c++ - OpenInventor 到 PCD : cannot convert RGB to decimal

Question

我正在编写一个小程序来将 OpenInventor 文件转换为 PCD 文件。为此，我有两个输入文件，即 OpenInventor 文件和 JPEG 图像。纹理坐标是介于 0.0 和 1.0 之间的浮点值。

我使用OpenCV提取RGB值并以十进制格式返回，但是下面的函数好像不能正常运行...

float get_color(cv::Mat img, float x, float y) {

    int i = x*img.cols;
    int j = y*img.rows;

    unsigned char R = img.ptr<unsigned char>(j)[3*i];
    unsigned char G = img.ptr<unsigned char>(j)[3*i+1];
    unsigned char B = img.ptr<unsigned char>(j)[3*i+2];

    return  R*pow(16,4) +
            G*pow(16,2) +
            B;
}

我加载图像

 cv::imread("filename.jpg", CV_LOAD_IMAGE_COLOR).

Answer 1

您的意思是将其作为 32 位整数返回吗？

unsigned int get_color(cv::Mat img, float x, float y) 
{

    int i = x*img.cols;
    int j = y*img.rows;

    unsigned char R = img.ptr<unsigned char>(j)[3*i];
    unsigned char G = img.ptr<unsigned char>(j)[3*i+1];
    unsigned char B = img.ptr<unsigned char>(j)[3*i+2];

    return  (R << 16) |
            (G << 8) |
            B;
}

或者您可能想将其作为 float 返回，在这种情况下您需要执行以下操作

struct FloatColour
{
    float r;
    float g;
    float b;
};

float get_color(cv::Mat img, float x, float y) 
{

    int i = x*img.cols;
    int j = y*img.rows;

    unsigned char R = img.ptr<unsigned char>(j)[3*i];
    unsigned char G = img.ptr<unsigned char>(j)[3*i+1];
    unsigned char B = img.ptr<unsigned char>(j)[3*i+2];

    FloatColour retCol;
    retCol.r = R / 255.0f;
    retCol.g = G / 255.0f;
    retCol.b = B / 255.0f;
    return retCol;
}