Blotch Detection Based on Texture Matching and Adaptive Multi-threshold

Blotch is a typical artifact in old films and the detection of them is an important step in film restoration. The existing simplified rank-ordered difference detector achieves higher detection rates by reducing the value of threshold. However, the corresponding higher number of false alarms is undesirable. To maximize the ratio between correct detections and false alarms, this paper proposes an improved blotch detector based on adaptive multi- threshold. According to different objects of blotches, the proposed detector can achieve the most appropriate threshold by convergence confinement. Meanwhile, texture matching is introduced to avoid the possible deviation caused by motion vector estimation in the regions with blotches. Performance evaluation is taken to the image sequences with both real blotches and artificially corrupted ones. The experimental results indicate higher correct detection rates and fewer false alarms simultaneously.