User Manual - pancroma

The problem lies in the division by the FFT of the deconvolution kernel. Thekernel can have a lot of small values as a result of transformed noise. When apixel in the transformed image is divided by one of these small values, anextremely large value results, resulting in an over-driven image.This can be remedied by adjusting the thresholding value. The default value is0.01. If you have a noisy image you can increase this value, increasing the effectof the noise filter.PANCROMA TM offers two deconvolution utilities: Fixed Kernel Size and VariableKernel Size, and three PSF distributions, Gaussian, Moffat and Exponential. Thedeconvolution kernel defines the extents of the selected distribution used todeconvolve the image. The fixed kernel size is five, meaning that the distributionis truncated at +/- 2 pixels from the pixel being operated on. Such a kernel for anormalized Gaussian distribution with sigma=1 is shown in the table below. (Thekernel is centered on the (2, 2) position with the partitioning shown.)0 1 2 3 40 0.002969 0.013306 0.021938 0.013306 0.0029691 0.013306 0.059634 0.09832 0.059634 0.0133062 0.021938 0.09832 0.162103 0.09832 0.0219383 0.013306 0.059634 0.09832 0.059634 0.0133064 0.002969 0.013306 0.021938 0.013306 0.002969295