One-Dimensional Processing for Adaptive Image Restoration
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DOCUMENT OFFICE 36-412 JRESEARCH LABORATORY OF ELECTRONtCS *l MASSACHUSETTS INSTITUTE OF TECHNOLOGY ~~~~~~~~~IllLf llii One-Dimensional Processing for Adaptive Image Restoration Philip Chan tl 1; 4 eo'p ON// Technical Report 501 June 1984 Massachusetts Institute of Technology Research Laboratory of Electronics Cambridge, Massachusetts 02139 _ ___I __ _ __ __I_L *1 One-Dimensional Processing for Adaptive Image Restoration Philip Chan Technical Report 501 June 1984 Massachusetts Institute of Technology Research Laboratory of Electronics Cambridge, Massachusetts 02139 This work has been supported in part by the Advanced Research Projects Agency monitored by ONR under Contract N00014-81-K-0742 NR-049-506 and in part by the National Science Foundation under Grant ECS80-07102. _ __YLII··_I__IIL____yll_·ll-... -____. -- 1~ - - -- 1-~· 1 --- I I - ---·---- -- - _I __I __I UNCLASSIFTED SECUNITY CLASSIFICATION OF rIS PAGE REPORT OOCUMENTATION PAGE l& RPICORT SECURITY CLASSFPlCATION 1I RISTRlCTIVI MARKINGS 2& SICURITY C1ASSIFICATION AUTHORITY 3. OISTrIUUTIONIAVAILA6I1UTY OF RIPORT Approved for public release: distribution =6 O0CLAIf CATNoOWNGrAOlING sc.eout.a unlimited A. PRAFORMING ORGANIZATION IrEPoRTHMUSll(S) S. MONITORING ORGANIZATION REPORT NUM6EE(S) G. NAMIE OF PRFORlOMING ORGcANIZATION . OFICI( SYMKOL 7 NAM_ OF MONITORING ORGANIZATION Research Laboratory of Elec to mehe, Office of Naval Research Massachusetts Institute of Te:hnology Mathematical and Information Scien. Div. 6. A^OORSS (Ct. Saw emd ZIP Code) 7b. AOORESS =Ct. 31w .nJi ZIP Come 77 Massachusetts Avenue 800 North Quincy Street Cambridge, MA 02139 Arlington, Virginia 22217 &L NAM OF IINOIN(OWSPONSORING a OFICE SYMh t.oL L Ps1OCUtEMENT INSTRUMENT OENTIltCATION NUMllR ORGANIZATION (If WIawieal Advanced Research Projects .gency N00014-8 1-K-0742 Se. A0OOR1S (City. State M ZIP CoMg IC. SOURC OF FUNOING NMOe 1400 Wilson Boulevard PROGRAM PROJcr TASK WORK UNIT Arlington, Virginia 22217 UAMNT N4. NO. NO. NO. ,. 1TL. aclm i,y ,,C clo,, One-neDimens i on.al 049 - 506 Processina for AdaPtive Imace Restoration" unclassified 12. P1O13NAL AUTWOR4)1 C..an . ph; I iI n t3.. TYPE oF RSPORT 13b rtIME COVERSO 14. OATrs OF RePORT Yr.. ... Qe7 15. PAGE COUNT Technical PRO" rO 1984 June 100 i1. SUFPL9.MNTARY NOTATION Technical Report No. 501 17. COSAct COOS, _ 1i . SUlJCr TRMS Cmauae on eem'e ifeewesn seamide4mty be bbme nub " PItO0 GPROUP I sue GR. 19. A6TtRACT Cotiurw o vW if MOmeesww se imdfy by btai rnubet A one-dimensional (1-0) approach to the problem of adaptive image restoration is pre- sented. n this approach, we use a cascade of four L-O adaptive filters oriented in the four major correlation directions of the image, with each filter treating the image as a 1-0 signal. The objective of this L-0 approach is to improve the performance of the more general two-dimensional (2-0) approach. This differs considerably from previous L-0 approaches, he objectives of which have typically been to approximate a more general 2-0 approach for computational reasons and not to improve its performance. The main advan- tage of this new 1-0 approach is its capability to preserve edges in the image while removing noise in all regions of the image, including the edge regions. To illustrate this point, the approach is applied to existing 2-0 image restoration algorithms. Exper- Lmental results with images degraded by additive white noise at various SNRs (signal-to- noise ratios) are oprsented. Further examples illustrate the application of -0 rstor- ation techniques based on this approach to images degraded by blurring and additive white noise and images degraded by multiplicative noise. Another example shows ts use- fulness in the reduction of quantization noise in pulse code modulation image coding. 20. 01STRIBUTIONAVAILABI .ITY OF ABSTRACT 21. ASSTRACt SECURITY CZ.ASIIC ATION UNCLASSI.S eOIUNLIMITO SAMe S a. '-- OgTC U.iS * Unclassified 22& NME1 OF RESPONSiBLE INOIVIOAI 2 ELEPONE NUM6ER 22c. OFFICESYrMBOLA Kyra M. Hall (Ineid Am Ca"e P e T nTrt (617) 53-2569 .~ _ -L LJU rJ1liV 14/ , 4 A'R 501ON OF JAN 73 s Q50SOL.ETS. 1 UNCLASS IFZT' SECURITY C.ASSIFICAITON OF THS PAGa _X_____I_11____11-·I^I·_ULY·I·sYS..-. 111_1_1_11_111____·_ __1 I- _· __ __ -2- ONE-DIMENSIONAL PROCESSING FOR ADAPTIVE IMAGE RESTORATION by Philip Chan Submitted to the Department of Electrical Engineering and Computer Science, on May 11, 1984, in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering and Computer Science. ABSTRACr A one-dimensional (1-D) approach to the problem of adaptive image res- toration is presented. In this approach, we use a cascade of four 1-D adaptive filters oriented in the four major correlation directions of the image, with each filter treating the image as a 1-D signal. The objective of this 1-D approach is to improve the performance of the more general two-dimensional (2-D) approach. This differs considerably from previous 1-D approaches, the objectives of which have typically been to approximate a more general 2-D approach for computa- tional reasons and not to improve its performance. The main advantage of this new 1-D approach is its capability to preserve' edges in the image while remov- ing noise in all regions of the image, including the edge regions. To illustrate this point, the approach is applied to existing 2-D image restoration algorithms. Experimental results with images degraded by additive white noise at various SNRs (signal to noise ratios) are presented. Further examples illustrate the application of 1-D restoration techniques based on this approach to images degraded by blurring and additive white noise and images degraded by multipli- cative noise. Another example shows its usefulness in the reduction of quanti- zation noise in pulse code modulation image coding. Thesis Supervisor: Professor Jae S. Lim Title: Associate Professor of Electrical Engineering 111111···1(··111-Llltll_. ..-1Il-LII- -_I_ __ I __ I _ -3- ACKNOWLEDGEMENTS My deepest appreciation goes to Professor Jae S. Lim for his supervi- sion of this thesis. His encouragement, understanding, and patience have made my graduate study at MIT a very fruitful and enjoyable one. I would like to thank all members of the Digital Signal Processing Group at MIT who provided an excellent research environment. Special thank goes to members of the Cognitive Information Processing Group at MIT who assisted me in producing hard copies of the images in this thesis on their facili- ties. I am deeply indebted to my parents whose care and teaching have played an important role in the success of my study. Special thanks are due to my wife, Ai Hwa. Her loving care and encouragement have supported me throughout my stay at MIT. She has also helped in the preparation of this document. Finally, I gratefully acknowledge the financial support by the Govern- ment of Singapore whose DSO Scholarship has supported my graduate educa- tion. ___III·_____ILIY___111· 11 1_11_111_1-.__-·-·-LII-SP---^l---X-l-·-- I--· _I------ I -4- TABLE OF CONTENTS ABSTRACT 2 ACKNOWLEDGEIMENTS 3 TABLE OF CONTENTS 4 LIST OF FIGURES 7 LIST OF TABLES 12 CHAPTER 1 INTRODUCTION 13 Introduction 13 12 Scope of the Thesis 16 13 Organization of Chapters 18 CHAPTER 2: REVIEW OF IMAGE RESTORATION 20 21 Introduction 20 22 Representations of Images and Degradations 21 23 Nonadaptive Image Restoration 26 2.4 Adaptive Image Restoration 29 25 One-Dimensional Approximations to Two-dimensional Image Restoration 31 2.6 Summary 35 CHAPTER 3: A ONE-DIMENSIONAL APPROACH TO ADAPTIVE IMAGE RESTORATION 36 3.1 Introduction 36 32 Motivation of the Approach 37 33 The Basic Principle 38 3A Discussion 40 3A.4. Advantages of the Approach 40 _ ^I1_1II1_I______XYIl·llll·llillpl·I(IQ. 11141^. 111·1 II -~~~ ~I -5- 3.42 Comparison with Other 1-D Approaches 41 3.43 Practical Considerations 43 35 Conclusion 44 CHAPTER 4: APPLICATIONS OF THE ONE-DIMENSIONAL APPROACH 45 4.1 Introduction 45 42 Adaptive Filter Based on Local Statistics 46 421 The 2-D LLSE Algorithm 46 422 The 1-D LLSE Algorithm 49 423 Experimental Results 50 43 Adaptive Filter Based on a Noise Visibility Function 59 431 The 2-D S-type Filter 59 432 The -IDS-type Filter 63 433 Experimental Results 63 4A Short Space Spectral Subtraction Technique 65 4.41 The 2-D Short Space Spectral Subtraction Technique 65 4A2 The 1-D Short Space Spectral Subtraction Technique 67 4A43 Experimental Results 69 45 Summary and Conclusion 70 CHA PTER 5: FURTHER APPLICATIONS OF THE ONE-DIMENSIONAL APPROACH 73 51 Introduction 73 52 Restoration of Blurred and Noisy Images 74 521 The Principle of Inverse Filtering 74 522 Experimental Results 76 53 Restoration of Images Degraded by Multiplicative Noise 76 -6- 531 Filtering of Speckle Degraded Images in the Density Domain 79 532 Experimental Results 80 5.4 An Application to Noise Reduction in Image Coding 84 5.41 A Quantization Noise Reduction Scheme 84 542 Experimental Results 86 55 Conclusion 91 CHAPTER 6: SUMMARY AND CONCLUSION 93 61 Summary 93 62 Suggestions for Future Work 95 63 Conclusion 96 REFERENCES 97 _I_____·IIIYIUULI_- _III-----·- ^ ·-----I_·I · I--- _ ·__ I -7- LIST OF FIGURES Figure 31 (a) A 2-D restoration method. 39 (b) The proposed 1-D approach. Figure 32 General block diagram of other 1-D approaches. 42 Figuree41 General block diagram of a restoration technique 48 based on local statistics. Figure: 42 (a) Original image. 51 (b) Noisy image. (c) Image in (b) restored by the 2-D LLSE algorithm. Figure 43 (a) Figure 42(b) processed by the horizontal filter. 52 (b) Image in (a) processed by the vertical filter. (c) Image in (b) processed by the 45-degree filter. (d) Image in (c) processed by the 135-degree filter.