Chroma Subsampling

It is the practice of encoding images by implementing less resolution for chroma information than for Luma information, taking advantage of the human visual system's lower acuity for colour differences than for luminance.

It is used in many video and still image encoding schemes - both analog and digital - including in JPEG encoding.

Types of subsampling

• 4:4:4
• 4:2:2
• 4:2:1
• 4:1:1
• 4:2:0