パディングを回避する

gistfile1.cpp

#include <iostream>
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

// カスタムアロケータ
namespace cvut
{
    template<int alignment_bytes>
    class customAllocator: public cv::MatAllocator
    {
    public:
	customAllocator () {}
	virtual ~customAllocator() {}
	
	void allocate(int dims, const int* sizes, int type, int*& refcount,
		      uchar*& datastart, uchar*& data, size_t* step)
	{
	    // latest step is always equals with element size.
	    // e.g. step[1] == 24 when matrix is 2-d CV_8UC3.
	    step[dims-1] = CV_ELEM_SIZE(type);

	    // calculate each step[x] from bottom to top.
	    // cv::alignSize is effective when step[dims - 2].
	    for(int d = dims - 2; d >= 0; --d) {
		step[d] = cv::alignSize(step[d+1] * sizes[d], alignment_bytes);
	    }
	    
	    // total needed size of new allocation 
	    const size_t total
		= cv::alignSize(sizeof(size_t),     alignment_bytes)
		+ cv::alignSize(step[0] * sizes[0], alignment_bytes);

	    // allocate new memory region and save the its pointer.
	    uint8_t* const allocated_pointer = reinterpret_cast<uint8_t*>(cv::fastMalloc(total));

	    refcount         = reinterpret_cast<int*>(allocated_pointer);
	    data = datastart = reinterpret_cast<uint8_t*>
		(allocated_pointer + cv::alignSize(sizeof(size_t), alignment_bytes));

	    // set to refcount is 1 because its allocated now and its reference is 1
	    // until this method.
	    *refcount = 1;
	}
	
	// deallocate
	void deallocate(int* refcount, uchar* datastart, uchar* data)
	{
	    if (!refcount) return; // allocated by user
	    else           cv::fastFree(refcount); // allocated by its allocator
	}
    };

    customAllocator<4> allocator_gl;
}


int
main(int argc, char *argv[])
{
    cv::Mat src_mat(333, 333, CV_8UC3);// = cv::imread("../../image/lenna333x333.png", 1);
    if(src_mat.empty()) return -1; 

    int cols = 333, rows = 333;

    

    // カスタムアロケータを使用する
    cv::Mat dst_mat;
    dst_mat.allocator = &cvut::allocator_gl;
    src_mat.copyTo(dst_mat);

    std::cout << "src_mat" << std::endl;
    std::cout << "  size=(" << src_mat.cols << ", " << src_mat.rows << ")" << std::endl;
    std::cout << "  step=" << src_mat.step << std::endl;
    std::cout << "  isContinuous:" << (src_mat.isContinuous()?"true":"false") << std::endl;
    std::cout << "  isSubmatrix=" << (src_mat.isSubmatrix()?"true":"false") << std::endl;
    std::cout << "dst_mat" << std::endl;
    std::cout << "  size=(" << dst_mat.cols << ", " << dst_mat.rows << ")" << std::endl;
    std::cout << "  step=" << dst_mat.step << std::endl;
    std::cout << "  isContinuous=" << (dst_mat.isContinuous()?"true":"false") << std::endl;
    std::cout << "  isSubmatrix=" << (dst_mat.isSubmatrix()?"true":"false") << std::endl;
}