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“OBJECTIVE AND SUBJECTIVE IDENTIFICATION OF INTERESTING AREAS IN VIDEO SEQUENCES”

“OBJECTIVE AND SUBJECTIVE IDENTIFICATION OF INTERESTING AREAS IN VIDEO SEQUENCES”. Danko Toma š i ć DIPLOMA PROJECT Erasmus Student, University of Trieste, Italy Responsible Assistant: Elisa Drelie Gelasca Professor: Touradj Ebrahimi. Outline. Introduction Context Application

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“OBJECTIVE AND SUBJECTIVE IDENTIFICATION OF INTERESTING AREAS IN VIDEO SEQUENCES”

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  1. “OBJECTIVE AND SUBJECTIVE IDENTIFICATION OF INTERESTING AREAS IN VIDEO SEQUENCES” Danko Tomašić DIPLOMA PROJECT Erasmus Student, University of Trieste, Italy Responsible Assistant: Elisa Drelie Gelasca Professor: Touradj Ebrahimi

  2. Outline • Introduction • Context • Application • State of the Art • Problem Statement • Subjective Experiments for Segmentation Quality Evaluation • Generation of Synthetic Segmentation Errors • Experimental Method • Data Analysis • Work in progress • Conclusions and Future Work

  3. Motivation • REAL WORLD SCENES • presents a large quantity of information to the Human... • high visual acuity – fovea • eye movements – not random ! VISUAL ATTENTION SELECTIVITY Automatic method for .. REGIONS OF INTEREST (ROI) In video sequences

  4. APPLICATIONS • COMPRESSION - preserve the quality in ROIs • SEGMENTATION QUALITY EVALUATION - overall and individual object • IMAGE AND VIDEO QUALITY ANALYSIS • Perceptual PSNR.. • IMAGE AND VIDEO DATABASES - extract ROIs in each scene ‘a priori’ • DIGITAL WATERMARKING - perceptual marking • MACHINE VISION - real-time robot navigation

  5. FACTORS WHICH INFLUENCE VISUAL ATTENTION • high-level or top-down - presence of people - background / foreground • low-level or bottom-up - motion - position - size - color and brightness - contrast - shape - orientation slower volition controlled Relevance.. task dependent rapid saliency driven task independent

  6. SALIENCE AND RELEVANCE • Salience - bottom-up task-independent factors - connected with observal-external objects or properties - unexpectedness or unusualness of an object • Relevance - top-down volition-controlled and task-dependent factors - observal-internal factors (goals and motivations) - connected to the specific situation = Conspicuity

  7. PREVIOUS ATTENTION MODELS • Correia and Perreira - estimation of video object’s relevance - both individually and in a given context • Osberger - perceptual vision model for image quality assessment and compression applications - early vision model and higher level attention processes - Importance Maps

  8. PREVIOUS MODELS • Osberger and Rohaly - automatic detection of ROIs in video sequences - improvement of previous model - adding temporal and movement features • Pardo - extraction of semantic objects from still images - perceptual metric and Importance Maps - improvement of Osberger’s models

  9. COLOR – STATE OF THE ART • Osberger - redattracts attention more than other colors - red induces higher amount of masking • Correia and Perreira - bright and colored objects are more noticed - red seems to be preferred PROBLEM – NO OTHER QUANTIFIED SOLUTIONS !!!

  10. COLOR – SIGNALLING AND MARKETING • American Standards Association and French Standard - red - dinamic, warm - fireproof protection - red - salient ‘par excellence’ - orange and yellow - salient colors – danger - green - calming color - materials of first aid - blue - cold and calming - caution “psychologically active” PROBLEM–NO OTHER QUANTIFIED SOLUTIONS !!!

  11. Subjective Experiment on Color.. • COLOR ColorTest I Color Test II Color Test III

  12. COLOR – COLOR TEST I First cycle Tested colors in CIELab color space Second cycle

  13. COLOR TEST I - RESULTS

  14. COLOR – COLOR TEST II • Colored objects with semantical meaning • Annoyance and Salience of a color interconnected ? • Adding gaussian noise (sigma =...)to channel L in HSL color space • Matlab - RANDN (M,N) - normal distribution • mean = 0 variance = 0.005 • Rating the annoyance level

  15. COLOR – COLOR TEST II Tested colors in CIELab color space Test image

  16. COLOR TEST II - RESULTS

  17. COLOR TEST II - RESULTS Cyan Green Pink Magenta Red = 241 Light blue Blue Orange Yellow = 241

  18. COLOR – COLOR TEST III • Colored objects with semantical meaning • Annoyance and Salience of a color interconnected ? • Blurred images - 3 levels of blurriness • Rating the annoyance level

  19. COLOR – COLOR TEST III Original image Test image

  20. COLOR TEST III - RESULTS COLOR TEST I vs. COLOR TEST III Second cycle highest level of blurriness 5 CASES Most important Most annoying 3 CASES 1st or 2nd most 2nd or 1st most important annoying 4 CASESRED 3rd most annoying !!! 4 CASESCYAN 1st most annoying !!!

  21. COLOR TEST III - RESULTS COLOR TEST I vs. COLOR TEST III • Light blue • Violet • Dark Green • Maroon • Red • Yellow • Green • Blue Similar importance Similar annoyance Similar importance Similar annoyance

  22. COLOR TEST III - RESULTS Average level lines 2nd level of blurriness 3rd level of blurriness

  23. COLOR TEST III - RESULTS HSL color space CIELab color space

  24. OBJECTIVE IDENTIFICATION OF INTERESTING AREAS Proposed method

  25. SEGMENTATION • WATERSHED SEGMENTATION Sequence #1 - Akiyo Frame #15 ORIGINAL FRAME #15 WATERSHED SEGMENTATION RESULT OF MERGE

  26. FACTORS WHICH INFLUENCE ATTENTION • COLOR

  27. FACTORS WHICH INFLUENCE ATTENTION • CONTRAST Ri,j – considered region Rj – neighboring region L, a, b – CIELab coordinates Bi,j – border pixels in Ri,j with Rj kborder = 10

  28. FACTORS WHICH INFLUENCE ATTENTION • SIZE

  29. FACTORS WHICH INFLUENCE ATTENTION • POSITION

  30. FACTORS WHICH INFLUENCE ATTENTION • SKIN HSV color space

  31. FACTORS WHICH INFLUENCE ATTENTION • MOTION - OPTICAL FLOW Original video Movement mask

  32. FACTORS WHICH INFLUENCE ATTENTION • FINAL COMBINATION OF FEATURES

  33. SUBJECTIVE EXPERIMENTS • SEGMENTATION QUALITY Sequence #1 - Akiyo Frame #15 DEFECT IN THE MOST IMPORTANT REGION DEFECT IN THE LEAST IMPORTANT REGION

  34. SUBJECTIVE EXPERIMENTS • SEGMENTATION QUALITY Sequence #2 - Highway Frame #28 DEFECT IN THE MOST IMPORTANT REGION DEFECT IN THE LEAST IMPORTANT REGION

  35. SUBJECTIVE EXPERIMENTS • SEGMENTATION QUALITY Sequence #3 - VideoEPFL Frame #39 DEFECT IN THE MOST IMPORTANT REGION DEFECT IN THE LEAST IMPORTANT REGION

  36. SUBJECTIVE EXPERIMENTS • RESULTS Sequence #1 - Akiyo

  37. SUBJECTIVE EXPERIMENTS • RESULTS Sequence #2 - Highway

  38. SUBJECTIVE EXPERIMENTS • RESULTS Sequence #3 - VideoEPFL

  39. VISUAL PERCEPTION • extracting information from the light • Acquiring knowledge - HVS = video camera • Objects and events in the environment • Light emitted or reflected by objects

  40. VISUAL ATTENTION • processing different information within the visual field • Overt eye movements - determine available optic information • Covert selective attention - determines what gets full processing CAPACITY SELECTIVITY amount of available what gets processed perceptual resources and what does not

  41. COLOR TEST I - RESULTS

  42. COLOR TEST II - RESULTS Cyan Green Pink Magenta Red >>10 Light blue Blue Orange Yellow >>10

  43. FACTORS WHICH INFLUENCE ATTENTION • COLOR ColorExperiment 1 Color Experiment 2 Color Experiment 3

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