Tool to decompose an image in print colors. The separation of the CMYK channels (for the 4 colors Cyan, Magenta, Yellow and Key for Black) is used to analyze the colors of each part of an image.
CMYK Channels - dCode
Tag(s) : Image Processing
dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day!
A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!
CMYK Channels
Cyan/Magenta/Yellow/Black Channels Separation
Answers to Questions (FAQ)
What are CMYK channels in an image? (Definition)
In printing, CMYK are the initials of the 4 primary four-color process colors, namely: Cyan, Magenta, Yellow and (K) Black. Any image can be decomposed into 4 superimposable color channels to reform the original image.
How to separate CMYK values of an image?
The image will be analyzed in printing color components (4 layers). There are four main colors when printing: Cyan, Magenta, Yellow and Black.
The result will be returned in grayscale for each color. Between 0 for no color and 1 for pure color.
Example: The dCode logo do not have any Cyan (light blue)
Example: For magenta the C is very visible
Example: The yellow is dominating the whole image
Example: The black draws the contours of the image
In order to accelerate the calculation of channel separation, the image will be resized if it is too large.
How to calculate CMYK values from RGB values?
From RGB values $ R $, $ V $ and $ B $ between $ 0 $ and $ 1 $ (divide by 255 if the values are between 0 and 255)
CMYK values are calculated using formulas:
$$ K = 1-max(R, G, B) \\ C = (1-R-K) / (1-K) \\ M = (1-G-K) / (1-K) \\ J = (1-B-K) / (1-K) $$
Why the letter 'K' in CMYK?
In English, CMYK (instead of CMYB) stands for Cyan, Magenta, Yellow and Black. To not use the B letter for Black (as B stands for Blue in RGB code), term Key is preferred (the black component is often the most important when printing: the key)
Source code
dCode retains ownership of the "CMYK Channels" source code. Except explicit open source licence (indicated Creative Commons / free), the "CMYK Channels" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "CMYK Channels" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, or API access for "CMYK Channels" are not public, same for offline use on PC, mobile, tablet, iPhone or Android app!
Reminder : dCode is free to use.
Cite dCode
The copy-paste of the page "CMYK Channels" or any of its results, is allowed as long as you cite dCode!
Cite as source (bibliography):
CMYK Channels on dCode.fr [online website], retrieved on 2022-12-09,
- Cyan/Magenta/Yellow/Black Channels Separation
- What are Cyan/Magenta/Yellow/Black Channels Separation channels in an image? (Definition)
- How to separate Cyan/Magenta/Yellow/Black Channels Separation values of an image?
- How to calculate Cyan/Magenta/Yellow/Black Channels Separation values from RGB values?
- Why the letter 'K' in Cyan/Magenta/Yellow/Black Channels Separation?
