OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection

I successfully implemented the OpenCV square-detection example in my test application, but now need to filter the output, because it’s quite messy – or is my code wrong? I’m interested in the four corner points of the paper for skew reduction (like that) and further processing … Input & Output: Original image: click Code: double angle( … Read more

How to detect a Christmas Tree?

Which image processing techniques could be used to implement an application that detects the Christmas trees displayed in the following images? I’m searching for solutions that are going to work on all these images. Therefore, approaches that require training haar cascade classifiers or template matching are not very interesting. I’m looking for something that can … Read more