bmp文件结构(国外英语资料).docVIP

bmp文件结构(国外英语资料) *.bmp file structure The *.bmp file, like most graphics files, is divided into two parts: the file description area (header file information) and the image storage area (pixel data). The header file contains two parts: the information area and the palette area, and the information area can be subdivided into two parts: the file information area and the image information area. Here, take the 256 color 320*200 BMP image as an example. The offset length of the header file description area is 1078 bytes, that is to say, the image storage area is read from the file offset 1078. In the header file description area, the offset length of the header information area is 54 bytes, that is to say, the palette data area is 1024 bytes from 54-1078. In the header information area, the file information area occupies 14 bytes, while the image information area occupies 40 bytes. (1) document information area Typedef struct BMP_file { Unsigned int bfType; / / file type Unsigned long bfSize; //bmp file length Unsigned int Reserved1; Unsigned int Reserved2; Unsigned long bfOffset; / / file description area length, 16 color 118256 color 1078 }bitmapfile; Now count, there are 3 int, 2 long, exactly 3*2+2*4=14 bytes (2) image information area Type struct BMP_info { Unsigned long biSize; Unsigned long biWidth; Unsigned long biHeight; Unsigned int biPlanes; Unsigned int biBitCount; Unsigned long biCompression; Unsigned long biSizeImage; Unsigned long biXplosPerMeter; Unsigned long biYplosPerMeter; Unsigned long biClrUsed; Unsigned long biClrImportant; }bitmapinfo; Now count, 2 int, 9 long, exactly 2+2*9*4=40 bytes. (3) palette area Typedef struct RGB_BMP_typ { Unsigned char blue; Unsigned char green; Unsigned char red; Unsigned char reserved; }RGB_BMP, *RGB_BMP_ptr; Description: RGB + grayscale, a total of 4*256=1024 bytes. The following is a complete structural definition of the BMP file: Typedef struct bmp_picture_typ { Bitmapfile file; BITMAPINFO info; RGB_BMP palette[256]