Estimation of anisotropic blur for the restoration of confocal images
Filip Rooms, Wilfried R. Philips, Patrick Van Oostveldt · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2004
We present a novel method for joint estimation of the degradation and restoration of photon-limited images. Our method will be demonstrated on confocal microscope images, since confocal microscopy is an important tool in many academic (fundamental biology, . . . ) and industrial (material science, pharmaceutical industry, . . . ) applications. However, the observed images are usually degraded, which hinders analysis and interpretation of the images. Degradation in this kind of images is due to two sources: first, we have blurring due to the bandlimited nature of the optical system; second, Poisson noise contaminates the observations due to the discrete nature of the photon detection process. The proposed method iterates noise reduction and blur estimation using the steerable pyramid transform (which is a variant of the wavelet transform) and deconvolution in the signal domain. These steps are applied in two phases, a training phase and a restoration phase. In the first phase, these three steps are iterated until the blur estimation converges. The second phase is the actual restoration phase. During the iterations the blur estimation serves as a sharpness measure for the restored image, and is used to controls the number of iterations. So, our integrated method provides a completely automatic algorithm where no prior information about the image degradation is required. Our integrated technique was compared with other common restoration techniques for these kind of images, and provided the best restoration results, with least artifacts.