Digital restoration of images scanned from photographic paper
Gordana Pavlovic · Journal of Electronic Imaging · 1993
We address the restoration of noisy and blurred images that are scanned from photographic paper. In this case, we need to consider the nonilnearities introduced by both the photographic film and the paper. To this effect, we first transform the measured refiection density of the photographic paper into the scene exposure domain in which a linear convolutional relationship between the orig- Thai scene and the degraded image can be established. As a result of this transformation, any additive noise Th the reflection density domaTh becomes multiplicative Th the scene exposure domaTh. We then propose a linear filter for deconvolution Th the exposure domaTh in the presence of multiplicative observation noise. Experiments with actual noisy and blurred images scanned from photographic paper Thdicate that the noniThear sensor characteristics must be Thcorporated Thto image restoration to obtaTh satisfactory results. We also compare the quality of the restoration results when the same blurred image is scanned from the photographic negative (film) and the prTht (paper) obtaThed from this negative.