Abstract-Temporal intensity flicker is a common artifact in old film sequences. Removing disturbing temporal fluctuations in image intensities is desirable because it increases both the subjective quality and, where image sequences are stored in a compressed format, the coding efficiency. We describe a robust technique that corrects intensity flicker automatically by equalizing local frame means and variances in the temporal sense. The low complexity of our method makes it suitable for hardware implementation. We tested the proposed method on sequences with artificially added intensity flicker and on original film material. The results show a great improvement.

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Blotches are common artifacts in old film sequences that manifest themselves as disturbing bright or dark spots. Existing methods for detecting blotches can achieve high detection rates. High detection rates are only useful if the corresponding number of false alarms is not too high, visible artifacts in the corrected sequence result otherwise. We show that the performance of blotch detectors can be improved significantly by takmg statistical influence of noise on the detection mechanism into account. Further improvements are achieved first by using a double-stage detection strategy and second by a constrained dilation technique.

An important topic in image restoration is interpolation of missing data in image sequences. Missing data is a result of dirt on film and of ageing processes where the film contents is replaced by data that bears little relationship with the original scene. We present a method for interpolating missing data with the aim of achieving lugher fidelity and more consistency in the interpolated results than can be achieved by existing methods. This by combining autoregressive models and markov-random field techniques. Experimental results confirm the superior performance of the proposed method over existing methods.

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