JP2915503B2 - Image processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

 The present invention relates to an image processing device.

[Prior art]

In conventional image processing in, for example, a digital copying machine, a document to be copied is irradiated with a halogen lamp or the like,
The reflected light is photoelectrically converted using a charge-coupled device such as a CCD, and then converted into a digital signal, and predetermined image processing is performed. Then, the image data after the image processing is converted into a laser beam printer, a liquid crystal printer, a thermal printer,
Visualization was performed using a recording device such as an ink jet printer. In such a copying apparatus, there is a demand for an output having a large amount of information due to colorization of a copy original.
2. Description of the Related Art In recent years, a copying apparatus having a plurality of color developing devices and performing copying by partially changing colors has been developed.

[Problems to be solved by the invention]

However, in a copying apparatus that has a plurality of color developing devices and forms an image by partially changing colors, it is required that the mechanism be complicated due to having many developing devices and that the image position accuracy be high. Is done. For this reason, it is expensive. Further, in a conventional copying apparatus, it is almost impossible to reproduce a specific color of a document, for example, yellow, due to the sensitivity characteristic of a photoreceptor (in a digital copying apparatus, the sensitivity characteristic of a light receiving element for reading an image). It was possible.

[Means for Solving the Problems]

The present invention has been made for the purpose of solving the problems described above, and has the following configuration as one means for achieving the object. That is, input means for inputting color image data of primary colors of a plurality of color components, signal processing means for obtaining one-component image data from the input color image data of primary colors of a plurality of color components, and signal processing means. Output means for outputting the image data to a single-color image recording means in order to form an image corresponding to the obtained image data, wherein the one-component image data obtained by the signal processing means is converted into the color image data of the plurality of primary colors. It is characterized by the minimum value. And, for example, further comprising a detecting means for detecting a specific hue from the color image data of the primary colors of the plurality of components, wherein the output means includes, for the peripheral part of the specific hue detected by the detecting means in the image data. And outputting to the single-color image recording means after edge trimming.

Embodiment 1 Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings. In the following description, an example in which the image processing apparatus of the present embodiment is applied to the following copying apparatus will be described. That is, a full-color original is exposed by an illumination source such as a halogen lamp or a fluorescent lamp, a reflected color image is captured by a color image sensor such as a CCD, and the obtained analog image signal is subjected to A / A.
It is digitized by a D converter or the like, and the digitized full-color image signal is processed, processed, and output to a printing means such as a thermal transfer printer, an ink jet printer, a laser beam printer, etc., and is applied to a copying apparatus for obtaining an image.
However, the device of the present embodiment is not limited to the application to the above-described devices.Either a device that processes images or a display device, a device that records image information on a recording medium, Various applications are possible. In the above-described copying apparatus, the original A is first irradiated by the exposure lamp 100, and the reflected light is read out by color separation for each image by a CCD sensor 102 which is a color reading sensor, and is amplified to a predetermined level by an amplifier circuit 103. You. Here, the driving pulse required for driving the CCD sensor 102 is
It is generated by the system pulse generator 101. FIG. 2 shows a detailed configuration of the CCD sensor 102 and the CCD sensor 1.
02 shows a drive pulse. FIG. 2A shows a CCD sensor 102 used in this embodiment.
63.5 μm in order to divide the main scanning direction into 5
１, 1024 pixels (400 pixels / inch (hereinafter referred to as “dpi”)) assuming one pixel in the main scanning direction
Since the image is divided into three by G, B, and R, the total number of effective pixels is 1024 × 3 = 3072 pixels). On the other hand, the chips 58 to 62 are formed on the same ceramic substrate, and the first, third and fifth (58a, 60a, 62a) of the sensor are on the same line LA, and the second and fourth sensors are four lines from the LA. (63.5μmx4 =
254 .mu.m), and scans in the direction of arrow AL when reading a document. Of the five CCD chips 58 to 62, the first, third and fifth are driven independently by the drive pulse group ODRV 118a, and the second and fourth are driven by the EDRV 119a independently and synchronously. O01A, O02A, ORS included in ODRV118a and E01A, E02A, ERS included in EDRV119a are charge transfer clock and charge reset pulse in each sensor, respectively, and are the first, third, fifth and second and fourth chips. Due to mutual interference with chips and noise limitations, they are generated completely synchronously so that they are not in jitter with each other. Therefore, these pulses are generated from one reference oscillation source OSC in the system pulse generator 101. FIG. 3A shows O in the system pulse generator 101.
A circuit block for generating the DRV 118a and the EDRV 119a is shown in FIG. 3 (b). Single OSC included in system pulse generator 101
A clock K0135a obtained by dividing the source clock CLK0 generated from the 558a by the frequency dividing circuit 63a is a clock for generating reference signals SYNC2 and SYNC3 for determining the generation timing of ODRV and EDRV, and SYNC2 and SYNC3 are connected to the CPU bus. The output timing is determined according to the set values of the presettable counter 64a and the presettable counter 65a set by the signal line 22 that has been set. The SYNC2 and SYNC3 initialize the frequency dividers 66a and 67a and the drive pulse generators 68a and 69a. That is, based on the HSYNC 118 input to this block as a reference, it is generated by the CLK0 output from the OSC 558a of one oscillation source and the frequency-divided clock generated in synchronization with each other.
Each pulse group of the RV118a and the EDRV119a is obtained as a synchronized signal without straddling, and signal disturbance due to interference between sensors can be prevented. Here, the sensor drive pulses obtained in synchronization with each other
ODRV118a is connected to the first, third and fifth sensors 58a, 60a and 62a, and the EDRV119a
Is supplied to the second and fourth sensors 59a and 61a, and the respective sensors 58a and 59a
a, 60a, 61a, 62a
1 to V5 are output independently. The video signals V1 to V5 are supplied to the amplifier 103 at the timings of OOS 129a, V1, V3, and V5, and at the timing of EOS134a, V2, V4F.
, And are amplified independently to a predetermined voltage value for each channel. The amplified color image signal is sent to the sample / hold circuit S / H104, where G (green), B
(Blue) and R (red). Therefore, S /
After H, 3x5 = 15 signal processing is performed. The analog color image signal sampled and held for each color R, G, B by the S / H circuit 104 is converted into a next-stage A / D conversion circuit 105.
Is digitized for each 1-5 channel, and each 1-5
The signals are output to the next stage in parallel independently of the channels. In this embodiment, as described above, four lines (63.5 μmx
4 = 254 μm) in the sub-scanning direction, and the original is read by five staggered sensors divided into five regions in the main scanning direction. For this reason, the reading positions of the channels 2 and 4 that are being pre-scanned are different from the reading positions of the remaining channels 1, 3 and 5. For this reason, the digitized color image signal is sent to a shift correction circuit 106 having a memory for a plurality of lines, and performs a shift correction for connecting correctly. Then, it is sent to the black correction / white correction circuit 107. Next, using FIG. 4 (a) and FIG. 4 (b),
First, the black correction operation in the white correction circuit 107 will be described. As shown in FIG. 4B, the black level outputs of the channels 1 to 5 have large variations between chips and pixels when the amount of light input to the CCD sensor 102 is very small. If this is output as it is and an image is output, streaks and unevenness will occur in the data portion of the image. Therefore, it is necessary to correct the output variation of the black portion. Therefore, in this embodiment, FIG.
This correction is performed by the circuit shown in FIG. Prior to the original reading operation, the original scanning unit is moved to a position of a black plate having a uniform density arranged in the non-image area at the leading end of the original platen, and halogen is transferred to input a black level image signal to this circuit. Since these configurations are known, their detailed description is omitted. For the blue signal B _in, in order to store one line of the image data to the black level RAM 78a, (the signal) by the selector 82a selects the A, (the signal) gate
Close 80a and open gate 81a. Thereby, the data signal lines are connected in the order of 151a → 152a → 153a. On the other hand, the address input 155a of the RAM 78a is initialized by ▲ ▼, and the address counter 84a counting VCLK is used.
Is output to the selector 83a so that the output 154a is input. As a result, the black level signal for one line is RA
It will be stored in M78a. The above control is referred to as a “black reference value capture mode”. At the time of image reading, the RAM 78a is in the data reading mode, and is read and input for each line and one pixel to the B input of the subtractor 79a along the data line 153 → 157a. That is, at this time, the gate 81a is closed (by a signal) and the gate 80a is opened (by a signal). The selector 86a has an A output. Therefore, the output 156a of the black correction circuit is the black level data DK
(I), for example, _in the case of a blue signal, Bin (i) -DK
(I) = B _out (i). The above control is called "black correction mode". Similar control by 77aG and 77aR is performed also _in green G _in and red R _in . In addition, control lines for each selector gate for this control,
,,, Are controlled by a latch 85a assigned as an I / O of the CPU 22, which controls the overall operation of the present embodiment shown in FIG.
Performed by PU control. By selecting the selectors 82a, 83a, 86a on the B side, the CPU 78 can access the RAM 78a. Next, the white correction (shading correction) operation of the black correction / white correction circuit 107 will be described with reference to FIG. In the white level correction, the sensitivity variation of the illumination system, the optical system, and the sensor is corrected based on the white data when the original scanning unit is moved to the position of the uniform white plate and irradiated. The basic circuit configuration is the same as that of FIG. 4 (a), except that the correction is performed by the subtractor 79a in the black correction, but the multiplier 79'a is used in the white correction. Therefore, the description of the same part is omitted. At the time of color correction, when the CCD sensor 102 for reading the original is at the reading position (home position) of the uniform white plate, that is, before the copying operation or the reading operation, the first
The exposure lamp 100 shown in the figure is turned on, and the image data of the uniform white level is stored in the correction RAM 78'a for one line. For example, if it has a width in the longitudinal direction of the main scanning direction A4, at least the capacity of the correction RAM is 16 pel / mm and 16 × 297 mm = 4
It has a capacity for 752 pixels, that is, at least 4752 bytes, and assuming that white plate data Wi (i = 1 to 4752) for the “i” th pixel as shown in FIG. As shown in FIG. 3C, data on a white plate for each pixel is stored. On the other hand, for Wi, the corrected data D _O = DixFF _H / Wi should be obtained for the read value Di of the normal image of the “i” -th pixel. Therefore, in this embodiment, the latch 85'a
Gates 80'a, 86'a are opened for ',', ',' and the selectors 82'a, 83'a, 86'a output so that B is selected, and the RAM 78'a is accessed by the CPU. Make it possible. Then, CPU 22 is operation processing of FF _H / W _O to the head pixel W _O in the procedure shown in FIG. 6, W ₁ to calculation of FF / W _1, ...,
And sequentially replace the data. In this way St
When the processing for the blue component of the color component image indicated by epB is completed, the replacement of the green component shown in Step G and the replacement of the red component shown in the next Step R are sequentially performed in the same manner.
In this manner, the gate 80'a is opened by the signal and the gate 81'a is closed by the signal so that D _O = DixFF _H / Wi is output for the input original image data Di. And control to select A of the selectors 83'a and 86'a,
The coefficient data FF _H / Wi read from the RAM 78'a is the signal line 1
53a → 157a, original image data 151 input from one side
Multiplied by a and output. As described above, in the black correction / white correction circuit 107, the black level sensitivity of the image input system, the variation of the dark current of the CCD sensor 102, the variation of the sensitivity between the sensor chips of the CCD sensor 102, and the variation of the light amount of the optical system. The black level and the white level are corrected based on various factors such as the white level sensitivity and the like. As a result, image data B _out 121, G _out 122, and R _out 123 that are uniformly corrected for each color in white and black over the main scanning direction are obtained. Next, the R, G, and B 8-bit image data subjected to white correction and black correction are input to the luminance signal generation unit 108 and the color detection unit 109 in FIG. First, the luminance signal generator 108 will be described. The luminance signal generation unit 108 generates an image over the entire wavelength region that has not been color-separated, that is, a black-and-white image, from the image image data read and color-separated by the CCD sensor 102. This is because the printer as the output unit of this embodiment has only a single-color output unit. For this purpose, the luminance signal generation unit 108 of the present embodiment calculates the average value of the input R, G, and B data to calculate the luminance signal by the following equation. In this embodiment, this operation is performed using an adder and a multiplier. The calculated luminance signal is output to selector 116 described later. The input data to the luminance signal generation unit 108 is also input to the color detection unit 109 at the same time. The color detection unit 109 detects a color component on a document for performing image processing in the present embodiment. FIG. 7 shows the detailed configuration of the color detection unit 109. In the present embodiment, a hue signal is used for a color detection method in the color detection unit 109. This is to make it possible to make an accurate determination even in the case of the same color even when the chromaticness and brightness are different (exactly, the hue is different from the normally expressed hue, In the description, it is described as “hue”). First, an outline of the color detection method will be described. The input R, G, is the data data for each 8 bits of B, and a total of 2 ²⁴ colors information. For this reason, using such enormous information as it is becomes expensive in view of its circuit scale. In the present embodiment, the following processing is performed using the above-described hue in consideration of the following points. The input R, G, B data is first input to a max / mid / min detection unit 201 that determines the magnitude. This is done by comparing each input data using a comparator,
x value (maximum value), mid value (intermediate value), min value (minimum value) are obtained, and each value is output. Further, each output value of the comparator is simultaneously output as a rank signal. It is known that a color space is represented by saturation, lightness, and hue, as is known in a Munsell solid or the like. Then, first, it is necessary to convert each data of R, G, B into a plane, that is, two-dimensional data. In the present embodiment, the common part of R, G, and B, that is, min (R, G, and B), which is the minimum value of R, G, and B, is an achromatic component, and the min (R , G, B) for each R, G, B
The data is subtracted from the data, and the remaining information is used as a chromatic component. This achieves conversion of a three-dimensional input color space into a two-dimensional color space with a simple configuration. The plane converted in this way is divided into six from 0 ° to 360 ° as shown in FIG. 8, and the order of the sizes of the input R, G, B, ie, R>G> B , R>B> G, G>B>
R, G>R> B, B>G> R, and B>R> G. In the present embodiment, the output ma
In order to subtract the achromatic component from the x value and the mid value by the subtracters 202 and 203, the minimum value min is subtracted from the max value and the mid value, and the subtracted value is input to the hue detection unit 204 together with the rank signal. The hue detection unit 204 is desirably constituted by a random access memory element such as a RAM or a ROM. In this embodiment, the hue detection unit 204 is constituted by a look-up table using a ROM. The hue detection unit 204, which is a look-up table constituted by the ROM, previously stores a value corresponding to the angle of the plane shown in FIG.
The corresponding hue value is output based on the (x-min) value and the (mid-min) value. Accordingly, a simple LUT (lookup table) or the like is used based on the order of the sizes of the input R, G, and B, and the maximum and intermediate values of the input R, G, and B. With the configuration,
The three-dimensional input color space is converted into a two-dimensional color space, and a corresponding hue is obtained. The hue values output in this manner are then input to window comparators 205 and 206. This comparator 2
The CPU 22 sets the reference comparison values to 05 and 206. This reference value is obtained by data input means (not shown) or the like.
After inputting color data to be originally patterned and giving a desired offset to a hue data value corresponding to the color by the CPU 22, the data is set to a comparator. The comparator 205 sets the reference value When a _1, relative hue data inputted, outputs "1" when the (input hue data) <(a _1). Similarly the comparator 206, the set reference value and a _2, to color data input, and is configured such that the output "1" when the (input hue data)> (a _2). Therefore, when (a− ₁ ) <(input hue data) <(a ₂ ), “1” is output from the color detection unit 109 by the subsequent AND gate 208. In the above description, only one set of window comparators is used. However, if a plurality of sets of window comparators are used, it goes without saying that a plurality of colors are detected. The determination signal determined by the color detection unit 109 in this manner is input to the AND gate 110 and the selector 116 in FIG. The AND gate 110 performs a gate process on a pattern signal generated from a pattern generation unit 111 described later. The selector 116 receives a luminance signal from the luminance signal generator 108 and a margined min (R, G, B) signal, which will be described later, based on a detection result from the color detector 109.
Switching processing of both signals is performed. Next, the pattern generator 111 that outputs a pattern signal to the AND gate 110 and the address controller 112 that selects the output pattern of the pattern generator 111 will be described. FIG. 9 is a diagram showing a detailed configuration of the pattern generation unit 111 and the pattern address control unit 112. As shown in FIG. 9, the pattern generating section 111 is substantially constituted by a ROM in which dot data for pattern is stored. The pattern generation unit 111 of this embodiment stores “1”, “1” in the address corresponding to the upper and lower addresses as shown in FIG.
In this configuration, data “0” is written. These values correspond to ON / OFF of one picture element, respectively, and actual patterning is represented as shown in FIG. 10 (b). The address control unit 112 generates the address signal of the pattern generation unit 111 by the main scanning counter 701 and the sub-scanning counter 703 synchronized with the pixel clock VCLK and the scanning reference signal HSYNC as shown in FIG. FIG. 11 shows output timing charts of the reference signals, ie, the ITOP signal, the HSYNC signal, and the VCLK signal. In FIG. 11, the ITOP signal is a signal indicating an image destination,
While the image is being read by the scanner unit, the level is low. The main scanning counter 701 counts the VCLK signal in synchronization with the HSYNC signal. The sub-scanning counter 703 counts the HSYNC signal in synchronization with the ITOP signal. The addresses of the pattern generator 111 are generated by the two counters 701 and 703. According to the determination result from the color detection unit 109, the pattern signal that has been subjected to the gate processing by the AND gate 110 is then output to the multiplier 11
In step 3, the signal indicating the minimum value among the R, G, and B color-separated video signals read from the hue detection unit 109, that is, the video of the darkest signal min (R, G, B) Multiplication with the signal is performed. The reason why the signal of min (R, G, B) is used is that the signal generated by the luminance signal generation unit 108 has a different signal level depending on the color. This is because the level approaches white and the image data of the document is lost. The signal of min (R, G, B) is also input to the contour extraction unit 114, where the contour of a read image or the like is extracted.
This contour extraction processing can be performed by a generally known Laplacian filter. Contour extraction unit 114
Is sent to the adder 115, and the pattern min (R, G,
B) Added to the signal. That is, the contour signal extracted by the contour extraction unit 114 shown in FIG. 12 (a) and the patterned min (R, G, B) signal output from the multiplier 113 shown in FIG. 12 (b). Is added, and the min (R, R,
G, B) signal is obtained. The signal output from the adder 115 is input to the selector 116. As described above, the selector 116 switches and outputs either the luminance signal or the framed min (R, G, B) signal based on the detection result from the color detection unit 109. One of the signals selected by the selector 116 is input to a LOG conversion unit 117 that converts a luminance signal into a corresponding density signal, and is output after being converted into a corresponding density signal. As described above, according to this embodiment, by adding an outline signal to a patterned image signal, the original input image shown in FIG. A good reproduced image shown in FIG. 13 (b) can be obtained. Further, for a document which is difficult to see without a border as shown in FIG. 14 (a), a very easy-to-view reproduced image as shown in FIG. 14 (b) can be obtained by adding a contour signal. it can. As described above, in this embodiment, any original image can be reproduced without making the image difficult to view. As described above, according to the present embodiment, in the conventional image processing apparatus, the characteristic color (for example, yellow) of the original is determined by the sensitivity characteristic of the photosensitive member and the sensitivity characteristic of the light receiving element that reads an image in the digital copying apparatus. However, according to the present embodiment, it is possible to provide an inexpensive image processing apparatus which can reproduce a specific color and does not lose color information of a document. . The input signals are not R, G, B, but Y, I, Q, L ^* , a ^* , b
^It may be a signal such as ^* . For these signals,
This is convenient because the hue can be determined only with the I and Q components and the a ^* and b ^* components. Further, by providing a plurality of sets of window comparators in FIG. 7, a plurality of colors can be designated to pattern the color information, and the pattern may be changed according to the colors. Further, a laser beam printer, a thermal transfer printer, an ink jet printer, a dot printer, or the like can be used for the printer section.

【The invention's effect】

As described above, according to the present invention, signal processing means for obtaining one-component image data from color image data of a plurality of primary colors, and the image processing means for forming an image corresponding to the image data obtained by the signal processing means Since there is an output unit for outputting data to the monochromatic image recording unit, it is possible to form an image with a reduced device scale. The image data output to the monochrome image recording means is
Since this is the minimum value of the color image data of the primary colors of the plurality of components, the reproducibility of yellow or the like having poor reproducibility can be improved when an average value of the primary colors is used, for example.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment according to the present invention, FIG. 2 (a) is a detailed configuration diagram of a CCD sensor of this embodiment, FIG. 2 (b) is a CCD sensor driving timing chart of this embodiment, FIG. 3 (a) is a detailed configuration diagram of the CCD sensor drive pulse generation circuit of the present embodiment, FIG. 3 (b) is an operation timing chart of the CCD sensor drive pulse generation circuit of the embodiment, FIG. 4 (a) Fig. 4 (b) is a diagram showing the concept of black correction of this embodiment, Fig. 5 (a) is a white correction circuit diagram of this embodiment, Fig. 5 (b) ) Is a diagram showing the concept of white correction of this embodiment, FIG. 5C is a diagram showing data for a white plate of this embodiment, FIG. 6 is a diagram showing a procedure of white correction of this embodiment, FIG. FIG. 7 is a detailed block diagram of the color detector of this embodiment, FIG. 8 is a diagram showing a hue plane for explaining color recognition, and FIG. 9 is a pattern diagram of this embodiment. FIG. 10 (a) is a diagram showing the relationship between the address and data of the pattern generator, and FIG. 10 (b) is a diagram showing the generation pattern of the pattern generator. FIG. 11 is a timing chart of a reference control signal input to the address control unit, FIG. 12 (a) is a diagram showing a contour image, FIG. 12 (b) is a diagram showing a patterned image, FIG. FIG. 12 (c) shows the outline image of FIG. 12 (a) and FIG. 12 (b)
13 (a) shows an example of a framed image based on the patterned image of FIG. 13 (a). FIG. 13 (b) shows an example of a framed image. FIG. 14 (a) is a diagram showing an example of an image without borders, and FIG. 14 (b) is a diagram showing an example of an image when the input image of FIG. FIG. 4 is a diagram illustrating an example of an image when the input image of FIG. In the figure, 22 CPU CPU, 100 exposure lamp, 102 CCD sensor, 104 S / H circuit, 105 A / D conversion circuit, 106 misalignment correction circuit, 107 black correction / White correction circuit, 108: luminance signal generation unit, 109: color detection unit, 111: pattern generation unit, 112: address control unit, 114: contour extraction unit, 116
…… Selector, 117 …… LOG converter, 201 …… max / mid / min
Detecting unit, 204: Hue detecting unit, 205, 206: Comparator, 701: Main scanning counter, 703: Sub-scanning counter.

Continuation of the front page (56) References JP-A-61-157074 (JP, A) JP-A-2-54283 (JP, A) JP-A-2-122768 (JP, A) JP-A-1-234889 (JP) , A) JP-A-63-24291 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 2/525 H04N 1/40 H04N 1/46

Claims (2)

(57) [Claims] An input unit for inputting color image data of primary colors of a plurality of color components; a signal processing unit for obtaining one-component image data from the input color image data of primary colors of the plurality of color components; Output means for outputting the image data to a single-color image recording means in order to form an image corresponding to the image data obtained by the means, wherein the one-component image data obtained by the signal processing means is converted into the color of the plurality of primary colors. An image processing apparatus, wherein a minimum value of image data is set. 2. The image processing apparatus according to claim 1, further comprising detecting means for detecting a specific hue from the color image data of the primary colors of the plurality of components, wherein the output means includes a peripheral part of the specific hue detected by the detecting means in the image data. 2. The image processing apparatus according to claim 1, wherein the image is output to the single-color image recording unit after performing a border.