How can I erase the edge of a waterprint? - image

Question

I have a src pic like that (the source pic is too large to upload):
and I have a white background logo like that :
I tried to use the OpenCV code:
std::string file_name = "E:\\xxx\\IMG_0001.JPG";
cv::Mat image = cv::imread(file_name);
cv::Mat mask_not;
cv::Mat mask = cv::imread("E:\\xxx\\white_eva.jpg",0);
cv::Mat logo = cv::imread("E:\\xxx\\white_eva.jpg");
cv::bitwise_not(mask,mask_not);
cv::cvtColor(mask_not,mask_not,cv::COLOR_GRAY2BGR);
std::cout<<mask_not.type()<<std::endl;
cv::Mat imageROI;
imageROI = image(cv::Rect(image.cols-logo.cols-10,image.rows-logo.rows-10,logo.cols,logo.rows));
cv::imwrite("E:\\xxx\\imageROI.jpg",imageROI);
logo.copyTo(imageROI,mask_not);
cv::imwrite("E:\\xxx\\test.JPG",image);
The result like that:
As you can see from the result pic, there is a white edge around the logo. At first, I think the reason is that the mask doesn't large enough to mask the logo all. But as you can see the edge of the logo seems to show entirely. So, it confused me. The first question is that how can erase the white edge of the waterprint?

Answer 1

I tried adding morphology operations on your mask image. So this is what I could reach.
std::string file_name = "./image1.jpg";
cv::Mat image = cv::imread(file_name);
cv::Mat mask_not;
cv::Mat mask = cv::imread("./eva.jpg",0);
cv::Mat logo = cv::imread("./eva.jpg");
// MORPHOLOGY OPS HERE
cv::Mat element = cv::getStructuringElement(cv::MORPH_RECT,
Size(5, 5),
Point(-1, -1));
for (int i = 0; i < 20; ++i) {
cv::morphologyEx( mask, mask, cv::MORPH_CLOSE, element );
cv::morphologyEx( mask, mask, cv::MORPH_CLOSE, element );
cv::morphologyEx( mask, mask, cv::MORPH_CLOSE, element );
cv::medianBlur(mask, mask, 5);
}
cv::Mat element_dilate = cv::getStructuringElement(cv::MORPH_RECT,
Size(5, 5),
Point(-1, -1));
cv::dilate(mask, mask, element_dilate);
cv::bitwise_not(mask,mask_not);
cv::imshow("win", mask_not);
cv::waitKey(0);
cv::cvtColor(mask_not,mask_not,cv::COLOR_GRAY2BGR);
std::cout<<mask_not.type()<<std::endl;
cv::Mat imageROI;
imageROI = image(cv::Rect(image.cols-logo.cols-10,image.rows-logo.rows-10,logo.cols,logo.rows));
cv::imwrite("./imageROI.jpg",imageROI);
logo.copyTo(imageROI,mask_not);
cv::imwrite("./test.JPG",image);
Result image (I resized images a bit, so you may be need to change kernel sizes in morphology operations):