No abstract

ABSTRACT. Fifty patients aged from 30 to 69 years (mean 54.7 * 11.3 years, SD) with a UV-protected monofocal polymethylmethacrylate intraocular lens (IOL) were examined with the Farnsworth-Munsell 100 hue (FM 100) test and the Color Vision Meter 712 anomaloscope. The spectral transmission of the same kind of IOLs as was used surgically was measured with Lambda 2 W / V I S Spectrometer. In the FM 100 test, there was no significant difference between the results of the IOL eyes and normal eyes. However, the IOL eyes showed better error scores than the normal eyes in the blue-purple box IV in the FM 100 test. In the anomaloscope testing, the Rayleigh (red-green) equation showed no differences between the IOL patients and controls. In the Moreland (blue) equation, however, the mid matching point was significantly shifted towards more green (meaning better blue colour sensitivity) in the IOL eyes than in the control eyes. This is due to the spectral transmission of the IOLs which showed 80-90% transmission already starting at the wavelength of about 420 nm. In comparison, the transmission of the normal human lens reaches those percentages near 500 nm or even further at advanced age.

Texture plays an important role in vision research and in many practical applications, as well. Texture reseach has been wide in applied sciences, and thus many methods for texture analysis have been proposed. To recognize texture in real time modern optics may offer new tools, which is the theme of the present paper. We investigate the applicability of complex matched filter, and phaseonly filters to recognize textures. Natural textures of the Brodatz collection3 were used as the test samples. We show that optical correlators are useful in texture recognition. The recognition is based on the peak-to-correlation ratio, which is much higher for phase-only filters than for the matched filter. However, if we consider output signal-to-noise ratio the matched filter remains valuable.

Colors called "white' are found in a small but yet not sharply defined region of the color space. The main characteristics of a white sample are high ligthness, tristimulus value Y > 70 and low saturation, excitation purity p