JP3134756B2 - Image processing apparatus and image processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an apparatus for performing image processing including compression / expansion processing of image data.
The present invention relates to an image processing apparatus and an image processing method for appropriately reproducing a document image in which a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing are mixed in accordance with the image area.

[0002]

2. Description of the Related Art In recent years, digital color copying machines have been devised in which a full-color image is read by a color image input device, converted into an electric signal, subjected to image processing and editing, and output by a color laser printer. One of the most important issues in such digital color copiers is
Without deteriorating image quality, minimize cost increase,
There is how the printout speed can be improved.

In general, in a conventional digital color copying machine, K (black), Y
(Yellow), M (magenta), and C (cyan) development and transfer processes of four colors are repeated four times to obtain a full-color image. Here, FIG. 13 is a conceptual diagram showing a schematic configuration of a one-drum type digital color copying machine. In the figure,
The image signal of the original image for each line obtained by the first scanning in the sub-scanning direction by the color image reading device 1 is subjected to various processes such as color correction and editing in the image processing unit 2 and then output to the image output unit. The signal is sent to the signal generator 3 and is converted into a light emission drive signal to the semiconductor laser oscillator 4 in the image output signal generator 3.

The laser light, which is turned on / off for each pixel by the semiconductor laser oscillator 4, is scanned in the main scanning direction (perpendicular to the direction of rotation of the drum) by the rotation of the polygon mirror 5. An electrostatic latent image is formed in units. The K (black) of the color developing device 7 is applied to the electrostatic latent image obtained by the end of the first scan.
Is selected, and a K toner image is drawn on the photosensitive drum 6. On the other hand, the transfer paper fed from the paper feed tray 8a or the paper feed tray 8b is electrostatically attracted to the transfer drum 9 and, at the same time, the K toner is transferred on the photosensitive drum 6.

This series of steps is completed by the end of the first scan, and thereafter, in synchronization with the second to fourth scans of the color image reading apparatus 1 in the sub-scanning direction, Y, M,
The development of C is repeated, and the transfer paper wound around the transfer drum 9 at the time of the first scan is scanned with Y, M, and C in synchronization with the second to fourth scans of the color image reading device 1.
By repeating the transfer twice, a transfer image in which the K, Y, M, and C scan signal images are superimposed is obtained.

Thereafter, the transfer paper is peeled off from the transfer drum 9 and is conveyed to a fixing device 10 to obtain a fixed color copy image on a paper discharge tray 11. By taking such development and transfer steps in synchronization with the four reading operations, a color copy image can be obtained without an image memory for each frame.

In the above-described one-drum type color copier, four scans are performed to read an original, and K, Y, M, and C images are sequentially obtained each time. There is a disadvantage that the time until the printout is long. Therefore, in order to increase the printout speed, an image memory (a plurality) for storing image data read in one scan is provided, and each of K, Y,
There is known a color copying machine which prepares a drum for each of M and C and performs the above-described development and transfer processes in sequence.

FIG. 14 is a conceptual diagram showing a schematic configuration of a color copying machine (tandem type) having a mechanism for increasing the printout speed. The parts corresponding to those in FIG. 13 are denoted by the same reference numerals. In the illustrated tandem-type color copying machine, four developing drums independent of K, Y, M, and C, a first developing drum 7a, and a second developing drum 7 are provided.
b, a third developing drum 7c, and a fourth developing drum 7d are independently provided, and further, the transfer paper is moved by the transfer belt 15, so that the development and transfer steps can be performed in parallel with a time difference. , Basically, as shown in FIG.
The color copying operation can be performed at four times the speed of the drum system.

In the conventional color copying machine having the above-described configuration, during the development of K (black) by the first development drum 7a, the development of Y by the second development drum 7b starts, If the second copy process is not starred before the copy process is completed,
Essentially, the high-speed operation of the configuration itself cannot be realized. Therefore, in a conventional tandem-type color copying machine,
An image memory for each frame is provided for each of K, Y, M, and C, and an image signal (laser oscillation drive signal) supplied to a developing process of the first to fourth developing drums 7a to 7d is time-controlled. It is necessary to do. At this time,
If the image memory is simply used, the capacity of the image memory becomes enormous. Therefore, a technique of compressing and storing the data is usually used.

[0010]

In the above-described color copying machine, it is necessary to determine whether each pixel is a pixel having an edge such as a character or a halftone pixel such as a photograph. By performing image area separation, a region data signal indicating whether the image is a character or a photograph for each pixel is generated, and a process of controlling a tone or a screen mesh in pixel units according to the region data signal, that is, an image In order to reproduce the image quality, it is necessary to perform the optimal control processing at least according to the type of. In addition, in order to minimize an increase in memory capacity, it is necessary to efficiently compress and store, in addition to image data to be processed, an area data signal obtained by image area separation without deteriorating image quality. .

In the above-described color copying machine, the above-mentioned optimal control processing is realized, for example, in Japanese Patent Laid-Open No.
JP-A-334834. Here, FIG. 15 is a block diagram showing a configuration of a conventional color copier image processing system to which the above-described optimal control processing is applied. In the figure,
In a conventional tandem type color copier, the image reading device 2
The RGB image data read at 0 is converted by the color conversion / color correction unit 21 into image data of an L * a * b * color space (a first device-independent color space), and then subjected to color conversion. The image data is further converted into image data in a CMY color space (a color space to a device-dependent second color space) by the / color correction unit 22. The image data of L * a * b * is determined by the region separation determining unit 30 for each pixel, whether the pixel is a line drawing such as a character or a halftone such as a photograph. It is determined whether the pixel is a color pixel or a black pixel.

The result of the determination by the area separation determining section 30 is expressed by a total of two bits, one bit indicating one of a character and a photograph and one bit indicating one of a color pixel and a black pixel. Is obtained as an area data signal S1. The 2-bit area data signal S1 is 16dot / mm × 297mm × 16dot / mm, assuming that the input / output resolution is 16dot / mm.
× 420 mm × 2 bits = 8 Mbytes (document size A
3), a very large memory capacity is required as in the case of image data to be described later. Therefore, after being compressed to 1/16 (0.5 Mbytes) by the compression unit 31 in predetermined block units,
The information is temporarily stored in the area memory 32.

On the other hand, the under-color removal / black generation section 23 performs under-color removal and black generation on the image data converted into the CMY color space based on the area data signal S1. Further, the spatial filter units 24a to 24d
In the above, the image data is subjected to edge enhancement or smoothing processing for each pixel also based on the region data signal S1.

Each of the spatial filter sections 24a to 24d performs a filtering process by a plurality of (at least two) different filter coefficients for each pixel. In other words, the spatial filter units 24a to 24d are configured as shown in FIG.
A spatial filter having various types of spatial frequency characteristics; and a coefficient determining unit that determines a filter coefficient of the spatial filter based on the region data signal S1 (not shown). When the data signal S1 is a character, an edge emphasis type (high band gain) band-pass filter or a high band emphasis filter (Laplacian type) is applied to improve the character reproducibility. When the data signal S1 is a photograph, a smoothing filter having a spatial frequency characteristic with a cutoff point is applied in order to suppress image noise and enhance granular reproducibility. After that, the image data is compressed by the compression units 25a to 25d provided correspondingly, and is temporarily stored in the image memories 26a to 26d.

The Y, M, C, and K image data stored in the image memories 26a to 26d are used when the image data is developed by the first to fourth developing drums 7a to 7d. The data is sequentially read out at a predetermined timing so as to match the delay time depending on the interval between the developing drums, and is expanded by the expansion units 27a to 27d. Next, in the tone correction units 28a to 28d, the characters /
The tone correction control (20
LUT control for compensating the difference in tone reproduction between the 0-line and 400-line screens) is performed, and is converted into a light emission control signal to the semiconductor laser. At this time, an SG (screen generator) for generating an emission control signal to the semiconductor laser
In the sections 29a to 29d, the screen cycle (200 lines, 400 lines) is also performed based on the area data signal S1.
Is controlled by switching.

According to the above processing, even when a black character / color photograph mixed image is input, the black character is processed by a single black color process.
After the edge emphasizing process, the image is output on a 400-line screen emphasizing the resolution.
After colorization, the image is band-enhanced and smoothed, and output on a 200-line screen emphasizing reproduction of gradation and graininess.

In the conventional color copying machine, when compressing the above-mentioned 2-bit area data signal S1, the compression unit 31 sets, for example, a block of 4 pixels × 4 pixels (16 bits in total). If there is a determination result indicating a character even for one pixel in each block, it is determined that all of the inside of the block of 4 pixels × 4 pixels is a character, and the determination result indicating even one pixel is a color pixel in the same block. if there is,
It is assumed that all the pixels in the block of 4 pixels × 4 pixels are color pixels. As a result, the area data signal S1 of 4 pixels × 4 pixels × 2 bits (32 bits) becomes 2-bit data compressed to 1/16.

However, in the conventional image processing apparatus,
Since the compression of the area data signal S1 is resolution compression in which 32-bit data is simply replaced with 2-bit data, the area data signal S1 after expansion by the expansion unit 33 is compressed.
When tone correction and screen switching are performed, the reproducibility of the edge part separated by the image area is greatly deteriorated. For example, assuming that the input / output resolution is 16 dots / mm, the character or line edge when reproduced with the region data before compression shown in FIG. , 4 dots / mm unit (4 pixels x 4
In the case of pixel block compression), tone correction and screen switching are controlled, and therefore, as shown in FIG. 17B, the internal jaggy particularly at the edges of bold characters and bold lines is enlarged four times. There was a problem that it would.

The present invention has been made in view of the above circumstances, and has as its object to provide an image processing apparatus and an image processing method capable of reproducing an image in which line drawing characters and halftone photographs are mixed with high quality. .

[0020]

In order to solve the above-mentioned problems, according to the first aspect of the present invention, a binary image area composed of characters and lines and a photograph Image area separation means for generating image area separation data for identifying halftone image areas such as dot printing, and compressing the input image data and the image area separation data generated by the image area separation means. Means for reading and expanding image data and image area separation data stored in the compression and storage means, and attribute detecting means for detecting an image attribute of the image data expanded by the expansion means Image data decompressed by the decompression means based on the image attribute detected by the attribute detection means and the image area separation data decompressed by the decompression means. Characterized by comprising an image processing means for performing processing.

According to the second aspect of the present invention, in the first aspect,
5. The image processing apparatus according to claim 1, wherein the attribute detection unit performs image area separation processing of a different style from image area separation processing performed by the image area separation unit on the image data expanded by the expansion unit. the second image area separation data obtained by in, characterized by using the second image area separation data as the image attribute.

According to the third aspect of the present invention, the first aspect of the present invention is provided.
The image processing apparatus according to claim 1, further comprising: a color conversion unit configured to perform a color space conversion process on the image data that has been subjected to the image area separation processing by the image area separation unit; And compressing and storing the image data that has been color-converted.

According to the fourth aspect of the present invention, there is provided the first aspect.
In the above-described image processing apparatus, the image processing unit performs tone reproduction control or resolution reproduction control on the image data expanded by the expansion unit.

According to the fifth aspect of the present invention, in the first aspect,
The image processing apparatus according to the above aspect, wherein the image attribute detected by the attribute detection unit is edge information.

Further, according to the invention described in claim 6, according to claim 1,
The image processing apparatus according to claim 1, wherein the attribute detection unit includes a plurality of spatial filters having different filter coefficients,
By performing image processing on the image data after expansion by the plurality of spatial filters, edge information indicating whether the pixel is an edge is detected for each pixel, and the edge information is set as the image attribute. Features.

According to a seventh aspect of the present invention, there is provided an input means for inputting compressed image data and compressed image area separation data corresponding to the compressed image data. Decompression means for decompressing the compressed image data and the compressed image area separation data input by the input means; attribute detection means for detecting an image attribute of the image data decompressed by the decompression means; Image processing means for performing image processing on the decompressed image data based on the image attribute detected by the attribute detection means.

[0027] According to the invention of claim 8, according to claim 7,
In the above-described image processing apparatus, the image processing unit performs tone reproduction control or resolution reproduction control on the image data expanded by the expansion unit.

According to the ninth aspect of the present invention, the seventh aspect of the present invention is provided.
The image processing apparatus according to the above aspect, wherein the image attribute detected by the attribute detection unit is edge information.

According to a tenth aspect of the present invention, in the image processing apparatus of the seventh aspect, the attribute detecting means includes:
A plurality of spatial filters having different filter coefficients are provided, and image processing is performed on the decompressed image data by the plurality of spatial filters to detect edge information indicating whether or not the pixel is an edge for each pixel. The edge information is used as the image attribute.

In order to solve the above-mentioned problems,
According to the eleventh aspect of the present invention, image area separation data for distinguishing between a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing for input image data. An image area separation step of generating; a compression accumulation step of compressing and storing the input image data and image area separation data generated by the image area separation means; and an image area separation compressed by the compression accumulation step. A decompression step of reading and decompressing data and image data, an attribute detection step of detecting an image attribute of the image data decompressed by the decompression step, and an image attribute detected by the attribute step and decompressed by the decompression step. A process determining step of determining image processing to be performed on the decompressed image data based on the image area separation data; and And having an image processing step of applying to the image data and the image processing is the elongation is.

According to a twelfth aspect of the present invention, in the image processing method according to the eleventh aspect, in the attribute detecting step, the image data decompressed in the decompression step is subjected to vertical / horizontal pixel units. The method is characterized in that the edge amount in the direction and the edge amount in the oblique direction are extracted, and when the edge is larger than a predetermined threshold, an image attribute indicating that an edge is present is generated.

In order to solve the above problems,
According to the thirteenth aspect of the present invention, a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone dot printing are distinguished from the input image data composed of the first color space. First image area separation means for generating first image area separation data for the first image area separation data, and converting the input image data based on the first image area separation data generated by the first image area separation data. First image processing means for performing image processing on the image data;
A color conversion unit for performing a color conversion process for converting the image data into the color space of the second color space, and image data composed of the second color space subjected to the color conversion by the color conversion unit and the second image data generated by the first image area separation unit. Compression / accumulation means for compressing and accumulating the image area separation data, expansion means for expanding the image data and image area separation data stored in the compression / storage means, and a second color expanded by the expansion means Second image area separation means for performing image area separation processing on image data composed of a space to generate second image area separation data for identifying the presence or absence of an edge, and the second image area separation means And a second image processing means for performing image processing on image data composed of a second color space expanded by the expansion means based on the second image area separation data generated by the image processing apparatus. And

According to a fourteenth aspect of the present invention, in the image processing apparatus according to the thirteenth aspect, the second image processing means performs processing on the image data composed of the second color space expanded by the expansion means. And performing tone reproduction control or resolution reproduction control.

According to a fifteenth aspect of the present invention, in the image processing apparatus according to the thirteenth aspect, the first image area separating means and the second image area separating means are arranged so that the first color space and the second color space are separated from each other. The image data of the second color space and the image data of the second color space are subjected to different types of image area separation processing.

According to a sixteenth aspect of the present invention, in the image processing apparatus according to the thirteenth aspect, the first image processing means includes a spatial filter applied to the input image data, Filter coefficient determining means for determining a filter coefficient of the spatial filter based on the first image area separation data generated by the area separating means.

According to a seventeenth aspect of the present invention, in the image processing apparatus of the thirteenth aspect, the color conversion means comprises:
A color space is converted from a device-independent first color space to a device-dependent second color space.

In order to solve the above-mentioned problem,
According to the eighteenth aspect of the present invention, a first image area for identifying a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing for input image data. First image area separating means for generating separated data, and performing image processing on the input image data based on the first image area separated data generated by the first image area separating means. (1) image processing means, compression and accumulation means for compressing and accumulating image data subjected to image processing by the first image processing means, and decompression means for reading and decompressing the image data accumulated in the compression and accumulation means A second image area separation unit that performs image area separation processing on the image data expanded by the expansion unit to generate second image area separation data for identifying the presence or absence of an edge; 2 image area separating means Characterized by comprising a second image processing means for performing image processing on the image data expanded by said expansion means based on the second image area separation data generated Te.

According to a nineteenth aspect of the present invention, in the image processing device according to the eighteenth aspect, the second image processing means performs tone reproduction control or image reproduction control on the image data expanded by the expansion means. It is characterized in that resolution reproduction control is performed.

According to a twentieth aspect of the present invention, in the image processing apparatus according to the eighteenth aspect, the first image area separation means and the second image area separation means respectively It is characterized in that different types of image area separation processing are performed.

According to a twenty-first aspect of the present invention, in the image processing apparatus according to the eighteenth aspect, the first image processing means includes a spatial filter applied to the input image data and the first image processing means. The first generated by the area separating means
And a filter coefficient determining means for determining a filter coefficient of the spatial filter based on the image area separation data.

According to the present invention, the image area separating means performs an image area separation process on the input image data, so that a binary image area composed of characters and lines and a photograph, halftone dot printing, etc. Image area separation data for identifying the halftone image area is generated. The input image data and the image area separation data generated by the image area separation means are compressed and accumulated by the compression accumulation means. The compressed and stored image data and image area separation data are read out at a predetermined timing and decompressed by decompression means. The attribute detecting means detects an image attribute of the image data expanded by the expanding means. Next, the processing determining means determines image processing to be performed on the expanded image data based on the image attributes detected by the attribute detecting means and the image area separation data expanded by the expanding means. Then, the image processing means performs the image processing determined by the processing determining means on the decompressed image data. As described above, the image processing to be performed on the image data is determined based on the image attributes that faithfully represent the characteristics of the decompressed image data. It is possible to reproduce with quality.

[0042]

Embodiments of the present invention will now be described with reference to the drawings.

A. Configuration of Embodiment FIG. 1 is a block diagram illustrating a configuration of an image processing system according to an embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to FIG. However, the compression units 25a to 25d, the area separation determination unit 30, the compression unit 31, the expansion unit 33, the tone correction units 28a to 28d, and the SG unit 2
9a to 29d will be described in detail because they are constituent elements related to the present invention. Further, in the present embodiment, the input / output resolution (in both the main scanning direction and the sub-scanning direction) of the image processing apparatus is set to 16 dots / mm as described above.

A-1. Configuration of compression units 25a to 25d First, the compression units 25a to 25d that compress image data
Each of them is subjected to compression processing for reducing the capacity of the image memory. However, in order to easily realize editing and processing processing provided as an additional function of the copying machine, fixed-length block coding (Lossy) is performed. The corresponding C,
The M, Y, and K image data are compressed. Here, FIG.
FIG. 3 is a conceptual diagram illustrating a configuration of compression units 25a to 25d that compress image data. Note that in FIG. 2, Block true
Although block encoding by the nuncation method is shown, the present invention is not limited to this. However, even in the block coding, the variable-length coding such as the JPEG coding complicates the editing process on the image memory. Therefore, it is desirable to use a fixed-length coding coding.

In the figure, the compression units 25a to 25d respectively block the corresponding C, M, Y, K image data (8 bits each) into 4 pixels × 4 pixels (4 × 4 × 8 =
The average value calculation circuit 40 calculates the average value of the pixel values in the block. In the illustrated example, the average value is (110 × 8 + 90 × 8) / 16 = 100. Next, the high-density pixel average value calculation circuit 41 calculates an average value of pixel values having a value larger than the average value in the block. On the other hand, the low density pixel average value calculation circuit 42
In the block, an average value of pixel values having a value smaller than the average value is calculated. In the illustrated example, 110 × 8/8 = 110 in the high density pixel average value calculation circuit 41, and 90 × 8/8 = 90 in the low density pixel average value calculation circuit 42.
Becomes

Further, the compression units 25a to 25d binarize the pixels in the binary pattern generation unit 43 based on the average value in the block calculated by the average value calculation circuit 40. In the illustrated example, since the average value is 100, 11
A pixel having a value of 0 is “1 (black)”, and a pixel having a value of 90 is “0 (white)”. Note that the output of the binary pattern generation unit 43 is 4 × 4 = 16 bits.

The compression units 25a to 25d either use the binary pattern as it is or as shown in the vector quantizer 4
It is vectorized by 4 (from 16 bits to 8 bits) and supplied to the merge circuit 46 via the selector 45. The merge circuit 46 sequentially combines the above-described average value of high density pixels (8 bits), the average value of low density pixels (8 bits) and the above-described binary pattern (16 bits or 8 bits), and outputs a total of 24-32 bits. Output as compressed data.

Thus, the input 4 × 4 × 8 = 12
The 8-bit image data is compressed to 1/4 and becomes 32 bits when the pattern is left as it is, and is compressed to about 1/5 and becomes 24 bits when vector-quantized. As a result, the capacity of the image memories 26a to 26d can be reduced.

A-2. Configuration of Region Separation Determination Unit 30 Next, the region separation determination unit 30 uses the color conversion / color correction unit 21 to temporarily convert the image data (8 each) into the L * a * b * that is the first color space. Bit), it is determined whether the pixel is a line drawing such as a character or a halftone such as a photograph, and whether the pixel is a color pixel or a black pixel. Under color removal / black generation section 23, spatial filter sections 24a-2 as first area data signal S1
4d and to the compression unit 31.

(A) Area Separation Processing by Area Separation Determining Unit 30 FIG. 3 is a conceptual diagram showing the structure of the area separation processing by the area separation determining unit 30. In the figure, a region separation determination unit 30 receives L * supplied from a color conversion / color correction unit 21.
A window of N pixels × N pixels (5 pixels × 5 pixels in this example) is set for the image data (8 bits), and the maximum value calculator 50a sets the maximum value Ma in the window.
x is calculated, and the minimum value Min is calculated by the minimum calculator 50b. Next, the maximum value Ma is calculated by the subtractor 51.
x, and calculates the difference between the minimum value Min and the minimum value Min.
At 2, it is determined whether or not it is greater than a predetermined threshold th1. When the difference is larger than the threshold value th1, the target pixel is temporarily set to the character pixel “1”. When the difference is smaller than the threshold value th1, the photograph pixel is set to “0”.
Is temporarily determined.

Next, the delay circuits 53a and 53b and the FIFOs 54a and 54b hold a tentatively determined state of five vertically and vertically cross-shaped pixels centering on the tentatively determined target pixel. Further, the logic circuit 55 performs a logical operation on the provisionally determined state of the five pixels to determine whether or not a pixel having the same value as the pixel of interest is among the four pixels in the vertical and horizontal directions.
If there is at least one pixel having the same value as the target pixel among the four pixels before and after the upper and lower sides, the value is left as the final determined value of the target pixel, and if there is no pixel, the value is inverted. In other words, if the pixel value is a character pixel “1”, the pixel value is changed to “0”, and if the pixel value is “0”, the pixel value is changed to “1”. By performing the above processing for all pixels,
Whether the pixel of interest is a character area or a photograph area can be identified by a 1-bit signal.

(B) Color Judgment Process by Region Separation Determination Unit 30 Next, FIG. 4 is a conceptual diagram showing the structure of the color judgment process by the region separation judgment unit 30. In the figure, the region separation determination unit 30 synchronizes with the above-described character / photo region determination,
Similarly, a *, b supplied from the color conversion / color correction unit 21
After setting a window of N pixels × N pixels (5 pixels × 5 pixels in this example) for the image data (8 bits each) of *, the C * calculating circuit 56 sets C * = √ ( a * 2
+ B * 2), or C * = |
a * | + | b * |, by adding both absolute values, a C * value (a characteristic value representing saturation) for each pixel
Is calculated. Next, the comparator 57 compares whether or not the C * value is larger than a predetermined threshold value th2,
* If the value is larger than the threshold value th2, the output is set to the color area “1”; if smaller, the output is set to the black area “0”.

Next, the 0 counter 58a counts the number of black areas "0" in the current window, and
The counter 58b counts the number of color areas “1”. Each count value is required to be 5 bits in the case of a window of 5 × 5 pixels. Also, the majority decision circuit 60
Determines which count value is larger, and uses the larger result as the color determination result of the pixel of interest. By performing the above processing on all the pixels, it is possible to identify whether the target pixel is a color pixel or a black pixel by a 1-bit signal.

As described above, the first area data signal S1
Is a 1-bit signal indicating whether each pixel is a character or a photograph (halftone) and a 1-bit signal indicating whether the pixel is a color pixel or a black pixel. When storing for pixels of a page, as described above,
Since a very large memory capacity is required, the compression unit 31
After compression, the data is stored in the area memory 32.

A-3. FIG. 5 is a conceptual diagram illustrating a configuration of the compression unit 31 that compresses the first area data signal S1. In the figure, the compression unit 31 blocks the first area data signal S1 (2 bits) supplied from the area separation determination unit 30 by M pixels × M pixels (4 pixels × 4 pixels in this example), In each block, if there is a determination result indicating that the character is “1” even for one pixel, all characters in the block of 4 pixels × 4 pixels are set to the character “1”.
In addition, if there is a determination result indicating that even one pixel is a color pixel “1” in the same block, the entirety of the 4 × 4 pixel block is set to the color pixel “1”. Then, the merging circuit 61 combines the bits and forms the area memory 3 shown in FIG.
Feed to 2. As a result, as described above, 4 pixels × 4
The determination result of pixel × 2 bits (total 32 bits) is 1 /
This means that the data has been compressed to 16 and becomes 2 bits per block of 4 × 4 pixels.

A-4. Configuration of Image Area Separation Determination Units 34a to 34d Next, the image area separation determination units 34a, 34b, and 34 shown in FIG.
c and 34d will be described. Image area separation determination section 34a-
34d are respectively generated by the region separation determination unit 30,
In order to compensate for the first area data signal S1 whose resolution has been degraded due to the compression, the C, M, Y, K image data (8 each) after the image data compressed by the above-described processing is expanded. ), A second area data signal S2 for identifying the presence of a line drawing by binary data such as a character or a line, in other words, the presence or absence of an edge is generated. Since the second area data signal S2 is generated at the timing of reading out the C, M, Y, and K image data, the second area data signal S2 is once required to synchronize with the image data, which is necessary in the image area separation determination unit 30. However, there is no need to store the data in the memory. Therefore, naturally, compression processing is not required.

FIG. 6 is a conceptual diagram for explaining the configuration of the image area separation judging sections 34a to 34d according to the present embodiment. In the figure, image area separation determination sections 34a to 34d
Performs image area separation by a method different from the image area separation processing performed by the image area separation determination unit 30 which has been conventionally used. Each of the image areas is separated from the corresponding C, M, Y, and K image data by 5%. A window of pixels × 5 pixels is set, and second derivative operators 65 a and 65 having two kinds of band pass characteristics are set.
The edge is detected by b. Each of the second derivative operators 65a and 65b has a table composed of the same 5 × 5 pixel window as the window set for the input image data. The filter coefficient is set to "-1" for the pixel, "4" for the center pixel, and "-1" for the horizontal and vertical pixels at the corners. That is, the second derivative operators 65a and 65b have the spatial frequency characteristics shown in FIGS. 7 and 8, respectively.

As shown in FIG. 7, the secondary differential operator 65a is set with a spatial frequency characteristic that increases the sensitivity in the main scanning direction and the sub-scanning direction. It is easy to extract the edge of the line drawn in. On the other hand, as shown in FIG. 8, the secondary differential operator 65b is set with a spatial frequency characteristic that increases the sensitivity in the oblique direction. Is easy to extract.

In the second derivative operators 65a and 65b,
By multiplying the value of each pixel in the window of 5 × 5 pixels by the value of the corresponding pixel in the illustrated tables 65a and 65b and adding the respective multiplied values, the image data in the window becomes horizontal. It is determined whether the edge has an edge drawn in a vertical direction or an edge drawn in an oblique direction. In other words, the two differentiating operators 65a and 65b determine whether or not the character area is likely to be jagged conventionally. In the illustrated example, the output of the second derivative operator 65a is 4 × 60 + (− 1) × 110 + (− 1) × 60 +
(-1) × 60 + (− 1) × 90 = 240−110−6
0-60-90, that is, "-80". on the other hand,
The output of the second derivative operator 65b is 4 × 60 + (−
1) × 150 + (− 1) × 150 + (− 1) × 90 +
(-1) × 90 = 240−150−150−90−9
0, that is, “−240”.

Next, in the image area separation judging sections 34a to 34d, the absolute values of the values obtained by the two types of second derivative operators 65a and 65b are calculated by the absolute value circuits 66a and 66b, respectively, and the maximum value is calculated. The circuit 67 selects the larger one of the two absolute values and supplies it to the comparator 68 as the edge amount of the pixel of interest. In the example shown, the absolute value 6
The output of 6a is “80”, and the output of the absolute value 66b is “240”. Therefore, the output of the maximum value circuit 67 is the larger “240”, in other words,
That is, it is determined that an edge drawn in an oblique direction exists. The comparator 68 compares the larger absolute value selected by the maximum value circuit 67 with a preset threshold value L1, and if the absolute value is larger, the character area “1” (= there is an edge) , If smaller, photo area "0" (= no edge)
Is supplied to the logic circuit 35 shown in FIG. 1 as the second area data signal S2. The threshold value L1 is a boundary value for determining whether a character or a photograph.

As described above, the area separation determining sections 34a to 34d applied in the present embodiment are different from the image area separation determining section 30 described above.
The reason why a simple configuration may be used is that the image area separation determination unit 30
This is because the spatial filter controlled by has already performed the edge enhancement processing on the character area and the band enhancement smoothing processing on the photographic area, so the latitude of separation increases and the edge detection accuracy of the character area increases. is there. In this embodiment, an example is shown in which two types of differential operators having different characteristics are used. However, it is needless to say that further different filter operators may be added in order to obtain higher discrimination performance. . The characteristic at this time may be a primary differential operator.

Next, the logic circuit 35 outputs the second area data signal S supplied from each of the image area separation determining sections 34a to 34d.
2 (1 bit each) and the signal (1 bit) of the first area data signal S1 supplied from the decompression unit 33 indicating whether the area is a character area or a photographic area, and a logical pixel Together with a 1-bit signal indicating whether the pixel is a black pixel or a black pixel, the tone correction units 28a to 28d and the SG units 29a to 29d form a final 2-bit third area data signal S3.
29d.

That is, the first image area data signal by the image area separation determining section 30 is transmitted to the tone correcting sections 28a to 28d and the SG sections 29a to 29d in the character area "1", and
Only when the second area data signal S2 by the image area separation determining units 34a to 34d is a character area "1", "1" is supplied as a signal indicating whether the area is a character area or a photographic area. Therefore, in this case, the pixel is processed as being the character area “1”. On the other hand, even if the first image area data signal by the image area separation determining section 30 is a character area "1", the image area separation determining section 34a
When the second area data signal S2 according to .about.34d is a photographic area "0", "0" is supplied as a signal indicating whether it is a text area or a photographic area. Therefore, in this case, the pixel is processed as being in the photographic area “0”.

Similarly, when both are pictures "0", "0" is supplied as a signal indicating whether the picture area is a text area or a picture area. Will be processed. When the first image area data signal by the image area separation determining unit 30 is a photographic area “0”
When the second area data signal S2 by the image area separation determination units 34a to 34d is a character area “1”, “0” is set as a signal indicating whether the area is a character area or a photograph area. Supplied. Therefore, in this case, the pixel is processed as being in the photographic area “0”.

As described above, the input / output resolution is 16 do
When t / mm is set, the image area separation determination units 34a to 34a
At 34d, the second area data signal S2 is generated based on the decompressed image data.
mm resolution. On the other hand, the first area data signal S1 from the image area separation determination section 30 is supplied to the tone correction sections 28a to 28d and the SG sections 29a to 29d.
At the time of supply, the resolution is only 1/4 and the resolution is only 4 dots / mm. For this reason, in the present embodiment, tone correction and screen switching conventionally performed at a resolution of 4 dots / mm are changed to 16 dots / m.
m resolution. Therefore, it is possible to improve jaggies generated at a resolution of 4 dots / mm at the inner edge of the bold character / line. In order to obtain the third area data signal S3 used in the tone correction sections 28a to 28d and the SG sections 29a to 29d, the logical product of the first area data signal S1 and the second area data signal S2 is obtained. Not limited to, for example, the second area data signal S2
May be forcibly used, and this configuration will be described in a modified example described later.

A-5. Compensation processing by tone correction units 28a to 28d Next, the tone correction units 28a to 28d shown in FIG. Compensates for differences in tone reproduction between 200-line and 400-line screens switched between -29d. Here, FIG. 9 is a conceptual diagram for explaining compensation by the tone correction units 28a to 28d. In the figure, in SG units 29a to 29d described later,
Based on the final second area data signal S2 supplied from the logic circuit 35, that is, depending on whether the pixel of interest is a character or a halftone such as a photograph, a 200-line screen and a 400-line screen are used. At this time, the screens have different density reproducibility, as shown in the figure. In the case of a 400-line screen, it tends to swell upward, and in the case of a 200-line screen,
It tends to swell downward. Therefore, the tone correction unit 28a
In the case of .about.28d, the correction is performed so as to approach the illustrated straight line based on the final third area data signal S3.

A-6. Configuration of SG Units 29a to 29d Next, the SG units 29a to 29d shown in FIG.
Based on the final third area data signal S3 supplied from 5, a 200-line screen and a 400-line screen are switched, and the image signal converted into an analog signal is converted into a laser oscillation drive signal. Here, FIG.
It is a block diagram which shows the structure of G part 29a-29d. In the figure, a pattern generator 70a generates a pattern (triangular wave) for obtaining a 200-line screen used for halftones such as photographs, and a pattern generator 70b generates a 400-line screen used for edges of characters and the like. Generate a pattern (triangular wave) to obtain The selector 71 selects one of the patterns of the pattern generator 70a or the pattern generator 70b according to the final third area data signal S3 supplied from the logic circuit 35 described above. The D / A converter 72 converts the 8-bit image data into an analog image signal. The comparator 73 is
The image signal of 256 gradations converted into an analog signal is converted into a laser oscillation drive signal having a resolution of 256 steps according to the pattern (screen) selected by the selector 71.

B. Next, the operation of this embodiment will be described.

The RGB image data read by the image reading device 20 is subjected to L * a * b
After being converted into image data in the color space of *, the image data is further converted into image data in the CMY color space by the color conversion / color correction unit 22. The image data of L * a * b * is determined by the region separation determining unit 30 for each pixel, whether the pixel is a line drawing such as a character or a halftone such as a photograph. It is determined whether the pixel is a color pixel or a black pixel, and is output as a 2-bit first area data signal S1. The first area data signal S
1 is temporarily stored in the area memory 32 after being compressed by the compression unit 31 in blocks of 4 pixels × 4 pixels.

On the other hand, the under color removal / black generation section 23 performs under color removal and black generation on the image data converted into the CMY color space based on the first area data signal S1. You. That is, when the target pixel is determined to be a black pixel by the first image area data signal S1, the image data of Y, M, and C is set to “0” for that pixel, and the image of K is Create data. Next, in the spatial filter units 24a to 24d, the above Y, M, C, K
Is subjected to edge enhancement or smoothing processing for each pixel based on the first area data signal S1. Thereafter, the image data is compressed at a fixed length by the corresponding compression units 25a to 25d, and is temporarily stored in the image memories 26a to 26d.

The Y, M, C, and K image data stored in the image memories 26a to 26d are used when the image data is developed by the first to fourth developing drums 7a to 7d. These are sequentially read out at a predetermined timing so as to match the delay time caused by the distance dmm between the developing drums, expanded by expansion units 27a to 27d, and supplied to tone correction units 28a to 28d.

On the other hand, the image area separation determining sections 34a to 34d respectively set a 5 × 5 pixel window for the corresponding C, M, Y, K image data, and
Second derivative operator 6 having two kinds of bandpass characteristics
An edge is detected based on 5a and 65b. If the edge amount of the pixel of interest is larger than a predetermined threshold value L1, the character area is "1", and if the edge amount is smaller than the predetermined threshold L1, the picture area is "0".
Is generated and supplied to the logic circuit 35.

Next, in the logic circuit 35, the logic of the second area data signal S2 supplied from each of the image area separation judging sections 34a to 34d and the first area data signal S1 supplied from the decompression section 33 is used. The products are taken, and the tone correction units 28a to 28a are output as the final two-bit third area data signal S3.
d and SG units 29a to 29d.

Therefore, the tone correction units 28a to 28d
And in the SG units 29a to 29d, the image area separation determination unit 34
a to 34d of the second area data signal S2
Will be used preferentially. That is, in the tone correction units 28a to 28d, the third area data signal S3
Based on (S2), 200 in the SG units 29a to 29d
The density reproduction characteristic is corrected according to the switching between the line screen and the 400-line screen. Also, the SG units 29a-
In 29d, either the 200-line screen or the 400-line screen is selected according to the final third area data signal S3 supplied from the above-described logic circuit 35, and the image signal of 256 gradations has 256 levels. It is converted into a laser oscillation drive signal having resolution and output.

As described above, in the present embodiment, since the input / output resolution is 16 dots / mm, the image area separation determination sections 34a to 34d have a resolution of 16 dots / mm. Therefore, as compared with the conventional case where the tone correction units 28a to 28d and the SG units 29a to 29d are corrected and controlled by the first area data signal S1 from the image area separation determination unit 30 (FIG. 11A). 11), in the image processing apparatus according to the present embodiment, as shown in FIG.
The jaggy generated at the resolution of mm can be eliminated.

Further, in the present embodiment, the image area separation processing performed by the image area separation determining section 30 which has been conventionally performed,
If a certain degree of separation accuracy is obtained, the first area data signal S1 from the image area separation determining section 30 is used when the image area separation determining sections 34a to 34d perform image area separation processing. If the threshold L1 shown in FIG. 6 is controlled, the separation accuracy can be improved.

That is, if a pixel is a character or a photograph can be identified with high precision by the image area separation processing by the image area separation determination section 30, for example, a certain pixel is If it is determined that the character is a character, the pixel is likely to be a character. Therefore, the threshold value L1 in the image area separation determining units 34a to 34d is set to be low, so that it is easy to determine the character. On the other hand, the image area separation determination unit 3
At 0, for example, when a certain pixel is determined to be a photo, the pixel is likely to be a photo, and thus the threshold L1 in the image area separation determination units 34a to 34d is set to a high value. Make judgment easier.

Thus, the first area data signal S1 and the image area separation judging sections 34a to 34 by the image area separation judging section 30 are obtained.
d compared with the simple calculation of the second area data signal S2 by the logical operation and the image area separation determination sections 34a to 34
The threshold value L1 for d is set in two ways, which is equivalent to a logical operation performed on the first area data signal S1 by the image area separation determining unit 30, and the image area can be identified with higher accuracy.

C. Modifications Further, the image processing apparatus according to the present invention can also be realized by the configuration shown in FIG. In this modification, in this modification, the image area separation determination unit 3 that performs tone correction and screen control on the decompressed image data on the decompressed image data
4a to 34d, the second area data signal S2
Only to be implemented. Therefore, in order to synchronize the first area data signal S1 by the conventionally used image area separation determination unit 30 with the expanded image data,
Since there is no need to store the information, there is no need to provide the compression unit 31, the area memory 32, and the decompression unit 33.
The circuit can be greatly reduced. Although the image quality level according to the present modification has also been described in the above-described embodiment, since the spatial frequency processing optimal for both the character / photograph area is performed by the image area separation determination unit 30, the latitude of the determination is wide. Therefore, it is possible to obtain almost the same image quality as the image processing apparatus shown in FIG.

In the above-described embodiment, an IOT for forming a toner image (Y, M, C, K) on recording paper by a well-known electrophotographic method is used as an image output device. However, the present invention is not limited to this. Alternatively, a color image output device such as a thermal transfer system, an inkjet system, or a sublimation system may be used.

The input image data described above is
Not only data supplied from an image reading device such as a scanner but also image data stored in a storage medium or image data supplied from another terminal (computer) via a network may be used. Further, the image data supplied from another terminal via the storage medium or the network may be compressed image data. In this case, together with the compressed image data, the compressed image data The corresponding compressed image area separation data is also provided. Therefore, the input means described in claim 7 is an interface for enabling data transmission and reception via the network when receiving image data via the network, and when receiving image data via the storage medium. Corresponds to a drive and an interface for enabling data exchange with a storage medium.

Further, in the above-described image processing system, the image reading device, the image processing device, and the image output device may be integrated or may be separated from each other by a cable or the like. In this case, the image processing apparatus may be an ordinary computer, and each unit described in the above embodiment and each unit described in the claims may be realized by software. Therefore, a storage medium storing the above program can be understood as a concept of the present invention.

[0083]

As described above, according to the present invention, according to the present invention, a binary image area composed of characters and lines and a photograph and halftone printing are applied to the input image data by the image area separating means. After generating image area separation data for identifying a halftone image area such as, for example, the compression storage means compresses and stores the input image data and the image area separation data generated by the image area separation means. Then, after the image data and the image area separation data stored in the compression storage means are read out and expanded by the expansion means, the attribute detection means detects the image attribute of the image data expanded by the expansion means, The processing determining means performs processing on the expanded image data based on the image attribute detected by the attribute detecting means and the image area separation data expanded by the expanding means. The image processing to be performed is determined, and the determined image processing is performed on the decompressed image data by the image processing means. Even when an original image containing both mixed / photographs is input, appropriate image processing can be performed on both, and image quality degradation in a reproduced image can be reduced as much as possible.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a configuration of compression units 25a to 25d for compressing image data of the image processing apparatus according to the embodiment.

FIG. 3 is a conceptual diagram illustrating a configuration of a region separation process in a region separation determination unit 30 of the image processing apparatus according to the embodiment.

FIG. 4 is a conceptual diagram illustrating a configuration of a color determination process by an area separation determination unit 30 of the image processing apparatus according to the embodiment.

FIG. 5 is a conceptual diagram illustrating a configuration of a compression unit that compresses a first area data signal S1 of the image processing apparatus according to the embodiment.

FIG. 6 is a conceptual diagram for explaining a configuration of image area separation determination units 34a to 34d of the image processing apparatus according to the present embodiment.

FIG. 7 is a second derivative operator 65a in the image area separation determination units 34a to 34d of the image processing apparatus according to the present embodiment.
FIG. 3 is a conceptual diagram showing the spatial frequency characteristics of FIG.

FIG. 8 shows a secondary differential operator 65b in the image area separation determination units 34a to 34d of the image processing apparatus according to the present embodiment.
FIG. 3 is a conceptual diagram showing the spatial frequency characteristics of FIG.

FIG. 9 is a conceptual diagram for explaining compensation by tone correction units 28a to 28d of the image processing apparatus according to the present embodiment.

FIG. 10 is an SG unit 2 of the image processing apparatus according to the present embodiment.
It is a block diagram which shows the structure of 9a-29d.

FIG. 11 is a conceptual diagram for describing an effect of the image processing apparatus according to the present embodiment.

FIG. 12 is a block diagram showing a configuration of an image processing device according to a modification of the present invention.

FIG. 13 is a conceptual diagram showing a schematic configuration of a one-drum type digital color copying machine.

FIG. 14 is a conceptual diagram showing a schematic configuration of a color copying machine (tandem type) having a mechanism for increasing a printout speed.

FIG. 15 is a block diagram illustrating a configuration of a conventional image processing apparatus of a color copying machine.

FIG. 16 shows a spatial filter unit 24 in a color copying machine.
It is a conceptual diagram which shows the spatial frequency characteristic which a-24d has.

FIG. 17 is a conceptual diagram for describing a problem in a conventional image processing apparatus.

[Explanation of symbols]

22 color conversion / color correction unit (color conversion unit) 23 under color removal / black reproduction unit (first image processing unit) 24a to 24d spatial filter unit (first image processing unit, spatial filter, filter coefficient determination unit) 25a to 25d Compression unit (compression storage unit) 26a to 26d Image memory (compression storage unit) 27a to 27d Decompression unit (decompression unit) 28a to 28d Tone correction unit (image processing unit, second image processing unit) 29a to 29d SG section (image processing means, second image processing means) 30 image area separation determining section (image area separation means, first image area separation means) 31 compression section (compression storage means) 32 area memory (compression storage means) 33 decompression unit (decompression means) 34a to 34d image area separation determination unit (attribute detection means, second
S1 First area data signal (image area separation data) S2 Second area data signal (image attribute)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-356873 (JP, A) JP-A-7-212601 (JP, A) JP-A-4-10765 (JP, A) JP-A-5-205 199383 (JP, A) JP-A-5-30354 (JP, A) JP-A-5-191643 (JP, A) JP-A-5-191632 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 1/40-1/409 H04N 1/46 H04N 1/60

Claims (21)

(57) [Claims] An image for generating image area separation data for identifying a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing for input image data. Area separation means; compression storage means for compressing and storing the input image data and image area separation data generated by the image area separation means; image data and image area separation stored in the compression storage means Decompression means for reading and decompressing data; attribute detection means for detecting an image attribute of the image data decompressed by the decompression means; image attributes detected by the attribute detection means; and an image area decompressed by the decompression means. An image processing apparatus comprising: an image processing unit that performs image processing on image data expanded by the expansion unit based on separated data. 2. The image processing apparatus according to claim 1, wherein the attribute detection unit performs image area separation processing of a different style from image area separation processing performed by the image area separation unit on the image data expanded by the expansion unit. to obtain a second image area separation data, the image processing apparatus according to claim 1, wherein the use of said second image area separation data as the image attribute. 3. The image processing apparatus according to claim 1, further comprising: a color conversion unit configured to perform a color space conversion process on the image data that has been subjected to the image area separation processing by the image area separation unit. 2. The image processing apparatus according to claim 1, wherein the converted image data is compressed and stored. 4. The image processing apparatus according to claim 1, wherein the image processing unit performs tone reproduction control or resolution reproduction control on the image data expanded by the expansion unit. 5. The image processing apparatus according to claim 1, wherein the image attribute detected by the attribute detection unit is edge information. 6. The attribute detecting means includes a plurality of spatial filters having different filter coefficients, and performs image processing on the decompressed image data by the plurality of spatial filters, so that each pixel has an edge for each pixel. 2. The image processing apparatus according to claim 1, wherein edge information indicating whether or not there is an image is detected, and the edge information is used as the image attribute. 7. Input means for inputting compressed image data and compressed image area separation data corresponding to the compressed image data; and said compressed image data and said compression input by said input means. Expanding means for expanding the extracted image area separation data, attribute detecting means for detecting an image attribute of the image data expanded by the expanding means, and the image data extracted based on the image attribute detected by the attribute detecting means. An image processing apparatus comprising: an image processing unit that performs image processing on image data. 8. An image processing apparatus according to claim 7, wherein said image processing means performs tone reproduction control or resolution reproduction control on the image data expanded by said expansion means. 9. An image processing apparatus according to claim 7, wherein said image attribute detected by said attribute detecting means is edge information. 10. The attribute detecting means includes a plurality of spatial filters having different filter coefficients, and performs image processing on the decompressed image data by the plurality of spatial filters, so that each pixel has an edge for each pixel. 8. The image processing apparatus according to claim 7, wherein edge information indicating whether or not there is an image is detected, and the edge information is used as the image attribute. 11. An image for generating image area separation data for distinguishing between a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing for input image data. An area separation step; a compression accumulation step of compressing and storing the input image data and the image area separation data generated by the image area separation means; an image area separation data and an image compressed by the compression accumulation step A decompression step of reading and decompressing data; an attribute detection step of detecting an image attribute of the image data decompressed by the decompression step; an image attribute detected by the attribute step and an image area separation decompressed by the decompression step A process determining step of determining image processing to be performed on the decompressed image data based on the data, and Image processing method characterized by and an image processing step of performing image processing on the decompressed image data. 12. The attribute detecting means extracts vertical and horizontal edges and diagonal edges of the image data decompressed in the decompression step for each pixel, and determines whether the edge amount is a predetermined value. 12. The image processing method according to claim 11, wherein an image attribute indicating that an edge exists is generated when the value is larger than the threshold value. 13. An input image data comprising a first color space, a second image area for distinguishing between a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing. A first image area separation unit for generating one image area separation data; and an image for the input image data based on the first image area separation data generated by the first image area separation unit. First image processing means for performing processing, color conversion means for performing color conversion processing for converting the image data from the first color space to second color space, and color conversion by the color conversion means. Compression and accumulation means for compressing and accumulating the applied image data composed of the second color space and the first image area separation data generated by the first image area separation means; Image data and image area separation data And performing image area separation processing on the image data composed of the second color space expanded by the expansion means and generating second image area separation data for identifying the presence or absence of an edge. Second
Image processing means for image data comprising a second color space expanded by the expansion means based on the second image area separation data generated by the second image area separation means. An image processing apparatus comprising: a second image processing unit that performs the following. 14. The image processing apparatus according to claim 1, wherein the second image processing means performs tone reproduction control or resolution reproduction control on the image data composed of the second color space expanded by the expansion means. Item 14. The image processing device according to item 13. 15. The first image area separation means and the second image area separation means are different from each other with respect to the image data composed of the first color space and the image data composed of the second color space. 14. The image processing apparatus according to claim 13, wherein the image area separation processing is performed in a style. 16. The image processing apparatus according to claim 1, wherein the first image processing unit includes: a spatial filter applied to the input image data; and a first image area separation data generated by the first image area separation unit. 14. The image processing apparatus according to claim 13, further comprising: filter coefficient determining means for determining a filter coefficient of the spatial filter. 17. The apparatus according to claim 13, wherein said color conversion means converts a color space from a device-independent first color space to a device-dependent second color space. Image processing device. 18. First image area separation data for distinguishing between a binary image area composed of characters and lines and a halftone image area such as a photograph or halftone printing for input image data. First image area separation means for generating, and a first image for performing image processing on the input image data based on the first image area separation data generated by the first image area separation means Processing means; compression and accumulation means for compressing and accumulating image data subjected to image processing by the first image processing means; decompression means for reading and decompressing image data accumulated in the compression and accumulation means; Second image area separation means for performing image area separation processing on the image data expanded by the expansion means to generate second image area separation data for identifying the presence or absence of an edge; Generated by area separation means The image processing apparatus characterized by comprising a second image processing means for performing image processing on the image data expanded by said expansion means based on the second image area separation data. 19. An image processing apparatus according to claim 18, wherein said second image processing means performs tone reproduction control or resolution reproduction control on the image data expanded by said expansion means. . And 20. wherein the first image area separation means the second image area separation means includes a characterized by applying to the image data, the image area separation processing <br/> Ru manner different respectively Claim 1
9. The image processing apparatus according to 8. 21. The first image processing means, comprising: a spatial filter applied to the input image data; and a first image area separation data generated by the first image area separation means. 19. The image processing apparatus according to claim 18, further comprising: a filter coefficient determining unit that determines a filter coefficient of the spatial filter.