Satomi Tanaka, Kaori Kiyomitsu, Masanori Maki, Akihiro Kakinuma, Naohiro Kamijo, Hiroshi Takahashi and Norimichi Tsumura
JIST 2017 (accepted)
Abstract
Current digital cameras have various automatic control systems. In automatic
camera systems, extracting focusness from an image is a very important
problem. Automatic extraction of the main subject makes taking photos very
easy, even for an amateur photographer. Methods have been proposed to evaluate
focusness by visual saliency, which assume that an area with high saliency
also has high focusness. However, various differences exist between focusness
and saliency. In this study, we compare the values between focusness and
saliency maps. We evaluate the focusness of 80 images in an image evaluation
experiment with 20 observers. Saliency maps are calculated using six conventional
algorithms. We show that the individual variations of focusness are very
few in images that include only one major object. Furthermore, we apply
a GIST feature to the saliency method by using a center-surround histogram
and extract focusness from images with high accuracy.
[PDF] (to appeare)