Resolution requirements for digital images in dermatology.
BACKGROUND
The digital image has become an important tool in dermatology because of the rapid development of computer hardware, networks, and the World Wide Web.


OBJECTIVE
Our purpose was to examine the resolution requirements for digital images.


METHODS
Slides of eight selected images showing characteristic lesions were produced in five different resolutions each, ranging from 192 x 128 x 24 (192 pixels x, 128 pixels y, and 24-bit color depth) up to 3072 x 2048 x 24. They were compared side by side by a group of six experienced dermatologists using a standardized questionnaire.


RESULTS
Images at the resolution of 768 x 512 x 24 were perceived as equivalent to higher resolutions, whereas a clear difference was visible between 768 x 512 x 24 and 384 x 256 x 24. The slide projector had a significant influence on the rating of the images.


CONCLUSIONS
For digital images in dermatology a resolution of 768 x 512 x 24 is suitable to recognize the relevant details of the source image.
Bittorf
A
A
Department of Dermatology, University of Erlangen, Germany.
Fartasch
M
M
Schuler
G
G
Diepgen
T L
TL
D003880:Dermatology / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D010781:Photography; D011795:Surveys and Questionnaires