在做了有趣的图像格式转换()一整天后,我现在可以回答自己的问题了。
Matlab将图像存储为三维数组:高度×宽度×颜色
OpenCV将图像存储为二维数组:(颜色×宽度)×高度
此外,为了获得最佳性能,OpenCV使用零填充对图像进行补齐,以使行始终对齐于32位块。
我已经在Matlab中完成了转换。
function [cv_img, dim, depth, width_step] = convert_to_cv(img)
img2 = permute( img(:,end:-1:1,:), [2 1 3] );
dim = [size(img2,1), size(img2,2)];
if( isa(img2, 'double') )
img2 = single(img2);
end
if( ndims(img2) == 3 && size(img2,3) == 3 )
depth = 3;
else
depth = 1;
end
if(depth == 3 )
img2(:,:,[3 2 1]) = img2;
img2 = reshape( permute(img2, [3 1 2]), [size(img2,1)*size(img2,3) size(img2,2)] );
end
width_step = size(img2,1) + mod( size(img2,1), 4 );
img3 = uint8(zeros(width_step, size(img2,2)));
img3(1:size(img2,1), 1:size(img2,2)) = img2;
cv_img = img3;
cv_display(cv_img, dim, depth, width_step);
将此转换为IplImage的代码位于MEX文件中:
#include "mex.h"
#include "cv.h"
#include "highgui.h"
#define IN_IMAGE prhs[0]
#define IN_DIMENSIONS prhs[1]
#define IN_DEPTH prhs[2]
#define IN_WIDTH_STEP prhs[3]
void mexFunction(int nlhs, mxArray **plhs, int nrhs, const mxArray **prhs) {
bool intInput = true;
if(nrhs != 4)
mexErrMsgTxt("Usage: cv_disp(image, dimensions, depth, width_step)");
if( mxIsUint8(IN_IMAGE) )
intInput = true;
else if( mxIsSingle(IN_IMAGE) )
intInput = false;
else
mexErrMsgTxt("Input should be a matrix of uint8 or single precision floats.");
if( mxGetNumberOfElements(IN_DIMENSIONS) != 2 )
mexErrMsgTxt("Dimension vector should contain two elements: [width, height].");
char *matlabImage = (char *)mxGetData(IN_IMAGE);
double *imgSize = mxGetPr(IN_DIMENSIONS);
size_t width = (size_t) imgSize[0];
size_t height = (size_t) imgSize[1];
size_t depth = (size_t) *mxGetPr(IN_DEPTH);
size_t widthStep = (size_t) *mxGetPr(IN_WIDTH_STEP) * (intInput ? sizeof(unsigned char):sizeof(float));
CvSize size;
size.height = height;
size.width = width;
IplImage *iplImage = cvCreateImageHeader(size, intInput ? IPL_DEPTH_8U:IPL_DEPTH_32F, depth);
iplImage->imageData = matlabImage;
iplImage->widthStep = widthStep;
iplImage->imageDataOrigin = iplImage->imageData;
cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);
cvShowImage("mainWin", iplImage);
}