Creates an image of a 'pie slice' of a circle. Creates a 2D array of size (2rx2r) with values between 0 and 1. Specifically, mask has values 1 inside the pie slice of the circle defined by angleStart and angleSiz. For example, using angleStart=-pi/4 and angleSiz=pi/2 would give a quarter circle facing right. nsample conrols the accuracty of the circle at its boundaries. That is if nSamples>1, pixels at the boundary which will have fractions values (when a pixel should be say half inside the circle and half outside of the circle). Note that running time is O(nSamples^2*radius^2), so don't use a value that is too high for either. A series of masks whose angles together go from 0-2pi will sum exactly to form a radius r circle. r may be either an integer, or an integer + .5. A pixel is considered to belong to the circle iff it is within the given angle and has a value strictly smaller then r. USAGE mask = maskCircle( angleStart, angleSiz, r, [nSamples] ) INPUTS angleStart - start position of circle angleSiz - number of radians to continue circle for r - mask radius (integer or integer+.5) nSamples - [1] controls sampling accuracy OUTPUTS mask - the created image, size 2r by 2r EXAMPLE mask1 = maskCircle( -pi/8, pi/4, 20, 20 ); figure(1); im(mask1); mask2 = maskCircle( pi/8, pi/8, 20, 20 ); figure(2); im(mask2); figure(3); im(mask1+mask2); See also MASKELLIPSE, MASKSPHERE Piotr's Computer Vision Matlab Toolbox Version 2.0 Copyright 2014 Piotr Dollar. [pdollar-at-gmail.com] Licensed under the Simplified BSD License [see external/bsd.txt]