I am working with Android OpenCV .I have a square shape marker image .I have to find out the position of four corners of marker in the live feed with their index's position. I am able to get the position of these four points in the live feed having the frame size 640\*480. But the problem with the index's positions those are not fixed ,sometimes i am getting the 0th index on the top left position and sometimes 1th index at that position ... How to solve this problem or is there any alternative for findContour() method.