Improved blotch detection in color old films through a robust preprocessing

Blotches are artifacts that contaminate old films and cause the loss of some information in the film. Their detection is required prior to any restoration. The goal of this paper is to reduce the false alarm rate of the detection. By assuming that blotches correspond to local illumination variations between the degraded frame and its surrounding ones, the novelty of the approach we propose is threefold. Firstly, an appropriate photometric parametricmodel is adopted. Secondly, a motion analysis involving a robust adaptive cross-correlationmeasure is used to locally measure the illumination variation. Thirdly, the extension to color sequences is performed. Experimental evaluation shows the efficiency of the proposed preprocessing.