How Does Canny Edge Detection Sound ?
A sonification of the OpenGL implementation of Brad Larson’s “GPUImage Canny Edge Detection Implementation” which applies the edge detection process described by John Canny in “Canny, J., A Computational Approach To Edge Detection, IEEE Trans. Pattern Analysis and Machine Intelligence, 8(6):679–698, 1986” and implemented in OpenGL ES by “A. Ensor, S. Hall. GPU-based Image Analysis on Mobile Devices. Proceedings of Image and Vision Computing New Zealand 2011.”
“It starts with a conversion to luminance, followed by an accelerated 9-hit Gaussian blur. A Sobel operator is applied to obtain the overall gradient strength in the blurred image, as well as the direction (in texture sampling steps) of the gradient. A non-maximum suppression filter acts along the direction of the gradient, highlighting strong edges that pass the threshold and completely removing those that fail the lower threshold. Finally, pixels from in-between these thresholds are either included in edges or rejected based on neighboring pixels.”