Color subsampling is an image processing technique that reduces color resolution without affecting the intensity of the image, also called chroma subsampling. Its main purpose is to reduce the storage space or bandwidth used by images and video signals without compromising on the quality of the image. The technique is designed to utilize the human eye’s higher sensitivity to luminance variations compared to color.
A video signal comprises of two components: the luminance component (luma) and the chrominance component (chroma). The luma component forms the bulk of the image and provides the visible shapes and details while the chroma, or color component, provides the color information seen on the screen. Chroma subsampling is a method that compresses the color data of the video signal allowing more luma data to be provided, which reduces file sizes by up to 50% while still maintaining image clarity.
Chroma subsampling is achieved by compressing the color data in a video signal or file. The chroma subsampling compression levels are referred to as ratios, such as 4:4:4, 4:2:2, and 4:2:0, where 4:4:4 is uncompressed since it has equal amounts of chroma data and luma data. A ratio of 4:2:2 has half the chroma data compared to 4:4:4 while a ratio of 4:2:0 has a quarter of the chroma data compared to a ratio of 4:4:4.
What is the importance of chroma subsampling?
Chroma subsampling is essential in reducing the storage space or bandwidth required for high volume images or video signals without significantly compromising the final image quality.
What are the components of a video signal?
The two primary components are Luma (luminance) and Chroma (chrominance).
What are chroma subsampling compression ratios?
The levels of chroma subsampling compression ratios are 4:4:4, 4:2:2 and 4:2:0.
Color subsampling, also referred to as Chroma subsampling, is a technique that reduces color resolutions without affecting intensity. It reduces bandwidth use and file sizes for images and video signals. Chroma subsampling compresses color data in video signals and files resulting in a higher amount of luma data for a similar or smaller size of the video while maintaining image quality. Its main purpose is to create better compression ratios without compromising image quality.