In this paper we present tests and results of an automatic color
fading restoration process for digitized movies. The proposed
color correction method is based on the ACE model, an unsupervised
color equalization algorithm based on a perceptual approach and
inspired by some mechanisms of the human visual system. This
perceptual approach is local, robust and does not need any user
region selection or any other user supervision. However the model
has a small number of parameters that has to be set once before
the filtering. The tests presented in this paper aim to study
these parameters and find their effect on the final result.
The cinematographic archives represent an important part of our collective memory. We present in this paper some advances in automating the color fading restoration process, especially with regard to the automatic color correction technique. The proposed color correction method is based on the ACE model, an unsupervised color equalization algorithm based on a perceptual approach and inspired by some adaptation mechanisms of the human visual system, in particular lightness constancy and color constancy. There are some advantages in a perceptual approach: mainly its robustness and its local filtering properties, that lead to more effective results. The resulting technique, is not just an application of ACE on movie images, but an enhancement of ACE principles to meet the requirements in the digital film restoration field. The presented preliminary results are satisfying and promising.
This document presents several approaches to extract interest points within compressed images (based on DCT compression methods). The goal is to minimize the stages and/or the calculation costs for image sequence indexing tasks or database retrieval from a significant MPEG file repository.
Initially, only the fixed images (I-Frames) are take under consideration, motion will be integrated in further research. The traditional invariant feature points (Harris corner points, points with remarquable principal curvatures) are extracted from images using a gradient estimate (first order derivative) or the Laplacian (second-order derivative) of an image. So the first part of this paper handles in detail the derivation of the signal from DCT blocks.
The trials to implement feature points detection as close as possible to the DCT coefficient are explained. Results provided by our last DCT-blockwise curvature estimatiorare also shown.
The motion pictures represent a precious cultural heritage, however the chemical support on which they are recorded becomes unstable with time, unless they are stored at low temperatures. Some defects affecting color movies, such as bleaching, are out of reach of photochemical restoration means, digital restoration is hence unquestionable. We propose an original automatic technique for faded image correction. Bleaching results in damage to one or two chromatic layers, giving a drab image with poor saturation and an overall color cast. Our automatic fading correction technique consists in reviving the colors of the image (color enhancement), then in balancing the colors of the image.