有没有老哥有jpg转bmp的源码啊？
想要给我的上位机增加这个功能 C语言JPEG转BMP源码#include <stdio.h>
#include <stdlib.h>
#include <jpeglib.h>
void write_bmp_header(FILE *bmp_file, int width, int height) {
unsigned char bmpfileheader = {
0x42, 0x4D, // BM
0, 0, 0, 0, // file size
0, 0, // reserved
0, 0, // reserved
54, 0, 0, 0 // start of pixel data
};
unsigned char bmpinfoheader = {
40, 0, 0, 0, // size of this header
0, 0, 0, 0, // width of bitmap
0, 0, 0, 0, // height of bitmap
1, 0, // number of color planes
24, 0, // number of bits per pixel
0, 0, 0, 0, // compression method (no compression)
0, 0, 0, 0, // size of pixel data (can be 0 for BI_RGB bitmaps)
0, 0, 0, 0, // horizontal resolution
0, 0, 0, 0, // vertical resolution
0, 0, 0, 0, // number of colors in palette
0, 0, 0, 0 // important colors (0 = all colors are important)
};
int filesize = 54 + 3 * width * height;
bmpfileheader = (unsigned char)(filesize);
bmpfileheader = (unsigned char)(filesize >> 8);
bmpfileheader = (unsigned char)(filesize >> 16);
bmpfileheader = (unsigned char)(filesize >> 24);
bmpinfoheader = (unsigned char)(width);
bmpinfoheader = (unsigned char)(width >> 8);
bmpinfoheader = (unsigned char)(width >> 16);
bmpinfoheader = (unsigned char)(width >> 24);
bmpinfoheader = (unsigned char)(height);
bmpinfoheader = (unsigned char)(height >> 8);
bmpinfoheader = (unsigned char)(height >> 16);
bmpinfoheader = (unsigned char)(height >> 24);
fwrite(bmpfileheader, 1, 14, bmp_file);
fwrite(bmpinfoheader, 1, 40, bmp_file);
}
void jpeg_to_bmp(const char *jpeg_file, const char *bmp_file) {
FILE *infile = fopen(jpeg_file, "rb");
if (infile == NULL) {
fprintf(stderr, "Error opening JPEG file %s\n", jpeg_file);
return;
}
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
jpeg_read_header(&cinfo, TRUE);
jpeg_start_decompress(&cinfo);
int width = cinfo.output_width;
int height = cinfo.output_height;
int pixel_size = cinfo.output_components;
unsigned char *buffer = (unsigned char *)malloc(width * pixel_size);
if (buffer == NULL) {
fprintf(stderr, "Memory allocation failed\n");
return;
}
FILE *outfile = fopen(bmp_file, "wb");
if (outfile == NULL) {
fprintf(stderr, "Error opening BMP file %s\n", bmp_file);
return;
}
write_bmp_header(outfile, width, height);
unsigned char *row = (unsigned char *)malloc(3 * width);
if (row == NULL) {
fprintf(stderr, "Memory allocation failed\n");
return;
}
while (cinfo.output_scanline < height) {
jpeg_read_scanlines(&cinfo, &buffer, 1);
for (int i = 0; i < width; i++) {
row = buffer; // B
row = buffer; // G
row = buffer; // R
}
fwrite(row, 3, width, outfile);
}
free(row);
fclose(outfile);
free(buffer);
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);
}
int main(int argc, char *argv[]) {
if (argc != 3) {
fprintf(stderr, "Usage: %s <input.jpg> <output.bmp>\n", argv);
return 1;
}
jpeg_to_bmp(argv, argv);
return 0;
}
编译： 使用gcc编译此程序，并链接libjpeg库：
bash
gcc jpeg_to_bmp.c -o jpeg_to_bmp -ljpeg 运行： 执行程序时传入JPEG文件和目标BMP文件路径：
bash
./jpeg_to_bmp input.jpg output.bmp 该程序假定输入的JPEG文件是24位的无损压缩图像。如果处理其他类型的JPEG文件，可能需要更多的处理步骤。 如果需要处理更复杂的图像格式（如灰度图），则需要修改代码来适应不同的颜色深度。 通过这个源码，你可以将JPEG文件转换为BMP格式，并且可以根据实际需求对代码进行进一步修改
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