用C语言实现RANSAC算法

RANSAC算法是一个随机采样一致性算法，用于估计数据集中的模型参数。下面是用C语言实现RANSAC算法的代码示例：

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

#define MAX_POINTS 1000
#define MAX_ITERATIONS 1000
#define THRESHOLD 0.1

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

int main() {
    Point points[MAX_POINTS];
    int num_points;
    srand(time(NULL));

    // Generate some random points
    num_points = rand() % MAX_POINTS;
    for (int i = 0; i < num_points; i++) {
        points[i].x = (float)rand() / RAND_MAX;
        points[i].y = (float)rand() / RAND_MAX;
    }

    // RANSAC algorithm
    int best_inliers = 0;
    float best_slope, best_intercept;

    for (int i = 0; i < MAX_ITERATIONS; i++) {
        // Randomly select two points to form a line
        int index1 = rand() % num_points;
        int index2 = rand() % num_points;
        float x1 = points[index1].x;
        float y1 = points[index1].y;
        float x2 = points[index2].x;
        float y2 = points[index2].y;

        // Compute the slope and y-intercept of the line
        float slope = (y2 - y1) / (x2 - x1);
        float y_intercept = y1 - slope * x1;

        // Count the number of inliers
        int num_inliers = 0;
        for (int j = 0; j < num_points; j++) {
            float distance = fabs(points[j].y - slope * points[j].x - y_intercept);
            if (distance < THRESHOLD) {
                num_inliers++;
            }
        }

        // Update the best line if this iteration found more inliers
        if (num_inliers > best_inliers) {
            best_inliers = num_inliers;
            best_slope = slope;
            best_intercept = y_intercept;
        }
    }

    // Print the best line
    printf("Best line: y = %fx + %f\n", best_slope, best_intercept);

    return 0;
}

该代码首先生成一些随机点，然后使用RANSAC算法估计最佳拟合直线的斜率和截距。在每次迭代中，它随机选择两个点来形成一条直线，并计算所有点到该直线的距离。如果距离小于阈值，则将该点标记为内点。最终，该算法会选择具有最多内点的直线作为最佳拟合直线。