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Abstract

A number of successful tone mapping operators for contrast compression have
been proposed due to the need
to visualize high dynamic range (HDR) images on low dynamic range devices. They
were inspired by Øelds
as diverse as image processing, photographic practice, and modeling of the
human visual systems (HVS). The
variety of approaches calls for a systematic perceptual evaluation of their
performance.
We conduct a psychophysical experiment based on a direct comparison between the
appearance of real-world
scenes and HDR images of these scenes displayed on a low dynamic range monitor.
In our experiment, HDR
images are tone mapped by seven existing tone mapping operators. The primary
interest of this psychophysical
experiment is to assess the diÆerences in how tone mapped images are perceived
by human observers and to Ønd
out which attributes of image appearance account for these diÆerences when tone
mapped images are compared
directly with their corresponding real-world scenes rather than with each
other. The human subjects rate image
naturalness, overall contrast, overall brightness, and detail reproduction in
dark and bright image regions with
respect to the corresponding real-world scene.
The results indicate substantial diÆerences in perception of images produced by
individual tone mapping
operators. We observe a clear distinction between global and local operators in
favor of the latter, and we
classify the tone mapping operators according to naturalness and appearance
attributes.ce attributes.