70 likes | 88 Views
MRFs. (X 1 ,X 2 ). 1. 2. 3. X 3. X 1. X 2. 4. (X 2 ,X 3 ,X 3 ). X 4. CRFs. Image I. (X 1 ,X 2 ,I). 1. 2. 3. X 3. X 1. X 2. 4. (X 2 ,X 3 ,X 3 ,I). X 4. CRF. MRF. Examples. X = Image patches. [Quattoni et al. ]. X = Patches on a regular lattice. [Kumar].
E N D
MRFs (X1,X2) 1 2 3 X3 X1 X2 4 (X2,X3,X3) X4
CRFs Image I (X1,X2,I) 1 2 3 X3 X1 X2 4 (X2,X3,X3,I) X4
CRF MRF Examples X = Image patches [Quattoni et al.] X = Patches on a regular lattice [Kumar]
Examples X = pixels, regions, image [He et al.]
Issues • Inference • Easy only when the planets are aligned • Approximate solutions only How good are they? • Learning • Difficult and slow • Limits the complexity of the models
Issues • Generality • Can use arbitrary models but limited to restricted models in practice because of inference and learning challenges • Global label inference • Inference over global labeling of the data in theory, but limited propagation across image in practice • Support limited by the complexity of learning and inference • Use of complex graph and clique structure is difficult