我正在将一些代码从 matlab 转换为 opencv。我尝试在 opencv 中使用 Sobel,但 opencv 和 matlab 的输出完全不同,这可能是原因。如何使opencv的输出与matlab相同?我的 MATLAB 代码是:
[sobel_edges,T,V,H] = edge(rgb2gray(im),'sobel',0.03);
sobel_angles = atan2(V,H);
sobel_weights = (V.*V+H.*H).^0.5;
其中 0.03 是阈值。在 opencv 中,当我使用预建的 Sobel 滤波器时,输出与 matlab 完全不同,即使在 openc 中计算的角度和幅度也不同。opencv代码是:
Mat gray_img=Mat::zeros(img.size(),CV_8U);
Mat gradientX=Mat::zeros(gray_img.size(),CV_64F);
Mat gradientY=Mat::zeros(gray_img.size(),CV_64F);
Mat sobel_edge=Mat::zeros(gray_img.size(),CV_64F);
cvtColor(img, gray_img, CV_BGR2GRAY);
Sobel(gray_img, gradientX, gradientX.type(), 1, 0, 3);
Sobel(gray_img, gradientY, gradientY.type(), 0, 1, 3);
Sobel(gray_img,sobel_edge,sobel_edge.type(),1,1,3);
sobel_edge.convertTo(sobel_edge,CV_8U);
sobel_edge.convertTo(sobel_edge,CV_64F);
sobel_edge=sobel_edge/255.0; //I divided this my 255 becuz in MATLAB the output is between 0 to 1
imshow("Sobel",sobel_edge);
Mat magnitude(gray_img.size(), CV_64F, cv::Scalar(0.0));
Mat angles=Mat::zeros(gradientX.size(),CV_64F);
bool anglesInDegrees = true;
cartToPolar(gradientX, gradientY, magnitude, angles, anglesInDegrees);
sobel 边缘本身不同,幅度和角度也不同,我尝试通过查看 matlab 中的边缘函数来手动转换 opencv 中的 sobel,但输出仍然不同,因为结果是 opencv 的 filter2D 和 matlab 中的 imfilter 返回不同的输出。如何在matlab和opencv中得到相同的sobel输出???matlab的sobel手动转换为opencv的代码为:
Mat gray_img=Mat::zeros(img.size(),CV_32FC1);
cvtColor(img, gray_img, CV_RGB2GRAY);
double minVal,maxVal;
cv::Mat gray = cv::Mat(gray_img.size(),CV_32FC1);
gray_img.convertTo(gray_img,CV_32FC1);
gray=gray_img/255.0;
cout<<gray<<endl<<"End";
double data[]={1,2,1,0,0,0,-1,2,-1};
Mat op=Mat(3,3,CV_64F,data).clone();
op=op/8;
Mat x_mask;
transpose(op,x_mask);
cout<<x_mask<<endl;
Mat y_mask=op.clone();
int scale=4;
int offset[]={0,0,0,0};
double sobel_thresh=0.03;
Mat bx,by,bx_mul,by_mul,b;
Point anchor(0,0);
float delta = 0.0;
cv::filter2D(gray, bx, CV_32FC1, x_mask, anchor, delta, BORDER_REPLICATE);
bx=abs(bx);
imshow("f1",bx);
cv::filter2D(gray, by, CV_32FC1, y_mask, anchor, delta, BORDER_REPLICATE);
by=abs(by);
imshow("by",by);
pow(bx,2,bx_mul);
imshow("f2",bx_mul);
pow(by,2,by_mul);
b= bx_mul+by_mul;
imshow("f3",b);
double cut_off;
cut_off=pow(sobel_thresh,2);
Mat sobel_edge(gray.size(),CV_32FC1);
for(int i=0;i<b.rows;i++)
{
for(int j=0;j<b.cols;j++)
{
if((b.at<float>(i,j))>cut_off)
{
sobel_edge.at<float>(i,j)=1;
}
else
{
sobel_edge.at<float>(i,j)=0;
}
}
}
imshow("Sobel_edge",sobel_edge);