Detect spots empty parking OPENCV

Question

I want to apply a detector algorithm to detect empty areas of parking and I have read about SIFT and SURF, but I can't quite understand it. I have seen examples of comparison between two images, but that's not what I want. Could you explain about how to use SURF or SIFT on the issue of detecting empty spots on parking?

I have also read about color histogram, can I have some documentation about it?

I am working with OpenCV python 2.4.9 and 2.7

Answer 1

It depends on what you exactly want to achieve - if just want to find an empty spot and your camera higher than parking, it's quite possible that finding spots in color of road (most likely asphalt) will be enough for you(see http://docs.opencv.org/modules/core/doc/operations_on_arrays.html#cv2.inRange). Of course you have to manually find lower and upper boundary (don't forget about lighting differences - asphalt will have different color at night, probably it will be easier to find good boundaries using HSV color space) and filter parts of parking which are not empty areas (roads etc.).

BTW - look at this Using OpenCV to detect parking spots