CHANNELS See also Fast channel feature computation code based on the papers: [1] P. Dollár, Z. Tu, P. Perona and S. Belongie "Integral Channel Features", BMVC 2009. [2] P. Dollár, S. Belongie and P. Perona "The Fastest Pedestrian Detector in the West," BMVC 2010. [3] P. Dollár, R. Appel and W. Kienzle "Crosstalk Cascades for Frame-Rate Pedestrian Detection," ECCV 2012. Please cite a subset of the above papers if you end up using the code. Code written and maintained by Piotr Dollar and Ron Appel. Channels: chnsCompute - Compute channel features at a single scale given an input image. chnsPyramid - Compute channel feature pyramid given an input image. chnsScaling - Compute lambdas for channel power law scaling. Constant time image smoothing: convBox - Extremely fast 2D image convolution with a box filter. convMax - Extremely fast 2D image convolution with a max filter. convTri - Extremely fast 2D image convolution with a triangle filter. Gradients and gradient histograms: gradient2 - Compute numerical gradients along x and y directions. gradientHist - Compute oriented gradient histograms. gradientMag - Compute gradient magnitude and orientation at each image location. hog - Efficiently compute histogram of oriented gradient (HOG) features. hogDraw - Create visualization of hog descriptor. Miscellaneous: imPad - Pad an image along its four boundaries. imResample - Fast bilinear image downsampling/upsampling. rgbConvert - Convert RGB image to other color spaces (highly optimized).