FOCUSED IMAGE RECOVERY FROM 2 DEFOCUSED IMAGES RECORDED WITH DIFFERENT CAMERA SETTINGS

Two new methods are presented for recovering the focused image of an o bject from only two blurred images recorded with different camera para meter settings. The camera parameters include lens position, focal len gth, and aperture diameter. First a blur parameter sigma is estimated using one of our two recently proposed depth-from-defocus methods. The n one of the two blurred images is deconvolved to recover the focused image. The first method is based on a recently proposed spatial domain convolution/deconvolution transform. This method requires only the kn owledge of sigma of the camera's point spread function (PSF). It does not require information about the actual form of the camera's PSF. The second method, in contrast to the first, requires full knowledge of t he form of the PSF. As part of the second method, we present a calibra tion procedure for estimating the camera's PSF for different values of the blur parameter sigma. In the second method, the focused image is obtained through deconvolution in the Fourier domain using the Wiener filter. For both methods, results of experiments on actual defocused i mages recorded by a CCD camera are given. The first method requires mu ch less computation than the second method. The first method gives sat isfactory results for up to medium levels of blur and the second metho d gives good results far up to relatively high levels of blur.