将点云Z向数据生成伪彩图、灰度图（最小值和最大值区间映射RGB三通道）

最新推荐文章于 2024-08-09 11:44:18 发布

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最新推荐文章于 2024-08-09 11:44:18 发布 · 809 阅读

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#算法 #c# #图像处理

C# 指针遍历+for循环多线程

public unsafe static HObject PointXYZ_To_GrayColorHobject(ref PointXYZ[] PointCloudData, int ImgWidth, int ImgHeight, float ZMin, float ZMax,out HObject colorImg)
{
    try
    {
        HObject ImgHobject = null;
        colorImg = null;
        if (PointCloudData == null) return ImgHobject;
        //归一化后按 0-1/3  1/3-2/3  2/3-1 进行颜色映射
        float cut1 = 1.0f / 3.0f;
        float cut2 = 2.0f / 3.0f;
        int numPoints = PointCloudData.Length;
        float RangeZ = ZMax - ZMin;//点云数据范围
        float coefficient = RangeZ > 0 ? 255 * 1.0f / RangeZ : 0;//灰度系数
        //byte[] grayArr = new byte[numPoints];
        IntPtr colorPtr = Marshal.AllocHGlobal(numPoints * 3 * sizeof(byte));//分配伪彩图RGB内存
        IntPtr grayPtr = Marshal.AllocHGlobal(numPoints * sizeof(byte));//分配灰度图内存
        int numProcessedPoints = ImgWidth - (ImgWidth % 4); // 可以处理的点的数量（4的倍数）
        fixed (PointXYZ* pData = PointCloudData)
        {
            float* pHeight = (float*)pData;
            byte* colorPtrTemp = (byte*)colorPtr;
            byte* grayPtrTemp = (byte*)grayPtr;
            Parallel.For(0, ImgHeight, Row =>
            {
                float* PRowIndexPointData = pHeight + Row * ImgWidth * 3;//点云指针
                byte* pDest = colorPtrTemp + Row * 3 * ImgWidth;//伪彩图图像遍历指针
                byte* pGrayDest = grayPtrTemp + Row * ImgWidth;//灰度图图像遍历指针
                for (int Col = 0; Col < numProcessedPoints; Col += 4)
                {
                    float height1 = PRowIndexPointData[2];
                    float height2 = PRowIndexPointData[5];
                    float height3 = PRowIndexPointData[8];
                    float height4 = PRowIndexPointData[11];
                    #region gray灰度映射
                    pGrayDest[0] = (byte)((height1 >= ZMin && height1 <= ZMax) ? (height1 - ZMin) * coefficient : 0);
                    pGrayDest[1] = (byte)((height2 >=