CODEWITHSUNDEEP
opencvimage-processing
kcc__
kcc__

Reputation: 1648

Mapping 2 image in Opencv

I know this is very simple but i just cant make it work in Opencv. I have 2 images of same size, one in RGB and other in black and white. The black and white image is obtained after some transformation in Opencv. Now i want to map the black white image to the RGB image and only keep the pixel corresponding to the white pixel in the black and white image. The black is simply discarded.

In C# its easy but since i am using c++ opencv, I want to do it in openCV. How can i do it?

In c# is like this:

for(i = 0; i < image.lenght; i+=4)
{
if(img_bw != 255)
image[i] = 0;image[i+1] = 0;image[i+2] = 0;
}

Upvotes: 0

Views: 1304

Answers (2)

lightalchemist
lightalchemist

Reputation: 10211

cv::Mat blackAndWhiteMask = ...; // You black and white image
cv::Mat image = imread("original_image.jpg"); // Your original image
cv::Mat result;
image.copyTo(result, blackAndWhiteMask);
image = result;

Upvotes: 3

Bull
Bull

Reputation: 11941

Based on http://docs.opencv.org/doc/tutorials/core/how_to_scan_images/how_to_scan_images.html

cv::Mat bw = ...;
cv::Mat clr = ...;  // clr.size() == bw.size()

for(int i = 0; i < bw.rows; ++ i)
{
    uchar* bw_r = bw.ptr<uchar>(i);
    cv::Vec3b* clr_r = clr.ptr<Vec3b>(i);
    for(int j = 0; j < bw.cols; ++j)
        if(br_r[j] != 255)
            clr_r[j] = cv::Vec3b(0, 0, 0);
}

Upvotes: 2

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