introduction heesoo myeong and kyoung mu lee department of ece, asri, seoul national university,...
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INTRODUCTION
Heesoo Myeong and Kyoung Mu LeeDepartment of ECE, ASRI, Seoul National University, Seoul, Korea
http://cv.snu.ac.kr
Tensor-based High-order Semantic Relation Transfer for Semantic Scene Segmentation
Goal
PROPOSED METHOD Results on Jain et al. Dataset
Quantitative Results on Standard Datasets
Jain et al. dataset (Jain et al., ECCV10): 250 training images, 100 test images, 19 labels SIFT Flow dataset (Liu et al., CVPR09): 2,488 training images, 200 test images, 33 labels Polo dataset (Zhang et al., CVPR11): 80 training images, 237 test images, 6 labels
Table 1: Per-pixel classification rates and (average per-class rates)
1. For a test image, retrieve similar training images using global features
2. Apply semantic relation transfer algorithm to transfer third-order semantic relation from each training image to the test image
3. Integrate the high-order score into MRF optimization framework and ob-tain semantic scene segmentation
EXPERIMENTS
Inference Use fully connected third-order Markov random field (MRF)
model:Key idea
Our Contributions The use of high-order semantic relations for semantic segmentation
A novel tensor-based representation of high-order semantic relations
A quadratic objective function for learning the semantic tensor and an effi-cient approximate algorithm
Semantic scene segmentation: identifying and segmenting all objects in a scene
Among superpixels ( is the number of total superpixels, is the number of object classes), third-order semantic relation is defined as a number of semantic tensors
The variable indicates confidence score of how likely the region triplet would be labeled as , respectively
To describe observed third-order semantic relation within the retrieved im-age, we define another number of semantic tensors
where denotes the ground truth class of region
Now, the semantic relation transfer problem is reformulated as the problem of estimating the magnitude of confidence scores for all superpixel triplets and for all object class triplets based on
We have presented a novel approach to learn high-order semantic relations of regions in a nonparametric manner
We develop a novel semantic tensor representation of the high-order se-mantic relations
We cast the high-order semantic relation transfer problem as a quadratic objective function of semantic tensors and propose an efficient approximate algorithm
𝒥 (c )=∑𝑖
𝐸𝐷 (𝑐𝑖 )+¿∑𝑖 , 𝑗
𝐸𝑃 (𝑐 𝑖 ,𝑐 𝑗)+∑𝑖 , 𝑗
𝐸𝐻 (𝑐 𝑖 ,𝑐 𝑗 ,𝑐𝑘) ,¿where represents data term, represents pairwise term, and is confidence score by the semantic relation transfer algorithm
Exploiting high-order(mostly third-order) semantic relation
sky
tree
building car
road
Test image Semantic scene segmenta-tion
build-ing
car
sky
road
sky
per-son
car
sky
tree
High-order relations in the training dataset
Previous works & Limitations Conventional context models mainly focus on learning pairwise relation-
ships between objects
Pairwise relations are not enough to represent high-level contextual knowl-edge within images
skytree
build-ing
car
roadroad
car
sky
per-son
tree
tree
build-ing
Query im-age
Integrated high-order relationSemantic segmenta-tion
Retrieved im-ages
…
Groundtruth
sky
road
building
tree
car
side-walkAnnotations of
retrieved im-ages
Predicted top scored high-order
relation
tree
sky
road
building
sky
car
tree
per-son
road
Results on LMO Dataset
Results on Polo Dataset
Overview
Semantic Relation Transfer Algorithm
[ ]ijk ijkx X
1 if ( ) , ( ) , ( ) , ( , , )
otherwis,
0 e
i j k i j k
ijk
retrievedG s c G s c G s c s s s Sy
skysky
road
We separately deal with the semantic relations transfer problem with re-spect to
The quadratic objective function with respect to as
where is the triplet-wise similarity between two region triplets and
111 112{ , ,..., }KKKX X X X
111 112{ , ,..., }KKKY Y Y Y
Y
Problem Statement
Objective FunctionY
2 2,
, , , , , , ,
1( ) ( ) ( ) ,
2
N N
ijk lmn ijk lmn ijk ijki j k l m n i j k
F w x x x y X
Pairwise semantic relation
car
build-ing
car
build-ing
Y
grassgrass
grass grassgrass grass
horsehorse
horsehorse
horse horse
horsehorsegrass grass
personperson
personpersonpersonperson
QueryGround truth
Pro-posed
QueryGround truth
Pro-posed
building
build-ing
sky
skyskyskysky
buildingbuilding
building
side-walk
side-walk
moun-tain
moun-tain
window
doorwindow
doorbuild-
ing
sky
window
carcar
QueryGround truth
Pro-posed
QueryGround truth
Pro-posed
skytree
building carroad
sky
road
build-ing
tree
car
side-walk
build-ing
build-ing
tree
car
tree
roadroad
build-ing
building
carroad
bison
mountain
grass grass
bison
tree
QueryGround truth
Pro-posed
QueryGround truth
Pro-posed
CONCLUSION