用c语言实现膨胀和腐蚀算法

膨胀和腐蚀是数字图像处理中常用的基础算法，可以用于图像的形态学处理和特征提取。下面是用 C 语言实现膨胀和腐蚀算法的示例代码。

膨胀算法：

void dilate(unsigned char *img, int width, int height) {
    unsigned char *tmp = malloc(width * height * sizeof(unsigned char));
    memcpy(tmp, img, width * height * sizeof(unsigned char));
    int kernel[3][3] = {{1, 1, 1}, {1, 1, 1}, {1, 1, 1}};
    for (int i = 1; i < height - 1; i++) {
        for (int j = 1; j < width - 1; j++) {
            unsigned char max_val = 0;
            for (int k = -1; k <= 1; k++) {
                for (int l = -1; l <= 1; l++) {
                    if (kernel[k + 1][l + 1] == 1) {
                        unsigned char val = tmp[(i + k) * width + (j + l)];
                        if (val > max_val) {
                            max_val = val;
                        }
                    }
                }
            }
            img[i * width + j] = max_val;
        }
    }
    free(tmp);
}

腐蚀算法：

void erode(unsigned char *img, int width, int height) {
    unsigned char *tmp = malloc(width * height * sizeof(unsigned char));
    memcpy(tmp, img, width * height * sizeof(unsigned char));
    int kernel[3][3] = {{1, 1, 1}, {1, 1, 1}, {1, 1, 1}};
    for (int i = 1; i < height - 1; i++) {
        for (int j = 1; j < width - 1; j++) {
            unsigned char min_val = 255;
            for (int k = -1; k <= 1; k++) {
                for (int l = -1; l <= 1; l++) {
                    if (kernel[k + 1][l + 1] == 1) {
                        unsigned char val = tmp[(i + k) * width + (j + l)];
                        if (val < min_val) {
                            min_val = val;
                        }
                    }
                }
            }
            img[i * width + j] = min_val;
        }
    }
    free(tmp);
}

这里采用了 3x3 的结构元素，可以根据实际需要修改结构元素的大小和形状。另外，为了避免膨胀和腐蚀操作时对原图像的影响，我们在操作过程中使用了一个临时缓冲区，最后再将结果拷贝回原图像数组中。