Edith Cowan University Research Online Theses : Honours Theses 2007 A comparison of edge detection methods for segmentation of skin lesions in mobile-phone-quality images Khanh Linh Hua Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses_hons Part of the Software Engineering Commons Recommended Citation Hua, K. L. (2007). A comparison of edge detection methods for segmentation of skin lesions in mobile- phone-quality images. https://ro.ecu.edu.au/theses_hons/1275 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses_hons/1275 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorize you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. 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Signature: :2 11 A COMPARISON OF EDGE DETECTION METHODS FOR SEGMENTATION OF SKIN LESIONS IN MOBILE-PHONE­ QUALITY IMAGES A thesis submitted in partial fulfilment of the requirements for the degree of Bachelor of Science (Software Engineering) with Honours By: KHANH LINH HUA Faculty of Computing, Health and Science Edith Cowan University Supervisor(s): Dr ALFRED TAN Dr MARTIN MASEK Mr. MICHAEL COLLINS Date of submission: Semester 2, 2007 Declaration I certify that this thesis does not incorporate without acknowledgement any material previously submitted for a degree in any institution of higher education, and that, to the best of my knowledge and belief, it does not contain any material previously published or written by any other person except where due acknowledgement is made. Signature: _ Date: ____t"-'-+l/_o? 4'J____..,U(l/~_· _ 111 TABLE OF CONTENTS ABSTRACT ................................................................................................................................................................. 1 ACKNOWLEDGEMENTS ........................................................................................................................................ 2 1 INTRODUCTION ............................................................................................................................................. 3 1.1 BACKGROUND STUDY ................................................................................................................................. 3 1.2 RESEARCH QUESTIONS: ............................................................................................................................... 7 2 LITERATURE REVIEW ................................................................................................................................. 8 2.1 OVERVIEW OF EDGE DETECTORS ................................................................................................................. 8 2.2 ROBERTS CROSS EDGE DETECTOR ............................................................................................................... 8 2.3 SOBEL EDGE DETECTOR ............................................................................................................................... 9 2.4 PREWITT EDGE DETECTOR ......................................................................................................................... 10 2.5 LAPLACIAN OF GAUSSIAN ......................................................................................................................... 10 2.6 CANNY EDGE DETECTOR ........................................................................................................................... 11 2.7 REVIEW OF SEGMENTATION METHODS TO DETECT SKIN CANCER .............................................................. 13 2.8 EDGE DETECTORS AS PART OF THE PROCESS OF DETECT SKIN CANCER ...................................................... 14 3 THEORETICAL FRAMEWORK ................................................................................................................. 16 3.1 STRENGTHS AND WEAKNESS OF EDGE DETECTOR ...................................................................................... 16 3.2, QUALITY OF VGA CAMERA PHONE IMAGES .............................................................................................. 16 4 MATERIALS AND METHODS .................................................................................................................... 18 4.1 DATAANDEQUIPMENTS ............................................................................................................................ 18 4.2 EDGE DETECTION METHODS AND PROCEDURES ......................................................................................... 18 4.3 EVALUATIONMETHODS ............................................................................................................................ 19 5 RESULTS ANp FINDINGS ........................................................................................................................... 21 5.1 PRE-PROCESSING PHASE ............................................................................................................................ 21 5.2 FINDING THE LESION BORDER ................................................................................................................... 29 5.2.1 Approach !-Automatic edge parameters .......................... ,........ ,.......... ,........................................... 29 5.2.2 Approach 2- Manual tuning ofedge parameters ............... ,.... ,.... ,..................................................... 38 6 CONCLUSION ................................................................................................................................................ 42 7 FUTURE WORK ............................................................................................................................................. 43 8 GLOSSARIES .................................................................................. ~ ............................................................... 44 8.1 IMAGE PROCESSING TERMINOLOGIES ........................................................................................................ 44 8.2 SKIN CANCER TERMINOLOGIES .................................................................................................................. 45 9 REFERENCES ................................................................................................................................................. 48 IV 10 APPENDIX .•.........................•.............................•.•....•....•.........................................••...................................... 53 10.1 APPENDIX A ........................................ , ........................................................................................................... 53 10.1.1 SKIN LESSJON I!v!AGES ........................................................................................................................ 53 1 0.1.2 Images take from camera phone ............................................................................................................. 58 10.2 APENDIX B (SOURCE CODE) ............................................................................................................................ 64 1 0.2.1 Function pre-process.m .......................................................................................................................... 64 10.2.2 Function colorspace.m ............................................................................................................................ 65 10.2.3 Function gaussgradient2.m ..................................................................................................................... 74 10.2.4 Function Canny_detector.m .................................................................................................................... 76 10.2.5 Function LoG detector.m ......................................................................................................................