LIST OF SYMBOLS AND ABBREVIATIONS

Transcription

1 viii TABLE OF CONTENTS CHAPTER NO. TITLE PAGE NO. ABSTRACT LIST OF TABLES LIST OF FIGURES LIST OF SYMBOLS AND ABBREVIATIONS iii xii xiii xvi 1 INTRODUCTION GENERAL IMAGE REPRESENTATIONS COLOR AND COLOR IMAGES Physics of Color Human Perception of color COLOR MODELS PORTABLE NETWORK GRAPHICS FILE Image Layout Palette Chunk Transparency Chunk Alpha Channel Image Color Types COLOR PALETTE CONTENTION PROBLEM PROBLEM DESCRIPTION Objectives Problem Definition General Steps in Color Reduction CONSTRAINTS IN COLOR REDUCTION 23

2 ix CHAPTER NO. TITLE PAGE NO. 1.9 APPLICATIONS ORGANIZATION OF THE THESIS SUMMARY 26 2 LITERATURE REVIEW INTRODUCTION GENERAL CLASSIFICATION ADAPTIVE Vs FIXED PALETTES FIXED PALETTE CREATION METHODS ADAPTIVE PALETTE CREATION METHODS Pre-Clustering Methods Post-Clustering Methods Improved Scalar Quantization APPLICATION-SPECIFIC METHODS ERROR DIFFUSION SHORTCOMINGS OF PREVIOUS 47 TECHNIQUES 2.9 SUMMARY 48 3 SINGLE IMAGE COLOR REDUCTION INTRODUCTION DESIGN CONSIDERATIONS ALGORITHM AND EXPERIMENTS Algorithms Images used Experiments 83

3 x CHAPTER NO. TITLE PAGE NO Error Free (Without Error Diffusion) Error Diffusion GUI FOR ADD/EDIT COLORS BY USERS SUMMARY AND RESULTS MULTIPLE IMAGES COLOR REDUCTION INTRODUCTION DESIGN CONSIDERATIONS EXTENSION OF PACRA FOR MULTIPLE IMAGES COLOR REDUCTION RESULTS OF PACRA FOR MULTIPLE IMAGES WITHOUT TRANSPARENCY RESULTS OF PACRA FOR MULTIPLE IMAGES WITH TRANSPARENCY PACRA WITH ERROR DIFFUSION FOR MULTIPLE ALPHA IMAGES SUMMARY APPLICATIONS INTRODUCTION BANDWIDTH REDUCTION DIGITAL BROADCASTING A Sample BML Program COLOR IMAGE SEARCHING Color Dictionary Color Image Database Creation Registration Process 128

4 xi Modes of Operation Sample Outputs for Multi-Color Search Mode Sample Output for Query Image Search Mode SUMMARY CONCLUSION AND FUTURE WORK 134 REFERENCES 136 LIST OF PUBLICATIONS 142 CURRICULUM VITAE 143

5 xii LIST OF TABLES TABLE NO. TITLE PAGE NO. 1.1 PNG file image color types Sample image data Illustration of adaptive thresholding and bin center updation MSSIM values for the test images by different color reduction algorithms with 32 colors in the color reduced images Computation time for the test images with different colors in the color reduced images using PACRA for single image without transparency Natural alpha image color reduction results Synthetic alpha image color reduction results Multiple srgb images color reduction results Multiple alpha images color reduction results Compression ratio Vs number of colors in the color reduced (output) images Compression ratio comparison between existing color reduction algorithms and PACRA Distribution of number of colors in each mode of broadcasting MDB table for image search engine MySQL query in the multi-color search mode 131

6 xiii LIST OF FIGURES FIGURE NO. TITLE PAGE NO. 1.1 Wavelength ( ) of the spectrum visible to humans RGB Color Space CMY Color Space Cylindrical representation of HSI color model Example of an indexed color image Illustration of alpha channel Union of colors of three indexed images Common palette creation problems Steps in color reduction Examples of color reduction with different set of colors Classifications of color reduction algorithms Examples of adaptive palette results Examples of fixed palette results Results of uniform quantization Example image results of error diffusion Error diffusion filters Flow diagram of the PACRA for single image Sample image data sets Output images and color cube Examples of srgb images color reduction results with 32 colors Natural alpha image results Synthetic alpha image results 82

7 xiv FIGURE NO. TITLE PAGE NO. 3.7 MSSIM values Vs number of colors in the output palette for the test images Color reduction results of Ladybug image with 16 colors Example of color distributions in ladybug image MSSIM values Vs threshold T S for test images with different number of colors in the output palette Color reduction with error diffusion results MSSIM Vs number of colors in the output palette for different error diffusion filters GUI for add/edit colors Example of checker pattern Flow diagram of the multiple image color reduction algorithm Multiple srgb image color reduction results Common color palette of color reduced multiple srgb images Multiple alpha image color reduction results Common color palette of color reduced multiple alpha images Multiple alpha images color reduction results with error diffusion Compression ratio Vs number of colors in the color reduced (output) images Compression ratio comparison plots 117

8 xv FIGURE NO. TITLE PAGE NO. 5.3 Distribution of number of (reserved) colors in each mode of broadcasting A sample BS/CS mode BML file Example of CLT File creation at broadcasting station Example of color reduction in terrestrial mode Sample DTV Screen BML program results Colors used in proposed image search engine Flowchart of image registration process Multi-color search mode results Query image search results 132

9 xvi LIST OF SYMBOLS AND ABBREVIATIONS ECMA Script - A scripting language T d - Adaptive (Dynamic)Threshold ACR - Adaptive Color Reduction ARIB - Association of Radio Industries and Businesses ACoPa - Automatic Color Palette BML - Broadcast Markup Language BS - Broadcasting Satellite CSS - Cascading Style Sheets CLT - Color Look up Table CIE - Commission International d Eclairage CS - Communication Satellite CMY - Cyan, Magenta, Yellow DTV - Digital Television D-map - Distinctiveness map DOM - Document Object Model XHTML - Extensible Hypertext Markup Language XML - Extensible Markup Language Float - Floating point 4-D - Four Dimensional FCM - Fuzzy C-Means FLVQ - Fuzzy Learning Vector Quantization GCMA - Genetic C-Means Algorithm GUI - Graphical User Interface GIF - Graphics Interchange Format T S - Hard (Static)Threshold value HCL - Hierarchical Competitive Learning

10 xvii HAM - Histogram Accumulate Matrix H-map - Homogeneity map - Hue HSI - Hue Saturation Intensity HSV - Hue Saturation Value HVS - Human Visual System IDAT Chunk - Image Data Chunk IHDR Chunk - Image Header Chunk IEND Chunk - Image Trailer Chunk Int - Integer z - Intensity ISCC - Inter Society Color Council JPEG - Joint Photographic Experts Group Kb - Kilobyte LKM - Local K-Means LUT - Look Up Table MDB - Master Database MSE - Mean Square Error MSSIM - Mean Structural Similarity Index Measure MPEG - Moving Picture Experts Group MCS - Multi-Color Search MySQL - My Structured Query Language nm - nanometer NBS - National Bureau of Standards NTSC - National Television System Committee 1-D - One Dimensional PAM - Palette Accumulate Matrix PLTE Chunk - Palette Chunk PSO - Particle Swarm Optimization

11 xviii PSNR - Peak Signal to Noise Ratio PNG - Portable Network Graphics PACRA - Probabilistic Adaptive Color Reduction Algorithm QIS - Query Image Search RTOS - Real Time Operating System RGB - Red Green Blue RGBA - Red Green Blue Alpha RMSE - Root Mean Square Error r - Saturation SL.No. - Serial Number SOFM - Self Organizing Feature Map SOM - Self Organizing Map SONN - Self Organizing Neural Network SSQ - Sequential Scalar Quantization srgb - Standard RGB (True Color) SSIM - Structural Similarity Index Measure TIFF - Tagged Image File Format TV - Television THz - Terahertz 3-D - Three Dimensional trns Chunk - Transparency Chunk 2-D - Two Dimensional UHAM - Unique Histogram Accumulate Matrix UPAM - Unique Palette Accumulate Matrix VC - Varchar VQ - Vector Quantization - Wavelength in Nanometer WTSE - Weighted Total Square Error