Spotting of disc haemorrhages on fundus pictures; on Kodachrome slides and on digitally enhanced images.
OBJECTIVE
To find out whether digital processing can facilitate interpretation of fundus photographs.


METHODS
Digitised fundus pictures were manipulated and enhanced by a process called histogram equalisation. Essentially, the gamma values for red (R), green (G), and blue (B) were separately modified. The principle is explained and exemplified.


RESULTS
Small disc haemorrhages, which may normally be hard to detect, became more visible after histogram equalisation, which is demonstrated in test series.


CONCLUSIONS
Digital histogram equalisation offers a new way of looking at fundus pictures, which, alone or combined with other capabilities of digital processing, has great potential for diagnosis, as well as for follow up studies. The possibility to decide the true nature of suspect spots after applying the enhancement procedure is likewise of great value.
Holm
O
O
University Eye Clinic, UMAS, Malmö, Sweden. olle.holm@oftal.mas.lu.se
Krakau
C E
CE
D003937:Diagnosis, Differential; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D009898:Optic Disk / Q000098:blood supply*; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D012166:Retinal Hemorrhage / Q000175:diagnosis*