要求: 用c语言编写一个程序,可以在命令行输入参数,完成指定文件的缩放,并存储到新文件,命令行参数如下 zoom file1.bmp 200 file2.bmp 第一个参数为可执行程序名称,第二个参数为原始图像文件名,第三个参数为缩放比例(百分比),第四个参数为新文件名
时间: 2024-05-10 09:15:14 浏览: 7
以下是一个简单的 C 语言程序,可以实现对 BMP 格式的图片进行缩放:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#pragma pack(1)
typedef struct tagBITMAPFILEHEADER {
unsigned short bfType;
unsigned int bfSize;
unsigned short bfReserved1;
unsigned short bfReserved2;
unsigned int bfOffBits;
} BITMAPFILEHEADER;
typedef struct tagBITMAPINFOHEADER {
unsigned int biSize;
int biWidth;
int biHeight;
unsigned short biPlanes;
unsigned short biBitCount;
unsigned int biCompression;
unsigned int biSizeImage;
int biXPelsPerMeter;
int biYPelsPerMeter;
unsigned int biClrUsed;
unsigned int biClrImportant;
} BITMAPINFOHEADER;
int main(int argc, char *argv[])
{
if (argc != 4) {
printf("Usage: %s [input file] [scale percent] [output file]\n", argv[0]);
return 1;
}
char *in_file = argv[1];
char *out_file = argv[3];
float scale_percent = atof(argv[2]) / 100.0;
FILE *fp_in = fopen(in_file, "rb");
if (!fp_in) {
printf("Error: %s\n", strerror(errno));
return 1;
}
BITMAPFILEHEADER bfh;
BITMAPINFOHEADER bih;
fread(&bfh, sizeof(BITMAPFILEHEADER), 1, fp_in);
fread(&bih, sizeof(BITMAPINFOHEADER), 1, fp_in);
int width = bih.biWidth;
int height = bih.biHeight;
int channels = bih.biBitCount / 8;
int row_size = ((width * channels + 3) / 4) * 4;
int new_width = width * scale_percent;
int new_height = height * scale_percent;
int new_row_size = ((new_width * channels + 3) / 4) * 4;
int new_size = new_row_size * new_height;
unsigned char *data = (unsigned char *) malloc(row_size * height);
unsigned char *new_data = (unsigned char *) malloc(new_size);
fread(data, row_size, height, fp_in);
fclose(fp_in);
for (int y = 0; y < new_height; y++) {
for (int x = 0; x < new_width; x++) {
int src_x = x / scale_percent;
int src_y = y / scale_percent;
for (int c = 0; c < channels; c++) {
new_data[y * new_row_size + x * channels + c] = data[src_y * row_size + src_x * channels + c];
}
}
}
FILE *fp_out = fopen(out_file, "wb");
if (!fp_out) {
printf("Error: %s\n", strerror(errno));
return 1;
}
fwrite(&bfh, sizeof(BITMAPFILEHEADER), 1, fp_out);
fwrite(&bih, sizeof(BITMAPINFOHEADER), 1, fp_out);
fwrite(new_data, new_size, 1, fp_out);
fclose(fp_out);
free(data);
free(new_data);
return 0;
}
```
这个程序可以从命令行接受三个参数:原始图像文件名、缩放比例(百分比)和新文件名。例如,你可以在命令行输入以下命令来使用这个程序:
```
zoom.exe file1.bmp 200 file2.bmp
```
这个命令会将 `file1.bmp` 图像放大两倍,并保存到 `file2.bmp` 文件中。注意,这个程序只支持 BMP 格式的图片,其他格式的图片需要按照不同的格式解析和处理。