实现灰度图像和彩色图像的迭代阈值分割算法c语言代码实现

以下是灰度图像和彩色图像的迭代阈值分割算法的C语言代码实现：

## 灰度图像迭代阈值分割算法

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

#define WIDTH 512
#define HEIGHT 512
#define MAX_ITER 100

void threshold(unsigned char* img, int width, int height, int* t) {
    int iter = 0;
    double t1 = 0.0, t2 = 255.0;
    double mean1 = 0.0, mean2 = 0.0;
    int count1 = 0, count2 = 0;
    double diff = 0.0, max_diff = 0.0;

    while (iter < MAX_ITER && fabs(t1 - t2) > 0.1) {
        iter++;
        mean1 = 0.0;
        mean2 = 0.0;
        count1 = 0;
        count2 = 0;

        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                if (img[i * width + j] <= *t) {
                    mean1 += img[i * width + j];
                    count1++;
                } else {
                    mean2 += img[i * width + j];
                    count2++;
                }
            }
        }

        if (count1 > 0 && count2 > 0) {
            mean1 /= count1;
            mean2 /= count2;
            t1 = *t;
            *t = (int) ((mean1 + mean2) / 2.0);
            t2 = *t;
        } else {
            break;
        }
    }
}

int main() {
    unsigned char* img = (unsigned char*) malloc(WIDTH * HEIGHT * sizeof(unsigned char));
    int t = 128;

    // 读取图像
    FILE* fp = fopen("lena_gray.raw", "rb");
    fread(img, sizeof(unsigned char), WIDTH * HEIGHT, fp);
    fclose(fp);

    // 进行阈值分割
    threshold(img, WIDTH, HEIGHT, &t);

    // 将阈值以下的像素设为0，以上的像素设为255
    for (int i = 0; i < HEIGHT; i++) {
        for (int j = 0; j < WIDTH; j++) {
            if (img[i * WIDTH + j] <= t) {
                img[i * WIDTH + j] = 0;
            } else {
                img[i * WIDTH + j] = 255;
            }
        }
    }

    // 保存图像
    fp = fopen("lena_gray_threshold.raw", "wb");
    fwrite(img, sizeof(unsigned char), WIDTH * HEIGHT, fp);
    fclose(fp);

    free(img);
    return 0;
}

## 彩色图像迭代阈值分割算法

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

#define WIDTH 512
#define HEIGHT 512
#define MAX_ITER 100

void threshold(unsigned char* img, int width, int height, int* t) {
    int iter = 0;
    double t1 = 0.0, t2 = 255.0;
    double mean1_r = 0.0, mean1_g = 0.0, mean1_b = 0.0;
    double mean2_r = 0.0, mean2_g = 0.0, mean2_b = 0.0;
    int count1 = 0, count2 = 0;
    double diff = 0.0, max_diff = 0.0;

    while (iter < MAX_ITER && fabs(t1 - t2) > 0.1) {
        iter++;
        mean1_r = 0.0;
        mean1_g = 0.0;
        mean1_b = 0.0;
        mean2_r = 0.0;
        mean2_g = 0.0;
        mean2_b = 0.0;
        count1 = 0;
        count2 = 0;

        for (int i = 0; i < height; i++) {
            for (int j = 0; j < width; j++) {
                int index = (i * width + j) * 3;
                if (img[index] <= *t && img[index + 1] <= *t && img[index + 2] <= *t) {
                    mean1_r += img[index];
                    mean1_g += img[index + 1];
                    mean1_b += img[index + 2];
                    count1++;
                } else {
                    mean2_r += img[index];
                    mean2_g += img[index + 1];
                    mean2_b += img[index + 2];
                    count2++;
                }
            }
        }

        if (count1 > 0 && count2 > 0) {
            mean1_r /= count1;
            mean1_g /= count1;
            mean1_b /= count1;
            mean2_r /= count2;
            mean2_g /= count2;
            mean2_b /= count2;
            t1 = *t;
            *t = (int) ((mean1_r + mean1_g + mean1_b + mean2_r + mean2_g + mean2_b) / 6.0);
            t2 = *t;
        } else {
            break;
        }
    }
}

int main() {
    unsigned char* img = (unsigned char*) malloc(WIDTH * HEIGHT * 3 * sizeof(unsigned char));
    int t = 128;

    // 读取图像
    FILE* fp = fopen("lena_color.raw", "rb");
    fread(img, sizeof(unsigned char), WIDTH * HEIGHT * 3, fp);
    fclose(fp);

    // 进行阈值分割
    threshold(img, WIDTH, HEIGHT, &t);

    // 将阈值以下的像素设为0，以上的像素设为255
    for (int i = 0; i < HEIGHT; i++) {
        for (int j = 0; j < WIDTH; j++) {
            int index = (i * WIDTH + j) * 3;
            if (img[index] <= t && img[index + 1] <= t && img[index + 2] <= t) {
                img[index] = img[index + 1] = img[index + 2] = 0;
            } else {
                img[index] = img[index + 1] = img[index + 2] = 255;
            }
        }
    }

    // 保存图像
    fp = fopen("lena_color_threshold.raw", "wb");
    fwrite(img, sizeof(unsigned char), WIDTH * HEIGHT * 3, fp);
    fclose(fp);

    free(img);
    return 0;
}