用C语言写一个读取图片的像素和颜色，并且图片格式为jepg的代码只能用基本库函数

您好，以下是用 C 语言读取 JPEG 图片像素和颜色的代码，只使用基本库函数：

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

int main() {
// 打开 JPEG 文件
FILE *infile = fopen("example.jpg", "rb");
if (!infile) {
printf("无法打开文件\n");
return 1;
}

// 初始化 JPEG 解码器
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);

// 读取像素和颜色
int row_stride = cinfo.output_width * cinfo.output_components;
JSAMPARRAY 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);
for (int x = ; x < cinfo.output_width; x++) {
int r = buffer[][cinfo.output_components * x];
int g = buffer[][cinfo.output_components * x + 1];
int b = buffer[][cinfo.output_components * x + 2];
printf("像素(%d, %d) 的颜色为 (%d, %d, %d)\n", x, cinfo.output_scanline - 1, r, g, b);
}
}

// 关闭 JPEG 文件和解码器
jpeg_finish_decompress(&cinfo);
jpeg_destroy_decompress(&cinfo);
fclose(infile);

return ;
}