帮我用c语音写一个把bmp图像分割成指定块数,成为个小块的bmp图像
时间: 2024-03-19 07:45:16 浏览: 17
好的,以下是一个简单的示例程序,用于将一个bmp图像分割成指定块数的小块bmp图像。请注意,这个程序仅支持24位bmp图像,且未做过多的错误处理和优化,仅供参考。
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#pragma pack(push, 1)
typedef struct {
char type[2];
int size;
short reserved1;
short reserved2;
int offset;
} bmp_header;
typedef struct {
int size;
int width;
int height;
short planes;
short bit_count;
int compression;
int size_image;
int x_pels_per_meter;
int y_pels_per_meter;
int clr_used;
int clr_important;
} bmp_info;
typedef struct {
unsigned char b;
unsigned char g;
unsigned char r;
} pixel;
#pragma pack(pop)
void split_bmp(char* src_file, char* dst_prefix, int block_size) {
FILE *fp_src, *fp_dst;
bmp_header header;
bmp_info info;
pixel **pixels, **blocks;
int i, j, k, l, x, y, dst_size;
// 打开源文件
if ((fp_src = fopen(src_file, "rb")) == NULL) {
printf("Cannot open file %s.\n", src_file);
return;
}
// 读取bmp头信息
fread(&header, sizeof(bmp_header), 1, fp_src);
fread(&info, sizeof(bmp_info), 1, fp_src);
// 检查是否为24位bmp图像
if (info.bit_count != 24) {
printf("%s is not a 24-bit BMP image.\n", src_file);
fclose(fp_src);
return;
}
// 计算每个小块的宽度和高度
int block_width = info.width / block_size;
int block_height = info.height / block_size;
// 分配像素数据和小块数据的内存
pixels = (pixel**)malloc(info.height * sizeof(pixel*));
blocks = (pixel**)malloc(block_height * sizeof(pixel*));
for (i = 0; i < info.height; i++) {
pixels[i] = (pixel*)malloc(info.width * sizeof(pixel));
}
for (i = 0; i < block_height; i++) {
blocks[i] = (pixel*)malloc(block_width * sizeof(pixel));
}
// 读取像素数据
for (i = 0; i < info.height; i++) {
for (j = 0; j < info.width; j++) {
fread(&pixels[i][j], sizeof(pixel), 1, fp_src);
}
}
// 分割并保存小块bmp图像
for (i = 0; i < block_size; i++) {
for (j = 0; j < block_size; j++) {
// 计算小块的左上角位置
x = j * block_width;
y = i * block_height;
// 复制小块的像素数据
for (k = 0; k < block_height; k++) {
for (l = 0; l < block_width; l++) {
blocks[k][l] = pixels[y + k][x + l];
}
}
// 保存小块bmp图像
char dst_file[256];
sprintf(dst_file, "%s_%d_%d.bmp", dst_prefix, i, j);
if ((fp_dst = fopen(dst_file, "wb")) == NULL) {
printf("Cannot create file %s.\n", dst_file);
fclose(fp_src);
return;
}
dst_size = sizeof(bmp_header) + sizeof(bmp_info) + block_height * block_width * sizeof(pixel);
header.size = dst_size;
header.offset = sizeof(bmp_header) + sizeof(bmp_info);
info.width = block_width;
info.height = block_height;
info.size_image = block_height * block_width * sizeof(pixel);
fwrite(&header, sizeof(bmp_header), 1, fp_dst);
fwrite(&info, sizeof(bmp_info), 1, fp_dst);
for (k = 0; k < block_height; k++) {
fwrite(blocks[k], sizeof(pixel), block_width, fp_dst);
}
fclose(fp_dst);
}
}
// 释放内存
for (i = 0; i < info.height; i++) {
free(pixels[i]);
}
free(pixels);
for (i = 0; i < block_height; i++) {
free(blocks[i]);
}
free(blocks);
// 关闭文件
fclose(fp_src);
}
int main() {
split_bmp("test.bmp", "block", 4);
return 0;
}
```
这个程序将会把名为"test.bmp"的bmp图像分割成4x4的小块bmp图像,并保存在以"block"为前缀的文件名中。您可以根据自己的需要修改输入输出文件名和块数等参数。