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 resize an image with OpenCV2.0 and Python2.6

I want to use OpenCV2.0 and Python2.6 to show resized images. I used and adopted this example but unfortunately, this code is for OpenCV2.1 and does not seem to be working on 2.0. Here my code: import os, glob import cv ulpath = “exampleshq/” for infile in glob.glob( os.path.join(ulpath, “*.jpg”) ): im = cv.LoadImage(infile) thumbnail … Read more

How can I quantify difference between two images?

Here’s what I would like to do: I’m taking pictures with a webcam at regular intervals. Sort of like a time lapse thing. However, if nothing has really changed, that is, the picture pretty much looks the same, I don’t want to store the latest snapshot. I imagine there’s some way of quantifying the difference, … Read more