Abstract
Purpose: :
To analyze the impact of (i) opacities in the optical pathway and (ii) image compression of 32-bit raw data to 8-bit JPEG images on quantified optical coherence tomography (OCT) image analysis.
Methods: :
In 18 eyes of 9 healthy subjects, OCT images were acquired from the central macula (Zeiss Stratus® OCT). To simulate opacities in the optical system, neutral density filters with linear absorption spectra were placed between the OCT device and examined eyes. Light reflection profiles (LRP) of images acquired with various neutral density filters were compared. LRPs of the 32-bit raw data were compared with those obtained from the 8-bit JPEG compressed images.
Results: :
Neutral density filters induced a linear decrease of reflectivity in OCT images, depending on initial signal intensity. Quantitative OCT analysis showed no significant difference between 32-bit raw data and 8-bit JPEG files (p>0.05).
Conclusions: :
Quantitative OCT analysis is not significantly influenced by data compression. A mathematical model can correct for optical opacities to "improve" OCT images.
Keywords: retina • image processing