c语言代码实现位图直方图均衡，编写一个程序，可以在命令行输入参数，完成指定文件的直方图均衡，并存储到新文件，命令行参数如下 hist file1.bmp file2.bmp

好的，以下是 C 语言代码实现直方图均衡的示例，您可以在命令行中输入 "hist file1.bmp file2.bmp" 来进行图像处理。其中 file1.bmp 是您要进行直方图均衡的源文件名，file2.bmp 是您要保存结果的目标文件名。

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

#pragma pack(2)
typedef struct {
    uint16_t type;
    uint32_t size;
    uint16_t reserved1;
    uint16_t reserved2;
    uint32_t offset;
} BMPHeader;

#pragma pack(2)
typedef struct {
    uint32_t size;
    int32_t width;
    int32_t height;
    uint16_t planes;
    uint16_t bits_per_pixel;
    uint32_t compression;
    uint32_t image_size;
    int32_t x_pixels_per_meter;
    int32_t y_pixels_per_meter;
    uint32_t colors_used;
    uint32_t colors_important;
} BMPInfo;

void histogram_equalization(uint8_t* image, int width, int height) {
    int histogram[256] = { 0 };
    int cdf[256] = { 0 };
    int cumulative = 0;

    // 统计每个像素值的出现次数
    for (int i = 0; i < width * height; i++) {
        histogram[image[i]]++;
    }

    // 计算累计分布函数
    for (int i = 0; i < 256; i++) {
        cumulative += histogram[i];
        cdf[i] = cumulative;
    }

    // 直方图均衡化
    for (int i = 0; i < width * height; i++) {
        int pixel = image[i];
        int new_pixel = 255 * cdf[pixel] / (width * height);
        image[i] = new_pixel;
    }
}

int main(int argc, char** argv) {
    if (argc != 3) {
        printf("Usage: hist <source_file> <target_file>\n");
        return 0;
    }

    char* source_file = argv[1];
    char* target_file = argv[2];

    FILE* fp = fopen(source_file, "rb");
    if (!fp) {
        printf("Failed to open source file\n");
        return 0;
    }

    BMPHeader header;
    BMPInfo info;
    fread(&header, sizeof(header), 1, fp);
    fread(&info, sizeof(info), 1, fp);

    if (header.type != 0x4d42 || info.bits_per_pixel != 8) {
        printf("Unsupported image format\n");
        fclose(fp);
        return 0;
    }

    int width = abs(info.width);
    int height = abs(info.height);
    int padding = (4 - ((width * 8) % 32) / 8) % 4;

    uint8_t* image = (uint8_t*)malloc(width * height);
    fread(image, 1, width * height, fp);
    fclose(fp);

    histogram_equalization(image, width, height);

    fp = fopen(target_file, "wb");
    if (!fp) {
        printf("Failed to save target file\n");
        free(image);
        return 0;
    }

    fwrite(&header, sizeof(header), 1, fp);
    fwrite(&info, sizeof(info), 1, fp);
    fwrite(image, 1, width * height, fp);

    uint8_t pad[4] = { 0 };
    for (int i = 0; i < padding; i++) {
        fwrite(pad, 1, 4, fp);
    }

    fclose(fp);
    free(image);

    printf("Histogram equalization completed\n");

    return 0;
}

该程序使用了标准 C 库函数和文件操作函数，读取和保存图像文件，以及进行直方图均衡化。在函数 `histogram_equalization` 中，使用了与 Python 版本相同的直方图统计、累计分布函数计算和直方图均衡化算法。程序中还包括了 BMP 文件头和信息头的结构体定义和读写代码，以及对图像格式的判断和错误处理。