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Image Search Using Deformable Contours. By : Preeyakorn Tipwai Advisor : Suthep Madarasmi, Ph.D Computer Vision Laboratoy, Computer Engineering Department King Mongkut’s University of Technology Thonburi. A target is assumed to be a scaled, rotated version of the template
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Image Search Using Deformable Contours By : Preeyakorn Tipwai Advisor : Suthep Madarasmi, Ph.D Computer Vision Laboratoy, Computer Engineering Department King Mongkut’s University of Technology Thonburi
A target is assumed to be a scaled, rotated version of the template with edges distorted Problem
Inspiration Jain et al [1] , “Object Matching Using Deformable Templates” Our Methodogy Finding Hypotheses : MGHT Peak Clustering : Watershed Method Contour Matching : Smooth Membrane Fitting Methodology
Preprocessing • Given a sketched template • Find tangent direction • Given a target image • Calculte edge map : Canny Edge Detection • Find tangent direction
r1, a1, q1, l1 r2, a2, q2, l2 r3, a3, q3, l3 r4, a4, q4, l4 0...19 15,180,195,99 9,179,219,101 8,177,216,102 9,176,198,100 20...39 17,160,23,5 14,159,38,7 18,161,175,62 15,162,195,95 30…49 19,165,31,53 20,170,8,52 22,167,15,52 18,159,158,12 … … … … … 340...359 23,105,346,11 24,103,165,11 21,102,346,18 22,104,195,24 MGHT A line at the contour edge is extended in the g direction until it meets the other end of the contour R-Table
= 30-200 = -170 = 190 = 300-110 = 190 MGHT • Invariant rotation and scale of
MGHT Rotation Factor: xc = x + S r cos (a + b) yc = y + S r sin (a + b) Scaling Factor : New ref. Point :
Watershed for Peak Clustering 1. Shed, by labeling, at the first level, calculate peaks of each label 2. Increase to higher level, shed again 2.1 Meet an area of previous level, shed to that area 2.2 Not meet any area of previous level, make a new area , calculate a new peak
Parameter : (Dx,Dy) or (u,v) Deformation : Contour Matching
Coarse and Fine Matching • Grid Matching : Data and Smoothness Constraints • Inter-grid Matching: Consistency between adjacent grids
Coarse and Fine Matching • Inter-grid Matching: Example
Matching Algorithm Update (u,v) :Gibbs Sampler with simulated annealing to minimize energy function Template Target Edge
Experiment on Contour Matching Template Target Edge Result
Experiment on Contour Matching Template Target Edge Result
Experiment on Image Search Template Target Edge Map Result Hough Space
Experiment on Image Search 1st Match Hypotheses Target Edge 2nd Match 3rd Match 4th Match
Experiment on Image Search Template Target Edge Map Hough Space The Best Match
Experiment on Image Querying Database Search for Circle shape Search for bulb shape
Conclusion • A deformation model • Contour Matching • A method for image search • Future work: large image database, efficient method for minimizing energy, coarse-and-fine approach to computer vison modules
Similarity Retrieval Effectiveness heart shape bulb shape circle shape max : 100, min : 96 ave : 98 max : 100, min : 92 ave : 95 max : 96, min : 8 ave : 75
Experimental Result 2.705226 0.929011 3.986274 Template Target Edge Hypotheses Threshold : 1.0 - 2.6
Experimental Result Template Target Edge Hypotheses Threshold : 1.0-1.6 1.755835 2.165488 0.965049
Experimental Result Template Hypotheses Edge Map Threshold : 1.2-1.6 5.074061 1.799267 1.114566
Experimental Result Template Target Edge Hypotheses 0.868600 0.879799 3.799124 Threshold : 0.9-3.6
Experimental Result Threshold : 1.5-3.2 Template Target Edge Hypotheses 1.293034 1.452130 3.364521 4.4185782