This selection represents that the compression carried out is lossy compression
. Let K be the set of indices of the M selected coefficients and [f.sub.M] be the compression obtained.
SPARTAN  is a system that takes advantage of attribute semantics and data-mining models to perform lossy compression
of massive data tables, which is based on the novel idea of exploiting predictive data correlations and prescribed error tolerances for individual attributes to construct concise and accurate Classification and Regression Tree (CaRT) models for entire columns of a table.
Given the data volume challenge we face, we should consider the wider use of more aggressive data compression techniques, such as lossy compression
, as a matter of course.
As one more option of DI lossy compression
implementation we will consider a way which is not the accepted standard, but it is often used during the work with images .
Lossless and lossy compression
technique is applied on ROI and non-ROI parts respectively (Kaur et al., 2011).
This kind of compression is "lossy." While most of the modern compression algorithms, including JPEG, MP3, and MPEG-4, most commonly use lossy compression
, they often also allow the user to choose the level of "loss." (8) The accompanying manuals and technical reports classify the results of the compression in various groups, which they give names like "very good" or "excellent quality" results.
Texture is encoded by lossy compression
in a way similar to minimum description length (MDL) principle, but here the length of the data given the model is approximated by the number of samples times the entropy of the model.
However unlike PNG, WebP allows lossy compression
of images with transparency.
Conversely, lossy compression
does not allow for perfect reconstruction of the data, but has the advantage that much higher CRs can be obtained.
The video quality is influenced by two different types of distortion which arise, on the one hand, from the effects of lossy compression
introduced by the source encoding (source distortion), and on the other hand, from the lossy transmission channel (loss distortion) .
Data compression methods can be divided into two categories: Lossless Compression methods without losing any part of the data and Lossy Compression
Basic ideas of lossless and lossy compression
algorithms are covered.