霍夫变换直线检测程序c语言

霍夫变换直线检测是一种常用的图像处理算法，用检测图像中的直线。下面是一个使用C语言实现的简单霍夫变换直线检测的示例：

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

#define MAX_VOTES 1000

typedef struct {
    int x;
    int y;
} Point;

typedef struct {
    float rho;
    float theta;
} Line;

void houghTransform(int width, int height, unsigned char* image, int threshold, Line* lines, int* numLines) {
    int maxRho = sqrt(width * width + height * height);
    int numThetas = 180;
    int* accumulator = (int*)calloc(maxRho * numThetas, sizeof(int));

    // Voting
    for (int y = 0; y < height; y++) {
        for (int x = 0; x < width; x++) {
            if (image[y * width + x] > 0) {
                for (int theta = 0; theta < numThetas; theta++) {
                    float angle = theta * M_PI / numThetas;
                    float rho = x * cos(angle) + y * sin(angle);
                    int rhoIndex = (int)(rho + maxRho / 2);
                    accumulator[rhoIndex * numThetas + theta]++;
                }
            }
        }
    }

    // Finding lines
    *numLines = 0;
    for (int rhoIndex = 0; rhoIndex < maxRho; rhoIndex++) {
        for (int theta = 0; theta < numThetas; theta++) {
            if (accumulator[rhoIndex * numThetas + theta] > threshold) {
                lines[*numLines].rho = rhoIndex - maxRho / 2;
                lines[*numLines].theta = theta * M_PI / numThetas;
                (*numLines)++;
                if (*numLines >= MAX_VOTES) {
                    return;
                }
            }
        }
    }

    free(accumulator);
}

int main() {
    int width = 640;
    int height = 480;
    unsigned char* image = (unsigned char*)malloc(width * height * sizeof(unsigned char));

    // Load image data here

    Line lines[MAX_VOTES];
    int numLines = 0;
    int threshold = 100;

    houghTransform(width, height, image, threshold, lines, &numLines);

    printf("Detected %d lines:\n", numLines);
    for (int i = 0; i < numLines; i++) {
        printf("Line %d: rho = %.2f, theta = %.2f\n", i+1, lines[i].rho, lines[i].theta);
    }

    free(image);

    return 0;
}

这个程序实现了一个简单的霍夫变换直线检测算法。它首先对输入的图像进行霍夫变换，然后根据设定的阈值找到符合条件的直线，并输出检测到的直线的参数（rho和theta）。