bmp is an image file format and a bitmap format. bmp uses a bit map storage format and does not use any other compression except for the optional image depth. Therefore, bmp files usually occupy a larger space, and the bmp image format is only used in certain specific occasions.
BMP (full name Bitmap) is the standard image file format in the Windows operating system and can be divided into two categories: device vector dependent bitmap (DDB) and device Vectorless dependent bitmap (DIB) is very widely used. It uses a bit-mapped storage format and does not use any other compression except for the optional image depth. Therefore, the BMP file takes up a lot of space. The image depth of BMP files can be selected from lbit, 4bit, 8bit and 24bit.
When BMP files store data, the image is scanned from left to right and bottom to top.
Since the BMP file format is a standard for exchanging graph-related data in the Windows environment, all graphics and image software running in the Windows environment support the BMP image format.
bmp format composition
A typical BMP image file consists of four parts:
1. Bitmap header file data structure, which Contains BMP image file type, display content and other information;
2. Bitmap information data structure, which contains BMP image width, height, compression method, and definition color and other information;
3. Palette, this part is optional. Some bitmaps require a palette, and some bitmaps, such as true color images (24-bit BMP), do not require a palette;
4 , Bitmap data, the content of this part varies according to the number of bits used in the BMP bitmap. In 24-bit images, RGB is used directly, while others less than 24 bits use the color index value in the palette.
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