finding chessboard corners with GPUImage

Question

I used OpenCV (cv::findChessboardCorners) to find chessboard corners in iOS app, but the performance is not where I need it to be. What is a best (fastest/most reliable) way to detect chessboard corners with GPUImage? Is there another GPU accelerated library for iOS that would make sense to evaluate for chessboard detection?

Answer 1

You'll want the GPUImageHarrisCornerDetectionFilter or its variants to do this right now. You set a block on that which will return an array of detected corners (in normalized view coordinates) and the number of total corners detected. See the FilterShowcase and feature detection sample applications for how this works in practice.

I am working on a faster corner detector, as well as a means of not having to raster over all image pixels on the CPU to extract the final corner points. Both of those should improve corner detection performance, but you can work with the above for now.