JP2815962B2 - Image processing apparatus and image processing method - Google Patents

Description

The present invention relates to an image processing apparatus and an image processing method,
For example, the present invention relates to an image processing apparatus and an image processing method such as an image scanner, a printer, a digital copying machine, and a facsimile machine.

[Prior Art] Conventionally, for example, in a digital copying machine, a document is irradiated with a light source such as a halogen lamp, and reflected light from the document is subjected to CCD.
After performing photoelectric exchange using a solid-state imaging device such as a (charge-coupled device), the signal is converted into a digital signal, a predetermined correction process is performed, and a laser beam printer, a liquid crystal printer, a therm printer, an ink jet printer, etc. The recording image is formed by using the recording apparatus of (1).

Also, in such digital copying machines, the output of a large amount of information has been demanded along with the colorization of originals to be copied, and in recent years, a plurality of color developing units have been provided to partially change colors. A copying apparatus using a multi-color laser beam printer for performing copying is developed.

[Problems to be Solved by the Invention] However, the above-described copying apparatus which includes a plurality of color developing devices and partially changes the color to form an image has many developing devices. For this reason, the mechanism becomes complicated, and an image with high positional accuracy is required, so that it is expensive. This has a similar problem in a copying apparatus using a multicolor ink jet printer or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image processing apparatus capable of outputting a color and a density of a color image in a form that can be distinguished by a user without requiring a full-color image forming unit. And a method.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a first discriminating unit for discriminating a color of an input color image, and a discriminating result by the first discriminating unit. First generating means for generating a first signal representing a graphic pattern, second determining means for determining the density of the input color image, and a second signal corresponding to the density determined by the second determining means A first signal generated by the first generator and a second signal generated by the second generator.
An image comprising: synthesizing means for synthesizing signals to generate a graphic pattern signal representing the color and density of an input color image; and output means for outputting a graphic pattern signal synthesized by the synthesizing means. A processing device is provided.

In order to achieve the above object, the present invention further comprises a step of determining a color of an input color image, a step of generating a first signal representing a graphic pattern according to a result of the color determination, Determining a density of the input color image, generating a second signal corresponding to the determined density, and combining the first signal and the second signal to generate a graphic pattern signal representing the color and density of the input color image And outputting the generated graphic pattern signal.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of the overall circuit configuration of an image processing apparatus of a digital copying apparatus to which the present invention is applied. In FIG. 1, reference numeral 101 denotes an image sensor of an image pickup unit that converts a color original image formed through an optical system such as a rod lens into G (green), B (blue), and R (red) electric signals. It is a CCD (charge coupled device) as a color reading sensor and has a color separation filter. 102 is an amplifier circuit for amplifying the output signal of the CCD 101, 103 is a coaxial cable, 104
Is a sample-and-hold (S / H) circuit that samples and holds (S / H) the color image signal output from the amplifier circuit 102 via the coaxial cable 103 and separates the color image signal into three colors of G, B, and R. 1
05 is an analog / digital (A / D) conversion circuit for converting an analog color image signal sampled and held by the sample and hold circuit 104 into a digital color image signal, and 106 is a CC
A shift correction circuit 107 for electrically correcting the reading position shift between the channels of D101, and a black correction / white correction circuit 107 for performing black level correction and white level correction (shading correction) to be described later on the digital image signal. is there.

Reference numeral 108 denotes a luminance signal generation unit that generates a luminance signal from a digital color image signal that has undergone black correction and white correction.
A color discrimination circuit 109 performs color discrimination for each pixel of the digital color image after black correction and white correction, and outputs a color discrimination signal corresponding to the color difference signals I and Q in this example. 110 is RA
This is a pattern generation circuit composed of an M or ROM storage device, and generates a predetermined figure pattern corresponding to the color of each pixel based on the color determination result (I, Q signals) of the color determination circuit 109. In this example, the pattern generation circuit 110 reads and outputs one of the figure patterns stored in advance as a read address using a color determination signal corresponding to the level of the color difference signals I and Q.

Reference numeral 111 denotes a pattern synthesizing circuit for synthesizing the luminance signal generated by the luminance signal generating unit 108 and the graphic pattern generated by the pattern generating circuit 110. Reference numeral 112 denotes a log conversion unit that converts an output signal of the pattern synthesis circuit 111 into a density signal and outputs the density signal to various connected printers. The portion A surrounded by a chain line in FIG. 1 corresponds to a video image processing circuit of an image reading device (image scanner).

The image copying apparatus of this example exposes a full-color original with an illumination source such as a halogen lamp or a fluorescent lamp (not shown), captures a reflected color image with a color image sensor such as a CCD, and converts the obtained analog image signal into an analog image signal. This is a device that digitizes with a / D converter or the like, processes and processes the digitized full-color image signal, and outputs it to a thermal transfer printer, ink jet printer, laser beam printer, etc. (not shown) to obtain an image. The details are as described below.

Color reading sensor The original is first irradiated by an exposure lamp (not shown),
The reflected light is color-separated for each image by the color reading sensor 101 and read, and is amplified to a predetermined level by the amplifier circuit 102. Here, the driving of the CCD 101 is generated by a system pulse generator (not shown).

FIG. 2 shows a color reading sensor and a driving pulse. FIG. 2 (A) shows a color reading sensor used in this example. This sensor uses 63.5 μm as one pixel (400 dots / inch (hereinafter referred to as dpi)) in order to divide the main scanning direction into five parts for reading. Since 1024 pixels, that is, one pixel is divided into three in the main scanning direction by G, B, and R as shown in FIG.
The number of effective pixels is 024 × 3 = 3072. On the other hand, the chips 58 to 62 of this sensor are formed on the same ceramic substrate, and the first, third and fifth sensors (58a, 60a, 62a) are on the same line LA.
Above, the 2nd and 4th are 4 lines of LA (63.5 μm × 4 = 254
.mu.m), and scans in the direction of arrow AL when reading a document.

Of the five CCDs, the first, third, and fifth drive pulse groups are ODRV11
In 8a, the second and fourth are driven independently and synchronously by the drive pulse group EDRV 119a. Drive pulse group ODRV11
Pulse signal O01A, O02A, ORS and drive pulse group E included in 8a
The pulse signals E01A, E02A, and ERS included in the DRV119A are a charge transfer clock and a charge reset pulse in each sensor, respectively. Generated completely synchronously so as not to have jitter. Therefore, these pulses are generated from one reference oscillation source OSC (not shown).

FIG. 3A shows the drive pulse groups ODRV118a and EDRV119 described above.
FIG. 3 (B) shows a circuit block for generating a, and FIG. This circuit block is included in a system control pulse generator (not shown). A clock KO135a obtained by dividing the source clock CLKO generated from a single reference oscillation source OSC is used as a reference signal SYNC2, which determines the generation timing of the sensor drive pulse ODRV and the sensor drive pulse EDRV.
This is a clock for generating SYNC3. These reference signals SYN
The output timing of C2 and SYNC3 is determined according to the set values of the presettable counters 64a and 65a set by the signal line 22 connected to the CPU bus. Also, the reference signals SYNC2 and SYNC
3 initializes the frequency dividers 66a and 67a and the drive pulse generators 68a and 69a.

That is, the reference signals SYNC2 and SYNC3 are generated based on the horizontal period signal HSYNC118 input to the block and by the source clock CLKO output from one oscillation source OSC558a and the divided clocks all generated in synchronization. Therefore, the respective pulse groups of the ODRV 118a and the EDRV 119a are obtained as synchronized signals without any jitter, 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, amplified to a predetermined voltage value by independent amplifier circuits 501-1 to 501-5 for each channel shown in FIG. 1, and passed through a coaxial cable 101a as shown in FIG.
V1, V3, V5 signals are sent out at the timing of OOS129a,
At timing 134a, V2 and V4 signals are sent out and input to the video image processing circuit.

Sample Hold Circuit A color image signal obtained by reading the original input to the video image processing circuit by dividing it into five parts is G (green), B (blue), and R in the sample / hold circuit S / H104.
(Red). Therefore, after S / H, signal processing of 3 × 5 = 15 systems is performed.

A / D conversion circuit The analog color image signal sampled and held for each color R, G, B by the S / H circuit 104 is converted to the next-stage A / D conversion circuit 105.
Is digitized every 1 to 5 channels, and each 1 to 5
It is output to the next stage in parallel for each channel independently.

Shift Correction Circuit In this embodiment, as described above, four lines (63.5
(μm × 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. In positions 1, 3, and 5, the reading position is shifted. Therefore, in order to correctly connect the shifts, the shift correction is performed by a shift correction circuit 106 having memories for a plurality of lines.

Black Correction / White Correction Circuit Next, a black correction operation in the black correction / white correction circuit 107 will be described with reference to FIG.

As shown in FIG. 4 (B), the black level outputs of channels 1 to 5 have large variations between chips and pixels when the amount of light input to the sensor is small. If this is output as it is and an image is output, streaks (streaks) and unevenness (spots) occur in the data portion of the image.

Therefore, it is necessary to correct the output variation of the black portion, and the variation correction is performed by a black correction circuit as 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 a non-image area at the front end of the original platen, turning on the halogen,
A black level image signal is input to this circuit.

Regarding the blue signal B _IN , the selector 82a controls the A signal to store one line of the image data in the black level RAM 78a.
Select (), close () gate 81 a, and open 81 a. That is, the data line is connected from 151a to 152a to 153a, while the address input 155a of the RAM 78a is initialized by ▲ ▼, and the output to the selector 83a is input so that the output 154a of the address counter 84a for counting VCLK is input. Then, a black level signal for one line is stored in the RAM 78a (hereinafter referred to as a black reference value capturing 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 via the data line 153a → 157a. That is, at this time, the gate 81a closes () and the gate 80a opens (). The selector 86a has an A output. Therefore, the black correction circuit output 156a is, for example, B _IN (i) -DK (i) in the case of a blue signal with respect to the black level data DK (i).
= B _OUT (i) (hereinafter referred to as black correction mode).

Similarly, green G _IN and red R _IN are similarly controlled by 77aG and 77aR. The control lines of each selector gate for this control are controlled by a latch 85a assigned as an I / O of a CPU (not shown).
It is performed by control. The RAM 78a can be accessed by the CPU by selecting the selectors 82a, 83a, and 86a with B.

Next, white level correction (shooting correction) in the black correction / white correction circuit 107 will be described with reference to FIG.
White level correction is based on white data when the document scanning unit is moved to the position of a uniform white plate and illuminated.
The sensitivity variation of the optical system and the sensor is corrected. FIG. 5A shows a basic circuit configuration. The basic circuit configuration is the same as that in FIG. 4A, 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 101 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 exposure lamp (not shown) is turned on, and the image data of the uniform white level is output. The data is stored in the correction RAM 78'a for one line. For example, if it has a width in the longitudinal direction of A4 in the main scanning direction, 16pe1 / mm
16 × 297 mm = 4752 pixels, that is, at least the capacity of the RAM is 4752 bytes, and as shown in FIG. 5B, if the white plate data Wi (i = 1 to 4752) of the i-th pixel is RAM7,
As shown in FIG. 5 (C), 8 'stores data for a white plate for each pixel.

On the other hand, for Wi, the data Do corrected to the read value Di of the normal image of the i-th pixel should be Do = Di × FF _H / Wi.

Therefore, the latches 85'a ',', ','
The gates 80'a and 81'a are opened, and the selector 82 '
Output so that B is selected at a, 83'a, 86'a,
The RAM 78'a is made accessible to the CPU.

Next, in accordance with the procedure shown in FIG. 5 (D), the CPU sequentially performs FF _H / Wo for the _first pixel Wo, FF / W ₁ . When the processing is completed for the blue component of the color component image (Step B in FIG. 5D), the green component (Step
G) and red (Step R) in that order. Thereafter, the gate 80'a is opened (') and the gate 81 is opened so that Do = Di × FF _H / Wi is output for the input original image data Di. 'A is closed (') and A is selected by the selectors 83'a and 86'a, whereby the coefficient data FF _H / Wi read from the RAM 78'a passes through the signal line 153a → 157a and is input from one side. Multiplication with the obtained original image data 151a is performed and output.

As described above, the black level and white level are corrected based on various factors such as the black level sensitivity of the image input system, the dark current variation of the CCD, the sensitivity variation between each sensor, the variation of the optical system light amount, and the white level sensitivity. Over the scanning direction,
Image data B _OUT uniformly corrected for each color for both white and black
121, G _OUT 122 and R _OUT 123 are obtained.

Luminance signal generator Black- and white-corrected image data R _OUT 121, G _OUT 122,
The B _OUT 123 is input to the luminance signal generation unit 108 and the color determination circuit 109.

The luminance signal generation unit 108 averages the filter images read by the sensor 101 to create an ND image. FIG. 6 is for explaining the above operation. First, the input image data R _OUT 121, G _OUT 122, and B _OUT 123 are added by the adder 201, respectively. Then, divider 2
It is output after division by 1/3 in 02.

Next, the color determination circuit 109 will be described. In this embodiment, the color difference signals I and Q of the NTSC system used in televisions and the like are used to determine the color. These signals I and Q are generally obtained by the following equations.

I = 0.60R-0.28G-0.32B Q = 0.21R-0.52G + 0.31B The calculation of the above equation is performed by the IQ generation unit 701 shown in the circuit configuration of the color determination circuit 109 in FIG. Here, the I signal becomes red when it increases in the negative direction, achromatic near O, and blue-green when it increases in the positive direction. The Q signal becomes yellow-green when it increases in the negative direction, achromatic near O, and purple when it increases in the positive direction.

Next, the IQ signal obtained by the IQ generation unit 701 is input to a look-up table (LUT) ROM 702 at a subsequent stage. LUT
The ROM 702 divides the color plane represented by the IQ signal, writes the coded data in advance as data, and outputs a code signal corresponding to the input I and Q signals to the pattern generation circuit 110 as a color determination signal. I do.

Pattern Generation Circuit The pattern generation circuit 110 will be described with reference to FIG. In the pattern ROM 803, for example, dot patterns corresponding to each color as shown in FIG. 9 are written in advance. Each figure pattern has 16 × 16 dots as one pattern. The pattern ROM 803 performs pattern generation processing by repeatedly outputting this pattern in the main scanning direction and the sub-scanning direction in response to the color determination signal. The main scanning counter 802 operates by counting the video clock CLK in synchronization with the horizontal synchronization signal HSYNC, and the sub-scanning counter 801 operates by counting the horizontal synchronization signal HSYNC in synchronization with the ITOP signal.

The outputs of the counters 801 and 802 are each 4 bits, and the color determination signal is 5 bits, and a total of 13 bits are input as addresses of the pattern ROM 803. In other words, the configuration is such that 32 types of 16 dot × 16 dot patterns can be generated for the read color (type).

The output from the pattern ROM 803 has a data length of 8 bits, of which the MSB (most significant bit) is used as a control signal (HIT signal) in the pattern synthesis unit 111 described later. In the ROM 803, data is written so that the value is normally zero and the MSB is always 1 when a pattern is generated.

As a matter of course, the pattern ROM 803 may be a RAM or the like. Even when a RAM or the like is used, the capacity and the bit assignment of the address are the same as those of the ROM.

Pattern Synthesizing Unit Next, the pattern synthesizing unit 111 will be described with reference to FIG. The multiplier 902 multiplies the brightness signal input from the above-described brightness signal generator 108 by the value set in the register 901 by the CPU. That is, the CPU can control the density so that the density of the image data to which the pattern is added becomes lighter than the actual one as shown in FIG. The register 901 is composed of 8 bits.
That is, the multiplier 902 sets 0
Multiplication processing is performed with coefficients of / 128 to 255/128.

The luminance signal obtained by multiplying the through luminance signal and the above-described coefficient is input to the selector 903, switched by the HIT signal, and output. That is, at this time, when the HIT signal is HIT, the output from the multiplier 902 input to A of the selector 903 is selected. When the HIT signal is not HIT, the brightness of the through input input to B of the selector 903 is selected. It is controlled so that the signal is selected.

The signal selected by the selector 903 is then subjected to addition processing by an adder 904 to add a pattern signal from the pattern generation circuit 110.

Log conversion unit The image data that has been subjected to the addition processing is then converted into a density signal by the Log conversion unit 112 in FIG. 1 in order to perform luminance-density conversion.
In the Log conversion unit 112, a lookup table using a ROM is used. The signal converted to the density signal by the log conversion unit 112 is output to a single-color printer unit (for example, a laser beam printer) on which an image is to be formed.

FIG. 11 (A) shows an example of an original document read by the color reading sensor 101 in the above-described embodiment of the present invention, and FIG. 11 (B) reads the original document and performs the above-described image processing. Shows an example of the result output by the printer unit. The relationship between the color and the pattern uses the example shown in FIG.

FIGS. 12 (A) to 12 (D) show the operation of the above-mentioned embodiment of the present invention in an easy-to-understand manner. That is, in a copying apparatus using a monochromatic monochrome printer, for example, a normal white / black printer, a red original document as shown in FIG. However, according to the operation designation of the embodiment of the present invention, as shown in FIGS. 3C and 3D, a light gray pattern and a red pattern are combined. Since the image data is recorded and output, the color of the original document can be easily determined from the recorded graphic pattern even in monochrome printing.

[Effects of the Invention] As described above, according to the present invention, the color of an input color image is determined, a first signal representing a graphic pattern is generated according to the determination result, and the density of the input color image is determined. And generates a second signal corresponding to the determined density,
Since the first signal and the second signal are combined to output a graphic pattern signal representing the color and density of the input color image, the color and density of the input color image can be determined without using a full-color recording means. It is possible to output an image in such a form that the user can determine whether or not it is as expected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall circuit configuration of an image processing apparatus in a digital copying apparatus according to one embodiment of the present invention. FIGS. 2 (A) and 2 (B) show the color reading sensor and driving pulse shown in FIG. 3 (A) and 3 (B) show the sensor drive pulse ODRV shown in FIG.
CCD drive pulse generator and CCD to generate 118a and EDRV119a
4 (A) and 4 (B) are a block diagram and a conceptual diagram showing details of the black correction circuit of FIG. 1 and its black correction operation, and FIGS. (B), (C) and (D) show details of the white correction circuit of FIG. 1, the concept of white correction, data for a white plate, and a block diagram, a conceptual diagram, a format diagram, FIG. 6 is a conceptual diagram showing the operation of the luminance signal generating section of FIG. 1, FIG. 7 is a block diagram showing the circuit configuration of the color discriminating circuit of FIG. 1, and FIG. 8 is the pattern of FIG. FIG. 9 is a block diagram showing a circuit configuration of the generation circuit, FIG. 9 is a diagram showing an example of color-pattern correspondence generated by the pattern generation circuit of FIG. 8, and FIG. 10 is a circuit configuration of the pattern synthesis circuit of FIG. FIG. 11 (A) and FIG. 11 (B) show color-coded images according to the embodiment of the present invention. 12 (A), 12 (B), 12 (C) and 12 (D) are explanatory views showing the difference between the normal processing operation and the pattern output processing operation of the present embodiment. . 101: CCD, 102: amplifying circuit, 104: sample-and-hold circuit, 105: A / D converter circuit, 108: luminance signal generator, 109: color discriminating circuit, 110: pattern generating circuit, 111 …… Pattern synthesis circuit.

Claims (2)

(57) [Claims] A first determination unit configured to determine a color of an input color image; a first generation unit configured to generate a first signal representing a graphic pattern according to a determination result by the first determination unit; A second determining unit that determines the density of the input color image; and a second determining unit that determines the density according to the density determined by the second determining unit.
Second generating means for generating a signal; combining the first signal generated by the first generating means with the second signal generated by the second generating means to obtain the color and density of the input color image An image processing apparatus comprising: synthesizing means for generating a graphic pattern signal representing the following; and output means for outputting a graphic pattern signal synthesized by the synthesizing means. A step of determining a color of the input color image; a step of generating a first signal representing a graphic pattern according to a result of the color determination; a step of determining the density of the input color image; Generating a second signal according to the determined density; generating a graphic pattern signal representing the color and density of the input color image by combining the first signal and the second signal; and generating the generated graphic. Outputting a pattern signal; and an image processing method.