JPH0951441A - Image processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain high speed processing and to improve print quality by dividing an image area and applying a different coding system to the divided areas. SOLUTION: An RGB image of an original read by a scanner 101 is converted into a Y signal and color difference signals by a conversion section. A compression coding section 11 applies JPEG coding to the Y and color difference signals and the Y signal is binarized. An image area discrimination section 13 separates JPEG data into color area data and black/white area data. The color area data are replaced with zeros and the zero data and the binary data are given to a compression coding section 16, in which they are MMR-coded. A synthesis section 17 synthesizes the JPEG data and the MMR data and the synthesized data are sent from a MODEM 104. Thus, the JPEG and MMR data are generated from the beginning and the color component of the binary data are replaced with zeros, then the compression efficiency is considerably improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus used in a color facsimile apparatus or the like for transmitting a color image.

[0002]

2. Description of the Related Art Conventional facsimiles transmit black-and-white images, but color facsimiles are being put to practical use due to the increasing need for color images and the cost reduction of color scanners and color printers. Furthermore, personal computer facsimiles that perform a facsimile function on a personal computer have appeared, but if this personal computer facsimile has a color scanner or color printer, it is natural to want to transmit a color image,
The needs are ever increasing.

As an image processing method that has been proposed or partially put into practical use in order to realize a color facsimile, there is a method in which an original image is encoded by a compression encoding method such as a JPEG method and transmitted. . However, when compressing and coding a document image in which characters are present by the JPEG method, increasing the compression rate deteriorates the print quality of the characters. Therefore, if the compression rate is lowered, the amount of encoded data increases, the transmission time becomes longer, and the communication cost also rises.

For example, if one A4 size original is read at a resolution of about 200 dpi, the data amount is 10 in RGB three colors.
It becomes about MB, and this is coded with a compression rate of 1/20 to 1
Transmission at a speed of 4.4 kbps takes about 6 minutes of transmission time. Therefore, if the compression rate is increased to, for example, 1/100, the transmission time is shortened to about 1 minute, but it is unavoidable that the print quality of characters deteriorates.

In order to solve this problem, various proposals have been conventionally made in academic societies and the like. That is,
One document is divided into several image areas according to its contents, and each image area is assigned a coding method suitable for its contents.

[0006]

However, as described above, the method of dividing the original into image areas and assigning the encoding method requires a complicated algorithm for strict determination of the image area division. Therefore, it takes time to judge,
There was a problem that it was not practical.

The present invention has been made to solve the above problems, and an object thereof is to obtain an image processing apparatus capable of easily realizing a method of dividing an image area and assigning a coding method. There is.

[0008]

According to a first aspect of the present invention, there is provided a determination means for determining a color area and a monochrome area of input image data, and image data of the color area determined by the determination means. 1st encoding with 1 encoding method
And the second encoding means for encoding the image data of the black-and-white area determined by the determining means by the second encoding method.

According to another aspect of the present invention, there is provided a first encoding means for encoding the input image data by using the color data and the luminance data forming the input image data, and the first encoding means. From the brightness data and the replacement means, a determination means for determining the color area of the encoded data obtained from the encoding means, a replacement means for replacing the image data of the color area determined by the determination means with a predetermined value, There is provided a second encoding means for encoding the obtained data of the predetermined value by the second encoding method.

According to another aspect of the present invention, there is provided a judging means for judging the color area and the monochrome area of the input image data obtained by coding the image in block units, in the block unit, and the color judged in the judging means. There is provided blurring means for blurring data in the vicinity of the boundary between the area block and the black and white area block.

According to a tenth aspect of the present invention, first and second encoding means for encoding the input image data by the first and second encoding systems, respectively, and the first and second encoding means. Determining means for determining a color area and a black and white area of the image from the coded data respectively obtained from the encoding means is provided.

[0012]

According to the first aspect of the invention, the transmission time can be shortened and the printing quality can be improved. According to the invention of claim 2, the processing can be performed at high speed and the memory consumption amount can be reduced. Claim 4
According to the invention, it is possible to reduce the unsightly appearance that appears at the boundary between the color area and the black and white area. Claim 10
According to the invention, the amount of data can be reduced by performing the processing without waste.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the system configuration of a color facsimile apparatus using a personal computer applied to each embodiment. In the figure, at the time of facsimile transmission, an original image read by the color scanner 101 or information input from the keyboard 102 is processed by the personal computer 103 and then sent out to the line via the modem 104. At the time of facsimile reception, the data received by the modem 104 is processed by the personal computer 103 and then printed on the transfer paper by the color printer 105 or displayed on the monitor 106. Incidentally, 107 is a mouse.

Next, the signal processing performed in the personal computer 103 according to each embodiment at the time of transmission and reception will be described.

First, the first embodiment will be described. In general, in many originals, it is rare that the entire surface of one color original is colored, and in many cases, black and white characters often include a partially colored portion. Therefore, it is wasteful to process the entire original document as RGB three-color data.

Therefore, in the present embodiment, when the original is divided into image areas, the original is first divided into a color area which is a color portion and a black and white area. Second, the color area is set to JPEG, for example.
It is encoded by the method and sent, and the black and white area is binarized and, for example, MMR encoded and sent. This makes it possible to shorten the transmission time and prevent the print quality of characters from deteriorating.

Further, the following processing is performed in order to perform the above processing at high speed and with the memory consumption as small as possible. First, a one-page original image is read by the scanner 101 as RGB data, and this is converted into a luminance signal Y and a color difference signal. On the other hand, using Y and color difference, 1
JPEG data for one page is created, and at the same time, binary data for one page is created from Y on the other side.

When both data are created for one page,
Next, a color area and a monochrome area are determined from the JPEG data created above. Then, for the color area, the created JPEG data is transmitted. Regarding the black-and-white area, first, the portion determined to be the color area is replaced with white, and then the black-and-white area including the white portion is MMR encoded.

In general, the color area is not a natural image in many cases, and since binarization of that area causes 1 and 0 in the data to be finely inverted, the compression efficiency tends to be greatly reduced, but the area is white. By replacing it with 0, it becomes continuous 0, so that the compression efficiency can be significantly improved in the compression encoding of the binary binary data based on the run length.

Further, the memory capacity required to store the black-and-white binary data of one A4 size original in the memory at a resolution of 200 dpi is about 500 KB. On the other hand, the amount of color data is 500K because it is JPEG compressed from the beginning.
It fits in B grade. Therefore, even if the black-and-white data and the color data are combined, a small capacity memory of about 1 KB may be prepared.

Further, since the JPEG data is created from the beginning, the processing speed can be increased as compared with the case where the JPEG data is created again after the area is first determined. Furthermore, since the character portion is encoded by the reversible compression such as MMR, not the lossy compression called JPEG, the print quality of the character is not deteriorated.

As described above, according to the present embodiment, when a color original is transmitted, the compression ratio is sufficiently increased,
It is possible to improve the image quality of the color image portion and the character portion, reduce the memory capacity, and shorten the processing time.

FIG. 2 is a block diagram showing the first embodiment of the present invention, and FIG. 3 is a flow chart showing the processing according to the first embodiment. 2 and 3, RGB for one page of the document read by the scanner 101 in step S1
The data is converted by the conversion unit 10 into a Y signal and a color difference signal in step S2. Then, in step S3, the compression encoding unit 11 uses the Y signal and the color difference signal to perform JP
EG data is created, and at the same time, in step S4, the binarization unit 1
In step 2, the Y signal is compared with an appropriate threshold value to create black and white binary data. The created JPEG data is 1
Pages are stored in the memory in the image area determination unit 13. Next, in step S5, the image area determination unit 13 determines the JPEG data stored in the memory and divides the one-page original image into a color area and a monochrome area.

Next, in step S6, after the position information is added to the portion determined to be the color area, the replacing portion 14 replaces it with white, that is, 0. This 0 data is the second
Compression encoder 1 via the switch 15 used in the embodiment
In step S7, MMR coding is performed together with the binary data in step S7. In addition, the JPEG data of the portion determined to be the color area in step S8 is acquired. And step S9
At, the synthesizing unit 17 synthesizes the JPEG data and the MMR data in the color area. The combined data is transmitted via the modem 104 in step S10. It should be noted that, here, the data synthesis means that the MMR data is first arranged in the order of JPEG data, and the data is linked by an appropriate protocol.

Here, how much the compression efficiency can be increased will be described using specific numerical values. still,
The compression efficiency depends on the area ratio of the entire color region, but here, the case of an area ratio of 1/4 which is considered to be an average area ratio will be described.

The resolution of the original image data of the original is set to 200 dp.
i and the original is A4 size. The compression ratio of MMR is considered to be 1/10 to 1/20 on average by replacing the color area with white, and is set to 1/10 here. Further, the compression ratio of the color area is considered to be about 1/50 because the character portion, which is the weakest point in JPEG, is avoided. The results using the above numerical values are shown in Table 1.
In Table 1, all the data are 1/20 and 1 / for comparison.
The case of compression to 100 is also shown, and the case of the above numerical values according to the present embodiment is shown at the bottom.

[0027]

[Table 1]

As is clear from Table 1, according to the present embodiment, a smaller amount of data (100 KB) and transmission time (about 55 seconds) can be obtained as compared with the case where all data is JPEG-encoded to 1/100. You can Moreover, in the present embodiment, the image quality is naturally excellent because the compression ratio of the color area is low, and the printing quality is also excellent because the character portion is binary lossless encoded. On the other hand, JPEG with a compression ratio of 1/100
In this case, the image quality deterioration becomes conspicuous, and there is a great difference from the present embodiment. Also, this means that all data is compressed at a compression ratio of 1/1.
00 indicates that it is not realistic to make JPEG.

FIG. 4 is a flow chart showing the second embodiment, and the same step numbers are given to the same processing contents as in FIG. This embodiment is a modification of the first embodiment,
As shown in the figure, steps S11 and S12 for performing the processes of the switch 1 and the switch 2 are added. The processing of steps S11 and S12 is performed by the user operating the switch 15. This results in step S4
It is possible to select whether or not to include the data in which the color data is replaced with white in step S6 in the binarized black and white data.

According to this embodiment, for example, when the user on the transmitting side knows the facsimile system on the receiving side and the receiving side cannot restore the JPEG data, only the binary data can be restored. Appropriate data transmission can be performed by operating the switches 1 and 2 so as not to perform step S6.

Next, a third embodiment will be described. A complicated algorithm is required to properly separate the color area and the black-and-white area described above, and it takes time to make the determination, which is not practical. Therefore, as a practical method, a method of separating the image area in units of blocks of a predetermined size can be considered. However, in this method, the boundary of the block and the boundary of the image area do not always coincide with each other, which causes a problem that the reproduced image becomes unsightly.

For example, originals 1 to 20 as shown in FIG.
The image captured at 0 dpi is Y: RY-BY: BY = 4:
Consider the case where JPEG encoding is performed at 2: 2. J
Block the data to perform PEG coding,
The size of one block is 16 dots (Y has four blocks in it, but the color difference block must be taken as the minimum unit), so it is about 2 mm on the image.
It becomes a corner block. It is assumed that the entire image area is divided by such blocks and whether each block is assigned a JPEG code or a MMR binary code is determined.

If the original 1 shown in FIG. 5 has a color natural image portion 2 in the center and a character portion 3 in the other portion,
The natural image portion 2 is JPEG encoded and the other portions are MMR encoded. When this coding determination is performed in block units, as shown in FIG. 6, an image area boundary which is a boundary between the natural image portion 2 and the character portion 3 and a block boundary which is a boundary between the block A and the block B are separated from each other. There are quite a few disagreements. In FIG. 6, the block B is entirely in the character portion 3, but the block A extends over the natural image portion 2 and the character portion 3. At this time, it is assumed that the block A is determined to be the natural image portion 2 and the JPEG code is assigned, and the block B is determined to be the character portion or the original paper portion and the binary code is assigned.

When this encoded data is transmitted and the receiving side receives it through the modem 104 and decodes it, first of all, the value of the block B is that all pixels are R = G = B = 0, that is, "pure white". On the other hand, the pixel value obtained by decoding the right side portion of the block A, that is, the paper portion is generally R = G
= B = 0 does not hold. This is because when the document is read by the scanner, the document paper is white but has some color, or it is a little gray with no color and emits light 10
This is because there is no 0% reflection. In JPEG encoding, for example, gray is reproduced as gray, so a boundary portion that does not exist in the original document appears as a gray portion in the portion corresponding to the right side portion of block A of the reproduced image. .

In particular, when the original document sheet has a large amount of deviation from white, a noticeable boundary is generated in the reproduced image, and not only the original document is different,
In some cases, it may give an unsightly impression. The present embodiment solves such a problem.

In the present embodiment, when the block boundary is under a certain condition, the processing for blurring the block boundary is performed on the receiving side. When a JPEG block for JPEG encoding and a binary block for MMR encoding are in contact with each other, it is not necessary to blur if the binary block is “black”. Therefore, first, as shown in FIG. 7, the pixel data of one column which is in contact with the JPEG block in the binary block vertically and horizontally is detected, and when all or most of the pixels in the one column are black, they are blurred. The processing is not performed, and if not so, the blurring processing is performed.

Next, as shown in FIG. 7, the pixel data of the two columns in contact with the binary block in the JPEG block are examined, and based on the color density, the brightness level, the amount of high frequency components, etc., these two pixels are examined. It is detected whether or not the entire width area is a natural image. If the area of 2 pixel width is a natural image, it is considered that the block boundary and the image area boundary coincide with each other, and the blurring process is not performed. If not, the blurring process is performed.

Next, a specific method of blurring processing will be described.
I will tell. As shown in FIG. 8, the block boundary is centered at x₀When
And the pixels on the left and right sides are x_-Four, X _-3, X_-2, X_-1, X₀,
x₁, X₂, X_Three, X_FourAnd In addition, in FIG.
The boundaries are vertical, but if the block boundaries are horizontal
For example, the pixels are arranged in the vertical direction. Where x_nTo
The original pixel value, y_nAfter blurring
Let y be the pixel value of_nIs

[0039]

[Equation 1]

Is given by For example, y _n = (1/8) {5x _n + x _{n + 1} + x _{n + 2} + x _{n + 3} }
It is given by −4 ≦ n ≦ 8.

FIG. 9 is a block diagram showing this third embodiment. In FIG. 9, the block coded data received by the modem 104 is discriminated and separated into a JPEG block and a binary block by the image area determination unit 18. The JPEG block and the binary block are detected by the detection unit 19 as described with reference to FIG. The blurring processing unit 20 performs data blurring processing on each block or outputs the data as it is according to the respective detection results.
The output data of the blurring processing unit 20 is combined by the combining unit 21 and then sent to a printer or the like.

In the present embodiment, the blurring process is performed to solve the above-described problem of unsightlyness at the boundary of the image area, but in order to solve the above problem, the following process is performed. A method can be considered.

(1) The "color information" of the original paper is transmitted at the same time, and the binary "white" portion is replaced with this "color information" on the receiving side. (2) On the receiving side, the binary “white” part is replaced with the “color information” of the average document paper in the world.

Various proposals have already been made for the method (1), and the above-mentioned unsightly appearance can be eliminated if it is successful, but in reality, "color of original paper" (here, gray is also included). ) Requires a complex algorithm to detect and estimate, and is error prone.

Further, the method (2) described above works in many cases, but it does not work in a specific case, for example, when the manuscript paper is a cream type or a yellow type. Also,
As compared with the case where nothing is printed as "white", there are drawbacks that the printing time becomes longer and the ink consumption increases.

Therefore, in practice, the blurring process described in this embodiment and the methods (1) and (2) described above may be used while being switched according to the application and other conditions.

Next, a fourth embodiment of the present invention will be described. As in each of the above-described embodiments, the image area is divided into a color natural image area and a monochrome character area, and the JPEG code and the MMR code are assigned to the respective areas. In the case of “,” there arises a problem of which area to select. As a countermeasure against this, for example, it is conceivable to judge "black characters" instead of simply "characters", or to finely classify the image area into two or more.
If the image area is classified into many types, high image quality and high compression rate will be obtained, but it will cause a great deal of difficulty such as the image area determination algorithm becoming complicated.

A method of classifying the image area into "black character area" and "other area" is conceivable. This method is good when the image area is determined in pixel units, but the image area is determined in block units. If so, the following problems occur. That is,
As shown in FIG. 10, when a black character is thick and a block is included in the thickness, it becomes impossible to determine whether this block is a part of a natural image or a part of a black character. This embodiment is for solving the above problems.

This embodiment has the following features. (A) The image area is determined in block units. (B) The image area is divided into two parts, and the first image area is a "block composed only of elements that satisfy the condition that the line is black and the line is not thick (black thin line)". The second image area is an area other than the first image area.

(C) The second image area is block coded. (D) It is assumed that the block for determining the image area and the block for block encoding that encodes the second image area have an integral multiple relationship. (E) When determining which image area a certain unit block belongs to, the data in the unit block is used as follows. First, the block code uses DCT coefficients. Then, the DCT coefficient is used for the determination, and the value of the original pixel data is not directly used. The term “black” as used herein means that the color is lighter than a certain range and the brightness is lower than a certain value.

FIG. 11 is a block diagram showing this embodiment, and FIG.
2 is a flowchart showing the operation of this embodiment. First, in step S21, the document 1 is read by the scanner 101 and image data is input. Next, step S22
Then, the image area is determined for each block of the image data input by the image area determination unit 24, and it is determined whether the block belongs to the first image area or the second image area. As a criterion for determination, whether the color is lighter than a certain range, the luminance is lower than a certain value, or the line thickness is thinner than a certain value is used.

If the image area determination is performed in block units as described above, the problem described with reference to FIG. 10 arises. Therefore, in step S23, the correction unit 25 revises the determination result of its own block with reference to the determination results of the blocks that have obtained the determination result. For example, if all the blocks around the user's block are not in the region to which the user belongs, correction is performed such that the user's block is set as an image area different from them (isolated point correction).

For each block whose image area has been determined as described above, the first "black thin line" is determined in step S24.
The image area block is binarized and MMR encoded by the binarization unit 26. The blocks of the second image area “other than that” are DCT-transformed by the compression encoder 27, and the DCT coefficients are Huffman-encoded by the same method as the JPEG method. Then, after each coded data is combined by the combining unit 28 in step S25, the modem 10
Then, the transmission is completed via 4 and the processing is terminated.

If a "black thin line" exists in the central portion of the natural image, the block is erroneously determined as the first image area. Therefore, in order to prevent this, step S23 is executed.
I am trying to get better results, but this step S
Even if the process of No. 23 is not performed, practically no serious influence is exerted.

FIG. 13 is a block diagram showing a fifth embodiment of the present invention, and FIG. 14 is a flow chart showing its operation. The present embodiment prevents the above-mentioned erroneous determination. First, in step S31, the scanner 101
Image data of the original 1 is input. At this time, while inputting the image data, in step S32, the compression encoding unit 2
9. The binary coding unit 30 simultaneously performs at least halfway the JPEG coding and the binary coding to create two coded data. Then, in step S33, the image area determination unit 3
1, the image area is determined for each block of JPEG data (quantized DCT coefficient). The judgment criteria are the same as in the fourth embodiment. However, the value of the original pixel is not used and DC
The T coefficient is used. The image area determination will be described later in detail.

Next, in step S34, the correction section 32
After performing the correction processing of the determination result similar to step S23 of FIG. 12, in step S35, the data allocation unit 33 allocates MMR encoded data to the first image area and JPEG code to the second image area. After allocating and synthesizing the converted data, the data is transmitted from the modem 104 in step S36.
In the black-and-white binary encoding, data is first obtained in black-and-white multi-value, and the threshold level is optimized, and then the black-and-white binary encoding is performed.
By digitizing, the image quality can be further improved.

Next, the image area determination in step S33 will be described. When determining the image area, it is difficult to determine the thickness of the black line, but the following criteria are used here. That is, (1) the average brightness of the block is larger than a predetermined value. (2) The color is smaller than the predetermined value. (3) The high frequency component is larger than a predetermined value. In this case, it is regarded as "a set of black fine lines" and is determined to be the first image area.

The method of determining the above black thin line portion by the DCT coefficient will be described in more detail. First, because black means that the value of the DC component of the color difference signal is small, the sum of the absolute values of the DC component of the color difference signal or the sum of squares thereof is within a certain range on the color difference space. It may be determined to be black if the condition that is present is satisfied. That is, if even a part of the block has a colored portion, the above condition is not satisfied.

Next, regarding the condition of the thin line, it is considered that the high frequency component increases first. Therefore, it is a necessary condition that the absolute value of the high frequency component (coefficient) or the sum of squares thereof is larger than a certain value. This condition is satisfied even with thick lines,
If there is a thick black line, the overall brightness decreases. Therefore, as the condition of the thin line, in addition to the above condition, the condition that the direct current component of the luminance is equal to or higher than a certain value may be added as the AND condition.

In this case, as shown in FIG. 15, when a part of a thick line hits a block, the judgment result is "black thin line", but this block is actually a "black thin line". Therefore, it means that the condition is working properly.

The DCT coefficient used for image area determination is quantized, but it may be quantized. If the unquantized one is used, the determination accuracy is improved. Further, if the quantized data is used, the amount of data to be handled is reduced at that stage, that is, since the number of zeros is large, it is easy to handle and the processing speed can be increased.

In the present embodiment, since the block for block coding such as JPEG corresponds to the block for image area determination, data (eg, quantum Using the converted CDT coefficient), the amount of data has already been reduced at that stage, and processing is easy to perform. In addition, since the data used for allocation of the encoded data in the subsequent processing has also been created, there is no waste in the overall processing flow.

Although each of the embodiments described above is a case in which the present invention is applied to a personal computer type color facsimile system as shown in FIG. 1, the whole may be a built-in facsimile type.

[0064]

As described above, according to the first aspect of the invention, the transmission time can be shortened and the print quality can be improved. According to the invention of claim 2, the processing can be performed at high speed and the memory consumption amount can be reduced. According to the invention of claim 4, it is possible to reduce the unsightly appearance which appears at the boundary between the color area and the black and white area. According to the invention of claim 10, the amount of data can be reduced by performing the processing without waste.

Further, the block encoding method is used as the encoding method,
The data compression efficiency can be improved by using the binarized coding method to determine the image area in block units, and further, the image area determination can be made by "black thin line block", "other blocks", etc. By using as a reference, the determination can be performed accurately and easily.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a color facsimile system to which the present invention is applied.

FIG. 2 is a block diagram showing first and second embodiments of the present invention.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a flowchart showing the operation of the second embodiment.

FIG. 5 is a configuration diagram for explaining a third embodiment of the present invention.

FIG. 6 is a configuration diagram for explaining a third embodiment of the present invention.

FIG. 7 is a configuration diagram for explaining a third embodiment of the present invention.

FIG. 8 is a configuration diagram for explaining blurring processing according to a third embodiment.

FIG. 9 is a block diagram showing a third embodiment.

FIG. 10 is a configuration diagram for explaining a fourth embodiment of the present invention.

FIG. 11 is a block diagram showing a fourth embodiment.

FIG. 12 is a flowchart showing the operation of the fourth embodiment.

FIG. 13 is a block diagram showing a fifth embodiment of the present invention.

FIG. 14 is a flowchart showing the operation of the fifth embodiment.

FIG. 15 is a configuration diagram for explaining a fifth embodiment.

[Explanation of symbols]

 11, 16, 27, 29 compression coding unit 12, 26, 30 binarization unit 13, 18, 24, 31 image area determination unit 14 replacement unit 15 switch 19 detection unit 20 blurring processing unit

Claims (20)

[Claims] 1. A determination means for determining a color area and a monochrome area of input image data, and a first encoding method for encoding the image data of the color area determined by the determination means by a first encoding method. The encoding means and the image data of the monochrome area determined by the determination means are
An image processing apparatus comprising: a second encoding unit that encodes using the above encoding method. 2. A first encoding means for encoding in a first encoding method using color data and luminance data forming input image data, and the first encoding means. Judgment means for judging the color area of the encoded data, replacement means for replacing the image data of the color area judged by the judgment means with a predetermined value, the luminance data and the predetermined value obtained from the replacement means And an image processing device which encodes the data of 1. by a second encoding method. 3. The image processing apparatus according to claim 2, further comprising selection means for selecting whether or not the replacement means operates. 4. A judging means for judging a color area and a black-and-white area of input image data formed by coding an image in block units, and a block of the color area and the black-and-white area judged by the judging means. An image processing apparatus comprising: a blurring unit that blurs data in the vicinity of a boundary with a block of a region. 5. A detection means for detecting whether or not the vicinity of a boundary between the block of the color area and the block of the black and white area is a color image and activating the blurring means when the color image is not a color image. The image processing device described. 6. A detection means is provided for detecting whether or not the vicinity of a boundary with the color area in the block of the black and white area has a predetermined value and operating the blurring means when the value is not a predetermined value. The image processing device described. 7. The image processing apparatus according to claim 4, further comprising a replacing means for replacing the background color of the input image data with a predetermined color so as to selectively use the background color. 8. The image processing apparatus according to claim 7, wherein the predetermined color to be replaced by the replacing means is a color designated by background color information included in the input image data. 9. The image processing apparatus according to claim 7, wherein the replacing means replaces the data in the black-and-white area with the predetermined color when the data shows white. 10. The first and second encoding means for encoding the input image data by the first and second encoding methods respectively, and the first and second encoding means respectively. An image processing apparatus comprising: a determination unit that determines a color area and a black and white area of an image from encoded data. 11. The image processing apparatus according to claim 1, wherein the determination means determines the color area and the monochrome area of the input image data in block units. 12. The image processing apparatus according to claim 11, further comprising correction means for correcting the determination result of the block of the color area and the block of the black and white area determined by the determination means based on the determination of the surrounding blocks. 13. The image processing apparatus according to claim 11, wherein the determination means uses a block consisting of only elements satisfying a condition that the line is black and the line is not thick and a block other than that as a determination criterion. . 14. The image processing apparatus according to claim 1, wherein the first coding method is a block coding method. 15. The image processing apparatus according to claim 14, wherein the block coding method is a coding method using a DCT coefficient. 16. The image processing apparatus according to claim 1, wherein the second encoding method is a binary encoding method. 17. The image processing apparatus according to claim 14, wherein the determination means makes a determination using a coefficient that appears when encoding by the block encoding method. 18. The image processing apparatus according to claim 15, wherein the determination means uses a DCT coefficient before or after quantization. 19. The first encoding method is a block encoding method, and a block for encoding the block and the other block have respective sides whose lengths are integral multiples. The image processing device described. 20. The sum of absolute values of the AC component of luminance or the sum of squares and the DC component of the color difference component are used as a criterion for a block consisting of only the elements that satisfy the condition that the line is black and the line is not thick. The image processing device according to claim 13, wherein a sum of absolute values or a sum of squares is used.