Method of Digital Video Processing Based on Wavelet-Transform in Oriented Basis

This work researches a method of compressing digital video files using discrete wavelet transformation in an oriented basis, as well as comparison of its competitiveness amongst several other wavelets. The tasks were solved by conducting theoretical and experimental studies. Methods of discrete wavelet transforms, in particular, Haar, Daubechies and transformations in an oriented basis are used. As a result of the research, images and videos compressed with various quality loss settings were obtained and, based on their parameters, comparative characteristics were constructed. Recommendations on the choice of the type of transformation were formed based on the comparative characteristics and the compatibility of the wavelet transform with other methods of video compression is evaluated. A software model of an algorithm for discrete wavelet transform of images and video is constructed on the basis of Haar, Daubechies and wavelets in an oriented basis. Research showed that wavelet transorm in an oriented basis possesses best quality/compression ratio amongst all reviewed wavelets when it comes to the raw compression of visual data, which makes discrete wavelet-transform in oriented basis show great potential for further testing. However, it was also shown that this particular wavelet is ill-suited to use in conjunction with modern image/video compression methods due to the mismatch in their multiplicity. Also, with the combined use of discrete wavelet-transform in oriented basis and PNG format, the best compression results were obtained between the four wavelets. Discrete wavelet-transform in oriented basis has 1.5% better quality / compression ratio than Haar transform, but loses 5.6% at speed. As for compatibility with other compression methods, Haar is 5.21% more compatible with PNG than discrete wavelet-transform in oriented basis, 4.2% better with JPEG and 41.2% is better when used in conjunction with MPEG. In most cases, the discrete wavelet-transform in oriented basis with multiplicity of 3 is the better choice than Haar transform except JPEG, where Daubechies wavelets are between Haar and discrete wavelet-transform in oriented basis in regards to the compatibility criterion. Studies also found that a discrete wavelet-transform in oriented basis with 3 filters was poorly compatible with JPEG and MPEG compression formats because they were developed specifically on the basis of discrete cosine transform and function more effectively with Haar transfrom, which both possess conversion multiplicity equal to 2. The research results are of interest for the development and optimization of digital video compression algorithms based on the discrete wavelet transform in oriented basis. Further research may include but is not limited to attuning and modifying existing compression standards, namely JPEG and MPEG, to fit discrete wavelet transform in oriented basis and fully utilize it’s potential. Ref. 10, fig. 6, tabl. 3.