CN109886902A - A kind of plate making color separation method of the black-and-white image black based on three colors - Google Patents
A kind of plate making color separation method of the black-and-white image black based on three colors Download PDFInfo
- Publication number
- CN109886902A CN109886902A CN201910054924.2A CN201910054924A CN109886902A CN 109886902 A CN109886902 A CN 109886902A CN 201910054924 A CN201910054924 A CN 201910054924A CN 109886902 A CN109886902 A CN 109886902A
- Authority
- CN
- China
- Prior art keywords
- black
- image
- color separation
- gray level
- obtains
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Facsimile Image Signal Circuits (AREA)
Abstract
The invention discloses a kind of plate making color separation methods of black-and-white image black based on three colors, convert images into gray level image first；Then obtained gray level image is carried out contrast three times to adjust, obtains three kinds of color separation black print images；Obtain three kinds of different color separation black print images are merged again；Finally fused image is made a plate, is printed, the present invention is overlapped mutually, by the black print of three kinds of setting different tint hierarchies to realize the improvement of black and white screen effect using the black printing process of monochrome of different amounts three times.
Description
Technical field
The invention belongs to printing technologies, are related to a kind of plate making color separation side of black-and-white image black based on three colors
Method.
Background technique
Black-and-white image is more next because of stereovision pure with itself unique appeal and a kind of gracefulness, having exquisiteness
More by the favor of photographer.Photographer has the demand for printing black-and-white photography works simultaneously.
There are two types of the method for present printing black-and-white image is usual: first is that monochromatic black printing, i.e. exclusive use black ink is real
Existing, this process is simple, at low cost, but since the density of black ink is about 1.6 or so, gradation reproduction is bad,
The intention of photographer can not accurately be embodied；Another kind is four-color process black-and-white image, i.e., using green (C), product (M), Huang
(Y), black (K) four color double exposure forms, and this mode of printing can be improved print contrast, and image hierarchy increases, but due to human eye
Most sensitive to the grey of netrual colour, C, Y, M ink slightly deviate in printing process, colour cast will occur, and to view
Feel is affected, and double exposure difficulty is big.
Therefore, in order to carry out high-level, high efficiency, simplicity printing black-and-white image mode, it is necessary to find a kind of new
Printing technology.
Summary of the invention
The object of the present invention is to provide a kind of plate making color separation method of black-and-white image black based on three colors, solve existing
The problem for thering is printing technology to cause black-white colors impure.
The technical scheme adopted by the invention is that a kind of plate making color separation method of the black-and-white image black based on three colors,
Specific step is as follows:
Step 1, gray level image is converted images into；
Step 2, the gray level image obtained through step 1 is carried out contrast three times to adjust, obtains three kinds of color separation black print images；
Step 3, obtain through step 2 three kinds of different color separation black print images are merged；
Step 4, it will be made a plate, be printed through the fused image of step 3.
The features of the present invention also characterized in that:
Wherein step 1 specifically: image is subjected to gradation conversion by formula (1), obtains gray level image:
Gray=(0.2973R2.2+0.6274·G2.2+0.0753·B2.2)1/2.2 (1)
Wherein, R, G, B indicate the value in each channel of color image；Gray indicates the pixel value of the gray level image after conversion；
Wherein step 2 specifically includes:
Step 2.1, the gray level image obtained through step 1 is subjected to contrast adjustment by formula (2), obtains the first color separation black print
Image:
Wherein, x indicates that the pixel value of gray level image, y indicate the pixel value of transformed image, x1、y2Indicate the first color separation
The coordinate of the point of black print curve, x1Range in 5%~30%, y2Range 70%~100%；
Step 2.2, the image obtained through step 1 is subjected to contrast adjustment by formula (2) again, obtains the second color separation black print
Image:
Wherein x1Range in 60%~85%, y2Range 20%~40%；
Step 2.3, the gray level image obtained through step 1 is subjected to contrast adjustment through formula (3), obtains third color separation black print figure
Picture:
Wherein x1、y1、x2、y2Indicate the coordinate of the point of third color separation black print curve, wherein x1Range 0%~15%,
y1Range in 10%~30%, x2Range in 85%~100%, y2And y1It is identical.
Wherein step 3 is specially and merges the first, second, third black print color separated image by graphics software, obtains
Fused three colors black image.
The beneficial effects of the present invention are:
A kind of plate making color separation method of black-and-white image black based on three colors of the invention black can be made more accurate and
It is pure, variegated and colour cast is not had, the problem for avoiding traditional printing from causing black-white colors impure maintains the details of image,
Level is more abundant, and printing quality is more stable；Generally speaking, improve black white image effect, improve the performance of black white image
Power.
Detailed description of the invention
Fig. 1 is black in a kind of plate making color separation method of black-and-white image black based on three colors of the invention first, second
Version contrast adjusts curve；
Fig. 2 is third Black plack Gradation in a kind of plate making color separation method of black-and-white image black based on three colors of the invention
Adjust curve；
Fig. 3 is black and white to be printed in a kind of plate making color separation method of black-and-white image black based on three colors of the invention
Manuscript map；
Fig. 4 is conventional monochromatic black print in a kind of plate making color separation method of black-and-white image black based on three colors of the invention
The comparative diagram of the black-and-white image effect of brush；
Fig. 5 is a kind of black printing of three colors of the plate making color separation method of black-and-white image black based on three colors of the invention
Black-and-white image effect picture.
Specific embodiment
The following describes the present invention in detail with reference to the accompanying drawings and specific embodiments.
The present invention provides a kind of plate making color separation method of black-and-white image black based on three colors, the specific steps are as follows:
Step 1, gray level image: step 1 is converted images into specifically: image is subjected to gradation conversion by formula (1), is obtained
Gray level image:
Gray=(0.2973R2.2+0.6274·G2.2+0.0753·B2.2)1/2.2 (1)
Wherein, R, G, B indicate the value in each channel of color image；Gray indicates the pixel value of the gray level image after conversion.
Step 2, the gray level image obtained through step 1 is carried out contrast three times to adjust, obtains three kinds of color separation black print images:
Step 2.1, the gray level image obtained through step 1 is subjected to contrast adjustment by formula (2), obtains the first color separation black print
Image:
Wherein, x indicates that the pixel value of gray level image, y indicate the pixel value of transformed image, x as shown in Figure 11、y2Table
Show the coordinate of the point of the first color separation black print curve, x1In pixel coverage 5%~30%, y2In pixel coverage 70%~100%；
Step 2.2, the image obtained through step 1 is subjected to contrast adjustment by formula (2) again, obtains the second color separation black print
Image:
Wherein x1In pixel coverage 60%~85%, y2In pixel coverage 20%~40%；
Step 2.3, the gray level image obtained through step 1 is subjected to contrast adjustment through formula (3), obtains third color separation black print figure
Picture:
Wherein x1、y1、x2、y2Indicate the coordinate of the point of third color separation black print curve, wherein x1Pixel coverage 0%~
15%, y1In pixel coverage 10%~30%, x2In pixel coverage 85%~100%, y2And y1It is identical, according to fig. 2, general feelings
Under condition, y2And y1It is identical, can with according to different needs, characteristics of image, y2And y1It can not be identical.
Step 3, obtain through step 2 three kinds of different color separation black print images are merged；
Step 4, it will be made a plate, be printed through the fused image of step 3.
Advantages of the present invention is explained using operation logic:
Step 1, color image is converted, changes into grayscale mode image, conversion regime is shown according to the following formula, obtains ash
Spend image.
Gray=(0.2973R2.2+0.6274·G2.2+0.0753·B2.2)1/2.2(1)
Step 2, the gray level image obtained through step 1 is carried out contrast three times to adjust, obtains three kinds of color separation black print images；
Step 2.1, gray level image is subjected to contrast adjustment according to the following formula, obtains the first black print color separated image.
Step 2.2, gray level image is subjected to contrast adjustment according to the following formula, obtains the second black print color separated image.
Step 2.3, gray level image is subjected to contrast adjustment according to the following formula, obtains third black print color separated image.
The first, second, third obtained black print color separated image numberical range is identical with former RGB image numberical range: 0~
255, it to be converted into 0~100, is converted according to the following formula:
Y=100-x/255*100 (7)
Wherein, x indicates the first, second, third black print color separated image pixel number；After y indicates that pixel is transformed into 0~100
Value；
Step 3, it is established in the graphics softwares such as Photoshop, Illustrator, CorelDRAW and primary colour image is big
Small, the identical blank image of resolution ratio, color mode must be CMYK, and file format can be tiff, by first, second,
Three black print color separated images copy three channels into new image, such as C, Y, K channel respectively, while keeping the channel M is 0, is obtained
To fused three colors black image.
Step 4, it makes a plate, print: fused three colors black image being made a plate according to conventional printing technology, is printed,
Just obtain satisfactory printing black-and-white image.
The present invention is that come the method that carries out black-and-white image printing, the file that this method generates is black ink three times with print
The tif formatted file of CMYK mode, it is identical with the file that routinely prints, it is used directly for phototypesetting output or directly goes out CTP
Version, exports technique and equipment directly uses existing equipment.In printing, in conventional printing enterprise, multi-purpose four colors or more print
Brush machine printing color printed matter, the color of four-color process are blueness (C), product (M), Huang (Y), black (K) four color, i.e. four units respectively
The ink of upper tetra- kinds of colors of CMYK respectively, when being printed with conventional equipment, it is only necessary to which all upper tusche on three units has one
A unit tripping idle running, does not need existing printing enterprise and updates printing equipment.This method has good feasibility.
It is illustrated in figure 3 black and white original figure to be printed, after the black Plate making printing of conventional monochrome, obtained effect
Scheme as shown in the black-and-white image effect of the conventional monochromatic black printing of Fig. 4, it can be seen from the figure that the effect contrast of monochromatic black printing
Small, customers' approval degree is low, and the black-and-white image effect after Plate making printing is carried out using method of the invention is as shown in figure 5, effectively
The characteristics of having widened contrast, and effect is obvious, having highlighted black-and-white image, client's identification degree are high.
Claims (4)
1. a kind of plate making color separation method of the black-and-white image black based on three colors, which is characterized in that specific step is as follows:
Step 1, gray level image is converted images into；
Step 2, the gray level image obtained through step 1 is carried out contrast three times to adjust, obtains three kinds of color separation black print images；
Step 3, obtain through step 2 three kinds of different color separation black print images are merged；
Step 4, it will be made a plate, be printed through the fused image of step 3.
2. a kind of plate making color separation method of black-and-white image black based on three colors according to claim 1, feature exist
In the step 1 specifically: image is carried out gradation conversion by formula (1), obtains gray level image:
Gray=(0.2973R2.2+0.6274·G2.2+0.0753·B2.2)1/2.2 (1)
Wherein, R, G, B indicate the value in each channel of color image；Gray indicates the pixel value of the gray level image after conversion.
3. a kind of plate making color separation method of black-and-white image black based on three colors according to claim 1, feature exist
In the step 2 specifically includes:
Step 2.1, the gray level image obtained through step 1 is subjected to contrast adjustment by formula (2), obtains the first color separation black print figure
Picture:
Wherein, x indicates that the pixel value of gray level image, y indicate the pixel value of transformed image, x1、y2Indicate the first color separation black print
The coordinate of the point of curve, x1In pixel coverage 5%~30%, y2In pixel coverage 70%~100%；
Step 2.2, the image obtained through step 1 is subjected to contrast adjustment by formula (2) again, obtains the second color separation black print figure
Picture:
Wherein x1In pixel coverage 60%~85%, y2In pixel coverage 20%~40%；
Step 2.3, the gray level image obtained through step 1 is subjected to contrast adjustment through formula (3), obtains third color separation black print image:
Wherein x1、y1、x2、y2Indicate the coordinate of the point of third color separation black print curve, wherein x1In pixel coverage 0%~15%, y1
In pixel coverage 10%~30%, x2In pixel coverage 85%~100%, y2And y1It is identical.
4. a kind of plate making color separation method of black-and-white image black based on three colors according to claim 3, feature exist
In the step 3 is specially to merge the first, second, third black print color separated image by graphics software, after obtaining fusion
Three color black images.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910054924.2A CN109886902B (en) | 2019-01-21 | 2019-01-21 | Printing plate making color separation method of black and white image based on three-color black |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910054924.2A CN109886902B (en) | 2019-01-21 | 2019-01-21 | Printing plate making color separation method of black and white image based on three-color black |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109886902A true CN109886902A (en) | 2019-06-14 |
| CN109886902B CN109886902B (en) | 2022-10-11 |
Family
ID=66926405
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910054924.2A Active CN109886902B (en) | 2019-01-21 | 2019-01-21 | Printing plate making color separation method of black and white image based on three-color black |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109886902B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040004646A1 (en) * | 2002-07-06 | 2004-01-08 | Samsung Electronics Co., Ltd. | Method of adjusting process black and a driver thereof |
| CN103171316A (en) * | 2012-11-16 | 2013-06-26 | 北京雅昌彩色印刷有限公司 | Black grey four-color offset printing technology |
| CN105262930A (en) * | 2015-10-20 | 2016-01-20 | 北京圣彩虹文化艺术发展股份有限公司 | ICC file manufacturing method of converting RGB color mode to CMYK color mode |
-
2019
- 2019-01-21 CN CN201910054924.2A patent/CN109886902B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040004646A1 (en) * | 2002-07-06 | 2004-01-08 | Samsung Electronics Co., Ltd. | Method of adjusting process black and a driver thereof |
| CN103171316A (en) * | 2012-11-16 | 2013-06-26 | 北京雅昌彩色印刷有限公司 | Black grey four-color offset printing technology |
| CN105262930A (en) * | 2015-10-20 | 2016-01-20 | 北京圣彩虹文化艺术发展股份有限公司 | ICC file manufacturing method of converting RGB color mode to CMYK color mode |
Non-Patent Citations (2)
| Title |
|---|
| 楚高利等: "Photoshop中UCR与GCR分色参数设置及应用", 《广东印刷》 * |
| 陆亚萍: "彩色复制中黑版阶调的设定方法", 《广东印刷》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109886902B (en) | 2022-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2887158B2 (en) | Image processing device | |
| EP0356328B1 (en) | Tonal conversion method for pictures | |
| US20120090488A1 (en) | Methods and systems for multicolor process printing employing both process colors and spot colors in the process ink set | |
| JP2004180013A (en) | Color conversion device and color conversion method | |
| EP0341666B1 (en) | Tonal conversion method for pictures | |
| CN109327646B (en) | Image processing apparatus, image processing method, and computer-readable storage medium | |
| JP3989738B2 (en) | Image forming method, image forming apparatus, program, and recording medium | |
| CN1475860A (en) | Colour dichromic method and its printed product | |
| JPH0691612B2 (en) | Image gradation conversion method | |
| JP2010166506A (en) | Image output device, image output method, image output program and recording medium | |
| JP2001292331A (en) | Image processing method and device, image processing system and recording medium | |
| CN102218901A (en) | Gray balance correction of a printing process | |
| US20060244984A1 (en) | Reference tone settings for monotone images | |
| US5313310A (en) | Tonal conversion method for pictures | |
| US8064112B1 (en) | Color separation and reproduction method to control a printing process | |
| CN105262930A (en) | ICC file manufacturing method of converting RGB color mode to CMYK color mode | |
| CN109886902A (en) | A kind of plate making color separation method of the black-and-white image black based on three colors | |
| CN114393922B (en) | Color management method for newspaper printing | |
| TW202005817A (en) | Positive and negative halftone dot mixed plate-making printing method producing an integration of colors and metallic colors and high-quality images with high chroma and metallic color properties | |
| JP3749102B2 (en) | Image processing apparatus, image forming apparatus, and image processing method | |
| JP2542365B2 (en) | Color image processing device | |
| JPH08275010A (en) | Method and device for image processing | |
| KR101905470B1 (en) | Method of off-set printing | |
| JP2004104758A (en) | Method and system for processing multi-color image | |
| JPS6120949A (en) | Image processing method of computer graphics |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |