C语言对图像进行均值滤波

以下是C语言实现图像均值滤波的示例代码：

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

#define ROWS 256
#define COLS 256

void mean_filter(unsigned char input[ROWS][COLS], unsigned char output[ROWS][COLS], int kernel_size)
{
    int i, j, m, n, sum;
    int kernel_radius = kernel_size / 2;
    for (i = kernel_radius; i < ROWS - kernel_radius; i++) {
        for (j = kernel_radius; j < COLS - kernel_radius; j++) {
            sum = 0;
            for (m = -kernel_radius; m <= kernel_radius; m++) {
                for (n = -kernel_radius; n <= kernel_radius; n++) {
                    sum += input[i+m][j+n];
                }
            }
            output[i][j] = sum / (kernel_size * kernel_size);
        }
    }
}

int main()
{
    unsigned char input[ROWS][COLS];
    unsigned char output[ROWS][COLS];
    FILE *fp_in, *fp_out;
    int i, j;
    
    // 读取图像文件
    fp_in = fopen("input_image.raw", "rb");
    if (fp_in == NULL) {
        printf("Cannot open input_image.raw.\n");
        exit(1);
    }
    fread(input, sizeof(unsigned char), ROWS*COLS, fp_in);
    fclose(fp_in);
    
    // 进行均值滤波
    mean_filter(input, output, 3); // kernel_size = 3
    
    // 保存输出图像
    fp_out = fopen("output_image.raw", "wb");
    if (fp_out == NULL) {
        printf("Cannot open output_image.raw.\n");
        exit(1);
    }
    fwrite(output, sizeof(unsigned char), ROWS*COLS, fp_out);
    fclose(fp_out);
    
    return 0;
}

该代码使用了一个3x3的滤波器进行均值滤波。可以通过修改`kernel_size`变量来改变滤波器大小。`mean_filter`函数用于实现均值滤波，输入图像存储在`input`数组中，输出图像存储在`output`数组中。`main`函数用于读取输入图像文件，进行均值滤波，并保存输出图像文件。