Measurement of Non-Circular PSFs in Single Pixel Cameras

Abstract

This paper proposes an improved method for measuring Point Spread Function (PSF) of a camera. With this method the PSF is obtained by analyzing the image of a circular chart taken by the camera to be characterized. The main advantage over the existing methods is the capability to measure PSFs of various shapes not only circular. Single Pixel Camera is one of the imaging systems that could benefit of this method since depending of the light wavelength, the PSF can take either the shape of the aperture or that of Spatial Light Modulator cell. Other advantages of our methods are the capability to correct shear effects of the chart image and to infer the PSF from projections by Inverse Radon Transform. This last feature gives the possibility to also restore the images taken by the camera and not only to characterize the camera. The method is tested on synthetic images of the chart in the case of four different PSF shapes: circular, square, hexagonal and rounded square. The results show a correct estimation of the PSF shape and well restored images obtained by deconvolution with the measured PSF.