The deteriorated image resulting from imaging system performances can be recovered with inverse filtering by multiplying the inverse filtering function and the Fourier transform of the acquired image providing that the optical imaging transfer function is known and its inverse function or the corresponding i inverse filtering function can be found according to the measure or the priori knowledge of the imaging transferl function. If the inverse function is continuous about the origin it may actually be represented as the Tailor series. The inverse Fourier transform operation of the polynomial series is differentiation of orders corresponding no degrees in the polynomial. Consequently

the inverse Fourier transform of the recovered image is approximately realized in spatial domain by the linear combinations of the image and its derivatives rather than by complicated deoonvolution. It is considerable for the recovery of the spatially variant deterioration

such as the deterioration resulting from curvature of field. For images of space-variant degradation

the linear combining coefficients rare functions of spatial coordinates specified by the spatial variance. Detailed analysis and derivation of equations are presented. Finally

the processing results both in spatial invariant and variant systems are given.