ABSTRACT
PROJECT OUTPUT
SPIHT is computationally very fast and among the best image
compression algorithms known today. According to statistic analysis of
the output binary stream of SPIHT encoding, propose a simple and
effective method combined with Huffman encode for further compression.
In this paper the results from the SPHIT algorithm are compared with the
existing methods for compression like discrete cosine transform (DCT)
and discrete wavelet transform (DWT). In recent years, wavelet transform as a branch of mathematics
developed rapidly, which has a good localization property in the time
domain and frequency domain, can analyze the details of any scale and
frequency. So, it superior to Fourier and DCT. It has been widely
applied and developed in image processing and compression. Wavelet
Transform (WT) has received more and more significant attention in
signal compression. However, many differences lie in the performance of
different wavelets. There is a need to select the optimal matched
wavelet bases to analyze the signal and the signal needs to be expressed
with the fewest coefficients, i.e. sparse coefficients. The signal
compression with wavelet is a procedure in which the input signal is
expressed with a sum of a few of power terms for wavelet function. The
more similar the bases function is to input signal, the higher the
compression ratio is. But, at higher compression ratios we may
experience more errors, i.e. mean square error will be high at the
receiving end and hence PSNR will be very low.
More improvements over DWT are achieved by SPIHT, by Amir Said and
William Pearlman, in 1996 article, "Set Partitioning in Hierarchical
Trees". In this method, more (wide-sense) zero-trees are efficiently
found and represented by separating the tree root from the tree, so,
making compression more efficient. Experiments are shown that the images
through the wavelet transform, the wavelet coefficients‟ value in high
frequency region are generally Small , so it will appear seriate "0"
situation in quantify. SPIHT does not adopt a special method to treat
with it, but direct output. In this paper, focus on this point, propose a
simple and effective method combined with Huffman encode for further
compression. A large number of experimental results are shown that this
method saves a lot of bits in transmission, further enhanced the
compression performance.
PROJECT OUTPUT
Contact:
Mr. Roshan P. Helonde
Mobile: +91-7276355704
WhatsApp: +91-7276355704
Email: roshanphelonde@rediffmail.com
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