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MPEG-7 DCD Based Relevance Feedback Using Merged Palette Histogram. Ka-Man Wong and Lai-Man Po ISIMP 2004 Poly U, Hong Kong Department of Electronic Engineering City University of Hong Kong. A compact and effective descriptor Generated by GLA color quantization
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MPEG-7 DCD Based Relevance Feedback Using Merged Palette Histogram Ka-Man Wong and Lai-Man Po ISIMP 2004 Poly U, Hong Kong Department of Electronic Engineering City University of Hong Kong
A compact and effective descriptor Generated by GLA color quantization Maximum of 8 colors in storage Each color have a minimum distance (Td) of 15 in CIELuv color space MPEG-7 Dominant Color Descriptor
Commonly used RF techniques and limitations • Feature weighting relevance feedback technique • Assumes a fixed feature space (histograms) • Taking liner combinations on matching histogram bins. • Simple approach: Histogram averaging ( + ) / 2 =
H1 H’ H2 Commonly used RF technique and limitations • But DCDs of images might have different set of colors, similar images might not have any exactly matched colors. • The number of colors in updated query may greatly exceed the limit of the number of colors defined by MPEG-7 • Similar colors are separated. By definition of DCD, similar colors should be grouped together.
Limitation of feature weighting relevance feedbacktechnique • The Merged Palette Histogram Relevance Feedback • The updated query contains common colors among selected images • Represent the selected images efficiently
Proposed Merged Palette Histogram for Relevance Feedback • Merged Palette Histogram Relevance Feedback (MPH-RF) process - initialize • Obtain all DCD from selected images
+ + = Proposed Merged Palette Histogram for Relevance Feedback • Merged Palette Histogram Relevance Feedback (MPH-RF) process - 1 • Link all DCD together 8 colors 6 colors 20 colors 6 colors
Proposed Merged Palette Histogram for Relevance Feedback • Merged Palette Histogram Relevance Feedback (MPH-RF) process - 2 • Palette Merging • Find the closest pair of colorsbased on Euclidian distance in CIELuv • If minimum distance smaller than Td merge the color pair and sum up the percentages of merged colors • Iterate until minimum distance > Td 9 colors 20 colors
Proposed Merged Palette Histogram for Relevance Feedback • Merged Palette Histogram Relevance Feedback (MPH-RF) process - 3 • Approximation • Cut the least significant colors if number of colors >8 9 colors 8 colors
Approximated MPH Updated QueryHistogram Sum =1 Proposed Merged Palette Histogram for Relevance Feedback • Merged Palette Histogram Relevance Feedback (MPH-RF) process - 4 • Re-normalization • Adjust the histogram sum into 1 • An updated query is generated
Experimental Results of MPH-RF • Experiment Methodology • ANMRR • Image Database • 5466 Image from MPEG-7 common color dataset (CCD) • Pre-defined queries and ground truth set • Relevance Feedback • Ground truth images are selected as relevant images
Latest experimental results • MPH-RF gives improvement on both similarity measure methods • Combination of MPHSM and MPH-RF gives a significant improvement • Three iterations of relevance feedback give a significant result *ANMRR – smaller means better
Query image Ground truth images First RF retrieval, 6 of 8 ground truths hit, NMRR=0.2782 Initial retrieval, 4 of 8 ground truths hit, NMRR=0.5 Second RF retrieval, 7 of 8 ground truths hit, NMRR=0.1541 Experimental results • Visual results – Query #50 from MPEG-7 CCD, MPHSM • Visit http://www.ee.cityu.edu.hk/~mirror for more results
Experimental results • Visual results – Query #24 from MPEG-7 CCD, QHDM • Visit http://www.ee.cityu.edu.hk/~mirror for more results Query image Ground truth images First RF retrieval, 6 of 12 ground truths hit, NMRR=0.3738 Initial retrieval, 5 of 12 ground truths hit, NMRR=0.5125 Second RF retrieval, 9 of 12 ground truths hit, NMRR=0.1963
Conclusions on Merged Palette Histogram Relevance Feedback • A new MPH-RF for MPEG-7 DCD is proposed • MPH-RF generates a new DCD query using palette merging technique • Represents the selected relevant images naturally and effectively • Experiment result also found that proposed method improve DCD-QHDM by 0.0717 and MPHSM by 0.0637 using MPEG-7 Common Color Dataset • The proposed method also provide better perceptually relevant image retrieval.