c++ - 如何从 matlab 将图像值分配给 Triclops 结构

Question

我使用以下 C++ typedef 结构:

typedef struct TriclopsColorImage
{
 // The number of rows in the image.
 int             nrows;
 // The number of columns in the image.
 int             ncols;
 // The row increment of the image.
 int             rowinc;
 // The pixel data for red band of the image.
    unsigned char*    red;
 // The pixel data for green band of the image.
    unsigned char*    green;
 // The pixel data for blue band of the image.
    unsigned char*    blue;

} TriclopsColorImage;

我有一张图像作为 prhs[1] 传递给 mex 函数如何正确分配红色、绿色和蓝色的字段。我这里有

TriclopsColorImage colorImage;

我正在做这样的事情:

    colorImage.nrows=(int) mxGetN(prhs[1]);
    colorImage.ncols=(int) mxGetM(prhs[1]);
    colorImage.rowinc=colorImage.ncols*2;
    colorImage.red=?
    colorImage.green=?
    colorImage.blue=?

Answer 1

您必须将图像作为大小为 m-by-n-by-3 的 uint8 类型传递给您的 mex 函数。< br/>例如:

img = imread( 'football.jpg' ); 
myMeFunction( someArg, img ); % note that prhs[1] is the SECOND argument

现在在你的 mex 中:

colorImage.nrows=(int) mxGetM(prhs[1]); // M is number of rows!
colorImage.ncols=(int) mxGetN(prhs[1]) / 3; // assuming third dimension is three.
// for the colors:
unsigned char* p = (unsigned char*)mxGetData(prhs[1]);    
colorImage.red = p;
colorImage.green = p + colorImage.nrows*colorImage.ncols;
colorImage.blue = p + 2*colorImage.nrows*colorImage.ncols;

请仔细阅读mxGetN的描述.