Color invariance when matching frames [closed]
Is there a way to normalize incoming frames regarding the color? I am extracting ORB features from incoming frames and match them to a reference frame. But the different lightning conditions often make it really hard to match but when manually adjusting the brightness/contrast etc the matching improves. Is there a way to tell the ORB descriptors to adjust for higher lightning & color differences? Or is there a way to normalize the brightness of the complete frame? Or a complete different concept I should try?
have a look at equalizeHist: http://docs.opencv.org/modules/imgproc/doc/histograms.html?highlight=equalizehist#equalizehist
that sounds promising, but will it help if there are other objects in the scene in addition to the object which should be detected? there other objects would also change the histogram right?
Yes it also depends on the scene, but I wouldn't worry too much about it and just try it out. Alternatively you can also try a more localized histogram equalization, named CLAHE (http://en.wikipedia.org/wiki/Clahe#CLAHE), it is part of OpenCV, however not documented, see http://answers.opencv.org/question/12024/use-of-clahe/ for some examples.