1 / 24

Recovering High Dynamic Range Radiance Maps from Photographs

Recovering High Dynamic Range Radiance Maps from Photographs. Paul E. Debevec, Jitendra Malik. In SIGGRAPH 97, August 1997. Introduction. “Dynamic Range” of a scene is the contrast ratio (brightest / darkest parts) Recovering High Dynamic Range Radiance Maps Multiple Photographs

armand-bean
Download Presentation

Recovering High Dynamic Range Radiance Maps from Photographs

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Recovering High Dynamic Range Radiance Maps from Photographs Paul E. Debevec, Jitendra Malik. In SIGGRAPH 97, August 1997

  2. Introduction • “Dynamic Range” of a scene is the contrast ratio (brightest / darkest parts) • Recovering High Dynamic Range Radiance Maps • Multiple Photographs • Recover … Response function ( film response in exposure ) • Differently Exposed Photographs • Image-Based Modeling & Rendering • Image – same ( exposure setting , film response function ) • Recovering reflection models ( BRDF ) • require … absolute Radiance Values

  3. Image Acquisition Pipeline

  4. Film Response Recovery • The response of a film Optical Density of film against the Exposure digital number Z ( development , scanning , digitization process ) Input – Z ,

  5. Film Response Recovery • To complete description - ( unit exposure) - weighting function - pixel location ( Zmin ~ Zmax , image )

  6. Constructing the HDR Radiance Maps • Curve - Radiance values ( associated with g ) Combining the multiple exposures - reduce Noise, artifacts ( such as film grain )

  7. Constructing the HDR Radiance Map • Storage • Map  image format

  8. Rendering Synthetic Objects into Real Scene: Bridging Traditional and Image-Based Graphics with Global Illumination and High Dynamic Range Photography Paul E. Debevec,. In SIGGRAPH 98, July 1998

  9. Introduction • Scene Radiance & Global Illumination • High Dynamic Range Image-based model • Illuminate the NEW objects • 3 components • Distant Scene • Local Scene • Synthetic Objects

  10. Introduction • Light Probe • HDR Panoramic Radiance Map ( near rendered location ) • Light-Based Model

  11. Illuminating Synthetic Objects with Real Light • Accurately Recording Light in a scene • Large areas of Indirect Light • Concentrated areas of Direct Light • Recovering HDR • Measure of Scene Radiance

  12. The General Method • Distant Scene ( a Light-Based Model ) • Light-Based Model • Accurate measure of Incident Illumination • ( in vicinity of objects, desired viewpoint ) • Local Scene ( approximate Material-Based Model ) • Interact with the Synthetic Objects • Geometry, Reflectance characteristic • Synthetic Object • variety of Shapes , Materials

  13. Compositing using a Light Probe • Constructing a Light-Based Model of real scene • Fully Dynamic Range Omnidirectional Radiance Map • Radiance measurement  mapped ( geometry of Distant Scene ) • Mapping from the Probe to the scene model • Mapping coordinates ( ball , world ) • Position, Size, camera Parameter ( location in scene, focal length ) • Assume … Small , Orthograph  good approximation • Creating Rendering

More Related