JPH0490682A - Color picture processor - Google Patents

Abstract

PURPOSE:To exactly decide the colored/colorless state of an input color signal by changing a parameter for deciding the colored/colorless state of the input color signal corresponding to the magnification of a picture expressed by the input color signal. CONSTITUTION:An automatic color/monochromatic original discriminating device is composed of a scanner 101, YIQ conversion part 102, picture element discrimination part 103, original discrimination part 104, picture processing part 106, display 107, facsimile transmission part 108, printer 109, operation part 110 and CPU 111. In this case, when deciding the colored/colorless state of the input color signal, the magnification of the picture expressed by the input color signal is changed and corresponding to the magnification, the parameter of the decision is changed. Thus, the colored/colorless state of the input color signal can be exactly decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image processing apparatus such as a color copying machine, a color scanner, or a color facsimile machine, in particular a color image processing apparatus having a function of discriminating between color and black and white. It is related to.

[Conventional technology]

In conventional systems for reading color originals, chromatic/achromatic is determined using the ratio of three components of the three primary colors (RGB, XYZ, etc.) of an input image signal. For example, if the input levels of the three primary colors are similar, it is determined that the color is achromatic, and if the levels vary, it is determined that the color is chromatic. A technique is known in which this pixel-by-pixel determination is repeated for all pixels of the document, and if a chromatic color pixel exists, the document is determined to be color, and conversely, if there is no pixel, the document is determined to be black and white.

[Problem that the invention is trying to solve]

However, in the above-mentioned conventional technology, when the reading accuracy of the color sensor for image input is poor, pixels around black characters in the input image are often incorrectly determined to be chromatic.

For this reason, there is a problem in that even though the original is black and white, it is mistakenly determined to be a color original. In addition, there were cases where incorrect judgments were made when the background of the document had a light color. Furthermore, if you enlarge the original and scan it, the degree of color shift will become even greater, increasing the possibility that a black-and-white original will be mistakenly identified as a color original. In this case, the ratio of red lines to all pixels of the document is very low, so depending on the length of the underline, it may be determined that the document is a color document or a black and white document.

In addition, to distinguish between color originals and black and white originals, count the number of color pixels included in the original and compare it with a certain threshold.If the number of color pixels is larger than the threshold, it is a color original, and if it is smaller, a black and white original. That's what I judged. In this case, if the threshold value is fixed, when the size of the document changes or the reading magnification changes, the number of color pixels will change even for the same document, and there is a risk that the document cannot be discriminated accurately. If a black and white original is misidentified as a color original, the following problems will occur.

In the case of a color copying machine, when color inks (CMY) are superimposed to copy a black and white original, characters, lines, and halftone dots may become poorly defined due to color shifts and differences in the spectral characteristics of the inks.
It becomes difficult to see. In addition, in the case of color facsimile,
In addition to the above-mentioned drawback of poor print quality, there is also the drawback that even though the original is black and white, transmitting three primary colors takes time to transmit and increases communication costs.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a color image processing device that eliminates the drawbacks of the prior art described above and can accurately determine whether an input color signal is chromatic or achromatic.

[Means and operations for solving the problems] In order to solve the above problems, the color image processing device of the present invention includes a determining means for determining whether an input color signal is chromatic or achromatic, and The image processing apparatus is characterized by comprising a processing means for changing the magnification of an image to be displayed, and a control means for changing a parameter for determination by the determination means according to the magnification.

〔Example〕

(Principle of the present invention) A document is read from a color scanner and the data is transferred to the NT.
It is converted into SC RGB, and further converted into brightness data Y and chromaticity data 1 and Q. Figures 6 and 7 are graphs of IQ.

FIG. 6 shows the distribution when a monochrome original is read, and FIG. 7 shows the distribution when a color original is read. It can be seen that when a black and white document is read, the distribution is near the origin, and when a color document is read, the distribution is far from the origin. Therefore, the origin (1=0
．． The distance from Q=0) is calculated, and if there are many pixels separated by a large distance, the original is set as a color document, and if there are fewer pixels, the original is set as a black and white document. Documents can be determined based on this concept.

(Scanner Reading Accuracy) When reading black and white characters with a scanner, if the scanner accuracy is not good, the input image will be an image with color shift as shown in FIG. 8. In this case, the pixel with color shift is determined to be a color pixel, and as a result, there is a possibility that the document is erroneously determined to be a color document even though it is a black and white document. Therefore,
If a black pixel (a black and white pixel and a dark pixel) exists around the input pixel, it is determined that the input pixel is a pixel with color shift and is actually a black and white pixel. By doing so, errors in reading by the scanner can be reduced. Furthermore, when reading an enlarged document, the color shift area becomes larger as shown in Figure 13 (B) compared to the same magnification as shown in Figure 13 (A), and the black color located further away from the pixel of interest becomes larger. We need to find the pixel. As shown in FIG. 12, in the case of the same magnification, as shown in (A), eight pixels around the pixel of interest C (pixels in the shaded area) are referred to to determine whether a black pixel exists. Furthermore, when enlarging, for (B), it is determined whether a black pixel exists by referring to the eight pixels in the diagonally shaded area around the pixel of interest. By changing the surrounding reference pixels in accordance with the reading magnification in this way, accurate discrimination becomes possible.

(Original identification accuracy) When identifying a black and white original with red underlining, the total number of pixels in the original and the number of red pixels are too different, so the 50mm line and the 0.5mm line have the same ratio. This may result in incorrect judgments depending on the threshold settings.

In other words, a document with a red underline of 50 mm may be judged as a black and white document, or conversely, a document with a diameter of 0.5 mm may be judged as a black and white document.
A document containing dust on the order of mm may be determined to be a color document. Therefore, in order to make the ratio of color pixels (red underline) to all reference pixels as high as possible, the method shown in FIG. 11 is adopted. That is, a document 1101 as shown in FIG. 11(A) is divided into a plurality of small regions as shown in FIG. 11(B), and the document is determined for each small region.

For example, if it is determined that area 1 of 1102 and area 2 of 1103 are black and white document areas, and area 3 of 1104 is a color document area, it is determined that the document 1101 is a color document. Further, if no small area is determined to be a color document area, the document 1101 is determined to be a black and white document.

Whether the small area is a color original area or a black and white original area is determined by counting the color pixels in the small area and comparing it with a color pixel threshold value δ. Next is the size of the small area. For example, if we assume that one small area is the size of a document divided into eight equal parts as shown in Figure 14, the size of the small area will vary depending on the document size and the scaling factor. It will change. Therefore, the size of the small area is calculated, and the color pixel threshold value δ is set based on it. For example, suppose that if 0.1% or more of the total number of pixels in a small area are color pixels, it is set as a color original area, and if it is less than 0.1%, it is set as a monochrome original area. At the same magnification as shown in FIG. 14(A), the total number of pixels in the small area is 4800 pixels, so 48 pixels, which is 0.1% thereof, becomes the color pixel threshold δ.

Furthermore, when enlarging, the total number of pixels in the small area is 100,000 pixels, so the color pixel threshold value δ is 100.

In this way, the color pixel threshold value δ is changed depending on the document size and the enlargement/reduction magnification.

(First Example) FIG. 9 shows a flowchart of the process. The processing is thick (,
Parameter setting processing (S17.518) Pixel discrimination processing (
SL-S4), pixel correction processing (35-511), and document discrimination processing (812-516).

The pixel discrimination process is a process for discriminating whether the pixel of interest is color or monochrome, and the document discrimination process is a process for discriminating whether the entire document is a color document or a monochrome document. The details of the algorithm will be explained below according to the flow.

<Parameter setting process> First, the document size and copy magnification are specified using the operation unit (S17). According to this designation, the CPU sets determination parameters as described later (S18).

<Pixel judgment processing> First, color pixel determination processing will be explained.

Color pixel determination is processed in steps 81 to S4. It is determined for each pixel whether the input pixel is a color pixel or a monochrome pixel.

(2) Color space conversion processing In Sl, color space conversion processing is performed. That is, NTSCRG
The data normalized to B is converted into a luminance signal Y and a chromaticity signal 1.B according to equation (1). , converted to Q.

■Distance Calculation In S2 and S6, in order to create saturation information from I and Q, the distance calculation section calculates the distance. This indicates how far the target color is from the origin on the IQ chromaticity diagram. If this value is large, the saturation is high, and it can be said that the probability that the pixel is a color pixel is high.

■Saturation comparison section In S3, the saturation of the pixel of interest is compared with a threshold value.

As shown in Figure 10 (A), the pixel C of interest is a character or background (
If the color saturation is low (limited to white), the saturation is low (to satisfy the condition of D-mouth and < a, proceed to 84 and increase the number of black pixels BPLX by 1. Then, return to S2 again and perform the next step. Read the pixels and perform the same processing.

Furthermore, if the pixel of interest is located at a position that is considered to be a color pixel as shown in FIG. 10(B), the saturation does not satisfy the condition of high<C<a> and the process proceeds to S5.

(2) Pixel correction processing 85 to Sll are pixel correction processing units. This is Fl
o w 3 Even if the pixel is determined to be a color pixel by the saturation comparison section, there is a possibility that it will be mistakenly determined as a color pixel due to blurring of black characters caused by color shift of the sensor, so this misjudgment is This is provided for the purpose of correction. The pixel correction section will be explained below.

In S5, eight pixels S1 to S8 surrounding the pixel of interest C in FIG.
Input pixel by pixel. In S6, RG is created by color space conversion.
Perform B-YIQ conversion (same as Sl).

In S7, saturation information T is calculated (same as S2).

In S8, the saturation level 1 and luminance Y of the surrounding pixels are compared with a threshold value. For example, if the surrounding pixel S is a character part,
Since the saturation is low and the brightness is low, the conditions q < s and Y > γ are satisfied. As a result, the pixel C of interest is determined to be a color pixel in the pixel determination process, but it is actually determined to be due to color shift in the sensor and is originally a black pixel.The process proceeds to S9, and the number of black pixels BPIX is set by 1. increase. Surrounding pixel S6
In this case, since R1 does not satisfy the conditions of < B and Y > γ, it is determined that 86 is not a black pixel, and the process proceeds to FIowlO.

SIO checks whether all the surrounding eight pixels have been input. In this way, it is checked whether the surrounding eight pixels include a black pixel by repeating the processing from 85 to SIO to the eight pixels 81 to S8 surrounding the pixel of interest.

If even one black pixel is included in the surrounding eight pixels, the pixel C of interest is treated as a black pixel and the process proceeds to step 89. Furthermore, if the surrounding eight pixels do not include any black pixels, the pixel C of interest is not a color pixel due to color shift, but is considered a true color pixel.
Then, the number of color pixels CPIX is increased by one.

<Color/monochrome original discrimination> The above-described pixel discrimination (Sl-5ll) is applied to all pixels in a small area of the original, and the ratio of color pixels CPIX to monochrome pixels BPIX is determined. CPIX in S13 >
If the condition δ is satisfied, the target document area is determined to be a color document area, and if not, it is determined to be a black and white document area. This region determination is performed for all small regions of the document, and if there is even one small region determined to be a color document region, the entire document is determined to be a color document, and if there is no such small region, the entire document is determined to be a black and white document (S16).

The above is a flowchart in which processing is performed by, for example, computer software, but the circuit configuration for performing the above processing will be described below.

Scanner 10 configured by CCD using FIG.
When a document is placed on 1 and scanned, RGB data normalized to the NTSC standard is output.

The YIQ conversion unit 102 converts the RGB data output from the scanner 101 into a brightness (luminance) signal Y and chromaticity signals I and Q.
Convert to The pixel determining unit 103 determines whether an input pixel is a black and white pixel (low saturation) or a color pixel.

Reference numeral 104 denotes a document discrimination unit, which aggregates the discrimination results for each pixel to determine the ratio of the number of color pixels to the total number of pixels, and outputs a document discrimination signal indicating whether the document is color or black and white according to the ratio. 105 is output. 106 is an image processing unit that outputs an image reproduction signal of the magnification input from the operation unit 110;
107 is a display for displaying images; 108 is a facsimile transmitter for transmitting images; and 109 is a printer for reproducing images on a recording medium. Further, 110 is an operation unit for manually specifying the original size and copy magnification;
111 determines parameters for pixel discrimination and document discrimination according to the document size and copy magnification specified by the operation unit 110;
Outputs parameter signals 353, DATI, and DAT2.

The image processing unit 106 performs different processing on a monochrome original and a color original in accordance with the original discrimination signal 105.

For example, regarding the image signal sent to the facsimile transmission unit 108, in the case of a color original, the R, G, and B signals are compressed and encoded so that they can be stored, and in the case of a black and white original, they are converted into a density (luminance) signal. Normal MHSMR, MM
Performs compression encoding such as R.

Regarding image signals to be sent to the printer 109, in the case of color originals, logarithmic conversion is performed on R, G, and B signals, and U
Y, MSC,
The image is processed so that it becomes a frame-sequential signal, black-and-white processing is performed,
In the case of a black and white original, only a K (black) signal is generated to perform black monochrome printing.

Note that the printer may be of any type as long as it is capable of color printing, such as a racer beam printer, an ink sheet printer, a thermal transfer printer, or a dot printer.

FIG. 2 is a diagram showing a YIQ conversion section, which calculates equation (1). 203202.203 are RlG and B, respectively.
is the input signal of 204-212 are registers for setting the coefficients of equation (1), 213-221 are multipliers for multiplying input data and coefficients, 222.223.225.228
is an adder, and 226 and 229 are subtracters. The results of the calculation are outputted as Y in 224, I in 227, and Q in 230.

For example, when calculating Y, register 204 is set to 0.
．． 3. 0.59 in register 207, 0 in register 210
．． 11 is set, and the R data 201 and the contents of the register 204 are multiplied by the 213 multiplier. Similarly, the G data and the contents of the register 207 are multiplied by a multiplier 216, and the B data and the contents of the register 210 are multiplied by a multiplier 219.

Then, the three multiplication results are added by adders 222 and 223, and Y is finally obtained. Similarly, I and Q can be calculated.

FIG. 3 is a diagram showing a pixel discrimination section. 301 to Y130
Data of I and Q are input to 2 and 3030, respectively. (2) is squared by the multiplier 310. Further, Q is squared by a multiplier 311. (2) 2 and Q2 are added by an adder 312.

Next is the calculation of the seam, which is done by referring to the table. For example, if the input of ROM313 is 2, R
Address 2 of OM is accessed and data 1.414
is output. Further, R1 output from the ROM 313 is input to comparators 305 and 306. A threshold value β is set in the register 308, and a threshold value α is set in the register 309. Then, in the comparator 305, the threshold value β and the threshold T
When the comparison is made, 1 is output when β is equal to T, and 0 is output otherwise. Further, the comparator 306 compares the threshold value α with the position T, and outputs 1 when α is equal to the position T, and outputs O otherwise. The output result of this comparator 306 is called the first determination result.

Next, regarding the brightness (luminance) signal, a threshold value γ is set in the register 307, and a comparator 304 compares Y and γ. Outputs 1 when Y and γ, otherwise outputs O
Output. The outputs of comparators 304 and 305 are ANDed by AND gate 314. That is, when the luminance (brightness) is low (and the saturation is also low), the AND gate 314 outputs 1, and otherwise outputs O.
The output result of step 14 is called the second determination result. The output of the AND gate 314 is input to line memories of flip-flops (hereinafter referred to as FF) 320 and 315.

Further, the output of the line memory 315 becomes the input of the line memory 316 and the FF 325. Therefore, FF325 has 1
A pixel delayed by two lines is stored in the FF 329. Similarly, the pixels are sent to line memories 317 and 318, and as a result, the FF 334 stores pixels delayed by 3 lines, and the FF 338 stores pixels delayed by 4 lines.

In this way, the FFs 320 to 342 hold the output results of the questionnaire 314 in synchronization with the pixel clock. Therefore, at a certain point, the secondary determination result of the pixel of interest is F.
If it is held at F331, then FF320-34
2 (excluding FF 331) holds the secondary determination results of the surrounding 22 pixels. Also, the comparator 306
The output (first judgment result) enters the line memory 343, the output of the line memory 343 becomes the input of the line memory 344, and the output of the line memory 344 becomes the FF 345, F
It flows to F346 and FF347. That is FF311
and FF 347 respectively hold a primary determination result and a secondary determination result for the same pixel. The signal line 348 has a first
A total of nine signals, including the second determination result for the diagonally shaded pixel in FIG. 1(B) and the first determination result for the pixel of interest, flow. Further, a total of nine signals, including the second determination result of the diagonally shaded pixel in FIG. 11(A) and the first determination result of the pixel of interest, flow through the signal line 349. The selector 350 selects either of these signal lines.
is switched according to the selection signal SEL (353). CPU II according to the magnification specified by the operation unit 110.
When the reading magnification is small, the selection signal 353 output from I selects the signal line 349 and performs correction using the matrix shown in FIG. It is set to perform correction using the matrix B). The output of selector 350 is input to a NOR gate 351. The NOR gate 351 is a nine-manpower gate with one output, and outputs 1 as the color pixel determination signal 352 if at least one of the first and second determination results is l. That is, if the pixel of interest is determined to be a color pixel, the color pixel determination signal 352 becomes 1, and conversely, if the pixel of interest is determined to be a black and white pixel, it becomes O.

Further, a plurality of parameters may be set in the registers 307, 308, and 309, and the determination parameters γ, β, and α may be switched according to the selection signal 353. That is, when the reading magnification is large, there is a high possibility that color shift will occur, so when the magnification is small, the parameter γ1,
Parameter γ2 whose value is larger than β1 and α1
, β2, α2 (γ2>γ1, β2>β1, α2>α1)
Select.

FIG. 4 is a diagram showing the document discriminating section. Since the count enable 408 is set to 0 (enabled), the up counter 407 constantly counts up from the initial count data DAT2 (404) in synchronization with the pixel clock 402. When the carry CARRY2 (409) becomes 1, a reset is applied and counting starts again from the initial count data. This up counter 407 is for counting the number of pixels in a small area of the document. For example, if the number of pixels in the small area 1102 in FIG. 11 is 1000 pixels, the up counter 407 counts 1000 times, When the count is finished, the carry in 409 is set to 1 and the up counter 406 is reset. For example, if the up counter 407 is a 10-bit counter, by setting the initial count data 24 in DAT2, the pixel clock 402 can be set to 1.
Count 000 times and carry CARRY2 (409)
becomes 1.

406 is also an up counter, and 403 is an input.
There is initial count data DATI at 402, a pixel clock at 402, a color pixel determination signal at 401, and a carry hit at 410 as an output. The counter 406 counts up from the initial count data in synchronization with the pixel clock, but the period in which count-up is enabled is only during the color pixel determination signal month, and as a result, the color pixel determination signal is counted. become. For example, 406
When the document discrimination threshold (color pixel threshold) δ is 255 using a 10-bit counter, set 769 in DAT.
When the number reaches 55, the carry bit 407 becomes 1.
Since the number of color pixels in the document is 255 or more, the signal indicating that the target document is a color document (document discrimination signal 105) becomes 1. This document discrimination threshold (color pixel threshold) δ is calculated by the CPU 106 based on the document size and the enlargement/reduction magnification, and is set in the counter 406.

When the above-mentioned reading magnification is large or when the document size is large, a larger threshold value δ2 is used than the threshold value δ1 when the magnification is small or the document size is small. That is, by changing the threshold value δ set in DA'rl according to the document size and copy magnification specified on the operation section 110, an appropriate determination can be made. The value of δ may be changed continuously or discretely depending on the magnification.

Furthermore, the number of pixels in the small area set in DAT2 may be changed depending on the document size and magnification.

In this way, the judgment for each small area of the document is carried out by CARRYl.
(410) and latched to 411.

When all the small areas of the document have been identified, the results are 4.
It will be output from 12.

Through the above processing, it is possible to determine whether the document is in color or black and white.

[Second example] FIG. 5 is a diagram for explaining the second embodiment.

In the first embodiment, in order to realize the calculation of equation (1), the second
Although the configuration shown in the figure was used, in the second embodiment, the calculation of equation (1) is approximated using the configuration shown in FIG. If the coefficient of equation (1) is approximated by adding 1 to a power of 2, equation 2 is obtained. For example, the coefficient 0.3 in equation l is approximated to 0.25+0.0625. By doing so, it is possible to easily calculate 0.3*R by adding the data shifted by 2 bits and the data shifted by 4 bits.

515.516.517.518.521.523.5
27 is an adder, and 524.525.526 is a subtracter. The finally calculated data is output as Y in 528, I in 529, and Q in 530.

Next, the flow of data will be explained. The calculation method is Y, I.

Since the same calculation is performed for Q, we will take Y as an example and calculate the R term by performing a 2-bit shift at 504, a 4-bit shift at 507, and applying the results to an adder 517... (
2) Next, Figure 4 will be explained. 501, 502, and 503 are set with R, G, and B input data, respectively.
4 to 513, 519, and 520 are circuits for shifting input data in bit shift units. 514, shift the input G data by 1 bit at 509, 510
A 4-bit shift is performed at , and the result and the output of adder 517 are added by adder 522 . The output of adder 522 is
In the calculation of Y in Equation 2, the result is the addition of the R and G terms. Next, the input data 503 of B is shifted by 3 bits and input to the adder 523. As a result, adder 523
The output 528 becomes Y in equation (2).

As described above, according to the embodiment of the present invention, there are provided a means for separating each component signal of an input color signal into a lightness signal and a chromaticity signal, a means for generating a chroma signal from the chroma signal, and a means for generating a chroma signal from the chroma signal. means for comparing the saturation signal with a threshold value α, means for comparing the saturation signal with a threshold value β, and means for comparing the brightness signal with a threshold value γ;
As a result of comparing the saturation signal of the pixel of interest and the threshold value, if the saturation signal is less than α, there is a method for increasing the number of black and white pixels by 1, and as a result of comparing the saturation signal of the pixel of interest and the threshold value, if the saturation signal is ≧α, then For example, as a result of comparing the chroma signal and the threshold value β for the surrounding pixels, as a result of comparing the chroma signal 〈β and the brightness signal and the threshold value γ, the brightness signal 〈γ is determined. If a pixel satisfying this condition is included, the number of black and white pixels is increased by 1, and if it is not included, the number of color pixels is increased by 1, and a means for selecting the surrounding pixels according to the reading magnification. Then, the above pixel discrimination is performed for a certain number of unit pixels, and as a result of comparing the number of color pixels with a threshold value δ, if the number of color pixels>δ, means for determining that the original area of that unit pixel is a color original area. The accuracy of the scanner can be improved by providing means for performing the above-mentioned determination for each document area over the entire area of the document, and means for determining that the document is a color document if a color document area exists in the document area. Even if the document is not in good condition or has a light color on the base of the document, the document can be identified without misjudgment.

Furthermore, even documents with colored underlines can be accurately identified. Further, even when an original is enlarged or reduced and read, it is possible to accurately identify the original without worrying about color shift. As a result, it is possible to perform processing according to the type of document, and it is possible to improve print quality and reduce communication costs.

Note that the image input means is not limited to a scanner, and may be an interface of a host computer, a still video camera, a video camera, or the like.

Furthermore, the number of peripheral pixels to be referenced is not limited to eight pixels.

Furthermore, instead of OR processing, majority processing may be performed.

In addition to separating into (Y, L Q), (L*, a*b
Judgment may also be made by separating into (Thursday), (L*, U*, v') (Y% UN''), etc.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to accurately determine whether an input color signal is chromatic or achromatic.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an automatic color/black-and-white document discriminator according to a first embodiment of the present invention. FIG. 2 is a configuration diagram of the YIQ conversion section. FIG. 3 is a configuration diagram of a pixel discrimination section. FIG. 4 is a configuration diagram of the document discriminating section. FIG. 5 is a configuration diagram of the YIQ conversion section of the second embodiment. FIG. 6 is a diagram showing the distribution of I and Q when a monochrome original is read. FIG. 7 is a diagram showing the distribution of I and Q when a color original is read. FIG. 8 is a diagram showing the state of color shift. FIG. 9 is a diagram showing the overall flow of color/monochrome document discrimination. 10th is a diagram explaining pixel correction processing. FIG. 11 is a diagram illustrating dividing a document into small areas. FIG. 12 is a diagram illustrating surrounding reference pixels. FIG. 13 is a diagram showing the degree of color shift depending on the reading magnification. FIG. 14 is a diagram showing that the size of the small area changes depending on the document size and the enlargement/reduction magnification. 101...Scanner 102...YIQ conversion unit 103...Pixel discrimination unit 104...Original discrimination unit 105...Original discrimination signal (A) NO (B) (A) Figure (B) Hand Retail amendment (method) 6. Target of amendment November 15, 1990 Specification 7. Contents of amendment ``No. 10'' in the first line of page 28 of the specification was changed to ``No. Figure 10 is corrected to ``. 2. Name of the invention and its relationship to the color image processing device correction case

Claims (3)

[Claims] (1) A determining means for determining whether an input color signal is chromatic or achromatic, a processing means for changing the magnification of an image represented by the input color signal, and changing parameters for determination by the determining means in accordance with the magnification. An image processing apparatus comprising: a control means for controlling an image; (2) The color image processing apparatus according to claim 1, further comprising a correction means for correcting the determination result by the determination means by referring to surrounding pixels. 3. The color image processing apparatus according to claim 1, further comprising means for determining whether a document represented by an input color signal is black and white or color, using the determination result.