Speckle disturbance limit in laser-based cinema projection systems

Abstract

In a multi-disciplinary effort, we investigate the level of speckle that can be tolerated in a laser cinema projector based on a quality of experience experiment with movie clips shown to a test audience in a real-life movie theatre setting. We identify a speckle disturbance threshold by statistically analyzing the observers’ responses for different values of the amount of speckle, which was monitored using a well-defined speckle measurement method. The analysis shows that the speckle perception of a human observer is not only dependent on the objectively measured amount of speckle, but it is also strongly influenced by the image content. The speckle disturbance limit for movies turns out to be substantially larger than that for still images, and hence is easier to attain.

Nanolasers with Feedback as Low-Coherence Illumination Sources for Speckle-Free Imaging: A Numerical Analysis of the Superthermal Emission Regime

“…Technological development has enabled stronger emission in a cone that can escape the material, but the collection optics and the transfer of the emission to the sample to be illuminated remains more challenging than with self-collimated laser light. As a result, the laser naturally offers a larger amount of exploitable power-for the same amount of provided energywithout additional efforts; thus, explaining why the oxymoron low-coherence laser light has attracted so much interest [18][19][20][21][23][24][25][26][28][29][30][31][32][33]. At variance with what is known in macroscopic lasers, Figure 2a shows that the nanolaser output does not entirely consist of stimulated photons when P > P th .…”

“…Laser imaging, among them, has been attracting a great deal of attention thanks to the high brightness of its radiation, strong directionality, excellent color purity and high efficiency [18]. One additional advantage is the longer lifetime, normally one order of magnitude longer than that of arc lamps, while maintaining good properties throughout its operation [19]. It is, therefore, only natural that lasers should have attracted attention in the realm of imaging.…”

Suppression Effect of Randomly-Disturbed LC Alignment Fluctuation on Speckle Noise for Electronic Holography Imaging

“…The result shows the effect of LC alignment fluctuation frequencies obtained in Sections 4.1 and 4.2 on speckle noise reduction. The target of speckle noise reduction is to reduce the speckle contrast to at least less than 0.1 [12,13]. This is the value at which speckle is no longer perceived by humans.…”

Development Of A Nonlinear Frequency Compounding Method With Applications In Ultrasound Imaging And Thermometry

“…If N images are used in the compounding process, then the typical reduction in speckle is of the order √ N for statistically independent images [12,13,14]. Here, the amount of speckle is quantified by a speckle contrast value equal to the ratio of standard deviation over mean intensity of pixel values in a uniform region [15].…”