JP3028047B2 - Image color correction system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the production of various product catalogs such as lighting equipment and printed matter such as sample books, for example, a plurality of products having a certain correlation with each other, such as similar products, as one product group. The present invention relates to an image color tone correction system suitable for use when unifying the color tone of the background of a product group to the color tone of the background in a predetermined reference image set in advance.

[0002]

2. Description of the Related Art Generally, when creating a catalog of lighting equipment or the like, a photograph of a plurality of types of lighting equipment to be placed in the catalog is taken, and the catalog is created using these photographs as manuscripts.

When a catalog is created, it is sometimes required to match the background color of each product as much as possible. However, these original photographs are often taken under different conditions. Conventionally, the color tone of the background is not always the same, so conventionally, the catalog creator visually compares the background of the photograph of each product taken and the background of the photograph to be used as a reference, and Has been corrected by manuscript correction, plate making operation, etc., so that the color tone of the background matches the color tone of the background of the reference photograph.

[0004]

However, as described above, when the color tone is corrected by visual comparison, the correction accuracy is limited, and an error occurs in the color tone of the background of each product. In some cases, catalogs could not be created as requested.

[0005] In addition, when the color tones are compared visually, there is a problem that the operation requires considerable skill, labor and time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a color tone correction system for an image which can easily match the color tone of a background or the like to a desired color tone.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a color tone correction system for correcting the color tone of an image to be processed to the color tone of a reference image, and 1) an image for storing a plurality of types of images as image data. A storage unit; 2) by specifying an image having a desired color tone from among the images stored in the image storage unit, extracting the specified image as a reference image from the image storage unit; and Of the images stored in the storage means,
An image selecting unit for extracting an image whose color tone is to be corrected from the image storage unit by using the specified image as an image to be processed; and 3) a reference image and an image to be processed extracted by the image selecting unit. Density average value creating means for creating an average density value for each color component of both images from the respective image data of 4), 4) the density average values of the reference image and the processing target image created by the density average value creating means, respectively. Density comparing means for comparing the values for each color component to obtain a density difference between the two images; and 5) a density average for each color component of the processing target image based on the density difference obtained by the density comparing means. Color tone correction means for correcting the value to match the density average value for each color component of the reference image and outputting the image data as image data. It is a system.

According to the present invention, in the color tone correcting system for an image according to the present invention, the image stored in the image storage means is divided into regions for different color tones. By designating a predetermined area, the image data of the designated area is extracted from the image storing means by the image selecting means.

[0009]

According to the image color tone correction system of the present invention, when a reference image to be used as a reference and a processing target image whose color tone is to be changed are designated, the image of the designated reference image and processing target image is designated by the image selecting means. Data is extracted from the image storage means, and the image data is transmitted to the density average value creation means.

The density average value creating means creates an average value of the density for each color component of the processing target image and the reference image, and compares the created density average value between the two images by the density comparing means. Then, based on the result of the density difference between the two images obtained by this comparison, the color tone correcting means corrects the density average value of the processing target image so as to match (match) the density average value of the reference image. Are output as image data.

Also, by appropriately designating an area in the image extracted as the processing target image whose color tone is to be changed, the color tone of the designated area is changed to the color tone of the reference image (the image to be the background).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the image color tone correction system of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a color correction device main body which is a main part of the system, and a reading unit 2 including a scanner or the like for reading various images is connected to the color correction device main body 1. The image read by the reading unit 2 is output as image data.

The color tone correction device main body 1 is provided with a display unit 3 composed of a display and the like and an operation unit 4 composed of a keyboard, a mouse and the like. The display unit 3 displays various images and operation screens. The image is moved and the operation on the operation screen is performed by the operation unit 4.

As shown in FIG. 2, an operation screen composed of a plurality of divided frames is displayed on the display unit 3, and the image read from the reading unit 2 is displayed in each of the divided frames. Is projected.

In each frame of the operation screen, a specification S (specification) such as a model number of a product of the projected image is displayed, and further, each region of the projected image (for example, A color that divides an area including only a product, an area including only a background in an image, and the like, which is referred to herein as a mask) is displayed as a color palette P.

The operation unit 4 can specify a reference image and an image to be processed on the operation screen of the display unit 3.

Here, when the reference image is designated, the image to be used as the reference is designated from the images projected in the respective frames by the operation unit 4, and the color of the area to be used as the reference of the image is further designated. From the color palette P. In this way, the image of the color area corresponding to the color of the color palette P specified by the operation unit 4 is set as the reference image.

When an image to be processed is specified, the operation unit 4 specifies an image to be processed among the images projected in the respective frames, and further specifies an image to be processed as an area to be processed. The classification color is designated from the color palette P. By doing so, the image of the area of the color corresponding to the color of the designated color palette P is set as the processing target image.

Further, from the color tone correcting device main body 1, a printing device 5 such as a color printer and a film forming device 6 are provided.
The image data is output to the

In the printing device 5, an image is simply printed on paper based on the image data output from the color tone correcting device main body 1, and in the film forming device 6, the image is output from the color tone correcting device main body 1. On the basis of the image data, a film to be used in a subsequent printing process is created.

Next, the specific structure and functions of the color tone correcting device main body 1 will be described with reference to a functional block diagram shown in FIG.

As shown in FIG.
Are image storage means 11, selection means 12, density average value creation means 13, density comparison means 14, LUT means 17
The LUT means 17 is a LUT setting means 1
5 and a color tone correcting means 16. Note that L
The UT means 17 is equipped with a dot generator (not shown) on the LUT setting means 15 or color tone correcting means 16 side, and converts the dot percentage of input image data (pixel data) into a set correction value ( This is a circuit means for correcting (correcting) to a predetermined halftone dot percentage based on the (correction value) and outputting the same, and is constituted by a static ram (S-RAM) or the like.

The image storage means 11 includes the reading unit 2
Are stored as image data, and each area in each image is stored as mask data.

Further, as described above, when the reference image and the image to be processed are specified by the operation unit 4, the density selection means 12 performs the processing of the reference image of the specified area and the processing object of the specified area. Image data of an image is selected and extracted from the image storage means 11, and mask data of each designated area is selected and extracted from the image storage means 11.

That is, as shown in FIG. 4, the image of the designated area of the reference image (image A) and the image to be processed (image B) is extracted as image data and mask data by the image selecting means 12. It has become.

The image data selected and extracted by the image selecting means 12 is stored in the density average value generating means 1.
3 and the mask data is output to the color tone correcting means 16.

In the average value creating means 13, the image selecting means 1
2 based on the image data of the reference image (image A) and the image data of the processing target image (image B) output from Y, M,
Reference image (image A) in a designated area for each color component of C, K (yellow, magenta, cyan, black)
And a density average value for each of the image to be processed (image B).

The reference image (image A) and the image to be processed (image B) of the designated area sequentially output from the image selecting means 12
Are digital signals which are sequentially output as pixels in a matrix in the vertical and horizontal (matrix) directions as shown in FIG. Note that one pixel (pixel), which is the minimum unit of image data, is usually represented by 8 bits (1 byte), and 2 ⁸ = 256 for each color (Y, M, C, K).
It is possible to reproduce to a gradation of (output signal amount 0 to 255).

With respect to the generation of the density average value by the average value generation means 13 in the present invention, the image data of the reference image and the image to be processed which are sequentially output as pixels in a matrix form in the vertical and horizontal directions from the image selection means 12 are described below.
The density (output signal amount) of each pixel which is sequentially output is accumulated from, for example, a density of 0 to a maximum density of 250 as shown in FIG. 5, and the number of appearances of pixels (for example, 2 as shown in FIG. 5).
5) is stored in an accumulative memory, and is created by an arithmetic method of dividing the total density by the total number of appearances.

The density average value data created for each color component by the density average value creation means 13 is output to the density comparison means 14, and
The data is compared, and a difference (ΔD) between the average density values of the reference image (image A) and the processing target image (image B) is obtained.

Further, the difference (ΔD) data of the density average value obtained by the density comparison means 14 is sent to the LUT setting means 15 for the density of the reference image (set density;
The LUT setting means 15 generates a look-up table based on difference (ΔD) data.

Here, the LUT setting means sets the density value (density signal amount) of each pixel from the lowest density to the highest density of the image data of the image to be processed (image B) as an input value x,
A look-up table is created for each color component (for example, Y, M, C, K) using the difference (ΔD) data as a corrected density value (corrected density signal amount; lookup set value).

Further, the data of the look-up table created by the LUT setting means 15 is output to the color tone correcting means 16, and the difference (ΔD) for each color component of the lookup table is output by the color tone correcting means 16. Based on the data, the input value x of the processing target image (image B)
From the (parameters), an output value y (y = x + ΔD) corrected for each color component is created, and the density average value of each color component that matches (coincides with) the density average value of each color component of the reference image (image A) is calculated. An image to be processed (image B) is created.

In this way, the color tone correcting means 16
As shown in FIG. 6, the image data of the processing target image (image B) having the corrected color tone substantially the same as the color tone of the reference image (image A) is output together with the mask data from the selection means 12. Has become.

Next, a procedure for correcting a color tone by the color tone correction apparatus having the above configuration will be described with reference to a flowchart shown in FIG.

<Step S1> First, a reference image (image A) and an image to be processed (image B) are designated by the operation unit 4 from among the images in the frame displayed on the display unit 3. In this case, the selecting means 12
The image data of the reference image (image A) of the designated area and the image to be processed (image B) of the designated area are selected and extracted from the image storage unit 11.

<Step S2> If the reference image (image A) and the image to be processed (image B) are selected, the process proceeds to step S3, and if not, the process returns to step S1.

<Step S3> By designating the areas of the reference image (image A) and the processing target image (image B) using the operation unit 4, each of the reference image (image A) and the processing target image (image B) is specified. Is the selection means 12
Is selected from the image storage means 11 and pulled out.

<Step S4> If mask data has been selected, the process proceeds to step S5, and if mask data has not been selected, the process proceeds to step S3.

<Step S5> Density average value creating means 13
Thereby, a density average value for each color component is created from the selected image data of the reference image (image A) and the processing target image (image B). When the data amounts (the number of pixels) for obtaining the density average values of the reference image (image A) and the processing target image (image B) are different, the adjustment is performed so that the data amounts are equal.

<Step S6> The density comparing means 14 compares the density average value between the reference image (image A) and the image to be processed (image B).

<Step S7> Image data (pixel data) of the processing target image (image B) of the designated area selected and extracted from the image storage means 11 is stored in the LUT setting means 14 of the LUT (look-up table) means 17. ; Input value x)
And the comparison data (difference; Δ
D), a lookup table (correction access table) is created in the LUT (lookup table) means 17.

<Step S8> Based on the look-up table, the color tone correcting means 16 of the LUT (look-up table) means 17 matches the average density value of the image to be processed with the average density value of the reference image (image A). Modify as follows. Then, the image data of the corrected image to be processed (the image B) is output together with the mask data from the color tone correcting means 16.

Then, the catalog is simply printed by the printing apparatus 5, and the film of the catalog to be used in the next printing step is formed by the film forming apparatus 6.

In the above embodiment, the correction of the color tone at the time of creating the catalog of the lighting equipment and the like has been described. However, the correction of the color tone is not limited to the catalog and is applicable to any color correction. Of course you can.

[0046]

According to the image color tone correction system of the present invention, the color tone correction operation for correcting the color tone of the processing target image to the color tone of the reference image can be performed very easily and very accurately. In addition, the efficiency of the operation can be greatly improved as compared with the correction operation based on color comparison that has been performed visually.

That is, a catalog in which the color tone of the background of the product is unified with high accuracy and the product can be easily compared when purchasing the product,
This has the effect of being extremely easy to create.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating the configuration and functions of an image color tone correction system according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation screen displayed on a display unit included in the image color tone correction system according to the embodiment of the present invention.

FIG. 3 is a functional block diagram illustrating a configuration and functions of a color tone correction device main body that forms the image color tone correction system according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a reference image and a processing target image extracted by a selection unit included in the image color tone correction system according to the embodiment of the present invention.

FIG. 5 is a plan view showing output pixels when an average value of image density is obtained by an average density value creation unit that constitutes the image color tone correction system according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of a processing target image and a reference image whose color tone has been corrected by the image color tone correction system according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a color tone correction procedure performed by the image color tone correction system according to the embodiment of this invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Color correction device main body 2 ... Reading part 3 ... Display
DESCRIPTION OF SYMBOLS 4 ... Operation part 5 ... Printing apparatus 6 ... Film production apparatus 11 ... Image storage means 12 ... Image selection means 13 ... Density average value creation means 14 ... Density comparison means 15 ... LUT setting means 16 ... Color tone correction means 17 ... LUT means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-300531 (JP, A) JP-A-62-198967 (JP, A) JP-A-1-126607 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G06T 1/00 H04N 1/46 H04N 1/60

Claims (2)

(57) [Claims] 1. An image color tone correction system for correcting the color tone of an image to be processed to the color tone of a reference image, comprising: 1) image storage means for storing a plurality of types of images as image data; By specifying an image having a desired color tone from among the images stored in the storage unit, the specified image is pulled out from the image storage unit as a reference image, and the image stored in the image storage unit. Of which
An image selecting means for extracting an image whose color tone is to be corrected from the image storage means by using the specified image as an image to be processed; and 3) a reference image and an image to be processed which are extracted by the image selecting means. Density average value creating means for creating an average density value for each color component of the two images from the respective image data; 4) the density average of the reference image and the processing target image created by the density average value creating means, respectively. Density comparing means for comparing the values for each color component to obtain a density difference between the two images; and 5) a density average for each color component of the processing target image based on the density difference obtained by the density comparing means. Color tone correction means for correcting the value so as to match the density average value for each color component of the reference image and outputting the image data as image data. System. 2. The image stored in the image storage means is divided into areas for different color tones,
2. A color tone correcting system for an image according to claim 1, wherein by designating a predetermined area of said plurality of divided areas, image data of said designated area is extracted from said image storage means by said image selecting means.