Robust Automatic Line Scratch Detection in Films

Alasdair Newson (1, 2) , Andrés Almansa (2) , Yann Gousseau (2) , Patrick Pérez (3)

1 Technicolor R & I [Cesson Sévigné]
2 Télécom ParisTech
3 Technicolor [Cesson Sévigné]

Line scratch detection in old films is a particularly challenging problem due to the variable spatio-temporal characteristics of this defect. Some of the main problems include sensitivity to noise and texture, and false detections due to thin vertical structures belonging to the scene. We propose a robust and automatic algorithm for frame-by-frame line scratch detection in old films, as well as a temporal algorithm for the filtering of false detections. In the frame-by-frame algorithm, we relax some of the hypotheses used in previous algorithms in order to detect a wider variety of scratches. This step's robustness and lack of external parameters is ensured by the combined use of an a contrario methodology and local statistical estimation. In this manner, over-detection in textured or cluttered areas is greatly reduced. The temporal filtering algorithm eliminates false detections due to thin vertical structures by exploiting the coherence of their motion with that of the underlying scene. Experiments demonstrate the ability of the resulting detection procedure to deal with difficult situations, in particular in the presence of noise, texture and slanted or partial scratches. Comparisons show significant advantages over previous work.

Mots clés: Film restoration; line scratches; adaptive detection; a contrario methods; affine motion estimation

Domaines: Traitement des images [eess.IV]

Alasdair Newson, Andrés Almansa, Yann Gousseau, Patrick Pérez. Robust Automatic Line Scratch Detection in Films. IEEE Transactions on Image Processing, 2014, 23 (3), pp.1240-1254. ⟨10.1109/TIP.2014.2300824⟩. ⟨hal-00927007⟩