Chrominance

Chrominance

Diagram illustrating the separation of luma and chroma components in an image.

Chrominance is a component of a color video signal that carries information about the color of the picture, separate from the luminance (brightness) component. Chrominance is used in various color models and video encoding systems to represent the color information of an image or video.

Overview

Chrominance is often represented in conjunction with luminance, which describes the intensity or brightness of the image. The separation of chrominance and luminance allows for more efficient compression and transmission of video signals, as the human eye is more sensitive to changes in brightness than to changes in color.

In the YUV color model, which is commonly used in analog television broadcasting, chrominance is represented by the U and V components, while the Y component represents luminance. Similarly, in the YCbCr color model used in digital video, chrominance is represented by the Cb and Cr components.

Applications

Chrominance is crucial in various applications, including:

• Television Broadcasting: Chrominance allows for the transmission of color television signals while maintaining compatibility with black-and-white television sets, which only process the luminance component.
• Video Compression: By separating chrominance from luminance, video compression algorithms can reduce the amount of data required to represent color information, as chrominance can be subsampled more aggressively than luminance.
• Image Processing: In image processing, chrominance information can be manipulated independently of luminance to achieve effects such as color correction and enhancement.

Chrominance in Color Models

Chrominance is a key component in several color models used in video and image processing:

• YUV: Used in analog television, where Y represents luminance, and U and V represent chrominance.
• YCbCr: Used in digital video and image compression, where Y represents luminance, and Cb and Cr represent chrominance.
• HSV and HSL: Although not directly using chrominance, these models separate color information (hue and saturation) from brightness (value/lightness).

Related pages

• Luminance
• Color space
• Video compression
• Analog television
• Digital video