JPH07147629A - Color image processor - Google Patents

Abstract

PURPOSE:To provide the color image processor which can replace a certain part of an input image in a specified color with any desired color specified with high accuracy. CONSTITUTION:This device is provided with a supplying means (a) for supplying a color image signal corresponding to an original, correcting means (b) for performing any one kind of correction of masking color correction and gradation correction for image formation to the color image signal, discriminating means (c) for discriminating whether the color image signal before the correction due to the correcting means (b) contains the specified color or not, and converting means (d) for converting the specified color discriminated by the discriminating means (c) to the other specified color. Since the specified color is converted to the other specified color after it is discriminated whether the color image signal before the execution of masking color correction or/and gradation correction for image formation due to the correcting means (b) contains the specified color or not, the color conversion can be performed with high accuracy in comparison with conventional technique.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image processing apparatus, and more particularly to a color image processing apparatus capable of highly accurate free color replacement.

[0002]

2. Description of the Related Art Conventionally, a color image processing apparatus for recording color image information by an ink jet method, a thermal transfer method, an electrophotographic method or the like is well known.

FIG. 3 shows the essential structure of a conventional color image processing apparatus of this type. In this figure, 1a to 1c are input from an image reading unit or an image data storage unit (not shown).
Color signal, 1a is yellow (Y), 1b is magenta (M)
, 1c are cyan (C) input image signals. A color correction unit 2 performs various color corrections such as masking on these input image signals 1a, 1b, 1c. Reference numeral 3 denotes a gradation correction unit, which performs gradation correction on the image signal color-corrected by the color correction unit 2.
Reference numeral 4 denotes a printer such as an inkjet printer, which forms a yellow (Y), magenta (M), and cyan (C) image on a recording medium in accordance with the image signal whose gradation is corrected by the gradation correction unit 3. Then, the color image is recorded.

In the color image processing apparatus of this type, it is a primary point that color reproduction faithful to the color of the input image is desired. However, in some cases, it is desired to change the color of the input image for output. There are cases. For example, when designing a poster, there are cases where it is desired to change the color of one original picture in various ways. In particular, there is a strong demand for converting only a specific color portion in the original image into another color and outputting the converted color.

In the conventional color image processing apparatus as described above, for the input image signals of three colors of yellow (Y), magenta (M) and cyan (C), other colors that do not correspond to the respective signals are input. By printing with the printer 4, an image of a color different from the input image can be created. For example, if magenta (M) is printed with the yellow signal 1a, cyan (C) is printed with the magenta signal 1b, and yellow (Y) is printed with the cyan signal 1c, for example, the red portion of yellow + magenta is magenta-cyan. Reproduced in blue, the magenta + cyan blue part is reproduced in cyan + yellow green, cyan +
The yellow green part will be reproduced in yellow + magenta red.

[0006]

However, in the color replacement method in such a conventional apparatus, all the colors other than the single colors of yellow (Y), magenta (M), and cyan (C) are different from the input image. However, it was impossible to replace only a specific color part with another color.

It is an object of the present invention to provide a color image processing apparatus capable of eliminating the above-mentioned drawbacks and replacing a portion of a specific color in an input image with a desired color designated with high precision. To do.

[0008]

In order to achieve such an object, the present invention provides a supplying means for supplying a color image signal according to a document, a masking color correction for forming an image on the color image signal, and A correction unit that performs at least one of gradation correction, a determination unit that determines whether the color image signal before correction by the correction unit includes a specific color, and a determination that is determined by the determination unit. And a conversion means for converting a color into another specific color.

[0009]

According to the present invention, in the above structure, it is determined whether or not the color image signal before the masking color correction and / or the gradation correction for image formation by the correction means includes a specific color and then the specific color is determined. Since the color is converted into another specific color, the color conversion can be performed with high accuracy.

[0010]

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

FIG. 1 shows the basic construction of an embodiment of the present invention. In the figure, a is a supply means for supplying a color image signal corresponding to the original. Reference numeral b is a correction means for performing at least one correction of masking color correction and gradation correction for image formation on the color image signal. Reference numeral c is a determination unit that determines whether or not the color image signal before correction by the correction unit b includes a specific color. Reference numeral d is conversion means for converting the specific color determined by the determination means c into another specific color. Reference numeral e is an image reproducing means for reproducing a color image based on the color image signal corrected by the correcting means b.

FIG. 2 shows the circuit configuration of the embodiment of the present invention.
The same reference numerals as those in FIG. 3 described above indicate the same components.

In FIG. 2, reference numeral 5 denotes an original or a color film.
Color image such as CCD (charge coupled device) image sensor
Read it by the server and output it as Y, M, C three color signals 1a, 1b, 1c.
It is a reading unit. 6a, 6b, 6c are the corresponding signals 1a, 1b, 1c
It is a divided ROM (read only memory) that is divided into four. SW₁ 
~ SW₃ Specifies the color to be color converted.
With a triple switch that switches the destination of the output signals 7a to 7c of c
is there. 9 is a switch SW ₁ ~ SW₃ Split ROM via 6a-6c
RAM () that temporarily stores the signals 7a-7c selectively sent from
Random access memory). 10 is read from RAM9
And the signals sent directly from the split ROMs 6a to 6c.
Match and output match signal 16 if they match
It is a detection circuit. SW_Four Is the operation to specify the recording color after color conversion.
This is a work switch, for example, 24 colors can be selected and specified. 13a,
13b and 13c are switch SW_Four Color signal 14a corresponding to the specified color
It is a ROM that outputs the combined output of ~ 14c. 15 is a choice
It is a selector as a stage, and is "H" from the coincidence detection circuit 10.
When the match signal 16 of is input from ROM 13a, 13b, 13c
Output the signals 14a, 14b, 14c of the
Signal is not input, the output signal 15a of the gradation correction unit 3
15b and 15c are output to the printer 4.

Next, the operation will be described. First, in the color designation mode, the user causes the reading unit 5 to read only the portion of the color to be replaced in the document. The read three-color signals 1a to 1c of yellow, magenta, and cyan of that color portion are divided into four by the divided ROMs 6a to 6c and converted into 4-bit signals 7a to 7c. That is, if the color represented by the three-color signal is represented by (Y, M, C), 1a to 1c are represented in decimal notation (0,0,0) to (63,63,63). ) Total 64 ³ =
262144 colors, but the divided ROMs 6a to 6c represent (0,0,0) to (15,15,15) in 7a to 7c after conversion, and a total of 16 ³ = 40
96 colors.

In this color designation mode, the switch SW
₁ ~ SW ₃ are connected to contacts 8a, 8b, 8c, ROM6a ~ 6c
A total of 12-bit data of the signals 7a to 7c from are stored in the RAM 9.

Next, in the color designation mode, the user selects with the switch SW ₄ what color the color to be replaced is output. That is, this switch SW ₄
Is for selecting the output color, and one color is selected from 24 colors prepared in advance. switch
Different 5 bits of data are output from the terminals 11-1 to 11-24 of SW _{4, and} the number of bits is determined according to the number of colors that can be selected. For example, 5 bits can select up to 32 colors, and 6 bits can select up to 64 colors.

The 5-bit signal 12 selected by the switch SW ₄ is input as the address data of the ROMs 13a to 13c. Each of the ROMs 13a to 13c stores a printer drive signal necessary for outputting the selected color.

Assuming, for example, that the color portion to be replaced is to be printed in a green color, the three-color signal to be input to the printer 4 for printing this green color is (40,
20,50) (however, each color has 64 gradations from 0 to 63), ROM 13a when SW ₄ selects green
It is stored in advance so that the output 14a of 13c becomes “40”, 14b becomes “20”, and 14c becomes “50”.

In this way, the drive signals of the three colors corresponding to the respective colors are stored in the ROMs 13a to 13c, and the switch SW ₄
Outputs 14a to 14c corresponding to the selection signal 12 from the selector 15
To enter.

Next, when the print start button (not shown) is pressed to enter the print mode, the document is read by the reading unit 5, and the color correction unit 2 and the gradation correction unit 3 perform normal color correction, Three-color signals 15a to 15 with tone adjustment
c is input to the selector 15.

On the other hand, in the print mode, since the triple switches SW _{1 to} SW ₃ are connected to the contacts 8d, 8e and 8f, respectively, the original is read and the data 7a to 7c divided by the division ROMs 6a to 6c are , Is input to the coincidence detection circuit 10 as it is. At the same time, the data of the color to be replaced, which has already been read in the above-mentioned color selection mode, is read from the RAM 9 and input to the coincidence detection circuit 10 and compared with the original data 7a to 7c. Match detection circuit
In Fig. 10, the signals from the RAM 9 and the signals from the original 7a to 7c are compared for each bit by the internal exclusive OR circuit, and the high level is set to "H" only when they all match, and the low level otherwise. The coincidence signal 16 having the level “L” is output to the selector 15.

The selector 15 outputs the signals 14a to 14c from the ROMs 13a to 13c to the printer 4 when the coincidence signal 16 is "H", and outputs the signals 15a to 14c from the gradation correction unit 3 when the coincidence signal 16 is "L". Output 15c to the printer 4.

These signals 16a output from the selector 15
~ 16c is an inkjet printer, thermal transfer printer,
It is input to a color printer 4 such as an electrophotographic printer, printed in yellow, magenta, and cyan to reproduce a full-color image.

As a result, when the color of the original read in the print mode does not match the color read in the color designation mode and stored in the RAM 9, the signal subjected to normal color correction and gradation correction is applied. The image formation is performed by, but when they match, the image of the color designated in the color designation mode is printed. In this way, it is possible to replace only the portion of the specific color read in the color designation mode on the original with the desired color designated in the color designation mode and output.

In the above-mentioned embodiment, the divided ROMs 6a to 6c are 6
Although the one in which the bit signal is divided into four and the four-bit signal is output is used, the present invention is not limited to this, and it is needless to say that it may be divided into any number. However, if the input image signal is input to the RAM 9 as it is without being divided at all, it will not be replaced by a slight change in the input signal. Therefore, it is desirable to perform appropriate division.

Further, the coincidence detection circuit 10 of FIG. 2 is constituted by a ROM without using a logic element such as an exclusive OR circuit, and the signal from the RAM 9 is used as the upper bit of the address and the signal from the original is used as the lower bit of the address. , "1" is stored in advance in an address whose upper bit and lower bit are equal, and "0" is stored in an unequal address in advance.
Selector with the data "1" or "0" as signal 16
You may make it output to 15.

In the present embodiment, the printer 4 has been described as forming a color image by synthesizing the three colors of yellow, magenta and cyan. However, four colors in which black is added to these three colors or more It is also possible to add and combine colors, or conversely, a printer of two colors such as red and black.

In the present embodiment, the number of colors that can be selected in the color designation mode is 24, but the number is not limited to 24, and any number of colors may be prepared. In particular, it is convenient to add white and black to the selected colors as follows. For example,
If you add white to the color you want to print, you can output only the part of a specific color without printing anything, and later paint that part with a color such as gold or silver that cannot be expressed by a normal printer. It is convenient and convenient. Further, the black selected color is convenient when negative / positive inversion of a black and white image is performed.

[0029]

As described above, according to the present invention,
The specific color is converted to another specific color after determining whether or not the color image signal before the masking color correction and / or the gradation correction for image formation by the correction unit includes the specific color. Therefore, as compared with the case where the color conversion is performed on the color image signal after the masking color correction or the like, there is an effect that the color conversion processing can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a circuit configuration of an embodiment of the present invention.

FIG. 3 is a block diagram showing a circuit configuration of a conventional example.

[Explanation of symbols]

 1a to 1c 3 color input signal 2 color correction unit 3 gradation correction unit 4 printer 5 reading unit 6a to 6c split ROM 9 RAM 10 match detection circuit 13a to 13c ROM 15 selector

Claims (1)

[Claims] 1. A supply unit for supplying a color image signal according to a document, and a correction unit for performing at least one of a masking color correction and a gradation correction for image formation on the color image signal. A determination unit that determines whether the color image signal before correction by the correction unit includes a specific color; and a conversion unit that converts the specific color determined by the determination unit into another specific color. And a color image processing device.