Macroblock

What is a macroblock?
A macroblock is a processing unit in visual and video compression and is based on a linear block remodeling. This is then divided into transformation blocks and it is further divided into prediction blocks. A macroblock is usually a block of adjacent pixels, typically 16x16.
Standalone frames in an image are called I-frames. These are divided into 8 × 8 blocks that are not inherently overlapping. These are called pixels. These pixels are then further rearranged into 16 × 16 blocks called macroblocks. Each macroblock consists of a 16 × 16 matrix from Luma. These elements consist of 16 × 16 luma samples and 8 × 8 chroma samples. Luma samples denote the brightness or the achromatic components, while the chroma samples denote the chromatic or colored components. Thus, macroblocks can be viewed as 16 × 16 pixel areas. The JPEG image format is based on macroblocks.