用c语言编写直方图均衡算法

以下是用C语言实现直方图均衡算法的代码：

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

#define WIDTH 256
#define HEIGHT 256

int main() {
    unsigned char image[WIDTH][HEIGHT];
    int histogram[WIDTH] = {0};
    int cumulative_histogram[WIDTH] = {0};
    int equalized_histogram[WIDTH] = {0};
    int total_pixels = WIDTH * HEIGHT;

    // 读取图像数据
    FILE *fp = fopen("lena.raw", "rb");
    fread(image, 1, total_pixels, fp);
    fclose(fp);

    // 计算原始直方图
    for (int i = 0; i < WIDTH; i++) {
        for (int j = 0; j < HEIGHT; j++) {
            histogram[image[i][j]]++;
        }
    }

    // 计算累积直方图
    cumulative_histogram[0] = histogram[0];
    for (int i = 1; i < WIDTH; i++) {
        cumulative_histogram[i] = cumulative_histogram[i-1] + histogram[i];
    }

    // 计算直方图均衡化后的像素值
    for (int i = 0; i < WIDTH; i++) {
        equalized_histogram[i] = (cumulative_histogram[i] * (WIDTH-1) + total_pixels/2) / total_pixels;
    }

    // 应用直方图均衡化
    for (int i = 0; i < WIDTH; i++) {
        for (int j = 0; j < HEIGHT; j++) {
            image[i][j] = equalized_histogram[image[i][j]];
        }
    }

    // 输出结果
    fp = fopen("lena_equalized.raw", "wb");
    fwrite(image, 1, total_pixels, fp);
    fclose(fp);

    return 0;
}

该代码将图像数据读入一个二维数组中，然后计算原始直方图、累积直方图和直方图均衡化后的像素值，最后应用直方图均衡化，将结果输出到文件中。其中，WIDTH和HEIGHT分别表示图像的宽度和高度，lena.raw是输入文件名，lena_equalized.raw是输出文件名。