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This presentation explores innovative approaches to depth of field rendering by employing pyramidal image processing methods. Depth of field is crucial in photography and cinematography, providing a realistic focus effect that differs across various optical systems. We discuss related work, present our proposed method that focuses on real-time application without compromising image quality, and share experimental results comparing our technique to state-of-the-art methods. Future work aims to refine these techniques for enhanced performance in interactive environments.
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07 E U R O G R A P H I C S Depth-of-Field Renderingby Pyramidal Image Processing Martin Kraus (TU München) and Magnus Strengert (Universität Stuttgart)
00 Outline ofthis Talk 01Introduction 02Relatedwork 03Proposedmethod 04 Experiments 05 Future work
01 I N T R O D U C T I O N What Is Depthof Field? • The depth in front andbeyondthefocus plane whereobjectsappeartobe in focus • A propertyof all realopticalsystems • onlyvirtualpin-hole camerashave infinite depthoffield • Usedforimportantphotographicandcinematographictechniques
photoby Jon Sullivan (http://pdphoto.org/PictureDetail.php?mat=pdef&pg=8202)
photoby "che" (http://commons.wikimedia.org/wiki/Image:Dandelion_clock_detail.jpg)
02 R E L A T E D W O R K ClassificationofTechniques: • Splatting [Potmesil & Chakravarty 1982] • Stochasticsampling [Cook et al. 1984] • e.g., in distributedraytracingor in REYES • stateoftheart in offline rendering • Pre-filtering [Rokita 1993] • lots ofartifacts [Demers 2004] • stateoftheart in real-time rendering • Blurringof sub-images [Barsky 2004]
02 R E L A T E D W O R K High Quality in Real Time? • Real-time performancerequires: • independenceofscenecomplexity • excludesstochasticsampling • thus: image post-processingof a pin-hole colorimageanddepthmap • independenceofimagesynthesisforfree • convolutionfilteringistoo expensive • evenwith FFTs on GPUs • thus: blurringusingpyramidalgorithms
02 R E L A T E D W O R K High Quality in Real Time? • High imagequalityrequires: • smooth blurringwithoutinterpolationartifacts • pyramidblurring [Kraus & Strengert 2007] • noincorrectcolorbleeding • excludespre-filtering • separate blurringof sub-images • disocclusionof semi-transparent pixels • inpaintingofcolorsanddepthswithpyramidalgorithm [Strengert et al. 2006]
03 P R O P O S E D M E T H O D Overview pin-hole image & depthmap decompositioninto sub-images 3 1 4 disocclusion matting blurring 2 blendingof sub-images 5 resultingimage
03 P R O P O S E D M E T H O D Decomposition • decomposeinto sub-imagesandcullforegroundpixelsaccordingtodepthmap 1
03 P R O P O S E D M E T H O D Disocclusion • foreach sub-image: disoccludeculledforeground (using pyramidal inpainting) 2
03 P R O P O S E D M E T H O D Matting • foreach sub-image: computealpha-mattingaccordingtoeachpixel'sdepth 3
03 P R O P O S E D M E T H O D Blurring • foreach sub-image: blurcolorandalpha (using pyramidal blurring) 4
03 P R O P O S E D M E T H O D Blending • back-to-front blendingof all sub-images • resultcomputed in 70.4 ms • (12 sub-images,hardware: • NVIDIA GeForce 7900 GTX) 5
03 P R O P O S E D M E T H O D Main Features • independentofscenecomplexity • andindependentofimagesynthesis • interactiveperfomance on GPUs • real-time forsmallcirclesofconfusion • highimagequality • avoidsartifactsofpre-filteringtechniques • let's do someexperiments …
04 E X P E R I M E N T S OurMethod vs. pbrt • pbrtusesstochasticsampling • Whichiswhich?
04 E X P E R I M E N T S OurMethod vs. pbrt pbrt our method
04 E X P E R I M E N T S OurMethod vs. pbrt • Whichiswhich?
04 E X P E R I M E N T S OurMethod vs. pbrt pbrt our method
04 E X P E R I M E N T S Can We Break OurMethod? • Yes, with a very largelensradius. pbrt bleeding gray too opaque our method
04 E X P E R I M E N T S Can We Break OurMethod? • Video withvery large lensradii:eg07.mov • also availableat: http://wwwcg.in.tum.de/Research/Publications/DepthOfField
05 F U T U R E W O R K Are Wethereyet? • No, but weavoidtypicalrenderingartifactsof real-time techniques • Specializedvariantsforbetterperformanceandimagequality • Alternative blurfilters • High-potential application: • gaze-directedfocus
06 A C K N O W L E D G M E N T S • The photosappearcourtesyof "che" and Jon Sullivan. • The dragon model appearscourtesyofthe Stanford University Scanning Repository. • The pbrtsceneappearscourtesyof Gregory Humphreys and Matt Pharr.
07 E U R O G R A P H I C S Thankyou! Andhave a safetriphome! Questions?
07 E U R O G R A P H I C S