Semantic Texton Forests for Image Categorization and Segmentation.
Add to your list(s)
Download to your calendar using vCal
If you have a question about this talk, please contact David MacKay.
In this talk we’ll discuss Semantic Texton Forests, efficient and powerful
new low-level features proposed recently at CVPR 2008 . These are ensembles
of decision trees that act directly on image pixels, and therefore do not
need the expensive computation of filter-bank responses or local
descriptors. They are extremely fast to both train and test, especially
compared with k-means clustering and nearest-neighbor assignment of feature
descriptors, and the talk will be motivated with a real-time demo of object
segmentation. The nodes in the trees provide (i) an implicit hierarchical
clustering into semantic textons, and (ii) an explicit local classification
estimate. A bag of semantic textons combines a histogram of semantic textons
over an image region with a region prior category distribution. The bag of
semantic textons is computed over the whole image for categorization, and
over local rectangular regions for segmentation. Including both histogram
and region prior allows our segmentation algorithm to exploit both textural
and semantic context. Our third contribution is an image-level prior for
segmentation that emphasizes those categories that the automatic
categorization believes to be present. We evaluate on two datasets including
the very challenging VOC 2007 segmentation dataset. Our results
significantly improve segmentation accuracy, and more importantly
drastically increase execution speed.
This talk is part of the Inference Group series.
This talk is included in these lists:
Note that ex-directory lists are not shown.
|