One of the lines of the code that i'm editing from IplImage* to Mat is
CV_IMAGE_ELEM(output, float, pit->y, pit->x) = CV_IMAGE_ELEM(SWTImage, float, pit->y, pit->x);
Please tell me how to convert it into Mat format for C++.
the CV_IMAGE_ELEM was a macro in the old C opencv api in order to obtain the pixel value of an image. Assume a gray-scale image, access to the row i, column j pixel can be:
CV_IMAGE_ELEM (image, type, i, j);
or in case of a colour image:
CV_IMAGE_ELEM (image, type, i, Nc * j + c);
, where
For example:
CV_IMAGE_ELEM (image, uchar, i, 3 * j)
CV_IMAGE_ELEM (image, uchar, i, 3 * j +1)
CV_IMAGE_ELEM (image, uchar, i, 3 * j +2)
Now if you want to transform this into the new C++ api you can do it different ways:
You use the at method to access the value at a particular position (i, j):
type elem_a= matrix.at<type>[c](i,j); //access element aij, with i from 0 to rows-1 and j from 0 to cols-1
Instead of specifying the position with i and j, you can use a Point object:
Point p=Point(x,y);
type elem_a= matrix.at<type>[c](p); //Warning: y ranges from 0 to rows-1 and x from 0 to cols-1
or you can use the ptr method to obtain a pointer to a particular row. Then you use the [] to access a particular pixel in a particular channel:
type elem = matrix.ptr<type>(i)[Nc * j + c]
, where
Asked: 2015-05-29 03:14:16 -0600
Seen: 1,830 times
Last updated: May 29 '15
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