Patent ID: 9092089
Filing Date: 2015-07-28
Classification: G06F

Abstract:
1. A method for detecting an arbitrary number of touches from an input image delivered by a multi-touch device, said method comprising the following steps: processing at a processing device said input image and obtaining a processed image; segmentation at the processing device by thresholding of said processed image and obtaining a segmented image; identifying at the processing device regions of the segmented image; finding local maxima at the processing device, each local maximum being of size one pixel and belonging to a sub-region of size N×N pixels, wherein N is an odd integer number; wherein said finding comprises a plurality of iterations where at each iteration: discarding at the processing device some regions according to predetermined conditions; determining at the processing device at least one touch position based on said local maxima by computing a geometric center of each region that remains after said discarding, wherein said computing takes into account all the pixels of a region if said region contains one local maximum of size one pixel, and wherein said computing further takes into account only the pixels inside the sub-regions centered in each local maximum of a region if said region contains more than one local maxima of size one pixel.