Photorefractive Deamplification for Artifact Noise Reduction

Many optical image processing operations such as edge enhancement may be performed by suitable linear spatial filters. A broader class of operations is made available by extending this technique to nonlinear filters. An example of this is the use of a logarithmic nonlinearity for conversion of multiplicative to additive noise [1]. In this work, we demonstrate that phase preserving thresholding in the Fourier plane which linearly transmits signals above a certain intensity, reduces additive signal dependent noise, such as noise from coherent artifacts, image defects and uniformity noise.