我需要对bmp图像进行处理，并且更简单的代码

下面是一个简单的C语言代码，用于对BMP图像进行直方图均衡化处理：

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

#define WIDTHBYTES(bits) (((bits) + 31) / 32 * 4)

void histogram_equalization(unsigned char *img, int width, int height);

int main(int argc, char *argv[])
{
    if (argc != 2)
    {
        printf("Usage: %s image.bmp\n", argv[0]);
        return 1;
    }

    FILE *fp = fopen(argv[1], "rb");

    if (!fp)
    {
        printf("Failed to open file: %s\n", argv[1]);
        return 1;
    }

    unsigned char header[54];
    fread(header, sizeof(unsigned char), 54, fp);

    int width = *(int *)(header + 18);
    int height = *(int *)(header + 22);

    int bits_per_pixel = *(unsigned short *)(header + 28);

    if (bits_per_pixel != 24)
    {
        printf("Only support 24bit BMP image\n");
        fclose(fp);
        return 1;
    }

    int row_size = WIDTHBYTES(width * bits_per_pixel);

    unsigned char *img = malloc(row_size * height);
    fread(img, sizeof(unsigned char), row_size * height, fp);

    fclose(fp);

    histogram_equalization(img, width, height);

    fp = fopen("output.bmp", "wb");

    if (!fp)
    {
        printf("Failed to create output file\n");
        free(img);
        return 1;
    }

    fwrite(header, sizeof(unsigned char), 54, fp);
    fwrite(img, sizeof(unsigned char), row_size * height, fp);

    fclose(fp);

    free(img);

    return 0;
}

void histogram_equalization(unsigned char *img, int width, int height)
{
    int hist[256] = {0};
    int cdf[256] = {0};
    int pixel_count = width * height;

    for (int i = 0; i < pixel_count; i++)
    {
        int gray = 0.299 * img[3 * i + 2] + 0.587 * img[3 * i + 1] + 0.114 * img[3 * i];
        hist[gray]++;
    }

    cdf[0] = hist[0];

    for (int i = 1; i < 256; i++)
    {
        cdf[i] = cdf[i - 1] + hist[i];
    }

    for (int i = 0; i < pixel_count; i++)
    {
        int gray = 0.299 * img[3 * i + 2] + 0.587 * img[3 * i + 1] + 0.114 * img[3 * i];
        img[3 * i] = img[3 * i + 1] = img[3 * i + 2] =
            (unsigned char)(cdf[gray] * 255.0 / pixel_count + 0.5);
    }
}

该代码实现了对24位BMP图像的直方图均衡化，基本思路是读取BMP图像，然后计算图像灰度直方图，接着计算累计分布函数(CDF)，最后根据CDF对图像进行均衡化处理。该代码使用了24位BMP图像的RGB通道进行灰度计算，处理后的图像保存为output.bmp文件。