JP3147593B2 - Image processing device for color editing - 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 for processing image data with three-component data such as "brightness or density", "hue", and "saturation" to perform color editing on an image.

[0002]

2. Description of the Related Art Image data is called "brightness or density" or "hue".
In an image processing apparatus for processing with three-component data of "saturation" and editing an image, a binary signal is generated using a "brightness or density" signal, and color editing is performed on the image by the binary signal. The application method is known (Japanese Patent Application No. 3-10918).
No. 2). For example, if the document shown in FIG. 3A is colored at a position where the binarized signal is “1” (above the threshold), the character portion can be colored as shown in FIG. 3B. become. Also, by coloring the place where the binarized signal is “0” (less than the threshold value), the background portion can be colored as shown in FIG.

[0003]

However, when a binary signal is generated using only the "brightness or density" signal, there is no problem when the original is black and white. In the case of the system, since the density is low, the data for the “high lightness (low density)” and “high chroma” data is always below the threshold value, and there is a problem that color editing is not performed well.

The present invention has been made in order to solve the above-mentioned problem, and focuses on a "chroma" signal in addition to a "brightness or density" signal, thereby performing a binarization to obtain a yellowish color. It is an object of the present invention to provide a color editing image processing apparatus capable of satisfactorily color-editing “low brightness (low density)” and “high saturation” data.

[0005]

According to the present invention, the image data read by the image input device is color-corrected into three-component data such as lightness or density, hue, and saturation. The binarization processing is performed based on the density and saturation data, and color editing is performed on a predetermined area using the binarization data. Color correction suitable for the device, for example, R, G, B signals for a display, and Y, M, C signals for a printer, are output.

[0006]

The present invention focuses on the saturation signal in addition to the brightness or density signal, performs binarization based on these data, and performs color editing on the editing area according to the binarization data. As a result, good binarization of low-brightness (low-density) and high-saturation data of yellow can be achieved, and a problem that editing is not performed well due to low density can be avoided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention will be specifically described below based on embodiments with reference to the drawings. The description here uses lightness (denoted by L ^* ), hue (denoted by H ^* ), and saturation (denoted by C ^* ). In addition, it is assumed that the brightness quantization represents "white data" when L ^* = 0, and the brightness decreases when the value of L ^* is large.

(Embodiment 1) In FIG. 1, reference numeral 1 denotes an image input device for inputting a color original and outputting it as R (red), G (green), and B (blue) data. 2 is a color correction unit for R,
The G and B data are converted into a lightness signal L ^* , a hue signal H ^*, and a saturation signal C ^* . Various methods are known for the color correcting means, and are not the gist of the present invention. Reference numeral 3 denotes an image editing unit. After the image data is edited by the image editing unit 3, the image data is converted by the color correction unit 4 into image data suitable for the image output device 5.
Is output by For example, when the image output device 5 is a display, it is converted into R, G, and B by the color correction unit 4, and when the image output device 5 is a printer, the color correction unit 4 converts the color into yellow (Y) and magenta (M). , Sian (C), etc.

FIG. 2 illustrates the image editing unit 3 in detail. L ^* and C ^* among the lightness (L ^* ), hue (H ^* ), and saturation (C ^* ) input to the image editing unit 3 are sent to the binarization circuit 101. Color data to be edited is input to the palette 102 in advance, and the selector 103 uses the output of the binarizing circuit 101 and the edit area signal sent from the edit area generating unit (not shown) to output the image data and the palette 10.
By switching the output of No. 2, it becomes possible to edit the image data. When an area is designated by a marker, the editing area generating section reads a marker loop or a marker dot, and performs a painting process, a reverse copy process, and the like on a bitmap memory to generate an editing region signal.

Here, the binarization circuit 101 is characterized in that the color difference signal from white is binarized using a threshold value.
FIG. 4 shows a detailed block diagram of the binarization circuit. Memory 2
01 and the memory 202 are used as a look-up table for calculating the square. That is, L ^* and C ^* are used as address inputs, and data is set so that a square value of the address is output. The memory 201 calculates the square of L ^* , and the memory 202 calculates the square of C ^* . The adder 203 adds the outputs of the memories 201 and 202. The comparator 205 compares the output of the adder 203 with the value of the threshold register 204, and outputs “1” when the output of the adder 203 is equal to or greater than the set value of the threshold register 204. That is, in the present embodiment, the sum of the square of L ^{* and} the square of C ^* is binarized using the threshold. The square of L ^* and C ^*
Since the sum of the squares represents the color difference from white, it is possible to satisfactorily binarize data of “low brightness, high saturation” such as yellow. In this embodiment, the square of L ^* and C ^*
Are individually obtained by a look-up table using a memory, but a multiplier may be used instead of the look-up table. Alternatively, the sum of the square of L ^{* and} the square of C ^* may be obtained directly from the look-up table using L ^* and C ^* as addresses.

(Embodiment 2) Instead of the binarization circuit shown in Embodiment 1 (FIG. 4), the binarization circuit shown in FIG. It can be quantified. L ^* and C ^* are added by the adder 210. The comparator 212 sets the binarized output to “1” when the output of the adder 210 is equal to or greater than the setting of the threshold register 211. That is, in this embodiment, the sum of the two data of the “brightness signal” and the “saturation signal” is obtained and binarized by the threshold.

(Embodiment 3) Another embodiment of binarization is shown in FIG. The comparison unit 230 compares the values of L ^* and C ^* and outputs the larger data. The comparator 232 sets the binarized output to “1” when the output of the comparator 230 is equal to or greater than the set value of the threshold register 231. That is, in the present embodiment, the larger of the two data of the “brightness signal” and the “saturation signal” is obtained and binarized by the threshold.

(Embodiment 4) Another embodiment of binarization is shown in FIG. The comparator 242 sets the value of L ^{* to} the threshold register 2
If the value is equal to or greater than the set value of 40, “1” is output. The comparator 243 outputs “1” when the value of C ^* is equal to or more than the set value of the threshold register 241. The OR circuit 244 calculates the logical sum of the output of the comparator 242 and the output of the comparator 243, and the output of the OR circuit 244 becomes a binary output. That is, in the present embodiment, two data of the "brightness signal" and the "saturation signal" are binarized by different threshold values, and the respective binarized signals are ORed to obtain the entire binarized signal.

(Embodiment 5) FIG. 8 shows another embodiment of binarization. The OR circuit 250 calculates the logical sum of the most significant bits of L ^* and C ^* . Further, the OR circuit 251 L ^*, takes the logical sum of bits of one bit higher than the least significant bit of each of C ^*, taking L ^*, a logical sum of the least significant bits of each of C ^* is an OR circuit ing. The OR circuit (not shown) performs a logical OR operation on the data of the bits corresponding to L ^* and C ^* , and sets the output of the OR circuit 250 as the most significant bit and the output of the OR circuit 252 as the least significant bit. In the case where the OR circuit output signal is equal to or larger than the set value of the threshold register 253, the binarized output is set to "1". That is, in this embodiment, the logical sum of each bit of the two data of the “brightness signal” and the “saturation signal” is obtained and binarized by the threshold.

[0015]

As described above, according to the present invention, an image processing apparatus for processing image data with three component data of "brightness or density", "hue" and "saturation" to perform color editing on an image. Attention is paid to the "brightness or density" and "saturation" data, and binarization is performed, and color editing is performed according to the binarization data, so that "low brightness" and "high saturation" data such as yellow can be obtained. Good binarization can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an image processing apparatus according to the present invention.

FIG. 2 is a block diagram of an image editing unit.

FIG. 3 is a diagram illustrating an example of image editing.

FIG. 4 is a block diagram of a binarizing circuit according to the first embodiment;

FIG. 5 is a block diagram of a binarizing circuit according to a second embodiment.

FIG. 6 is a block diagram of a binarization circuit according to a third embodiment;

FIG. 7 is a block diagram of a binarizing circuit according to a fourth embodiment.

FIG. 8 is a block diagram of a binarizing circuit according to a fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image input device, 2 ... Color correction part, 3 ... Image editing part, 4
... color correction unit, 5 ... image output device, 101 ... binarization circuit,
102: palette, 103: selector, 201, 202
... memory, 203 ... adder, 204, 211, 231,
240, 241, 253... Threshold register, 205, 21
2,232,242,243,254 ... comparator,
244, 250, 251, 252... OR circuits.

Continuation of the front page (56) References JP-A-4-336869 (JP, A) JP-A-3-191677 (JP, A) JP-A-3-109182 (JP, A) JP-A-2-295363 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H04N 1 / 387,1 / 46,1 / 60

Claims (2)

(57) [Claims] 1. A color editing image processing apparatus for processing image data with data of three components of lightness or density, hue, and saturation, or data of equivalent components to perform color editing on an image. A binarized data generating means for comparing binarized data generated based on the saturation data with a threshold value to generate binarized data; and a binarized data generated by the binarized data generating means. An image processing apparatus for color editing, comprising: color editing means for performing color editing according to data. 2. The image for color editing according to claim 1, wherein said binarized data generating means obtains a color difference from white and generates binarized data by comparing with a threshold value. Processing equipment.