KEYWORDS: Cameras, Digital imaging, Image quality, Control systems, Camera shutters, Statistical modeling, Automatic exposure, Automatic control, Data analysis, Photography
The automatic exposure control (AEC) for a camera phone is typically a simple function of the brightness of the image.
This brightness, or intensity, value generated from a frame is compared to a predefined target. If the intensity value is
less than a specified target, the exposure is increased. If the value is greater, exposure will be decreased.
Is using an intensity target statistic a good model for AEC? In order to answer this question, we conducted
psychophysical experiments to understand subjective preferences. We used a high-end DSLR to take 64 different
outdoor and indoor scenes. Each scene was captured using five different exposure values (EV), from EV-1 to EV+1 with
half EV increments. Subjects were shown the five exposures for each scene and asked to rank them based on their
preferences.
The collected data were analyzed along different dimensions: preferences as a function of the subjects, EV levels, image
quality scores, and the images themselves. Our data analysis concludes that a dynamic intensity target is needed to match
the exposure preferences collected from our subjects.
A novel passive autofocus searching algorithm that takes account of human visual system limitations is presented. Comparing to the existing algorithms, the proposed method offers better overall performance in terms of converging speed, accuracy, and anti-backlash ability.
Conference Committee Involvement (9)
Digital Photography X
3 February 2014 | San Francisco, California, United States
Digital Photography IX
4 February 2013 | Burlingame, California, United States
Digital Photography VIII
23 January 2012 | Burlingame, California, United States
Digital Photography VII
24 January 2011 | San Francisco Airport, California, United States
Digital Photography VI
18 January 2010 | San Jose, California, United States
Digital Photography V
19 January 2009 | San Jose, California, United States
Digital Photography IV
28 January 2008 | San Jose, California, United States
Digital Photography III
29 January 2007 | San Jose, CA, United States
Digital Photography II
16 January 2006 | San Jose, California, United States
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