点云转化为深度图C++程序

点云转化为深度图的过程可以理解为将三维坐标映射到二维平面上，也就是将点云中每个点的深度信息转化为像素的灰度值。下面是一个简单的点云转深度图的 C 代码示例：

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

#define WIDTH 640
#define HEIGHT 480

typedef struct {
    float x, y, z;
} Point3f;

typedef struct {
    unsigned char r, g, b;
} ColorRGB;

typedef struct {
    Point3f pos;
    ColorRGB color;
} Vertex;

// 将点云投影到深度图上
void projectPointCloud(Vertex *pointCloud, int numPoints, unsigned short *depthMap)
{
    // 将深度图初始化为最大值
    for (int i = 0; i < WIDTH * HEIGHT; i++) {
        depthMap[i] = 0xFFFF;
    }

    float fx = 525.0f; // 相机内参
    float fy = 525.0f;
    float cx = 319.5f;
    float cy = 239.5f;

    for (int i = 0; i < numPoints; i++)
    {
        Point3f pos = pointCloud[i].pos;
        int x = (int)(pos.x * fx / pos.z + cx);
        int y = (int)(pos.y * fy / pos.z + cy);

        // 将点的深度信息转化为灰度值
        unsigned short depth = (unsigned short)(pos.z * 1000.0f);
        if (x >= 0 && x < WIDTH && y >= 0 && y < HEIGHT && depth < depthMap[y * WIDTH + x]) {
            depthMap[y * WIDTH + x] = depth;
        }
    }
}

int main(void)
{
    int numPoints = 10000;
    Vertex *pointCloud = (Vertex *)malloc(sizeof(Vertex) * numPoints);
    unsigned short *depthMap = (unsigned short *)malloc(sizeof(unsigned short) * WIDTH * HEIGHT);

    // 生成随机点云
    for (int i = 0; i < numPoints; i++) {
        pointCloud[i].pos.x = ((float)rand() / RAND_MAX - 0.5f) * 10.0f;
        pointCloud[i].pos.y = ((float)rand() / RAND_MAX - 0.5f) * 10.0f;
        pointCloud[i].pos.z = ((float)rand() / RAND_MAX) * 5.0f + 5.0f;
        pointCloud[i].color.r = (unsigned char)(255 * (pointCloud[i].pos.x / 10.0f + 0.5f));
        pointCloud[i].color.g = (unsigned char)(255 * (pointCloud[i].pos.y / 10.0f + 0.5f));
        pointCloud[i].color.b = (unsigned char)(255 * (pointCloud[i].pos.z / 10.0f));
    }

    // 将点云投影到深度图上
    projectPointCloud(pointCloud, numPoints, depthMap);

    // 保存深度图
    FILE *fp = fopen("depthMap.bin", "wb");
    fwrite(depthMap, sizeof(unsigned short), WIDTH * HEIGHT, fp);
    fclose(fp);

    free(pointCloud);
    free(depthMap);

    return 0;
}

这段代码中，我们首先定义了一个点云数据结构 `Vertex`，其中包含了每个点的坐标和颜色信息。然后我们实现了一个 `projectPointCloud` 函数，该函数将点云投影到深度图上，其中使用了相机内参和透视投影的知识。最后我们生成了随机点云数据，将其投影到深度图上，并将深度图保存到文件中。