JPH09121289A - Picture processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost and to increase the processing speed in the picture processor which performs color attribute discrimination processing of a document based on auxiliary scanning. SOLUTION: A space filter part 12 performs the normal space filter processing in normal picture processing. In the color attribute discrimination processing based on auxiliary scanning, a document picture is thinned and inputted by an image scanner 2 and is subjected to color correction by a color correction part 10 and is subjected to the space filter processing plural times in the space filter part 12, thus perfoming sufficient smoothing. The picture signal after smoothing is inputted to an ACS part 1, and the number of color picture elements is counted to discriminate the color attribute. That is, addition of a new constitution is minimized to realize the document color attribute discrimination processing by hardware, thereby providing the picture processor which minimizes the cost and realizes the higher-speed processing.

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, for example, an image processing apparatus that recognizes a color attribute of a document image.

[0002]

2. Description of the Related Art Conventionally, an image processing apparatus capable of color image processing has been capable of simultaneously performing monochrome image processing. For example, in a color copying machine or the like, preliminary scanning (prescanning) is performed prior to the copying operation of the original to roughly sample the original image signal. Then, as a result of the pre-scanning, whether or not the original image is a color image, and if it is a monochrome image, the density level of the background is checked to recognize the so-called color attribute of the original image. After that, by performing appropriate image processing on the basis of the recognized color attribute, it was possible to obtain an appropriate output image according to the color attribute of the document.

For example, in an ink jet type color copying machine, even if this preliminary scanning is included, the throughput in the case of monochrome output is secured at about 5 sheets / minute for A4 size, so that the reduction of the processing speed is not so problematic. Don't Further, in an electrophotographic color copying machine provided with four sets of photosensitive drums and image forming means, further speedup is possible.

[0004]

However, in the above-mentioned conventional image processing apparatus, the color attribute recognition processing of the document by the preliminary scanning is performed by executing a predetermined processing program by the CPU for controlling the apparatus. That is, since the processing is performed by software, it is unavoidable that the cost is high, such as securing a memory area for storing the processing program. Further, since the processing depends on the performance of the CPU, it has been difficult to achieve higher speed.

Further, the processing realized again by executing the processing program can be realized by using hardware, of course, and the processing speed can be expected to be improved, but a dedicated structure for that purpose is provided. That also leads to high costs.

Therefore, in the present invention, the color attribute determination processing by the preliminary scanning, which has been conventionally performed by the intervention of the CPU,
An object of the present invention is to provide an image processing apparatus that minimizes the addition of a new configuration and realizes it by hardware, thereby minimizing the cost and enabling higher-speed processing.

[0007]

As one means for achieving the above object, the image processing apparatus of the present invention has the following configuration.

That is, input means for inputting an image signal, smoothing means for smoothing the image signal, and judging means for judging the color attribute of the image based on the image signal smoothed by the smoothing means. An image processing apparatus having:
Further, the image signal includes control means for controlling the smoothing means to perform smoothing a plurality of times, and the judging means performs smoothing a plurality of times in the smoothing means by the control means. It is characterized in that the color attribute of the image is determined based on the generated image signal.

For example, the control means controls the image signal smoothed by the smoothing means so as to be smoothed again by the smoothing means.

Further, it is characterized by further comprising a luminance generating means for generating a luminance signal based on the image signal.

For example, the brightness generating means is capable of color correction of the image signal by matrix calculation.

For example, the determining means determines the color attribute of the image based on the number of color pixels in the image signal which has been smoothed a plurality of times by the smoothing means by the control means. .

For example, the input means is characterized in that the original image is scanned to optically read and input an image signal.

For example, the input means has a first mode for reading the original image as a predetermined number of pixels and a second mode for reading the original image at a high speed with a number of pixels smaller than the predetermined number of pixels. It is characterized by

For example, the input means thins out and reads the original image in the second mode.

For example, the control means may control the image signal to be smoothed by the smoothing means a plurality of times during one main scan of the input means in the second mode. And

For example, the input means is characterized in that the original image is thinned out to 1/2 or less and read in the second mode.

For example, the input means is characterized in that in the second mode, the original image is thinned out to 1/4 and read.

For example, the control means controls the image signal to be smoothed by the smoothing means three times during one main scan in the second mode of the input means. And

Further, it is characterized by further comprising forming means for forming an image based on the color attribute judged by the judging means.

The original image is read by the reading means based on the first mode for reading the original image by the reading means to determine the color attribute of the original and the color attribute judged by the first mode. An image processing apparatus having a second mode for performing image formation by reading in more detail than the first mode, comprising: a color determination unit that performs color determination based on an image signal in the first mode; Second
In the first mode, the color determination means in the first mode performs color smoothing based on the image signal subjected to smoothing by the smoothing means a plurality of times. It is characterized by making a judgment.

For example, in the reading means, the reading of the original in the first mode is faster than the reading of the original in the second mode.

Further, in the second mode, there is provided color correction means for inputting a CMY signal, performing color correction processing, and outputting a CMYK signal. In the first mode, the color correction means has a CMY signal. Input, color correction processing is performed, and C
It is characterized by outputting an MY signal and a luminance signal.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the drawings.

<First Embodiment> FIG. 1 is a sectional view of a digital electrophotographic color printer which is an embodiment of an image forming apparatus according to the present invention.

In FIG. 1, the recording paper is held on the outer circumference of the transfer drum 1120 by a paper feed roller 1118 from a paper feed unit 1117.

The photosensitive drum 1100 is uniformly charged to a predetermined polarity by the charger 1112, is output from the laser section 1110, and is exposed to the laser beam light L through the reflection mirror 1111 so that the latent image of each color is latent on the photosensitive drum 1100. An image is formed. The latent image formed on the photosensitive drum 1100 is visualized by the color developing devices Dy, Dm, Dc, and Dk, and transferred to the recording paper around the transfer drum 1120 multiple times to form a color image. Then, the recording paper is separated from the transfer drum 1120 by the separation claw 1114, the transferred color image is fixed by the fixing unit 1115, and is discharged to the paper discharge tray 1116. Incidentally, 111
A cleaner 3 removes toner of each color remaining on the surface of the photosensitive drum 1100.

Reference numeral 1119 denotes a control unit, which performs various image processes on image data from a scanner unit (not shown) and controls the above-mentioned units.

An operation unit 1300 such as an operation panel is used for inputting instructions from the operator and for notifying the operator of the status.

Next, the detailed structure of the above-mentioned control unit 1119 will be described with reference to FIG.

First, the image scanner 2 including a solid-state image pickup device such as a CCD reads an original image as an RGB signal at a resolution of 400 DPI, and the shading correction unit 3 uniformly corrects the unevenness of each solid-state image pickup device to perform color space conversion. In section 4, the color correction of the sensor filter is performed. Then, the logarithmic conversion unit 8 converts the luminance RGB signal into the density CMY.
Convert to signal. Then, in the color correction unit 10, this C
At the same time that the black signal K is generated from the MY signal, color correction based on the characteristics of the color material is performed. Then, after being scaled by the scaling unit 11 as necessary, the spatial filter unit 12 corrects the sharpness and removes moire. Then, the γ conversion unit 13 performs density correction. The present embodiment is characterized in that the color correction unit 10 and the spatial filter unit 12 are provided with an ACS mode for generating an image signal to be input to the ACS unit 1 that determines the color attribute of a document, but details will be described later. To do.

On the other hand, reference numeral 6 denotes an image area separation unit, which determines the image attribute in order to perform optimal processing according to the image attribute in each of the processing units described above. This image area determination is particularly effective for sharply recording a black character portion in an image with a single black color. An image editing unit 7 performs various image editing processes such as trimming, masking, moving and rotating, and gives an instruction to each processing unit.

The YMCK image signal whose density has been corrected by the gamma conversion unit 13 has a resolution conversion unit 14 if necessary.
In step 2, resolution conversion is performed, and in the halftone processing unit 15, multi-pseudo halftone processing is performed, thereby binarizing. Then, the binarized image signal is input to the recording unit 16 and output to the laser unit 110 as a recording signal for each color.

In FIG. 2, each of the components described above has a CPU 1
It is totally controlled by 7. 18 is a ROM,
It holds a control program, fixed variables, and the like that are referenced by the CPU 17. 19 is a RAM, and the CPU 17
Used as a work area.

Note that in each structure of FIG. 2, the resolution of the image data processed in the structure (400 DPI /
600 DPI) is also shown.

In the present embodiment, the processing by the image area separation unit 6 and the image editing unit 7 is performed on a multi-valued image signal of 400 DPI. Therefore, the image processing apparatus of the present embodiment can finally perform binary recording with a high resolution of 600 DPI. However, for example, by directly outputting the output signal from the γ conversion unit 13 described above to the multilevel recording apparatus. , 400
It is also possible to perform multi-valued recording with a low resolution of DPI.

In this embodiment, a low resolution image signal is converted into a high resolution image before forming an image. Therefore, γ
The 400 DPI output signal from the conversion unit 13 is two-dimensionally converted into 600 DPI at the input to the resolution conversion unit 14, for example, 600 DPI. Then, in the halftone processing unit 15, the multi-valued image signal of 600 DPI is binarized by a pseudo halftone process such as a dither method or an error diffusion method. Note that the resolution conversion processing in the resolution conversion unit 14 may be realized by any method such as normal linear interpolation or sync interpolation as long as it is processing for two-dimensional multivalued data.

As described above, when outputting at high resolution in this embodiment, only the resolution conversion section 14 and the halftone processing section 15 handle high resolution data of 600 DPI. Therefore, only the resolution conversion unit 14 and the halftone processing unit 15 are required to have a processing speed about 2.25 times as high as that in the case of the image signal processing of 400 DPI. Therefore, the cost increase can be minimized in the high resolution processing of this embodiment.

In other words, in the present embodiment, the so-called multi-valued image signal is subjected to two-dimensional processing on a low-resolution image,
By reducing the processing for high resolution images as much as possible,
High-resolution binary recording can be realized at low cost.

Further, in FIG. 2, the color space conversion section 4 is provided with an external I / F section 5 and is connected to an external computer or the like to handle a multi-value image signal of 400 DPI. For example, the image scanner 2 of the present image processing apparatus converts the original image into 4
400 DPI read as a multi-valued image signal of 00 DPI and output to the computer of the image section, or read by another scanner and held in the computer
It is possible to input a multi-valued image signal (so-called raster image).

In FIG. 2, reference numeral 1 is an automatic color selection (ACS) unit which is a feature of this embodiment. In the printer of this embodiment, the document is placed on the document table, and the operation unit 1
When the start of the copying process is instructed from 300, the preliminary scanning is performed prior to the normal copying operation (main scanning), and the ACS unit 1
At, the color attribute of the original image is determined.

The processing purpose of the ACS section 1 in this embodiment is to firstly judge whether or not the original is a color image, that is, to determine the color attribute of the original. And second,
Detects the background color level when the original is a black and white original,
This is to enable the copying process with the optimum recording density.

In this embodiment, the color attribute determination process of the original by the preliminary scanning is performed in real time at high speed and at low cost by using each image processing means (hardware) provided for the normal copying process. It is characterized in that it is feasible. That is, as described above, the color correction unit 10, the spatial filter unit 12, and the image scanner 2 perform different processing on the input image during the pre-scanning and the main scanning, thereby realizing the above characteristics. Hereinafter, the image scanner 2, the color correction unit 10, and
Also, the processing of the spatial filter unit 12 is referred to as “ACS mode” processing, and the normal copying processing by main scanning is referred to as “normal mode” processing.

The processes of the image scanner 2, the color correction unit 10 and the spatial filter unit 12 in the ACS mode will be described in detail below.

Image Scanner 2 Preliminary scanning in the image scanner 2 in the ACS mode will be described below. Since the processing speed is important in the pre-scanning, the original image is read as a 25% reduced image at a high speed, and the original image becomes 100%.
Each low resolution pixel signal of DPI is obtained. That is, 25% thinning processing is performed in the main scanning direction, and for example, 400D in the long side direction of an A4 size original image.
A signal of about 5000 pixels with a recording width of 300 mm read by PI is thinned out to about 1250 pixels and output to the shading correction unit 3 in the subsequent stage. Of course, in the present embodiment, the thinning is not limited to 25%, but it is necessary to perform thinning at 50% or less as described later.

Color Correction Unit 10 FIG. 3 shows a detailed block configuration of the color correction unit 10. In the color correction unit 10, the CM logarithmically converted by the logarithmic conversion unit 8
The Y signals 101, 102 and 103 are input, and the minimum value calculation unit 104 takes the minimum value to obtain the black signal K.

The selectors 111, 112 and 113 are CPUs.
The selection signal 116 controlled by 17 switches the output signal between the normal mode and the ACS mode.
That is, in the normal mode, the C, M and Y signals 10 respectively
1, 102, 103 side is selected. The coefficients B11 to B44 are multiplied by 16 sets of multipliers (211 to 244) and added to perform so-called matrix calculation, and color-corrected C, M, Y, and K four-color signals 10
8, 109, 110 and 115 are output. The coefficients B11 to B44 in the multipliers 211 to 244 are stored in the ROM.
18 or a predetermined area of RAM 19
Supplied by U17.

On the other hand, in the ACS mode, the selection signal 11
6, the selectors 111, 112 and 113 select the output side from the adders 105, 106 and 107, respectively.

Here, in the adder 105, so-called color correction is applied to only the input C, M, Y signals 101, 102, 103 by the sum of products operation using the coefficients B11, B12, B13, and the color is corrected. The corrected C signal 108 is output. That is, in the ACS mode, "0" is supplied to the coefficient B14 for the black signal K. Similar color correction processing is performed in the adders 106 and 107. That is, "0" is also supplied to the coefficients B24 and B34.

As described above, the adders 105, 106, 10
C, M, Y signals 108, 1 after color correction output from 7
09 and 110 are multiplied simultaneously with the coefficients B41, B42, and B43, respectively, and the K signal and the coefficient B are added in the adder 114.
The sum with the product of 44 is taken. Thereby, the adder 11
The output signal 115 from 4 is obtained as the luminance signal L.

As described above, in the color correction unit 10, as the output signals 108, 109, 110 and 115, the signals for each of the C, M, Y and K color planes are obtained in the normal mode, and the colors are output in the ACS mode. The C, M, and Y signals for easily recognizing the original and the luminance signal L for recognizing the background of the black and white original are simultaneously obtained.

As described above, the color correction unit 1 of this embodiment
At 0, a configuration for performing a matrix operation of 4 rows and 4 columns for color correction (16 multipliers 211 to 244)
In the ACS mode, at the same time, a color correction output of three colors is obtained by a matrix operation of 3 rows and 3 columns, and at the same time, the output is output to another matrix operation section of 1 row and 3 columns (multipliers 241-224).
A luminance signal can be obtained by inputting to 3). That is, a slight configuration (selectors 111, 112, 11
Only by adding 3), the color correction means (multipliers 211 to 244) for four colors that are normally provided is used as a means for generating color correction signals for three colors and a luminance signal based on the correction signals. This makes it possible to obtain appropriate color signals and luminance signals at high speed by hardware without increasing costs.

Spatial Filter Unit 12 The processing in the spatial filter unit 12 will be described in detail below.

FIG. 4 shows a detailed block configuration of the spatial filter unit 12. In FIG. 4, that is, 3 for one color
The structure which implement | achieves the spatial filter process of * 3 is shown.

First, in the normal mode, the input signal 120 is delayed and held for one line by the FIFO 121, and FI
The FO 122 further holds the delay for one line. Then, in the multiplier 322, the coefficient D22
For the pixel adjacent to the pixel of interest.
1, D12, D13, D21, D23, D31, D32, and D33 are respectively multiplied, and all are added by the adder 126, so that a normal smoothing filter calculation process is performed. Reference numeral 130 is a FIFO for delaying the operation result output from the adder 126 at a predetermined timing.
Is controlled so as not to operate in the normal mode by the control signal 131 from, and it becomes through.

Reference numeral 123 is a selector, and in the normal mode, only the input signal 120 is always selected based on the selection signal 124 supplied from the CPU 17.

Next, the most characteristic feature of this embodiment,
The outline of the operation of the spatial filter unit 12 in the ACS mode will be described first.

In the ACS mode, in order to properly determine the color attribute of the original, the image signal input from the image scanner 2 should be sufficiently smoothed to correct the color misregistration. desirable. The spatial filter unit 12 is characterized by performing more effective spatial filtering processing using an existing configuration.

In the ACS mode, the selector 123 first selects and outputs the input signal 120 based on the selection signal 124 supplied from the CPU 17, and the input signal 120 is subjected to the spatial filter processing as in the normal mode. It Next, the signal 127 output from the FIFO 130 after the spatial filter processing is also input to the selector 123, and this signal is selectively output. Therefore, the spatial filter processing is performed again on the signal 127 after the spatial filter processing.
As a result, in the ACS mode, a signal that has been subjected to the spatial filtering process twice is output.

The operation in the ACS mode will be described in more detail with reference to the timing chart of FIG. FIG.
In the figure, 28 indicates the timing of main scanning in the image scanner 2. Reference numeral 29 indicates an effective section of the input signal 120 at the main scanning timing. Reference numeral 30 denotes the effective section of the signal 127 after the input signal 120 within the 29 effective sections is filtered at the main scanning timing. Reference numeral 31 denotes an effective section of the signal 127 obtained after further filtering the signals in the effective signal section of 30 at the main scanning timing. Also, 32
Indicates a selection signal 124 supplied by the CPU 17, and 33 is a timing signal for extracting the effective section signal indicated by 31.

As described above, since the input signal 120 is decimated to 25% in the ACS mode, the effective section shown by 29 is one main scanning section (total 5000 pixels).
In FIG. 4, the section is shown by a diagonal line of 1/4 (about 1250 pixels) from the front.

The input signal 12 within the effective section indicated by 29
Spatial filter calculation processing is performed on 0 as in the normal mode, and the calculation result is delayed in the FIFO 130 by the effective section (1250 pixels). The result is
The signal 127 is indicated by the effective section (hatched portion) indicated by 30.

In the ACS mode, the selection signal 124 supplied to the selection unit 123 by the CPU 17 has the timing 32. The selection unit 123 selects the input signal 120 side at the timing when the selection signal 124 becomes the H level, and the FIF at the timing when the selection signal 124 becomes the L level.
Signal 12 output from O130 after spatial filtering
Select 7 side. (In the normal mode, the selection signal 124
Is always at the H level. As a result, the signal 127 in the effective section indicated by 30 can be subjected to the spatial filter processing again, further delayed by the FIFO 130, and output again as the signal 127 in the effective section indicated by 31. That is, the signal 127 of the effective section indicated by diagonal lines in 31
Is a signal that is once again spatially filtered for the 3 × 3 pixel region, and is again subjected to spatial filtering for the 3 × 3 pixel region.

Here, the control signal 133 is inputted to the extracting section 132 by the CPU 17, and the control signal 133 is inputted.
Is the timing indicated by 33 in FIG. Extraction unit 132
Then, the signal 127 in the effective section shown by 31 as described above is extracted and output at the timing shown by the control signal 133 shown by 33. (In the normal mode, the control signal 133 is always at the H level.) Since the above-described spatial filter processing is a two-dimensional processing, the effective section of the input signal 120 shown in 29 in the timing chart shown in FIG. On the other hand, the effective section shown by 30 actually delays one line and the delay of the FIFO 130 (1250 pixels), and similarly, the effective section shown by 31 is further delayed by one line and the delay of the FIFO 130 (1250 pixels).
Pixel) delay. The manner of correspondence between the respective valid sections in this delay is shown by arrows in FIG.

Further, the above-described spatial filter processing is simultaneously performed on the C, M, Y signals and the luminance signal L obtained by the color correction unit 10.

In the above-described spatial filter processing in the ACS mode, 2 × 3 × 3 pixel spatial filter arithmetic circuits are used.
Applied to the target pixel substantially 5 ×
The same effect can be obtained as when the spatial filtering process of 5 pixels is performed. In the spatial filter unit 12 of the present embodiment, an example in which the spatial filter calculation is repeated twice has been described for the sake of simplicity of explanation, but the processing is maximum for the 25% reduced image as described above. It is possible to repeat 3 times. This means that it is possible to perform substantially the same calculation as the spatial filter calculation of 7 × 7 pixels by using the spatial filter calculation circuit of 3 × 3 pixels.

Further, each coefficient D11 to D33 used in the spatial filter calculation can obtain an arbitrary filter characteristic by dividing the main scanning and switching to the division unit. The coefficients D11 to D33 are held in the ROM 18 or the RAM 19 and read by the CPU 17.

Further, in this embodiment, the spatial filter operation in the ACS mode is applicable to the image signal reduced to 50% or less because the operation is repeated at least twice at the timing of one main scanning. Therefore, at the time of preliminary scanning, it is necessary to perform high-speed scanning so that the total number of pixels of the document is 50% or less.

As described above, in the spatial filter section 12 of the present embodiment, the ordinary spatial filter processing means inputs the pixel signals of half or less of the number of pixels of one line and performs the filtering process, and the processing result is obtained. By inputting as the input signal again, the same filter calculation can be performed a plurality of times. Therefore, it is possible to perform a filter calculation over a wider range. That is, a slight configuration (selector 12
3, FIFO 130) is added, and the spatial filter processing means (multipliers 311 to 333) normally provided is provided.
By double-passing, the appropriate and sufficient spatial filter processing can be performed at high speed by hardware without increasing the cost.

[ACS Unit 1] The process in the ACS unit 1 will be described in detail below. In the ACS section 1, the C, M, Y signals and the luminance signal L, which have been sufficiently smoothed by the spatial filter section 12 described above, are input, but the color of the original is based on only the C, M, Y signals. Perform attribute determination. In FIG. 6, the ACS unit 1
The detailed block configuration of is shown. In the ACS unit 1, the minimum value calculation unit 21 and the maximum value calculation unit 22 calculate the maximum value MAX and the minimum value MIN at each pixel position based on the input CMY signal, and further the multiplier 27 and the adder 23.
The following calculation is performed by

S = MAX (CMY) -α × MIN (CMY) (where α> = 1) S obtained in this way is often a value forming color information, and therefore, in the comparator 24 A predetermined threshold value K is set, and when S is larger than the threshold value K, it is determined that the pixel has a color attribute (a color pixel). Then, the integrator 25 accumulates the number of color pixels having a color attribute.

When the above integration is completed for all the pixels input by the preliminary scan, the integration result is output to the comparator 26.
And a predetermined threshold value M is compared to determine whether or not there are a predetermined number M or more of color pixels having a color attribute. That is, if the integrated value is M or more, it is determined that the original is a color original, because there are many color pixels having the color attribute in the original. Therefore CPU1
It is possible to perform appropriate image processing of color / monochrome in the copy processing in the normal mode after the main scanning by referring to the determination signal in 7.

In the above equation, the closer α is to 1 and the smaller the threshold value K, the more easily the pixel having a muddy color or a light color is easily recognized as a color pixel having a color attribute.

On the other hand, the luminance signal L is input to the luminance selection section 28, and the pixels are input in the raster order, and are successively compared to obtain the minimum value. Then, the minimum value obtained at the time when the processing for all the pixels input by the preliminary scanning is completed is held in the memory 29 as the luminance signal of the brightest pixel in the document.

Then, in the normal mode by the main scanning,
When reproducing the image, the CPU 17 refers to the luminance signal held in the memory 29 and sets the recording signal corresponding to the signal value to “0”. As a result, it becomes possible to clearly record and reproduce a manuscript such as a newspaper having a background fog.

Since the minimum luminance signal held in the memory 29 is subjected to the filter processing of 5 × 5 pixels in the spatial filter unit 12, it is 25% in the 25% reduced image.
It is the average value of pixels. Therefore, on the actual original image, the average luminance value in a region of about 1.25 mm square, which corresponds to 20 × 20 pixels at 400 DPI, is shown.

Further, since the average value obtained in the ACS mode of the present embodiment is obtained in real time over the entire area of the original, the accuracy is higher than that in the conventional sampling in the preliminary scanning. Therefore, by adding the CMY signal, which is the input signal to the ACS unit 1 shown in FIG. 6, and the luminance signal L over the entire area of the original, the toner usage amount for the original or the curl degree of the copied image can be predicted. Alternatively, it becomes possible to control it.

Further, the present invention may be applied to a system composed of a plurality of devices such as a host computer, an interface and a printer, or to an apparatus composed of a single device such as a copying machine. Further, it goes without saying that the present invention can be applied to the case where it is implemented by supplying a program to a system or an apparatus. In this case, the storage medium storing the program according to the present invention constitutes the present invention. Then, by reading the program from the storage medium to the system or device, the system or device operates in a predetermined manner.

[0079]

As described above, according to the present invention, the existing signal processing unit used in the normal copying process is further applied to the color attribute determination process of the original document accompanied by the preliminary scanning, thereby further improving the processing. The color attribute determination processing can be performed at low cost and at high speed.

Further, by simultaneously generating the luminance signal when determining the color attribute of the original document accompanied by the preliminary scanning, the background color at the time of image formation can be appropriately determined, and even the original document with fog or the like is clear. Can be reproduced.

Further, by adding the color signal and the luminance signal obtained in the preliminary scanning over the entire area of the original, it is possible to predict and control the amount of toner used in the copying process by the main scanning.

[0082]

[Brief description of the drawings]

FIG. 1 is a side sectional view of an LBP that is an image processing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of a control unit 1119 in this embodiment.

FIG. 3 is a block diagram showing a detailed configuration of a color correction unit 10 in the present embodiment.

FIG. 4 is a block diagram showing a detailed configuration of a spatial filter unit 12 in the present embodiment.

FIG. 5 is a timing chart showing the operation of the spatial filter section 12 in the present embodiment.

FIG. 6 is a block diagram showing a detailed configuration of the ACS unit 1 in the present embodiment.

[Explanation of symbols]

 1 ACS section 2 image scanner 3 shading correction section 4 color space conversion section 5 external I / F 6 image area separation section 7 image editing section 8 logarithmic conversion section 10 color correction section 11 scaling section 12 spatial filter section 13 gamma conversion section 14 Resolution conversion unit 15 Halftone processing unit 16 Recording unit 17 CPU 18 ROM 19 RAM

Claims (16)

[Claims] 1. An input unit for inputting an image signal, a smoothing unit for smoothing the image signal, and a judging unit for judging the color attribute of the image based on the image signal smoothed by the smoothing unit. And an image processing device having a control means for controlling the image signal to be smoothed by the smoothing means a plurality of times, and the determining means is configured to perform the smoothing by the control means. Based on the image signal that has been smoothed multiple times by the smoothing means,
An image processing apparatus characterized by determining a color attribute of an image. 2. The control means controls the image signal smoothed by the smoothing means so as to be smoothed again by the smoothing means.
The image processing apparatus according to any one of the preceding claims. 3. The image processing apparatus according to claim 1, further comprising a brightness generating unit that generates a brightness signal based on the image signal. 4. The image processing apparatus according to claim 3, wherein the brightness generating unit is capable of color correction of the image signal by matrix calculation. 5. The determination means determines the color attribute of the image based on the number of color pixels in the image signal which has been smoothed a plurality of times by the control means by the smoothing means. The image processing apparatus according to claim 1. 6. The image processing apparatus according to claim 1, wherein the input unit scans a document image to optically read the document image and input an image signal. 7. The input means has a first mode for reading an original image as a predetermined number of pixels and a second mode for reading the original image at a high speed with a smaller number of pixels than the predetermined number of pixels. The image processing apparatus according to claim 6, wherein 8. The image processing apparatus according to claim 7, wherein the input unit thins out and reads the original image in the second mode. 9. The control means controls the smoothing means to perform smoothing on the image signal a plurality of times during one main scan of the input means in the second mode. The image processing apparatus according to claim 8. 10. The image processing apparatus according to claim 8, wherein the input unit thins out and reads the original image in half or less in the second mode. 11. The image processing apparatus according to claim 9, wherein the input unit thins out the original image by ¼ and reads the original image in the second mode. 12. The control means controls the image signal to be smoothed by the smoothing means three times during one main scan of the input means in the second mode. The image processing device according to claim 11. 13. The image processing apparatus according to claim 1, further comprising a forming unit that forms an image based on the color attribute judged by the judging unit. 14. A first mode for determining a color attribute of a document by reading a document image by a reading unit, and based on the color attribute determined by the first mode,
An image processing apparatus having a second mode in which the original image is read in more detail by the reading means than in the first mode to form an image, and color determination is performed based on an image signal in the first mode. And a smoothing unit that performs a smoothing process on the image signal in the second mode, and in the first mode, the color determining unit performs a plurality of smoothing operations by the smoothing unit. An image processing apparatus, characterized in that color determination is performed based on an image signal that has been applied. 15. The first means in the reading means
15. The image processing apparatus according to claim 14, wherein the reading of the original document in the second mode is faster than the reading of the original document in the second mode. 16. Further, in the second mode, CMY
In the first mode, the color correction means inputs a CMY signal, performs a color correction process, and performs a CMY signal, and outputs a CMYK signal. The image processing apparatus according to claim 14, wherein the image processing apparatus outputs a luminance signal.