Avoiding false positive due to flashlights in shot detection using illumination suppression algorithm

Existence of flashlights in videos leads to false detection of scene change. Many algorithms have been suggested to either detect the flashlight or differentiate between flashlight and abrupt transition. All the existing algorithms have certain limitation in terms of restriction on duration of flashlights, nature of flashlight, threshold selection and computation time. To address these practical problems we propose a novel algorithm based on discrete cosine transform and discrete wavelet transform. This method suppress illuminations and increase the difference between frames at abrupt transition location with respect to illumination. Proposed algorithm also suggest automatic threshold for shot detection in addition to fast computation. As illuminations are suppressed independent of the duration and nature of flashlight, almost all false detection due to flashlight is avoided. This illumination suppression algorithm can also be the first preprocessing block for existing methods. The proposed algorithm is tested on various movie videos and experimental results validate the effectiveness of the method to avoid false positive due to flashlight.