EE565: Advanced Image Processing Xin Li LDCSEE, Fall 2009 dehaze EE565 Advanced Image Processing Copyright Xin Li 2009 1 EE565 General Information • Lectures and office hours Meeting Time: TTh 9:30-10:45 in MRB 107 Office Hours: Mondays 2:00-3:00pm in ESB 939 Fragment Minutes: 15 minutes before and after each lecture • Contact information Instructor: xin.li@mail.wvu.edu For email submission of assignments, please use your MIX account EE565 Advanced Image Processing Copyright Xin Li 2008 2 • Prerequisites EE465: Introduction to Digital Image Processing or equivalent • Follow-up (Spring 2010) EE569: Digital Video Processing (more fun) • Texts No textbook is required. The instructor will provide lecture notes at the course website http://www.csee.wvu.edu/~xinl/courses/ee565/ee565.html Additional material (e.g., classical papers, MATLAB demos, assignments and solutions) will also be posted there EE565 Advanced Image Processing Copyright Xin Li 2008 3 • Working load - 8 assignments - One midterm and one final project • Grading Assignments 40% Midterm project 30% (Technical report 5% included) Final project 30% (Oral Presentation 5% included) Auditing policy: you need to turn in all the assignments EE565 Advanced Image Processing Copyright Xin Li 2008 4 Importance of Hand-on Experience Finishing all the assignments are necessary preparation for working on larger-size projects Midterm project will be development oriented (e.g., implementation of a published algorithm or some simple idea of your own) Final project will be research oriented (e.g., improve upon a published algorithm or the idea you have tested in midterm) Final project could lead to MS thesis or PhD qualifier exam problem EE565 Advanced Image Processing Copyright Xin Li 2008 5 How to Do Scientific Research? Inquiry (research)-based learning Difference between taking exams and doing research Difference between textbook knowledge and your own understanding Competition and collaboration Your classmates are your competitors (grading will be ranking-based) Your classmates are also your collaborators (cooperation is at the foundation of all engineering endeavors) EE565 Advanced Image Processing Copyright Xin Li 2008 6 Tools for Effective Learning http://masterxinli.wordpress.com/category/teaching/ee565/ In addition to classroom interaction, Blog offers a convenient platform for everyone to participate. I might also try several other techniques: Think-Pair-Share, Minute Paper and Group Discussion The most important lesson I have learned through years: Interest is the best instructor (everything I do is to try to get you hooked to learning this course – so pls. tell me when you feel bored) EE565 Advanced Image Processing Copyright Xin Li 2008 7 Course Overview Mathematical modeling of images Image restoration Improve image quality and usability Image communication Why do we care about images? Why do we take a mathematical approach? Move images from here to there and from now to then Image analysis Automatically extract information from images EE565 Advanced Image Processing Copyright Xin Li 2008 8 Technological Importance of Images Improve Human’s vision capabilities see far (e.g., watch Summer Olympics in Beijing) see small (e.g., microscopic structures such as neurons and cells) see through (e.g., ultrasound inspection of pregnant women) see better (e.g., in the darkness or adversary environmental conditions). EE565 Advanced Image Processing Copyright Xin Li 2008 9 Scientific Reasons Understanding how we see is the first step towards understanding human intelligence EE565 Advanced Image Processing Copyright Xin Li 2008 10 D. Hubel’s “Eyes, Brain and Vision” http://hubel.med.harvard.edu/bcontex.htm EE565 Advanced Image Processing Copyright Xin Li 2008 11 Neural Network View “The Next Generation of Neural Networks” http://www.youtube.com/watch?v=AyzOUbkUf3M EE565 Advanced Image Processing Copyright Xin Li 2008 12 Why Mathematical Modeling? What is mathematical modeling? A mathematical model uses mathematical language to describe a system Linear vs. nonlinear Deterministic vs. probabilistic Static vs. dynamic Homogeneous vs. heterogeneous Philosophical considerations Causality vs. Synchronicity EE565 Advanced Image Processing Copyright Xin Li 2008 13 Images of Favorite: Natural Images What is natural images? Why natural images? No rigorous definition to the best of my knowledge Loosely speaking, images of natural scenes acquired by CCD cameras (Others call photographic images) An important class of images with a variety of applications (consumer electronics, biometrics, entertainment) A good representative with high modeling complexity (arguably more challenging than other class such as medical images) Cautious note about model complexity EE565 Advanced Image Processing Copyright Xin Li 2008 14 To Understand Natural Images Image Processing is also about Physics EE565 Advanced Image Processing Copyright Xin Li 2008 15 Natural Scenes How many different objects can appear in natural scenes? Countless – human faces, animals, buildings, mountains … "Nature is not ecomonical of structures - only of principles" -Abdus Salam EE565 Advanced Image Processing Copyright Xin Li 2008 16 Resolution Invariance EE565 Advanced Image Processing Copyright Xin Li 2008 17 Scale Dependency 0.1m 10m EE565 Advanced Image Processing Copyright Xin Li 2008 1m 100m 18 Self-Similarity: Fractals EE565 Advanced Image Processing Copyright Xin Li 2008 19 Impact of Illumination Indoor Example EE565 Advanced Image Processing Copyright Xin Li 2008 20 Outdoor example EE565 Advanced Image Processing Copyright Xin Li 2008 21 Story of “Lena” Image in USC Dataset EE565 Advanced Image Processing Copyright Xin Li 2008 22 From USC to JPEG2K EE565 Advanced Image Processing Copyright Xin Li 2008 23 The Space of Natural Images textures smooth regions contours (Courtesy of Prof. SC Zhu at UCLA) By analogy, the space of natural images is very much like our universe EE565 Advanced Image Processing Copyright Xin Li 2008 24 Challenge 1: Image Restoration Practical limitation of image acquisition system Limited resolution (image size) Inevitable blurring and noise Distortion introduced by image transmission Wireless channel: fading errors Internet: packet loss If you work on communication, reliable communication of images through wired or wireless channel is a long-standing open problem EE565 Advanced Image Processing Copyright Xin Li 2008 25 Image Denoising denoising algorithm Y=X+W ^ X=f(Y) W: additive white Gaussian noise EE565 Advanced Image Processing Copyright Xin Li 2008 26 Our Tasks Understand classical Wiener filtering Gaussian source, Gaussian noise Theoretically optimal How does wavelet-based denoising work? Why do statistical methods outperform others (e.g., PDEbased)? EE565 Advanced Image Processing Copyright Xin Li 2008 27 Deblurring deblurring algorithm ^ X=f(Y|H) Y=HX+W H: linear blurring kernel When H is unknown, it becomes the notoriously difficult blind image Deconvolution problem EE565 Advanced Image Processing Copyright Xin Li 2008 28 Idea 1: Motion Deblurring “Removing camera shake from a single image” Presented at SIGGRAPH 2006, Boston http://people.csail.mit.edu/fergus/research/deblur.html EE565 Advanced Image Processing Copyright Xin Li 2008 29 Where is Blur? Easy for human eyes but difficult for computers EE565 Advanced Image Processing Copyright Xin Li 2008 30 Image Interpolation interpolation algorithm EE565 Advanced Image Processing Copyright Xin Li 2008 31 Superresolution EE565 Advanced Image Processing Copyright Xin Li 2008 32 Towards Gigapixel 3Mpel 1Gpel Link 1 http://www.tawbaware.com/maxlyons/gigapixel.htm Link 2 http://triton.tpd.tno.nl/gigazoom/Delft2.htm EE565 Advanced Image Processing Copyright Xin Li 2008 33 Idea 2: Barcode Superresolution How to extract the 1D barcode information from a 2D image? EE565 Advanced Image Processing Copyright Xin Li 2008 34 Image Inpainting Inpainting Algorithm EE565 Advanced Image Processing Copyright Xin Li 2008 35 Application of Inpainting EE565 Advanced Image Processing Copyright Xin Li 2008 36 Inpainting in Image Communication: Error Concealment EE565 Advanced Image Processing Copyright Xin Li 2008 37 Deblocking JPEG compressed image at low bit rate Restored image after post-processing EE565 Advanced Image Processing Copyright Xin Li 2008 38 Deringing JPEG2000 compressed image at low bit rate Restored image after post-processing EE565 Advanced Image Processing Copyright Xin Li 2008 39 Challenge II: Robust Image Coding 5Mpel camera: 3bytes per pixel, 15MB per image 512M memory: $40, $1 per image w/o compression Memory will become less and less expensive (see next slide) EE565 Advanced Image Processing Copyright Xin Li 2008 40 Holographic Recording Data 1011 1000 0110 0010 Dispersive channel SLM Image Detector Image Recovered Data 1011 1000 0110 0010 Channel Courtesy of Kevin Curtis, InPhase Technologies EE565 Advanced Image Processing Copyright Xin Li 2008 41 Bandwidth is STILL COSTY Do you know how much Sprint charges for wireless data? EE565 Advanced Image Processing Copyright Xin Li 2008 42 JPEG2000 vs. JPEG JPEG2000 JPEG Compression ratio is the same: 217 Online comparison demo: http://www.aware.com/products/compression/j2kmaindemo.html EE565 Advanced Image Processing Copyright Xin Li 2008 43 Our Tasks Why is wavelet coding better? Properties of wavelet transforms Statistical modeling of natural images Importance of location uncertainty How do we go beyond wavelet coding? Image quality assessment Rethink the role of bits (resolve location vs. intensity uncertainty) Biologically-inspired approaches EE565 Advanced Image Processing Copyright Xin Li 2008 44 Idea 3: Satellite Image Compression Imagine you are in real-state business, don’t you want to give your customers a virtual tour before a physical visit? EE565 Advanced Image Processing Copyright Xin Li 2008 45 Challenge III: Image Analysis From low-level vision (image-in-image-out) to high-level vision (image-in-information-out) Automatic target recognition EE565 Advanced Image Processing Copyright Xin Li 2008 46 Feature Point Matching at Low-level EE565 Advanced Image Processing Copyright Xin Li 2008 47 Object Segmentation at Middle Level EE565 Advanced Image Processing Copyright Xin Li 2008 48 Image Retrieval at High Level EE565 Advanced Image Processing Copyright Xin Li 2008 49 Popular Demo: Face Detection http://vasc.ri.cmu.edu/demos/faceindex/03282003/users/665.html EE565 Advanced Image Processing Copyright Xin Li 2008 50 Challenges with Face Detection http://vasc.ri.cmu.edu/demos/faceindex/12182002/users/2622.html EE565 Advanced Image Processing Copyright Xin Li 2008 51 Idea 4: Face Image Indexing How do we tell two people look alike? Eye Face mouth nose Q: Can we automatically sort out face images based on their perceptual similarities? EE565 Advanced Image Processing Copyright Xin Li 2008 52 Challenge IV: Image-related Security EE565 Advanced Image Processing Copyright Xin Li 2008 53 Image Forensics Courtesy of Dr. H. Farid at Dartmouth: http://www.cs.dartmouth.edu/farid/research/tampering.html EE565 Advanced Image Processing Copyright Xin Li 2008 54