a common problem in consumer photography. It occurs when a flash is
used in photography and the light reflecting from human retina makes
the eyes appear red. This artifact is drawing increased attention
with the popularity of digital cameras, in which camera size
continues to shrink and the distance between the flash and the lens
is decreasing. Although some cameras are equipped with
pre-flash hardware to alleviate redeye problems, they are not well
received since they do not always prevent the redeye artifact and
tend to result in people blinking during the actual photo taking. At
HP Labs, we are working on digital solutions to remove red eyes in
the post-processing stage.
many image processing software applications in the market offer
redeye removal solutions. However, the majority of them are
semi-automatic or manual solutions. The user has to either click on
the redeye or draw a box containing the redeye before the redeye
removal algorithms can find the redeye pixels and correct them.
Besides inconvenience, a typical problem with these algorithms is
poor segmentation. Even with user input, these algorithms sometimes
identify redeye pixels too aggressively, darkening eye lid areas, or
too conservatively, leaving many redeye pixels uncorrected.
contrast, HP solution comprises of a fully automatic redeye
detection module and a color correction module, which finds and
corrects red eyes without user interventions.
In the past years, researchers at HPL have built up core
expertise in two important areas that are relevant to the redeye
problem: pattern recognition and color science. Our most recent red
eye solution includes the following algorithm design:
- A training based detector design, which uses Adaboost
algorithm to simultaneously select relevant features and assign
feature weight for the classifier.
- A systematic, orientation independent feature computation
scheme for object detection.Because of this design, our trained
detector is able to detect red eyes of arbitrary in-plane
- An adaptive, high quality red eye recoloring algorithm.
In addition, because of the high efficiency of the algorithm, we
have successfully implemented in various embedded platforms in HP
For more technical details, please refer to the following papers:
H. Luo, J. Yen and D. Tretter, "An
Efficient Automatic Redeye Detection and Correction Algorithm”, to
appear in ICPR 2004. (pdf download)
A. Patti, K. Konstantinides, D. Tretter and Q. Lin,
"Automatic Digital Redeye Detection", ICIP, 1999.
Products & Applications
The most recent red eye remove algorithm we developed have been
used in various HP products. Among them includes: HP
Photosmart R707 camera,
HP Photosmart 7960 printer , etc. In addition, this algorithm is
also included in HP's RedBot
For more information about HPL redeye technology, please contact
Huitao Luo (email@example.com)
at Imaging Technology Dept., HP Labs.