Bag-of-features models
Many slides adapted from Fei-Fei Li, Rob Fergus, and Antonio Torralba
Overview: Bag-of-features models
• Origins and motivation
• Image representation
• Feature extraction
• Visual vocabularies
• Discriminative methods
• Nearest-neighbor classification
• Distance functions
• Support vector machines
• Kernels
• Generative methods
• Naïve Bayes
• Probabilistic Latent Semantic Analysis
• Extensions: incorporating spatial information
Origin 1: Texture recognition
• Texture is characterized by the repetition of basic elements
or textons
• For stochastic textures, it is the identity of the textons, not
their spatial arrangement, that matters
Julesz, 1981; Cula & Dana, 2001; Leung & Malik 2001; Mori, Belongie & Malik, 2001;
Schmid 2001; Varma & Zisserman, 2002, 2003; Lazebnik, Schmid & Ponce, 2003
Origin 1: Texture recognition
histogram
Universal texton dictionary
Julesz, 1981; Cula & Dana, 2001; Leung & Malik 2001; Mori, Belongie & Malik, 2001;
Schmid 2001; Varma & Zisserman, 2002, 2003; Lazebnik, Schmid & Ponce, 2003
Origin 2: Bag-of-words models
• Orderless document representation: frequencies of words
from a dictionary Salton & McGill (1983)
Origin 2: Bag-of-words models
• Orderless document representation: frequencies of words
from a dictionary Salton & McGill (1983)
US Presidential Speeches Tag Cloud
http://chir.ag/phernalia/preztags/
Origin 2: Bag-of-words models
• Orderless document representation: frequencies of words
from a dictionary Salton & McGill (1983)
US Presidential Speeches Tag Cloud
http://chir.ag/phernalia/preztags/
Origin 2: Bag-of-words models
• Orderless document representation: frequencies of words
from a dictionary Salton & McGill (1983)
US Presidential Speeches Tag Cloud
http://chir.ag/phernalia/preztags/