Scale-Invariant Primal Sketch Tokens

Introduction

This code is the implementation of T. Lindeberg's scale-invariant primal sketch that I use in my research on object detection and shape modeling. The code takes as input a grayscale image and convolves it with Gaussian kernels of increasing size. Using this scale-space, edge and ridge contours are found as maxima in space and scale of appropriate differential operators. These contours are then post-processed to obtain a sparse set of straight line segments. Apart from computing T. Lindeberg's primal sketch, additional functionalities that are generally useful include:

• Efficient Gaussian Filtering with a mex implementation of R. Deriche's IIR Filters.
• A line tracking algorithm along the lines of Nevatia and Babu.
• The line segmentation algorithm used in D. Lowe's SCEPRO system.

Related Publications

• I. Kokkinos and A. Yuille,
  Unsupervised Learning of Object Deformation Models,
  Proc. IEEE Int'l. Conf. on Computer Vision (ICCV), 2007.
  [pdf] [supplement]
  
• I. Kokkinos, P. Maragos and A. Yuille,
  Bottom-Up and Top-Down Object Detection Using Primal Sketch Features and Graphical Models,
  IEEE Conf. on Computer Vision and Pattern Recognition (CVPR), 2006.
  [pdf]

Downloads

Code, readme, documentation: PS_primal_sketch.zip.
Usage, demos etc: readme.pdf.