Planelets were developed at Warwick to efficiently represent locally planar spatiotemporal structures present in a video sequence. They are planar wave functions localised in time, space, frequency, and orientation. They are shown to yield plausible gains in terms of both SNR and visual quality when restoring noisy video sequences. The computation of discrete planelet transform is quite inexpensive and can be carried out in O(n) time, where n is the size of the analysis window (16x16x16, in the example below). Three-dimensional (3D) wavelet packets, on the other hand, are optimal in terms of representing local spatiotemporal frequencies. They, however, lack orientation selectivity and are relatively speaking computationally expensive.
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| Original | Noisy | Denoised with | Denoised with |
| frame | frame | Planelets | 3D Wavelet Packets |
| (0 dB) | (18.1 dB) | (18.9 dB) |
Click here to see the original, noisy, and denoised sequences side by side.
(Warning! High bandwidth may be required.)
Original Miss America sequence
Noisy (0dB white Gaussian noise)
Planelets denoising results (18.1 dB)
Wavelet packets denoising results (18.9 dB)
NM Rajpoot, Z Yao, RG Wilson,
Adaptive Wavelet Restoration of Noisy Video Sequences,
in Proceedings International Conference on Image Processing (ICIP'04), Singapore, October 2004
NM Rajpoot, RG Wilson, Z Yao,
Planelets: A New Analysis Tool for Planar Feature Extraction,
in Proceedings 5th International Workshop on Image Analysis for Multimedia Interactive Services (WIAMIS'04), Lisbon (Portugal), April 2004