Tone Reproduction

by Kathleen Marty

CS779, Spring 2003

Problem:

High Dynamic Range (HDR) radiance maps are used to capture the radiance lighting of real-world scenes. However, viewing an HDR map poses a problem: various common display devices (monitors, printers, etc.) are capable of displaying a much smaller dynamic range than found in real-world scenes. Therefore, how can we display HDR images on low dynamic range display devices while preserving the visual content?

Solution:

Implementation of the paper Gradient Domain High Dynamic Range Compression by Raanan Fattal, Dani Lischinski, and Michael Werman (SIGGRAPH 2002). The paper attempts to preserve local contrasts by attenuating the magnitudes of large luminance gradients. In addition, common artifacts such as halos and gradient reversals are avoided. No attempt is made at reproducing the human visual system response.

Results:

Results using the "Belgium house" as given in the paper by Fattal, et.al:

Attenuation map (darker shades indicate stronger attenuation):

Uncompressed lumanince image (original image - notice the light range is too high to see all the details):

Compressed lumanince image (result of running the gradient compression algorithm):

Final color adjustment added using the paper's formula (still a little washed out colors):

Results of using "Rossette":

Uncompressed lumanince image:

Compressed lumanince image:

05/19/2003