Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Image Compression


Image Compression Using Lifting Scheme

Yasir A. Ahmed Al-Obaidi; Hadeel N. Abdullah

Engineering and Technology Journal, 2010, Volume 28, Issue 17, Pages 5455-5467

This paper introduces, firstly, a proposed method of computing one and
two-dimensional wavelet transform .The proposed method reduces heavily
processing time for decomposition of image keeping or overcoming the quality of
reconstructed images. Also, the inverse procedures of all the transformations for
multi- dimensional cases verified.
Secondly, computes quantization and run length encoder. Different types
of quantization are presented in this paper with effects of these differences on
Compression Ratio (CR).
Thirdly, compute PSNR, RMSE, CR, and size. The effect noted this
difference in levels of FLWT on same picture, where PSNR, MSRE, SIZE, and
CR different from one level to another.

Image Compression Based on 2D Dual Tree Complex Wavelet Transform (2D DT-CWT)

Salih Husain Ali; Aymen Dawood Salman

Engineering and Technology Journal, 2010, Volume 28, Issue 7, Pages 1290-1305

By removing the redundant data, the image can be represented in a smaller
number of bits and hence can be compressed. There are many different methods of
image compression. This paper investigates a proposed form of compression based on
2D Dual Tree complex wavelet transform (2D DT-CWT). Many wavelet coefficients
are closed to zero. Thresholding can modify the coefficients to produce more zeros
that are allowed a higher compression rate. The wavelet analysis does not actually
compress a signal. Therefore Huffman coding is used with a signal processed by the
wavelet analysis in order to compress data. Wide range of threshold values is used in
the proposed form. From the results the proposed form give higher rate of
compression and lower RMS error compared with that forms based on Discrete
Wavelet Transform (DWT), Dual Tree Real Wavelet Transform (DT-RWT) and the
well known method based Discrete Cosine Transform (DCT).