Compressing and Companding High Dynamic Range Images with Subband Architectures
Yuanzhen Li, Lavanya Sharan, & Edward H. Adelson
Dept. of Brain
and Cognitive Sciences, and Computer Science and Artificial Intelligence Laboratory
Massachusetts Institute of Technology, Cambridge, MA
Transactions on Graphics, Proceedings of SIGGRAPH 2005
High dynamic range (HDR) imaging is an area of increasing importance, but most display devices still have limited dynamic range (LDR). Various techniques have been proposed for compressing the dynamic range while retaining important visual information. Multiscale image processing techniques, which are widely used for many image processing tasks, have a reputation of causing halo artifacts when used for range compressing. However, we demonstrate that they can work when properly implemented. We use a symmetrical analysis-synthesis filter bank, and apply local gain control to the subbands. We also show that the technique can be adapted for the related problem of "companding", in which an HDR image is converted to an LDR image, and later expanded back to high dynamic range.
New: matlab code ReadMe
the hdr doll image: doll.hdr
fast-forward slides (ppt)
poster at SCPV
Supported by a MURI grant via the Office of Naval Research (N00014-01-1-0625), NSF grant BCS-0345805, and contracts from NTT Labs, Shell Labs, and the National Geospatial Intelligence Agency (NGA).
Figure 7 (the companding flowchart) should be:
In the downloadable paper file above, this figure has been corrected. But in the printed proceedings, three arrows (marked in blue) have wrong directions.