Sub image from mat with Opencv4android

Question

i want to get a sub-image (the one bounded by the red box below) from an image (Mat format). how do i do this with opencv4 android ?

Answer 1

You can do the following,

• Convert to gray scale .

• Threshold the gray.

• Find contour and it's bounding box.

• Using the boundbox crop the ROI like

    Rect R; //bounding box for contour Mat src;//source image Mat cropped=src(R); //Crop the image 

Note: You should convert all these to Java or Use JNI to use C++ directly.