 |
    |
Knowing a Good HOG Filter When You See It: Efficient Selection of Filters for Detection*
Ejaz Ahmed1, Gregory Shakhnarovich2, and Subhransu Maji3
1University of Maryland, College Park, USA
ejaz@umd.edu
2Toyota Technological Institute at Chicago, USA
greg@ttic.edu
3University of Massachusetts, Amherst, USA
smaji@cs.umass.edu
Abstract. Collections of filters based on histograms of oriented gradients (HOG) are common for several detection methods, notably, poselets and exemplar SVMs. The main bottleneck in training such systems is the selection of a subset of good filters from a large number of possible choices. We show that one can learn a universal model of part “goodness” based on properties that can be computed from the filter itself. The intuition is that good filters across categories exhibit common traits such as, low clutter and gradients that are spatially correlated. This allows us to quickly discard filters that are not promising thereby speeding up the training procedure. Applied to training the poselet model, our automated selection procedure allows us to improve its detection performance on the PASCAL VOC data sets, while speeding up training by an order of magnitude. Similar results are reported for exemplar SVMs.
Electronic Supplementary Material:
LNCS 8689, p. 80 ff.
lncs@springer.com
© Springer International Publishing Switzerland 2014