Evaluation of an extensive speckle measurement method

The introduction of lasers for projection applications is hampered by the emergence of speckle. In order to evaluate the speckle distorted image quality, it is important to devise an objective way to measure the amount of speckle. Mathematically, speckle can be described by its speckle contrast value C, which is given by the ratio between the standard deviation of the intensity fluctuations and the mean intensity. Because the measured speckle contrast strongly depends on the parameters of the measurement setup, in this paper we propose a standardized procedure to measure the amount of speckle in laser based projection systems. To obtain such a procedure, the influence of relevant measurement set-up parameters is investigated. The resulting measurement procedure consists of a single digital image sensor in combination with a camera lens. The parameters of the camera lens are chosen such that the measured speckle contrast values correspond with the subjective speckle perception of a human observer, independent of the projector's speckle reduction mechanism(s). Finally, the speckle measurement procedure was performed with different cameras and the results were compared.

ISBN:978-0-8194-9128-2

Jaar van publicatie:2012

Trefwoorden:CONTRAST REDUCTION; LASER PROJECTION; DISPLAYS