| Abstract [eng] |
Image is the key tool to present graphical information. The more graphical information it contains, the easier it is to absorb this information, but a significant amount of graphical information will consume information technology resources and slows down the transmission speed without the need. In order to reduce the waste of resources in information graphics and speed up the information transmission speed, it is proposed to use image coding technologies. One of these technologies is a locally progressive image coding. Its essence is to improve only the selected fragment quality of the image. Also, this technology is an integral part of the discrete wavelet transform. On this paper new original procedure for the evaluation of discrete Haar spectra for separate fragments of a digital image is proposed and examined. The procedure explores specific properties of Haar wavelets, refers to the assumption that Haar spectrum of the whole image is known, and this procedure results is compared with direct evaluation of Haar spectral coefficients for the respective image blocks procedure results. Also Haar wavelet features and discrete Haar transform and its fast computing algorithm discovered. At this paper we also examine one of the most effective image compression algorithms SPIHT. This algorithm works in discrete wavelet transform spectral domain but we are facing one major issue with Haar spectrum: this spectrum elements are real numbers but SPIHT works only with integer numbers. In order to implement SPIHT with Haar spectra, Haar transform has been modified to produce integer numbers instead of real. Some experiment results are also presented. They corroborate our theoretical conclusions that SPIHT algorithm is partly able to work with Haar transform. |
