Overlaying A Facemask

Detect Faces

    // Capture the current frame
    cap >> frame;

    // Resize the frame
    resize(frame, frame, Size(), scalingFactor, scalingFactor, INTER\_AREA);

    // Convert to grayscale
    cvtColor(frame, frameGray, CV\_BGR2GRAY);

    // Equalize the histogram
    equalizeHist(frameGray, frameGray);

    // Detect faces
    faceCascade.detectMultiScale(frameGray, faces, 1.1, 2, 0CV\_HAAR\_SCALE\_IMAGE, Size(30, 30) );

Add Mask Image

    // Draw green rectangle around the face
    for(int i = 0; i < faces.size(); i++)
    {
        //Rect faceRect(faces\[i\].x, faces\[i\].y, faces\[i\].width, faces\[i\].height);

        // Custom parameters to make the mask fit your face. You may have to play around with them to make sure it works.
        int x = faces\[i\].x - int(0.1\*faces\[i\].width);
        int y = faces\[i\].y - int(0.1\*faces\[i\].height); // 0.0\*faces\[i\].height
        int w = int(1.1 \* faces\[i\].width);
        int h = int(1.3 \* faces\[i\].height);

        // Extract region of interest (ROI) covering your face
        frameROI = frame(Rect(x,y,w,h));

        // Resize the face mask image based on the dimensions of the above ROI
        resize(faceMask, faceMaskSmall, Size(w,h));

        // Convert the above image to grayscale
        cvtColor(faceMaskSmall, grayMaskSmall, CV\_BGR2GRAY);

        // Threshold the above image to isolate the pixels associated only with the face mask
        threshold(grayMaskSmall, grayMaskSmallThresh, 230, 255, CV\_THRESH\_BINARY\_INV);

        // Create mask by inverting the above image (because we don't want the background to affect the overlay)
        bitwise\_not(grayMaskSmallThresh, grayMaskSmallThreshInv);

        // Use bitwise "AND" operator to extract precise boundary of face mask
        bitwise\_and(faceMaskSmall, faceMaskSmall, maskedFace, grayMaskSmallThresh);

        // Use bitwise "AND" operator to overlay face mask
        bitwise\_and(frameROI, frameROI, maskedFrame, grayMaskSmallThreshInv);

        // Add the above masked images and place it in the original frame ROI to create the final image
        add(maskedFace, maskedFrame, frame(Rect(x,y,w,h)));
    }