Fei-Fei Li Lecture 12 - 3-Nov-2016vision.stanford.edu/teaching/cs131_fall1617/lectures/... ·...

Lecture 12 - 3-Nov-2016Fei-Fei Li

Lecture 12 - 3-Nov-2016Fei-Fei Li

•••

Lecture 12 - 3-Nov-2016Fei-Fei Li

Salvador Dalí “Man/couple with sleeping dog" (1948)

Lecture 12 - 3-Nov-2016Fei-Fei Li

•

Slide credit: Steve Seitz, Kristen Grauman

Lecture 12 - 3-Nov-2016Fei-Fei Li

•

Slide credit: Svetlana Lazebnik

Lecture 12 - 3-Nov-2016Fei-Fei Li

•

Berkeley Segmentation Dataset [Martin et al., ICCV 2001]

Lecture 12 - 3-Nov-2016Fei-Fei Li

••

“superpixels”

Slid

e cr

edit

: Sv

etla

na L

azeb

nik

Lecture 12 - 3-Nov-2016Fei-Fei Li

50x50 Patch50x50 Patch

Lecture 12 - 3-Nov-2016Fei-Fei Li

[Felzenszwalb and Huttenlocher 2004]

[Mori et al. 2005]

Lecture 12 - 3-Nov-2016Fei-Fei Li

“GrabCut” [Rother et al. 2004]

Lecture 12 - 3-Nov-2016Fei-Fei Li

Oversegmentation Undersegmentation

Multiple Segmentations

Lecture 12 - 3-Nov-2016Fei-Fei Li

Lecture 12 - 3-Nov-2016Fei-Fei Li

•––

•–

•–

•–

Lecture 12 - 3-Nov-2016Fei-Fei Li

•–

•–

•–

•–

Lecture 12 - 3-Nov-2016Fei-Fei Li

•–

•–

•–

…→

Lecture 12 - 3-Nov-2016Fei-Fei Li

Slide credit: Kristen Grauman

What things should be grouped?

What cues indicate groups?

Lecture 12 - 3-Nov-2016Fei-Fei Li

•••

Lecture 12 - 3-Nov-2016Fei-Fei Li

Slide credit: Kristen Grauman

Lecture 12 - 3-Nov-2016Fei-Fei Li

Slide credit: Kristen Grauman

[ ][ ][ ]

Lecture 12 - 3-Nov-2016Fei-Fei Li

Slide credit: Kristen Grauman

Lecture 12 - 3-Nov-2016Fei-Fei Li

Slide credit: Kristen Grauman

Lecture 12 - 3-Nov-2016Fei-Fei Li

Lecture 12 - 3-Nov-2016Fei-Fei Li

•

Lecture 12 - 3-Nov-2016Fei-Fei Li

●

[Gregory 1968]

Lecture 12 - 3-Nov-2016Fei-Fei Li

●

[Gregory 1968]

Lecture 12 - 3-Nov-2016Fei-Fei Li

••

Slid

e cr

edit

: Sv

etla

na L

azeb

nik

Lecture 12 - 3-Nov-2016Fei-Fei Li

•––

•

Untersuchungen zur Lehre von der Gestalt,Psychologische Forschung, Vol. 4, pp. 301-350, 1923

“I stand at the window and see a house, trees, sky. Theoretically I might say there were 327 brightnesses and nuances of colour. Do I have "327"? No. I have sky, house, and trees.”

Max Wertheimer(1880-1943)

Lecture 12 - 3-Nov-2016Fei-Fei Li

●

Imag

e so

urce

: Fo

rsyt

h &

Pon

ce

Lecture 12 - 3-Nov-2016Fei-Fei Li

Imag

e so

urce

: Fo

rsyt

h &

Pon

ce

Lecture 12 - 3-Nov-2016Fei-Fei Li

Imag

e so

urce

: Fo

rsyt

h &

Pon

ce

Lecture 12 - 3-Nov-2016Fei-Fei Li

Imag

e so

urce

: Fo

rsyt

h &

Pon

ce

Lecture 12 - 3-Nov-2016Fei-Fei Li

Imag

e so

urce

: Fo

rsyt

h &

Pon

ce

Lecture 12 - 3-Nov-2016Fei-Fei Li

https://en.wikipedia.org/wiki/Rubin_vase

Lecture 12 - 3-Nov-2016Fei-Fei Li

https://en.wikipedia.org/wiki/Rubin_vase

Multistability

Lecture 12 - 3-Nov-2016Fei-Fei Li

Man and crane, Mimbres culturepot, c. 1000 -1150 AD

second century B.C. Greek mosaic from the Acropolis

Lecture 12 - 3-Nov-2016Fei-Fei Li

Lecture 12 - 3-Nov-2016Fei-Fei Li

•••

Lecture 12 - 3-Nov-2016Fei-Fei Li

Lecture 12 - 3-Nov-2016Fei-Fei Li

(or bottom-up hierarchical clustering)

Simple algorithm

● Initialization: ○ Every point is its own cluster

● Repeat:○ Find “most similar” pair of clusters○ Merge into a parent cluster

● Until:○ The desired number of clusters has been reached○ There is only one cluster

Lecture 12 - 3-Nov-2016Fei-Fei Li

● Initialization: ○ Every point is its own cluster

Lecture 12 - 3-Nov-2016Fei-Fei Li

● Initialization: ○ Every point is its own cluster

● Repeat:○ Find “most similar” pair of

clusters

Lecture 12 - 3-Nov-2016Fei-Fei Li

● Initialization: ○ Every point is its own cluster

● Repeat:○ Find “most similar” pair of

clusters○ Merge into a parent cluster

Lecture 12 - 3-Nov-2016Fei-Fei Li

● Initialization: ○ Every point is its own cluster

● Repeat:○ Find “most similar” pair of

clusters○ Merge into a parent cluster

Lecture 12 - 3-Nov-2016Fei-Fei Li

● Initialization: ○ Every point is its own cluster

● Repeat:○ Find “most similar” pair of

clusters○ Merge into a parent cluster

Lecture 12 - 3-Nov-2016Fei-Fei Li

----

---

dist

ance

Lecture 12 - 3-Nov-2016Fei-Fei Li

●○

http://scikit-learn.org/stable/auto_examples/cluster/plot_agglomerative_clustering.html

Lecture 12 - 3-Nov-2016Fei-Fei Li

●

●

Lecture 12 - 3-Nov-2016Fei-Fei Li

••••

••••

Lecture 12 - 3-Nov-2016Fei-Fei Li

•••

Lecture 12 - 3-Nov-2016Fei-Fei Li