Upload
maud-tate
View
219
Download
0
Embed Size (px)
Citation preview
Hierarchical Matching with Side Information for Image Classification
Authors Qiang Chen et al.
Presenter Hyung-seok Lee (이형석 )
CVPR 2012
2
Motivation (1/2)• Bag-of-Words (BoW)• Frequency histogram of visual words• Not emphasize any elements with regard to image layout
3
Motivation (2/2)• Spatial Pyramid Matching (SPM)• Partitioning the image plane into fine sub-regions• Not optimum for object-centered recognition problem
Beyond Bags of Features : Spatial Pyramid Matching for Recognizing Natural Scene Categories, Svetlana Lazebnik et al.
4
Main Idea• Generalized Hierarchical Matching (GHM)• Extends the popular matching work• Integrate prior knowledge for enhancing feature matching
side information
5
Overview
Im-age
Hierarchi-cal cluster-
ing
Hierarchical structure
representation
Matching over each cluster
Local features &
side informa-tion
6
Side Information (1/4)• Object Confidence Map• Object position should be extremely beneficial• Shape model / Appearance model
7
Side Information (2/4)• Shape-based object detection : HOG features
• Appearance-based object detection : BoW features
Object Confidence Map
8
Side Information (3/4)• Visual Saliency Map• Aim to detect the important content in images• Explain human visual search strategies
SUN : A Bayesian Framework for Saliency Using Natural Statistics, Lingyun Zhang et el.
9
Side Information (4/4)• Use the saliency model SUN (Saliency Using Natural statistics)• Based on natural image statistics
10
Side Information Combination• Combine object confidence map & visual saliency map• Design a 3 level hierarchical structure
- Object confidence map is used in level 2
- Background area will be further utilized in level 3
11
Encoding & Matching (1/2)
12
Encoding & Matching (2/2)• Encoding is operated on each cluster• Matching over each corresponding cluster
13
Experiments (1/2)• Caltech-UCSD Birds 200 & Oxford Flowers 17 and 102
14
Experiments (2/2)• VOC 2007
• VOC 2010
15
Conclusion• Propose the Generalized Hierarchical Matching framework
- Extends the popular pyramid matching
• Two novel kinds of side information are introduced to enhance object-oriented image classification tasks
- Object confidence map- Visual saliency amp