. File header parsing of BMP pictures

BMP The file is fully parsed

A plane image , The result is a colorful two-dimensional matrix , The combination of three primary colors constitutes almost all colors visible to the naked eye , To display the color matrix , Use a high density of RGB A screen made up of color pixels , So the processor needs to know the color value of each pixel , That is to say, what constitutes color RGB Tricolor brightness . But at the beginning, there was no color display , A black-and-white display made only of tubes , It depends on the intensity of electrons emitted by the electron tube to define the black-and-white brightness information .

Color space

RGB Color space

RGB Mixed color

Because processors made of semiconductors can only handle binary , So the description of the pixels that make up the image is ultimately in binary form , Commonly used RGB888 Format , That is, the three primary colors that make up the color have 8 Bit resolution , namely 256 Level depth . But embedded platforms are commonly used RGB565 To reduce the color bit depth to reduce the memory occupation and speed up the image display .

Color depth