![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Rgb_vs_YJK.png/640px-Rgb_vs_YJK.png&w=640&q=50)
YJK
Color space implemented by the Yamaha V9958 graphic chip / From Wikipedia, the free encyclopedia
YJK[1][2][3] is a proprietary color space implemented by the Yamaha V9958[4][5][6] graphic chip on MSX2+ computers.[7][8] It has the advantage of encoding images by implementing less resolution for color information than for brightness, taking advantage of the human visual systems' lower acuity for color differences.[9] This saves memory, transmission and computing power.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/YJK_example_image.png/320px-YJK_example_image.png)
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Rgb_vs_YJK.png/640px-Rgb_vs_YJK.png)
YJK is composed of three components: ,
and
.
is similar to luminance (but computed differently),
and
are the chrominance components (representing the red and green color differences). The
component is a 5-bit value (0 to 31), specified for each individual pixel.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/9/96/Rgb.png/320px-Rgb.png)
The and
components are stored together in 6 bits (-32 to 31) and shared between 4 nearby pixels (4:2:0 chroma sub-sampling).[10][11][12]
This arrangement allows for the encoding of 19,268 different colors.[10][11][12]
While conceptually similar to YUV, chroma sampling, numerical relationship between the components, and transformation to and from RGB are different in YJK.