发一份调试成功可以读取拷贝bmp 图片的源码 [复制链接]

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#include  <stdio.h>
#include  <stdlib.h>

#include <sys/mman.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <sys/ioctl.h>
#include <linux/types.h>
#include <string.h>

typedef struct                       /**** BMP file header structure ****/
{
    unsigned int   bfSize;           /* Size of file */
    unsigned short bfReserved1;      /* Reserved */
    unsigned short bfReserved2;      /* ... */
    unsigned int   bfOffBits;        /* Offset to bitmap data */
} MyBITMAPFILEHEADER;

typedef struct                       /**** BMP file info structure ****/
{
    unsigned int   biSize;           /* Size of info header */
    int            biWidth;          /* Width of image */
    int            biHeight;         /* Height of image */
    unsigned short biPlanes;         /* Number of color planes */
    unsigned short biBitCount;       /* Number of bits per pixel */
    unsigned int   biCompression;    /* Type of compression to use */
    unsigned int   biSizeImage;      /* Size of image data */
    int            biXPelsPerMeter;  /* X pixels per meter */
    int            biYPelsPerMeter;  /* Y pixels per meter */
    unsigned int   biClrUsed;        /* Number of colors used */
    unsigned int   biClrImportant;   /* Number of important colors */
} MyBITMAPINFOHEADER;

typedef unsigned char BYTE;

typedef struct  tagRGBQUAD{

    BYTE rgbBlue;//蓝色的亮度（值范围为0-255)
    BYTE rgbGreen;//绿色的亮度（值范围为0-255)
    BYTE rgbRed;//红色的亮度（值范围为0-255)
    BYTE rgbReserved;//保留，必须为0
}RGBQUAD;

void SaveBmp(const char *filename,unsigned char *rgbbuf,int width,int height)
{
    MyBITMAPFILEHEADER bfh;
    MyBITMAPINFOHEADER bih;


    /* Magic number for file. It does not fit in the header structure due to alignment requirements, so put it outside */
    unsigned short bfType=0x4d42;
    bfh.bfReserved1 = 0;
    bfh.bfReserved2 = 0;
    bfh.bfSize = 2+sizeof(MyBITMAPFILEHEADER) + sizeof(MyBITMAPINFOHEADER)+width*height*3;
    bfh.bfOffBits = 0x36;

    bih.biSize = sizeof(MyBITMAPINFOHEADER);
    bih.biWidth = width;
    bih.biHeight = height;
    bih.biPlanes = 1;
    bih.biBitCount = 24;
    bih.biCompression = 0;
    bih.biSizeImage = 0;
    bih.biXPelsPerMeter = 5000;
    bih.biYPelsPerMeter = 5000;
    bih.biClrUsed = 0;
    bih.biClrImportant = 0;


    FILE *file = fopen(filename, "wb");
    if (!file)
    {
        printf("Could not write file\n");
        return;
    }

    /*Write headers*/
    fwrite(&bfType,sizeof(bfType),1,file);
    fwrite(&bfh,sizeof(bfh),1, file);
    fwrite(&bih,sizeof(bih),1, file);

    fwrite(rgbbuf,width*height*3,1,file);
    fclose(file);


}

int main()
{

    unsigned char *buffer;
    int length,imagesize;

    int fd,width,height;

    fd = open("k1.bmp", O_RDONLY);
    if (fd == -1) {
        printf("Unable to open file '\n");
        return;
    }

    imagesize = lseek(fd, 0, SEEK_END);
    printf("imgsize=%d \n",imagesize);
    lseek(fd, 0, SEEK_SET);


    buffer = malloc(imagesize);

    if (buffer == NULL) {
        printf("Unable to allocate memory for MJPEG image\n");
        return;
    }

    read(fd,buffer, imagesize);
    close(fd);

    SaveBmp("test.bmp", buffer+0x36 ,640, 360);


    return 0;

}

linux 下编译命令：

gcc bmp.c  -o bmp

运行：
./bmp     （运行前先将 k1.bmp  copy到运行目录下，运行后可发现有test.bmp 文件生成）