OpenCV Android Programming By Example

Detecting shapes

So, we have seen how to detect edges; however, this process is a pixel-by-pixel process answering the question of whether this pixel is an edge or not. Moving forward, in shape analysis, we would need more concrete information than just the edge test; we will need a better representation.

For example, if we have a picture of a box and we did the edge detection, we will end up with thousands and thousands of edge pixels; however, if we tried to fit a line to these edge pixels, we get a rectangle, which is a more symbolic and useful representation.

Understanding the Hough line transform

There are many ways to fit a line through a number of points, and Hough transform is considered an under constrained method, where we use only one ...