JP3297466B2 - Image processing apparatus and image processing method - Google Patents

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 and an image processing method.
Regarding the processing method .

[0002]

2. Description of the Related Art Conventionally, for example, in a black-and-white copying machine, it has been difficult to sufficiently reflect information of a document on an output image for a color document. Therefore, in order to respond to the demand for reflecting the information of the color original in the output image without losing the information in recent years, an expression method and a method of recognizing the color of the original and expressing the difference in the color by a pattern and outputting the pattern are used. Black and white copiers have been proposed.

[0003]

In order to express a difference in original color by a difference in pattern, a method of setting a fixed pattern for a fixed color in advance and a method of recognizing the color of the original prior to image formation are described. For example, there is a method in which a scan is performed to determine the color of the document, and at the time of image forming scan, the image is converted into a different pattern for each color of the document based on the recognized color information and output.

However, when performing pre-scan,
Since conversion into a pattern is performed using color information from a document, highly accurate color recognition is possible, but there is a problem that it takes time to perform prescan. Further, when the color pattern is converted into a color pattern without performing the pre-scan, the color of the document is converted into a fixed pattern regardless of the color of the document.

[0005]

According to the present invention, there is provided an image forming apparatus comprising: an input unit for inputting a color image;
Included in the first color recognition area for the input color image
A first image editing process is performed on the color to be
Color included in the color recognition area of the second color adjacent to the recognition area
Is an image processing means for performing a second image editing process,
According to a manual instruction, the first color recognition area and the
Adjusting means for adjusting a boundary with the second color recognition area;
The first color recognition area and the front
The area range of the second color recognition area is adjusted.
And an image processing method .

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 7 is a block diagram of the image processing apparatus according to the present embodiment.

In this embodiment, a CCD image sensor 70 reflects reflected light from a document exposed by an exposure lamp (not shown).
This exposure lamp is constructed so as to be movable in a direction perpendicular to the longitudinal direction of the exposure lamp so as to expose the entire surface of the original. Based on a thermal printer, not shown
The image is formed by a thermal transfer printer, an injection printer, a laser beam printer, or the like.

Next, a description will be given along the flow of image information of a document.

<Reading Optical System> First, reflected light from a document irradiated by an exposure lamp (not shown) is read by a CCD image sensor 701, photoelectrically converted,
The image signal output from the D image sensor 701 is amplified to a predetermined level by the amplifier circuit 703. Where CCD
The image sensor 701 is driven by a CCD driver 702.

In this embodiment, in order to read a color image of a document, light is emitted in red before the CCD image sensor 701.
A diffraction grating for decomposing into green and blue color components is arranged.
The CD image sensor 701 is configured to read each of the color-separated reflected lights. The means for color separation may be a dichroic mirror, a prism, an optical filter, or the like.

That is, the color image signal photoelectrically converted by the CCD image sensor 701 is supplied to the amplifier 70 for each color.
At 3, the signal is independently amplified to a predetermined voltage value. The amplification level of the amplifier for each color is given as a voltage level to each amplifier by a CPU (not shown).

Each color image signal amplified to a predetermined level is
A predetermined signal level is sampled and held in a sample and hold circuit (S / H) 704. The sampled and held analog color image signal is supplied to an A / D converter 705.
Is converted from an analog signal to a digital signal and input to the black correction / white correction circuit 706.

<Black Correction> When the light input to the sensor is very small, the output level in the dark portion becomes larger than the original value due to variations between pixels and flares. Therefore, if the image is read as it is, the whole image will be read brightly. When the exposure lamp is turned on with nothing on the platen,
The output level from the D image sensor 701 is offset adjusted so that the average value from the A / D converter 705 becomes about 04H. In addition, when the exposure lamp is turned on, the dark output level from the CCD image sensor 701 when the exposure lamp is turned off and the original is not used.
The sum of the output levels from the image sensor 701 is obtained, and the sum of the output levels is subtracted from the image signal at the time of exposure.

<White Correction> Next, based on white level correction (shading correction) and white data on the target irradiated by moving the original scanning unit to a uniform white plate position, sensitivity variations of the certification system, the optical system, and the sensor. Is corrected.

<Luminance Signal Generation Unit> The video signals of the respective colors subjected to the white correction and the black correction are input to a luminance signal generation unit 707 for generating monochromatic image data. The luminance signal generation unit 707 will be described with reference to FIG.

R _IN 801, G _IN 802, B _IN
Each of the image signals 803 is input to the adder 804, and the addition of each color data is performed. The data added by the adder 804 is then reduced by a divider 805 to 1/3. That is, the following calculation is performed. D _out = 1/3 (R _IN + G _IN + B _IN )

In the present embodiment, no weight is assigned to each color, but it is also possible to assign weights as needed.

<Smoothing> Next, the smoothing unit 708 will be described. The smoothing unit 708 and the majority decision unit 710 are processes for preventing erroneous determination that occurs in printed matter such as halftone dots when performing color recognition processing. The operation of the smoothing circuit will be described with reference to FIG. 9 taking the R (red) signal as an example.

The input R signal is transmitted to a Fifo memory 90.
At 0 and 901, each line is delayed by one line. The output signals 907 and 908 from each Fifo memory and the signal 906 before being delayed are added by an adder 902. After the added output signal is delayed by a predetermined number of pixels in the flip-flop group 903, the output signal from each flip-flop is added by the adder 904, then divided by the divider 905 and output. As a result, a 3 × 5 pixel area is smoothed and output. Similarly, the G signal and the B signal are also subjected to a smoothing process of 15 pixels and output.

<Color Determination Processing Unit> The output from the smoothing unit 708 is input to a color determination processing unit 709. The color determination processing unit 709 is a block for detecting a preset color from input image information. In the color determination process in the present embodiment, the determination is made by detecting the hue of the color. The configuration of the color determination processing unit 709 will be described with reference to FIG.

The input color signals are supplied to a maximum / minimum value detection unit 1001 and three comparators 1000a and 1000a.
00b and 1000c. Comparator 100
0a indicates R _IN and G _IN signals, and 1000b indicates G _IN and B signals.
_The B _IN and R _IN signals are input to the _IN signal and 1000c, respectively. The judgment results of the comparators 1000a to 1000c are input to the maximum value minimum value detection unit 1001 and the upper address of the hue ROM 1006. Here, the maximum value / minimum value detection unit 1001 is composed of a decoder and a selector, and the comparator 1000
a, 1000b, and 1000c are decoded, and the selector selects a maximum value, an intermediate value, and a minimum value. The output minimum value is then subtracted by the subtractor 10
02, 1003. Each subtractor has
The maximum value and a value between the maximum value and the minimum value are input, and the minimum value is subtracted from each value. This is subtracted because MIN (R _IN , G _IN , B _IN ) is an achromatic component and is not necessary for color determination. MAX-MIN, MIN-MIN,
The output of the comparator indicating the magnitude relationship between the signals R, G, and B is input to an address input unit of a hue ROM 1006 constituted by a ROM.

FIG. 11 shows the correspondence between the magnitudes of the input signals R, G, and B and the outputs of the comparators 1000a to 1000c.
(A). FIG. 11B shows a hue plane. The hue angle θ on the hue plane can be obtained by the following equation. θ = arctan {(MID-MIN) / (MAX-MIN)} / π

The calculation result MID is stored in the hue ROM 1006.
-MIN, MAX-MIN and comparator 1000a
Are stored in advance.
Note that the hue ROM 1006 stores two 360 ° hue planes.
The hue values from 0 to 239 divided by 40 are stored, and when the MID-MIN, MAX-MIN and the outputs of the comparators 1000a to 1000c are input as addresses,
The hue value corresponding to the address is output.

The hue value output from the hue ROM 1006 is input to the window comparator 1004. The window comparator 1004 determines whether or not the input hue value is within a predetermined range to determine whether the color is to be detected. Window comparator 1
Circuits 012 to 1017 detect similar colors with the same circuit as the window comparator 1004. That is, seven predetermined colors can be detected by the window comparators 1004, 1012 to 1017. When it is desired to increase the number of detected colors, the number of window comparators may be increased.

The window comparator 1004 has comparators 1004b and 1004c, and is connected to registers 1004a and 1004d, respectively. In the registers 1004a and 1004d, a lower limit value and an upper limit value of the hue value to be detected are set by a CPU (not shown). Fine adjustment of the recognition color is realized by changing a set value of a latch for setting each threshold value of the window comparators 1004, 1012 to 1017 by a CPU (not shown). The outputs of these window comparators pass through an AND gate 1004e to output a hit signal. After an output signal from each window comparator is encoded into a 3-bit signal by the encoder 1005, the signal is controlled by an achromatic / chromatic signal by an AND gate 1010, and is output as a color determination signal when the signal is chromatic.

The achromatic / chromatic signal is a signal for determining whether the image data (pixel data) is an achromatic signal, that is, a gray signal without a tint, or a chromatic color, that is, a signal having a tint. Is a signal used for not performing patterning on the signal. This signal is based on the maximum value MAX and the minimum value MI.
CPU (not shown) outputs an output value from subtracter 1002 with N
The threshold value is set by using a value preset in the register 1008 as a threshold value and the comparator 1009 compares the magnitudes of the threshold values. The comparator 1009 outputs 0 as an achromatic color signal and 1 as a chromatic color signal as an achromatic / chromatic signal.

<Majority Decision Circuit> Next, the majority decision circuit 710 will be described.

The coded color judgment signal is input to a majority decision circuit 710. The majority circuit 710 eliminates erroneous determinations, such as erroneous determinations that occur in halftone-printed originals and the like, and erroneous determinations such as isolated points, by performing majority voting on 3 × 5 pixels, that is, 15 peripheral pixels.

Details of the majority circuit 710 are shown in FIGS.
And its operation will be described.

The encoded color judgment signal is sent to a decoder 1202a and a FIFO (first-in first-out) memory 1201a, 1201b.
After the delay of the line portion and the delay of the two line portions, the colors of the pixels input to the decoders 1202b and 1202c are distributed to 0 to 7 and the total is calculated for each color code. Decoded 0 is used as the total arithmetic unit 1
200a, 1 are inputted to 1200b, and 7 is inputted to 1200h in order. Since the internal circuits are the same for the total calculation units 1200a to 1200h, only the total calculation unit 1200a will be described. The decoders 1202a to 1202c are configured to output 0 when the bit of the input code value is 1 and other bits. Each decoder 1
The signals decoded to 0 in 202a to 1202c are input to the total operation unit 1200a,
After one clock delay in 03, the adder 1204 performs an addition operation for three pixels. The output from the adder 1204 is delayed by one to four clocks by a flip-flop 1205. That is, the sum of three lines in the sub-scanning direction is calculated and delayed by the flip-flop 1205 in the main scanning direction to form a matrix of 3 lines × 5 pixels. Output signals from the flip-flops 1203 and 1205 are added to adders 1206a, 1206b and 1207.
And the sum is calculated. 4bi calculated
t of the output signals 1208a to 1208h, that is, 3 × 5
The total sum of each code signal existing in a total of 15 pixels is shown. Sum code 1208a to 1208h for each color
Is then input to the comparator shown in FIG. The configuration of the comparators 1301 to 1304 is composed of three comparators, a selector, and a gate circuit that encodes a comparator output, similarly to the configuration of the large / medium / small determination unit of the color recognition circuit shown in FIG. The maximum value of the signal is output. Detailed description of the comparators 1301 to 1304 is omitted.
The maximum value of the input 1208a to 1208c is output from the comparator 1301 and input to the comparator 1304. Similarly, the maximum value of the input signals 1208d to 1208f is determined by the comparator 1302 from the input signal 1208d.
The maximum values of g and 1208h are output from the comparator 1303 and input to the comparator 1304. The signal of the maximum value among them is output from the comparator 1304. The input signals 1208d to 1208h and the color code signals 1305a to 1305h corresponding to the respective signals are also input to the comparators 1301 to 1303, respectively. A total of 7 bits of the color code signal 3 bits are output. That is, the maximum sum value and the color code thereof are output from the comparator 1304.

The 7 bits of the majority signal are combined with 1 bit of the achromatic / chromatic signal to become an 8 bit signal, which is input to the B input of the selector 1305. The selector 1305 is for reading the hue signal of the original at the time of pre-scanning by the CPU using the RAM at the subsequent stage, and the A input of the selector 1305 has the hue R of FIG.
A hue signal 1007 output from the OM 1006 is input, and is controlled by a control signal from a port (not shown). This control signal is configured such that the A input is selected by Lo at the time of prescan and the B input is selected by Hi at the time of normal scan. The description of the operation in the prescan mode is omitted here.

<Decoration Circuit> FIG. 14 is a detailed diagram of the decoration circuit 711. The video signal from the luminance signal generation unit 707 is input to B of the selector unit 1402. Reference numeral 1401 denotes a color density generation unit, which is configured to generate predetermined multi-value fixed data according to a color determination signal. Another one
Reference numeral 427 denotes a color density conversion selector signal, which is output when a color determination signal is generated and color density conversion is set.
When the PU is set to "1" and no color determination signal is generated (for an achromatic color or the like), a CPU (not shown) is set to "0". That is, when a color determination signal is generated, a fixed density corresponding to the color determination signal is output instead of normal image information (luminance signal).

Reference numeral 1429 denotes a binary pattern signal,
431 is a color patterning select signal. The color patterning select signal is configured such that when a color code is generated and color patterning is set, the CPU sets the signal to "1" and the selector 1411 selects the A input.

Reference numeral 1404 denotes an information part fixing degree generator for the "1" portion of the binary pattern, which generates an arbitrary fixed density set by a CPU (not shown) according to a color determination signal.

Reference numeral 1405 denotes a background fixed density generation unit for the portion of "0" in the binary pattern, which generates an arbitrary fixed density. That is, multivalued pattern information is output from the 1406 selector according to the 1429 pattern signal.

Reference numeral 1407 denotes a two-input AND circuit. When the pattern signal 1429 becomes active (when the information part of the pattern is "1"), normal image information (output of the AND circuit 1403) flows, and In the background portion “0”, the image information is configured to be “0”, that is, white (00H) in the density image. That is, the image information output from the AND circuit 1407 is an image output in which the density information of the document image is added to the pattern.

Reference numeral 1408 denotes a two-input OR circuit. When the pattern signal 1429 becomes active (when the information part of the pattern is "1"), all outputs are High.
("1") and outputs black (FFH) as a density image. When the pattern signal is inactive (the background portion of the pattern), normal image information (output of the AND circuit 1403) flows. That is, the image information output from the OR circuit 1408 is obtained by superposing the density information of the document image on the background of the pattern.

Reference numeral 1409 denotes a three-input selector, which selects A, B, and C according to a select signal 1430. That is, the patterning mode of the color pattern is selected by the select signal 1430. This select signal 1
Reference numeral 430 denotes a signal from the CPU bus, which is generated from the operation unit based on the mode setting by the operator.

Blocks 4111 to 412
Reference numeral 6 denotes a circuit for performing a white contouring process, a flat shadowing process, a three-dimensional shadowing process, and a negative / positive reversal process, which are not related to the present invention, and thus the description thereof is omitted.

<Density conversion / gradation correction>
The gradation correction unit 712 will be described.

Here, gradation conversion processing for correcting the gradation of the density conversion and the output device is performed using an LUT (look-up table). First, a luminance signal read as density conversion processing is converted into a density signal, which is generally called log conversion. The log conversion table is
It is calculated from the following equation. D _OUT = −255 / D _MAX * LOG (D _IN / 255)

Next, the gradation correction table will be described.

The gradation correction table is for correcting the gradation characteristics of the output device. For example, the gradation characteristics of an electrophotographic printer are shown in FIG. FIG. 15B shows the characteristics of the correction table corresponding thereto.

In this embodiment, the correction processing is performed in the same ROM, and correction data = gradation correction (−255 / D _max * Log)
(D _IN / 255)) is written in the ROM. In this embodiment, a ROM is used as the lookup table.
It goes without saying that the present invention is not limited to this, and a storage element such as a RAM may be used.

FIG. 3 is a diagram showing an operation unit in this embodiment. Reference numeral 301 denotes an LCD display unit, and reference numeral 302 denotes an OK key, which is pressed when the setting is determined. A function key 303 is pressed when an item displayed at the lower right of the display unit is to be performed. A button 304 is pressed by the left arrow key to move the cursor to the left. A button 305 is pressed when the cursor is to be moved upward with the up arrow key. A button 306 is pressed when the cursor is to be moved downward with the down arrow key. A right arrow key 307 is used to move the cursor to the right, for example.

FIG. 1 shows a flow for selecting a color for color erasure and a flow for entering a fine adjustment setting.

FIG. 2 shows a fine adjustment setting flow.

In step 101, it is determined whether or not to end the setting of the color erasure. When the setting is to be ended (when the function key 303 is pressed in the display state of steps 401, 402, 403, 404, and 405 in FIG. 4) Goes to step 102 and ends. Otherwise, go to step 103.

In step 103, the presence / absence of the movement of the cursor (left / up / down / right keys 304, 305, 306, 307 in FIG. 3)
Is pressed), and if the cursor is moved, the process goes to step 104 to move the cursor (steps 402 to 403 in FIG. 4).

If there is no cursor movement, step 10
Go to 5.

In step 105, the cursor is located at the position of fine adjustment (see 405 in FIG. 4), and it is determined whether or not the OK key 302 has been pressed. If it has been pressed, the flow proceeds to step 108 (flow chart in FIG. 2). Otherwise, go to step 106.

In step 106, when the cursor is located at a position other than the fine adjustment, it is determined whether or not the OK key 302 has been pressed. When the OK key has been pressed, the process goes to step 107, where the color of the cursor is set to ON and the display unit is turned on. (See 401 to 402 in FIG. 4).

The flowchart of FIG. 2 will be described with reference to FIG.

In step 201, it is determined whether or not the fine adjustment has been completed.
Go to 02. In step 202, the fine adjustment setting is completed, and the process returns to the flowchart of FIG. Otherwise, the process proceeds to step 203.

In step 203, the up arrow key 305,
When the down arrow key 306 is pressed, the process goes to 204 and the cursor moves up and down (see 501 to 502 in FIG. 5).
Otherwise, the process proceeds to step 205.

In step 205, the left arrow key 304,
When the right arrow key 307 is pressed, the process proceeds to step 206; otherwise, the process proceeds to step 201.

Step 206 will be described with reference to 501 in FIG. The cursor is at the top, which is a fine-tuning of the border between red and yellow.

There are five stages of fine adjustment. In step 501, the leftmost (the boundary is the most red).
Here, when the right arrow key 307 is pressed, the boundary moves one position to the right (second from the red side).

FIG. 5 shows a setting image at the time of fine adjustment of the color recognition. This drawing will be described with reference to FIG.

Reference numeral 501 is a diagram of the display unit when fine adjustment of the boundary (boundary line 605 in FIG. 6) between the red recognition area and the yellow recognition area is performed. Here, if the boundary is shifted to the red color by the left key 304, the boundary line 605 moves in the direction of A in FIG.
The red recognition area 601 becomes smaller, and the yellow recognition area 602
Becomes larger. If the right key 307 is used to shift to yellow, the boundary line 605 moves in the direction of B in FIG.
02 becomes smaller, and the red recognition area 601 becomes larger.

Reference numeral 502 denotes a display unit for fine adjustment of the boundary between the yellow recognition area and the green recognition area (the boundary line 606 in FIG. 6). Here, if the boundary is shifted to yellow with the left key 304, the boundary line 606 moves in the direction C in FIG. 6, the yellow recognition area 602 becomes smaller, and the green recognition area 6 becomes smaller.
03 becomes larger. If the right key 307 is used to shift the color toward green, the boundary line 606 moves in the direction of D in FIG. 6, the green recognition area 603 becomes smaller, and the yellow recognition area 602 becomes larger.

Reference numeral 503 is a view of the display unit when fine adjustment of the boundary between the green recognition area and the blue recognition area (the boundary line 607 in FIG. 6) is performed. Here, if the boundary is shifted to green with the left key 304, the boundary line 607 moves in the direction of E in FIG.
The green recognition area 603 becomes smaller and the blue recognition area 604 becomes smaller.
Becomes larger. If the right key 307 is used to shift the color toward blue, the boundary line 607 moves in the direction of F in FIG.
04 becomes smaller and the green recognition area 603 becomes larger.

Reference numeral 504 denotes a display unit when fine adjustment of the boundary between the blue recognition area and the red recognition area (the boundary line 608 in FIG. 6) is performed. Here, if the boundary is shifted to blue with the left key 304, the boundary line 608 moves in the direction of G in FIG.
The blue recognition area 604 becomes smaller, and the red recognition area 601 becomes smaller.
Becomes larger. If the right key 307 is used to move toward red, the boundary line 608 moves in the direction of H in FIG.
01 becomes smaller and the blue recognition area 604 becomes larger.

Reference numeral 505 denotes a display unit for fine adjustment of the boundary between the black and white recognition area and the color recognition area (the circle 609 in FIG. 6). Here, if the boundary is shifted to black and white by the left key 304, the circle 609 becomes the circle 60 in the direction of I in FIG.
9 becomes smaller, the black and white recognition area 610 becomes smaller, and the color recognition areas 601, 602, 603, and 604 become larger. Use the right key 307 to move closer to the color circle 609
6, the circle 609 becomes larger in the direction of J in FIG. 6, the black-and-white recognition area 610 becomes larger, and the color recognition areas 601 and 60 become larger.
2, 603 and 604 are reduced.

[0066]

As described above, according to the present invention,
Input means for inputting a color image, and the input color
-For the image, the colors included in the first color recognition area
The image editing process of
The color included in the color recognition area of the second color
Image processing means for performing collection processing and user's manual instruction
According to the first color recognition area and the second color recognition area
Adjusting means for adjusting the boundary between the adjusting means and the adjusting means.
The first color recognition area and the second color recognition in accordance with
Since the area range of the area is adjusted , fine adjustment of the color recognition range can be performed so as not to cause erroneous determination.

[Brief description of the drawings]

FIG. 1 is a flowchart of a color erasure setting.

FIG. 2 is a flowchart of a color recognition fine adjustment setting.

FIG. 3 is a diagram illustrating an operation unit.

FIG. 4 is a diagram showing a display on an operation unit display unit at the time of setting color erasure.

FIG. 5 is a diagram showing a display on an operation unit display unit when color recognition fine adjustment is set.

FIG. 6 is a hue plane diagram for explaining color recognition fine adjustment.

FIG. 7 is a block diagram of an image processing apparatus according to an embodiment of the present invention.

FIG. 8 is a block diagram of a luminance signal generation unit circuit.

FIG. 9 is a block diagram of a smoothing circuit.

FIG. 10 is a block diagram of a color recognition circuit.

FIG. 11A is a diagram illustrating the magnitude relationship between R, G, and B signals and the output of a comparator. (B) is a diagram showing a hue plane for explaining color recognition.

FIG. 12 is a block diagram of a majority decision circuit.

FIG. 13 is a block diagram of a majority decision circuit.

FIG. 14 is a block diagram of a decoration circuit.

FIG. 15A is a diagram illustrating gradation characteristics of a printer. (B) is a diagram showing characteristics of the correction table.

[Explanation of symbols]

 300 Operation unit 701 CCD image sensor 709 Color recognition circuit 711 Decoration circuit 713 CPU

Claims (4)

(57) [Claims] An input unit for inputting a color image; and a first color recognition area for the input color image.
A first image editing process is performed on the included colors, and the first
Included in the color recognition area of the second color adjacent to the color recognition area
Image processing means for performing a second image editing process on the color, and the first color recognition area according to a manual instruction of a user.
Adjusting means for adjusting the boundary between the image and the second color recognition area
And the first color recognition area according to the adjustment by the adjusting means.
And the area range of the second color recognition area is adjusted
An image processing apparatus characterized by the above-mentioned. 2. The image editing process according to claim 1 , wherein the first color recognition is performed.
Area and a pattern corresponding to each of the second color recognition areas
2. The processing according to claim 1, wherein the processing is for adding an image.
Image processing device. 3. A color included in the first color recognition area and a color included in the first color recognition area.
The color included in the second color recognition area has a hue of each color.
2. The image processing device according to claim 1, wherein the image processing device is different. 4. An input step of inputting a color image, and the input color image is input to a first color recognition area.
A first image editing process is performed on the included colors, and the first
Included in the color recognition area of the second color adjacent to the color recognition area
An image processing step of performing a second image editing process on the color; and the first color recognition area according to a manual instruction of a user.
Adjusting the boundary between the image and the second color recognition area
And the first color recognition area according to the adjustment by the adjusting step.
And the area range of the second color recognition area is adjusted
An image processing method characterized by the following.