c语言jpg图像24位转16位raw数据
时间: 2023-06-24 08:07:18 浏览: 71
将24位的JPEG图像转换为16位的RAW数据需要经过三个步骤:
1. 解码JPEG图像:使用JPEG库(如libjpeg)将JPEG图像解码为RGB颜色空间的像素数据。
2. 转换RGB到YUV颜色空间:使用公式将RGB像素数据转换为YUV格式。公式如下:
Y = 0.299*R + 0.587*G + 0.114*B
U = -0.14713*R - 0.28886*G + 0.436*B
V = 0.615*R - 0.51498*G - 0.10001*B
3. 将YUV数据转换为16位RAW格式:将每个像素的Y,U和V值比例缩放到0-65535的范围内,然后将它们组合成一个16位的RAW数据。
下面是一个示例代码,演示如何将24位JPEG图像转换为16位RAW数据:
```c
#include <stdio.h>
#include <stdlib.h>
#include <jpeglib.h>
void convert_jpeg_to_raw(char *input_file, char *output_file)
{
struct jpeg_decompress_struct cinfo;
struct jpeg_error_mgr jerr;
FILE *infile, *outfile;
JSAMPARRAY buffer;
int row_stride;
if ((infile = fopen(input_file, "rb")) == NULL) {
fprintf(stderr, "Can't open %s\n", input_file);
exit(1);
}
if ((outfile = fopen(output_file, "wb")) == NULL) {
fprintf(stderr, "Can't open %s\n", output_file);
exit(1);
}
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_decompress(&cinfo);
jpeg_stdio_src(&cinfo, infile);
jpeg_read_header(&cinfo, TRUE);
jpeg_start_decompress(&cinfo);
row_stride = cinfo.output_width * cinfo.output_components;
buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);
while (cinfo.output_scanline < cinfo.output_height) {
jpeg_read_scanlines(&cinfo, buffer, 1);
// Convert RGB to YUV format
for (int i = 0; i < cinfo.output_width; i++) {
int r = buffer[0][i * 3];
int g = buffer[0][i * 3 + 1];
int b = buffer[0][i * 3 + 2];
int y = 0.299 * r + 0.587 * g + 0.114 * b;
int u = -0.14713 * r - 0.28886 * g + 0.436 * b;
int v = 0.615 * r - 0.51498 * g - 0.10001 * b;
// Scale values to 0-65535 range and pack into 16-bit raw data
unsigned short pixel = ((y * 65535 / 255) << 10) | ((u * 65535 / 255) << 5) | (v * 65535 / 255);
fwrite(&pixel, sizeof(unsigned short), 1, outfile);
}
}
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);
fclose(outfile);
}
```
在这个示例代码中,我们使用libjpeg库来解码JPEG图像,并将RGB像素数据转换为YUV格式。然后,我们将Y,U和V值缩放到0-65535的范围内,并将它们组合成一个16位的RAW数据,写入输出文件中。