I am working on a program that extracts the stickers on the puzzle and then later on finds the RGB of them. Currently, I am at the point where I want to remove any contours that aren't "square" like. I was wondering how I could do this.
What I do is I load the image, gray it, blur it, canny edge detection, dilate it find contours and draw them.
Is there a way I can draw around the contours instead of filling them in? And remove contours that aren't roughly the same size around or have almost 90 degree angles?
public static void main(String[] args) {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
Mat capturedFrame = Imgcodecs.imread("first.png");
//Gray
Mat gray = new Mat();
Imgproc.cvtColor(capturedFrame, gray, Imgproc.COLOR_BGR2GRAY);
//Blur
Mat blur = new Mat();
Imgproc.blur(gray, blur, new Size(3,3));
//Canny image
Mat canny = new Mat();
Imgproc.Canny(blur, canny, 20, 40, 3, true);
Imgcodecs.imwrite("test.png", canny);
//System.exit(0);
Mat kernel = Imgproc.getStructuringElement(1, new Size(3,3));
Mat dilated = new Mat();
Imgproc.dilate(canny,dilated, kernel);
List<MatOfPoint> contours = new ArrayList<>();
//find contours
Imgproc.findContours(dilated, contours, new Mat(), Imgproc.RETR_TREE, Imgproc.CHAIN_APPROX_NONE);
//draw contours
Imgproc.cvtColor(capturedFrame, capturedFrame, Imgproc.COLOR_BGR2RGB);
for(int i = 0; i < contours.size(); i++){
Imgproc.drawContours(capturedFrame, contours, i, new Scalar(0, 0, 255), -1);
}
Imgcodecs.imwrite("after.png", capturedFrame);
Imshow img = new Imshow("firstImg");
img.show(capturedFrame);
}
Here is the initial image:
Here is the image with the contours drawn: