matchShapes() example

yes123
1412 ●12 ●28 ●52

Hello Guys,

I would like to use matchShapes() function for finding an object inside a query image.

Let's say I have a model image of a book, i want to extract its shape and then try to find this book (its shape) inside another image.

I have googled a lot but couldn't find any real example on how to use matchShapes to achive this. The documentation lacks. Can someoen make a little example in C++ ?

Thanks a lot! (Note I know I can use SIFT/ORB etc, but i want to use matchShapes())

answered Jul 31 '12

Michael Burdinov
4638 ●6 ●33 ●86

First you will need to get contours of shapes from image. For example use Canny() to find edges in images. Than use findContours() on image of edges to get contours.

Than you can use matchShapes() to find contour that is most similar to your model contour (among all contours extracted by findContours()).

Note that this approach is very fast comparing to other methods of object detection, but if you can't get single contour around your book you will not able to find it. matchShapes() compares single contour to single contour.

Comments

Thanks a lot. that's a nice explanation. So after I have comapred all contours of a model image with each other of the query image I can know which couple of contours match best, and then maybe drawing them in the query image ?