted in the arrangement direction of the CCD, for example, the result is as shown in FIG. 302, 3 in FIG.
03, 304, and 305 are respectively 202 to 20 in FIG.
The horizontal axis indicates the pixel position in the CCD and direction, and the vertical axis indicates the pixel value closer to white (brighter) in the read signal value as it goes upward. Represents.

To explain the characteristics of each area, since the area 202 is a silver halide photographic area, the change 302 due to the position of the image signal to be read is relatively gradual, and the difference 312 between pixel values at a short distance is a small value. Become. Reference numeral 303 denotes a characteristic of the black character area 203. Since a black character is written on a white background, the plot of the signal value is such that the read signal value changes abruptly from the white background portion 313 to the character portion 323. Reference numeral 304 denotes the characteristic of the halftone dot region 204. The halftone dot region is a repetition of a white background 314 and a halftone dot 324 printed thereon. It becomes a characteristic that repeats at a high frequency. 305 is a plot diagram of a graph area. The signal value sharply decreases at the edge 315 of the graphic,
The inner colored portion 316 has such a characteristic that a certain intermediate level follows.

In order to determine these attributes, the above-described features of each area may be read from the read signal value to make the determination. For this purpose, the change amount of the image data in the vicinity of the pixel of interest or the integrated value of the change amount in a certain section, the luminance value of a peripheral pixel (white background or colored background), the white to black of the image data in the certain section It is possible to use a feature extraction method using a known method such as the number of times of change, and to use a well-known attribute discrimination method based on the feature extraction method.

FIG. 4 shows an example of the attribute flags generated for the document image of FIG. 2 in this way. Here, three types of flags, ie, a character flag, a graphic flag, and a halftone flag, are generated as attribute flags (flag data), but are not limited to them. FIG. 4A shows a character flag, in which a pixel represented by black in the figure is a pixel having a character attribute, and a character flag = 1 is generated, and in other cases, a character flag = 0 (white portion in the figure). . (B) is a graphic flag, which is 1 in a graphic area and becomes 0 in other cases, and (c) is a halftone flag which represents an area which becomes 1 in a halftone area and becomes 0 in other cases. .

Since the silver halide photographic area does not correspond to any of these, all the flags are set to 0, and do not appear in FIG.

When the attribute of the image is detected for each pixel by the above-described image area separation processing, next, the second input image processing unit 104 performs image processing according to the image attribute. Here, for example, the high-frequency component of the image is emphasized for the character region to enhance the sharpness of the character, and the halftone dot region is subjected to a so-called low-pass filter process to remove a moire component unique to the digital image. Can be performed. Switching between these processes can be performed in pixel units according to the attribute flag data generated in 103.

(Storing of image data) Image data read by a scanner and subjected to various input image processing, and attribute flag data generated by the above procedure are stored in the image memories 1 and 106 of the flag memories 105 and 106, respectively. 1 is temporarily stored. At this time, the image data and the attribute flag data are stored as an entire document page or as a partial image of a predetermined size of one page. With this storage configuration, it is possible to hold the image data and the flag data for a period corresponding to the time required for the compression processing that changes variously according to the amount of data of one page.

The temporarily stored image data and attribute flag data are compressed by the data compression section 109 and stored in the storage device 110. It is desirable that 110 is a high-speed storage unit such as a semiconductor storage device. The data compression unit performs different data compression processing on the image data and the flag data. In other words, image data is irreversible, such as JPEG compression, but is subjected to high-efficiency compression processing that makes image degradation less noticeable in consideration of human visual characteristics. Indicates that no attribute flag information is lost or changed.
It is desirable to use a lossless compression method such as BIG compression. With this configuration, it is possible to reduce the amount of data using an appropriate compression method according to the type of data. In this manner, the image data and flag data which have been subjected to different compression processing are stored in the unit 110 in units of one page of the document. In some cases, the data may be written to the stored data or the auxiliary storage device 111. The auxiliary storage device is preferably a medium, such as a hard disk, which can store a large amount of data although the recording speed is slightly slow. As described above, by using an auxiliary storage device such as a hard disk in addition to the semiconductor storage device, it becomes possible to efficiently store and accumulate many pages of document images.

(Reading of Image Data) 110 or 1
The image data and the attribute flag data stored in 11 are read out for output from the printing unit,
The compressed data is decompressed by the twelve data decompression units and written out to the image memory 2 at 114 and the flag memory 2 at 115, respectively. At this time, the pixel density converters 113a and 113b may convert the pixel density of the stored image data. This is used, for example, when the user wants to print out the stored image data by enlarging or reducing it, or when he wants to print out a plurality of stored pages by synthesizing them on one print output sheet.

The composite output of a plurality of pages is, for example, as shown in FIG. That is, two original images 501 and 5
02 is stored in the storage device in advance. This is a case where two sheets are combined on an output sheet of the same size as the original to obtain a print output like 503. For this purpose, first, the stored image data 501
From the storage means to decompress the compressed data,
3a, the image density is reduced at a predetermined magnification by a pixel density conversion unit 1 and rotated 90 degrees to the left by a rotation processing unit (not shown).
(A region corresponding to 504 in FIG. 5).

Next, the image data 502 is read out and subjected to decompression, resolution conversion and rotation processing in the same manner, and
Write to the area corresponding to 05. At this time, originals A and B
Are decompressed, converted to a resolution, and rotated (same magnification and rotation processing as the image data) in the same manner and written in the corresponding area of the flag memory 2. In this case, the pixel density conversion processing (reduction processing) Is executed by the second pixel density conversion unit 113b. In this manner, the image data is similarly scaled and rotated with respect to the corresponding flag data, so that when performing layout printing, adaptive image processing described later according to the flag data can be performed. Here, it is desirable to apply different techniques to pixel density conversion of image data and pixel density conversion of flag data. For example, a known method such as a linear interpolation method or a bicubic spline interpolation method can be applied to image data. In addition, it is desirable to use a pixel density conversion method suitable for binary data, such as a nearest neighbor processing method, for pixel density conversion of flag data. Details will be described later.

(Output of Image Data) When the image data and the flag data temporarily stored in the image memory 2 and the flag memory 2 reach a predetermined size, they are transferred to the output image processing section 116. In the output image processing unit 116, R
Well-known image processing for printing and outputting GB image data, that is, luminance / density conversion, RGB → CMYK conversion,
Processing such as gamma correction, binarization processing, and the like is performed, and the image data is transferred to the printer unit 117. The printer unit 117 drives the laser based on the transferred CMYK image signals, and forms and outputs a visible image on transfer paper in the same procedure as in FIG.

Here, the flag data stored in the flag memory 2 is used for switching the processing of the output image processing unit 116. That is, in the photograph area and the character area, RGB → C
By making the masking coefficients of the MYK conversion different, the quality of the output image can be improved. For example, for a character area, that is, for a pixel with a character flag = 1, a conversion coefficient such that a black character can be reproduced with only black toner (that is, a coefficient such that C, M, and Y = 0 when the image data is achromatic). And C, even if it is achromatic otherwise
M and Y do not become 0, and a coefficient that can reproduce deep black can be used.

In the binarization process, C, M, Y, K
The signal is converted into a binary signal of 0 or 1 using a well-known error diffusion process or dither process. At this time, the sharpness of the output image is prioritized in the character region and the graph region, so the error diffusion process is applied. In a photograph or a halftone dot region, gradation is emphasized, so that dither processing is applied. For example, the content of the binarization processing is switched by attribute flag data, so that the image quality of an output image can be improved.

An example of a block diagram of the configuration at this time is shown in FIG.
Shown in The image memory 2 at 114, the flag memory 2 at 115, and the printer unit 117 are the same as those in FIG. The RGB color image data read from the image memory 2 is converted into two RGB data of 601 and 602 in parallel.
The signals are input to the YK conversion circuit and are converted into CMYK image signals independently. Either the output of 601 or 602 is selected by the selector 1 of 603 according to the flag signal of the flag memory. When a conversion coefficient for a character area is set in 601 and a coefficient in other cases is set in 602, the output of 601 is selected when the character flag in the flag memory is 1, and the character flag is When it is 0, the output of 602 is selected.

The output of the selector 1 is also separated into two systems in parallel, one of which is the gamma correction circuit 1
Is input to the selector 2 of 608 as a binary CMYK signal through the error diffusion binarization processing unit. The other is 60
The gamma correction circuit 2 of No. 5 and the dither processing binarization circuit of 607 are also input to the selector 2 of 608 as binary CMYK signals.

The selector 2 selects one of the outputs 606 and 607 and transfers it to the printer unit. Here, since the error diffusion processing is selected in the character area and the flag area, the character flag = 1 or the graphic flag = 1 , The selector 2 selects the output of 606, otherwise, 6
07 output may be selected.

(Pixel Density Conversion of Image Data) Here, the above-described pixel density conversion method will be described in detail. Here, the image data and flag data decompressed by the data decompression unit are enlarged or reduced by the pixel density conversion units 113a and 113b, and the image memory 3 and the flag memory 2 are expanded.
A processing method for outputting to a.

FIGS. 7A and 7B are plots of read image data and flag data, respectively. The horizontal axis represents the pixel position (coordinate) of the image reading unit in the CCD array direction, and the vertical axis represents the pixel value (0 to 255) and the flag value (0 or 1) of the image, respectively. Also, (a) shows a G signal of RGB, for example, and (b) shows a character flag of a plurality of flag data, for example.

In the figure, white circles 701 and 702 indicate data of one pixel, respectively. In this embodiment, the reading resolution of the reader unit is 600 dpi, so that the interval between each pixel is equivalent to 600 dpi when converted into a document. 2
5.4 / 600 mm).

Consider a case where such image data is reduced to, for example, 0.75 times. (In the example of FIG. 5, this corresponds to the reduction ratio.) In this case, it is necessary to newly generate a pixel value at a position indicated by a dotted arrow in the drawing to generate reduced image data. This is equivalent to generating data for two pixels by reducing and thinning out three pixels of the original image data. Therefore, when the coordinates after the reduction are at the position 703, the original image data may be used as it is as the pixel value of the image after the reduction.
In this case, it is necessary to generate an operation from the preceding and succeeding pixel values. Therefore, when the linear interpolation method is used, the pixel value after the reduction becomes a black circle in FIG. 7C. Since the pixel value of 705 in the figure corresponds to the coordinate position 703, it is the pixel value of the original coordinate corresponding to the original (a). However, since the pixel value of 706 corresponds to the coordinate 704, the pixel value of both sides sandwiches the position. Are replaced by the average value of the two original pixel values.

The above processing is performed by the pixel density converter 1 of 113a.
Executed in

Next, the reduction processing of the flag data will be described. Since the resolution of the flag data is the same as the resolution of the image data, FIG. 7B shows the same pixel arrangement as that of FIG. 7A, and corresponds to the post-reduction data when the data is reduced to 0.75 times. The pixel coordinates are the positions indicated by the dotted arrows in (b) as in (a). Accordingly, the pixel value 709 corresponding to the coordinate 707 is the pixel value itself of the corresponding coordinate in FIG.
Needs to be generated by calculating from pixel values (flag values) on both sides.

However, since the flag data in (b) is binary information of 0 or 1, the above-described linear interpolation method cannot be applied. Therefore, a configuration may be employed in which the pixel value (flag value) at the closest position in the original image coordinates corresponding to the pixel position after the reduction is used as the pixel value after the reduction. This is called the nearest neighbor reduction processing.

However, if this method is simply used, the pixel value corresponding to the pixel 711 which was 1 in (b) is 71 in (d).
It turns out that it becomes 0 and has disappeared. Therefore, here, a processing method is adopted in which the OR of the flag values on both sides of the pixel position after reduction is used as the flag value after reduction. By doing so, the pixel value after reduction is 71
2, it is possible to prevent the original flag information before reduction from being lost due to the reduction processing.

The above processing is performed by the pixel density conversion unit 2 of 113b.
Executed in

If the reduced image data and the reduced flag data generated as described above are stored in the image memory 2 and the flag memory 2 of FIG. 1, a print output reduced by the above-described procedure can be obtained. .

Here, the image data and the flag data have been described as one-dimensional arrays. However, the linear scaling method can be extended to two-dimensional data as is well known, and the scaling processing of the flag data is also extended to two dimensions. It is possible. FIG. 8 is a diagram for explaining a case where the scaling method of the flag data is extended to two dimensions. In the figure, data represented by a white circle 801 indicates flag data of the original image before scaling, and has a value of 0 or 1. The black circle of 802 is scaled (reduced in this case)
This indicates a pixel position to be generated later, and also takes a value of 0 or 1. Here, assuming that the target pixel position is 803, four original image flag data 804 surrounding 803 are set.
By performing the OR operation using all of the above, the post-magnification flag data 803 can be obtained. That is, if all four pixels indicated by 804 are 0, 0 is generated for the target pixel, and otherwise, 1 is generated.

Here, the generation of the pixel value after scaling has been described as being generated by ethical sum processing of neighboring pixels. However, the present invention is not limited to this. For example, only the nearest pixel is detected. Various methods can be considered, such as setting the value to the same value, or counting the number of pixels that are 1 in the vicinity neighboring pixels, and setting the pixel value after zooming to 1 if the count value is equal to or greater than a predetermined value.

It is also possible to change the method of generating a pixel value after scaling according to the scaling factor. For example, when the scaling factor is 1 or less (reduction), a pixel value of interest is generated by the logical sum of a plurality of pixels near the pixel of interest, and when the scaling factor is 1 or more (enlargement), the pixel value of one pixel closest to the pixel of interest is generated. Can be directly generated as a target pixel value.

It is also possible to change the method of generating the pixel value after scaling according to the attribute of the flag. In the present embodiment, three types of flags, ie, a character attribute, a graphic attribute, and a halftone dot attribute, are shown. However, it is different for each attribute whether the logical sum processing is appropriate at the time of reduction or whether replacement with only one neighboring pixel is appropriate. In some cases. Therefore, for example, if the character flag and the figure flag are reduced by the OR processing, and the halftone flag is reduced by the replacement processing with the nearest pixel value, the erroneous determination flag when the halftone determination accuracy is insufficient is reduced. An effect that can sometimes be removed can be expected. Also, if the flag data of the neighboring pixels is 1
If the count value is equal to or greater than a predetermined value, and the pixel value after scaling is set to 1 when the count value is equal to or greater than the predetermined value, the halftone dot flag is erroneously determined in a region other than the halftone region due to erroneous determination. 1
However, since there is no halftone dot flag in the vicinity, the count value does not exceed a predetermined value and the influence of erroneous determination can be eliminated.

Further, the operation unit is provided with a manual switching unit for switching the interpolation method of the flag data and a sample instructing unit for outputting a sample print (thumbnail print) so that the actual printing is performed in accordance with the sample output instruction. Alternatively, a configuration may be employed in which the operator selects an interpolation method by manual instruction. Further, a process of giving an offset to the sampling coordinates in the pixel density conversion is also possible. FIG. 9 is a diagram for explaining the processing in that case.

FIG. 9A is a diagram for explaining the pixel density conversion of the image data, as in FIG. 7A. The start position of → corresponding to the pixel position after the pixel density conversion is indicated by 903. As shown in FIG. Fig. 7
Is the same as

By doing so, the case where the original pixel value is output as it is and the case where the original pixel value is interpolated and output are not alternately generated as shown in FIG. Since all output pixel values are generated by interpolation between neighboring pixels, output image quality may be improved.

When the sampling position is offset by the first pixel density conversion means, the same offset value ΔX must be set in the second pixel density conversion means. This is shown in FIG. 9B, where the start position 907 of the output pixel position is shifted by ΔX as in FIG. 9A.

In this case, since the distance relationship between the output pixel position and the original pixel position is deviated, the adjacent pixels subjected to the logical sum operation are different from those in FIG. 7, and the pixel density conversion pixel of the image data and the pixel of the flag data The corresponding positional relationship with the density conversion pixel is kept good.

<Other Embodiments> In the above description, the flow of image data from the scanner unit 101 in FIG. 1 has been described. Similarly, image data input from the external communication path 119 via the communication interface 118 is described. Even first
The processing of the embodiment can be applied.

A typical example of the image data sent from 119 is image data described in so-called PDL (Page Description Language). The PDL data input here is a group of commands for describing an image. If the PDL data is interpreted and converted into bitmap data similar to an image read by a scanner, the PDL data can be applied as it is.

That is, the PDL data input from 118 is converted by the interprinter 108 into an intermediate language format called a display list. This display list is sent to a RIP (raster image processor) 107 to develop it into bitmap data. The developed image data is stored in the image memory 1 of 105. At this time, the RIP 107 simultaneously generates the attribute information of the developed image data as flag data and stores it in the flag memory 1 of 106.

Here, it is not necessary to generate the flag data by the image area separation processing referring to the image data as described in the first embodiment, and the PDL data input to the RIP is held for each component. The flag data of the corresponding pixel of the developed image may be generated with reference to the attribute information (such as a photograph, a character or a graphic).

That is, when a PDL command for generating a character part is input to the RIP, the RIP generates a bitmap image of the character data and, at the same time, generates a character flag = 1 as flag data corresponding to the area where the character is generated. You just have to do it. After the image data and the flag data are generated as described above, the subsequent processing can be handled exactly the same as in the first embodiment.

<Another Embodiment of the Present Invention> A program for operating the configuration of the above-described embodiment so as to realize the functions of the above-described embodiment is stored in a storage medium, and the program stored in the storage medium is stored in code. A processing method that is read as a computer and executed by a computer is also included in the scope of the above-described embodiment, and a storage medium that stores the above-described program is also included in the above-described embodiment.

As such a storage medium, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, magnetic tape, nonvolatile memory card, and ROM can be used.

The present invention is not limited to the one that executes the processing by the program stored in the storage medium alone, and operates on the OS together with the functions of the other software and the expansion board to execute the processing of the above-described embodiment. The one that performs the operation is also included in the category of the above-described embodiment.

[0067]

As described above, according to the present invention, it is possible to easily handle images and to perform data output enabling high-quality image output without imposing a great burden on the user. An image can be generated at a magnification.
Also, the image storage capacity can be suitably determined by the type of data to be stored. Further, the pixel density conversion processing can be performed adaptively, and the image quality can be improved.

Further, the same processing can be performed when a document image is read by a scanner and printed out, and when a printed image using PDL (page description language) is output, the same processing can be performed. On the other hand, optimal image processing can be performed at an arbitrary magnification, and a high-quality output image can be obtained in any case.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a configuration for implementing the present invention.

FIG. 2 is an example of a document image applied to the present invention.

FIG. 3 is a diagram illustrating an example of an image area separation process according to the present invention.

FIG. 4 is a diagram illustrating an example of flag data according to the present invention.

FIG. 5 is a diagram illustrating an example of a layout synthesis output according to the present invention.

FIG. 6 is a block diagram illustrating an example of an output image processing configuration according to the present invention.

FIG. 7 is a diagram illustrating an example of a pixel density conversion method according to the present invention.

FIG. 8 is a diagram illustrating an example of a two-dimensional process of the pixel density conversion method according to the present invention.

FIG. 9 is a diagram illustrating an example of an offset process in the pixel density conversion method according to the present invention.

FIG. 10 is a diagram illustrating a conventional color image copying apparatus.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 1/46 H04N 1/46 Z 5C079 F term (Reference) 2C362 CA03 CA05 CB01 CB24 CB25 CB34 CB39 CB75 2H030 AA05 AD12 AD14 5B057 BA02 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC03 CD03 CD05 CD06 CE03 CE04 CE06 CE08 CE13 CE18 CG01 CH09 CH18 DA08 DA17 DB02 DB06 DB09 DC22 DC36 5C076 AA01 AA17 AA19 AA21 AA22 AA24 AA27 BB11 LL19 MP02 MP06 MP08 NN19 PP02 PP03 PP20 PP22 PP23 PP27 PP28 PP32 PP33 PP38 PP47 PP48 PP58 PP61 PP65 PP68 PQ08 PQ22 RR02 RR19 RR21 5C079 HB12 LA06 LA10 LA15 LA26 LA28 LA31 LA34 LA36 LA37 LA40 LC04 LC09 MA02 NA02 NA10 NA11

Claims (49)

[Claims] An input unit that inputs color image data; a storage unit that stores the color image data; a generation unit that generates, from the color image data, flag data indicating an image feature corresponding to the color image data; Flag data storage means for storing the generated flag data, first pixel density conversion means for converting the pixel density of the color image data read from the storage means at a designated magnification, read from the flag data storage means A second pixel density conversion means for converting the flag data obtained by the pixel density conversion at the same magnification as the designated magnification, a printer which associates the pixel density converted image data with the pixel density converted flag data on a pixel basis And an output unit for outputting the image data to a unit. 2. The image processing apparatus according to claim 1, wherein the flag data is a character flag, a graphic flag, and a halftone flag. 3. The image processing apparatus according to claim 1, wherein the feature of the image is a change in image data near a pixel of interest. 4. The image processing apparatus according to claim 1, wherein image processing is performed on the read image data according to the read flag data. 5. When the flag data is a character flag,
The image processing apparatus according to claim 4, wherein sharpness enhancement is performed on the image data. 6. When the flag data is a halftone flag,
The image processing apparatus according to claim 4, wherein a low-pass filter process is performed on the image data. 7. The image data according to claim 1, wherein the image data is subjected to irreversible compression in which deterioration of the image is made inconspicuous in consideration of human perceptual characteristics before being stored by the storage unit. Image processing device. 8. The image processing apparatus according to claim 1, wherein the flag data is subjected to lossless compression before being stored by the flag data storage unit. 9. The apparatus according to claim 7, wherein the input image data is temporarily stored as a partial image of one page or a predetermined size of the image before being compressed. Image processing device. 10. The image data storage means and the flag data storage means use a storage medium capable of high-speed data processing and a storage medium which has a low recording speed but can store a large amount of data. The image processing apparatus according to any one of the preceding claims. 11. The image processing apparatus according to claim 1, further comprising image processing means for performing at least one of a rotation process and a layout synthesis process on both the decompressed image data and the flag data. 12. The image processing apparatus according to claim 11, wherein one of a linear interpolation method and a bicubic spline interpolation is used for resolution conversion of the image data. 13. The image processing apparatus according to claim 11, wherein the resolution conversion for the flag data includes performing a resolution conversion suitable for binary data. 14. The method according to claim 2, wherein in the color conversion processing of the read image data, a color conversion coefficient is changed according to the read character flag data.
An image processing apparatus as described in the above. 15. The image processing according to claim 2, wherein in the binarization processing of the read image data, error diffusion processing and dither processing are switched according to the read character flag and graphic flag. apparatus. 16. The image according to claim 1, wherein the input image data is data described in a page description language, and the flag data is attribute information of the page description language. Processing equipment. 17. The first pixel density conversion processing means,
The second pixel density conversion process is a process of performing a logical operation process of a plurality of flag values near the target pixel, a process of using a nearest pixel of the target pixel, or a process of using a neighboring pixel. 17. The image processing apparatus according to claim 1, wherein the processing is performed using a result of counting peripheral flag data. 18. The apparatus according to claim 1, wherein said first pixel density conversion means and said second pixel density conversion means perform pixel density conversion processing based on the same scaling factor and the same offset value. 17. The image processing device according to item 16. 19. The method according to claim 1, wherein, in the pixel density conversion by the second pixel density conversion means, the first conversion method and the second conversion method are switched according to the scaling factor. Image processing device. 20. The method according to claim 1, wherein the second pixel density conversion means switches between a first conversion method and a second conversion method according to an attribute of the flag data.
An image processing apparatus as described in the above. 21. The second pixel density conversion process uses a result of a logical operation process of a plurality of flag values near the target pixel, a process using the nearest neighbor pixel of the target pixel, and a count of flag data around the neighbor pixel. 21. The image processing apparatus according to claim 19, wherein the processing is switched. 22. Inputting color image data, storing the color image data, generating flag data indicating characteristics of an image corresponding to the color image data from the color image data, Reading out the stored color image data, converting the pixel density at a specified magnification, reading out the stored flag data, converting the pixel density at the same magnification as the specified magnification, An image processing method, wherein the density-converted image data and the pixel density-converted flag data are output to a printer unit in association with each other on a pixel-by-pixel basis. 23. The method according to claim 22, wherein the flag data is a character flag, a graphic flag, and a halftone flag.
The image processing method described in the above. 24. The image processing method according to claim 22, wherein the feature of the image is a change in image data near a pixel of interest. 25. The image processing method according to claim 22, wherein image processing is performed on the read image data in accordance with the read flag data. 26. The image processing method according to claim 25, wherein when the flag data is a character flag, sharpness enhancement is performed on the image data. 27. The image processing method according to claim 25, wherein when the flag data is a halftone dot flag, a low-pass filter process is performed on the image data. 28. The image processing apparatus according to claim 22, wherein the image data is subjected to irreversible compression in which deterioration of the image is not noticeable in consideration of human perceptual characteristics before being stored by the storage unit. Image processing method. 29. The image processing method according to claim 22, wherein lossless compression is performed on the flag data before storing the flag data. 30. The apparatus according to claim 28, wherein the input image data is temporarily stored as a partial image of one page or a predetermined size of the image before being compressed. Image processing method. 31. The storage of the image data and the storage of the flag data using a storage medium capable of high-speed data processing and a storage medium that is slow in recording speed but capable of storing a large amount of data. The image processing method described in the above. 32. The image processing method according to claim 22, wherein at least one of a rotation process and a layout synthesis process is performed on both the read image data and the flag data. 33. The image processing method according to claim 32, wherein any one of a linear interpolation method and a bicubic spline interpolation is used for the resolution conversion of the image data. 34. The image processing method according to claim 32, wherein the resolution conversion for the flag data includes performing a resolution conversion suitable for binary data. 35. The color conversion process of the read image data, wherein a color conversion coefficient is changed in accordance with the read character flag data.
3. The image processing method according to 3. 36. The image processing according to claim 23, wherein in the binarization processing of the read image data, error diffusion processing and dither processing are switched by the read character flag and graphic flag. Method. 37. The image according to claim 22, wherein the input image data is data described in a page description language, and the flag data is attribute information of the page description language. Processing method. 38. The pixel density conversion process to the image data is a process of performing interpolation from a plurality of pixels near the target pixel, and the pixel density conversion process to the flag data includes a plurality of flag values near the target pixel. 38. The image processing method according to claim 22, wherein the logical operation processing of step (a), the processing using the nearest pixel of the pixel of interest, or the processing using a result of counting flag data around the neighboring pixel is performed. 39. The method according to claim 22, wherein the pixel density conversion to the image data and the pixel density conversion to the flag data are performed based on the same scaling factor and the same offset value. 37. The image processing method according to claim 37. 40. The image processing method according to claim 22, wherein a first conversion method and a second conversion method are switched in the pixel density conversion to the flag data in accordance with the scaling factor. . 41. The method according to claim 2, wherein the pixel density conversion to the flag data is switched between a first conversion method and a second conversion method according to an attribute of the flag data.
42. The image processing method according to 2, 37. 42. The pixel density conversion process to the flag data uses a result of a logical operation process of a plurality of flag values near the target pixel, a process using the nearest neighbor pixel of the target pixel, and a count of flag data around the neighbor pixel. 42. The image processing method according to claim 40, wherein the processing is switched. 43. A storage medium storing a code for executing the image processing method according to claim 22. 44. A means for color-separating a document image and reading it as a color digital signal for each pixel; a means for temporarily storing the read R, G, B color image signal; An image processing system comprising: means for detecting a feature amount for each pixel of a document image; means for generating flag data for identifying a feature of the pixel from the detected feature amount; and means for storing the flag data A first pixel density conversion means for converting the image data into a pixel density at a specified magnification, and a second pixel density conversion means for converting the flag data into a pixel density at the same magnification as the specified magnification. After reading out the stored image data and flag data from the storage means and converting the pixel densities by the first and second pixel density conversion means, The image processing system characterized by in association with the transfer to the printer section to form an output color image. 45. A means for inputting and temporarily storing R, G, B color image signals, and simultaneously inputting the color image signals, and inputting flag data for identifying characteristics of the input image signals for each pixel. And a means for temporarily storing the flag data, wherein the first pixel density conversion means for converting the image data to a pixel density at a specified magnification; and Second pixel density conversion means for converting the pixel density at the same magnification as the designated magnification, reading out the stored image data and flag data from the storage means, and setting the respective pixel densities to the first and second pixel densities. An image processing system, wherein the output color image is converted by the pixel density conversion means, and then transferred to the printer unit in association with each pixel. 46. The first pixel density conversion means is means for performing an interpolation operation from a plurality of pixel values near a pixel of interest.
The image processing system according to claim 1, wherein the second pixel density conversion unit is a unit that performs a logical operation on a plurality of pixel values near the target pixel. 47. The apparatus according to claim 1, wherein the first pixel density conversion means and the second pixel density conversion means are executed based on the same magnification value and the same offset value. Image processing system. 48. The apparatus according to claim 1, wherein the second pixel density conversion means is constituted by a plurality of different means, and the plurality of means can be selected according to a magnification of the density conversion.
An image processing system according to claim 1. 49. The method according to claim 1, wherein the second pixel density conversion means is constituted by a plurality of different means, and the plurality of means can be selected according to the attribute of the flag data. Image processing system.