Content deleted Content added
Citation bot (talk | contribs) m Add: issue, volume, date. | You can use this bot yourself. Report bugs here. | User-activated. |
|||
Line 8:
== Background ==
Texture can be regarded as a similarity grouping in an image. Traditional texture analysis can be divided into four major issues: feature extraction, texture discrimination, texture classification and shape from texture(to reconstruct 3D surface geometry from texture information). For tradition feature extraction, approaches are usually categorized into structural, statistical, model based and transform.<ref>{{cite book|last1=Duda|first1=R.O.|title=Pattern Classification and Scene Analysis|isbn=978-0471223610|date=1973-02-09}}</ref>
Wavelet transformation is a popular method in numerical analysis and functional analysis, which captures both frequency and ___location information. Gray level co-occurrence matrix provides an important basis for SCM construction.
SCM based on discrete wavelet frame transformation make use of both correlations and feature information so that it combines structural and statistical benefits.
=== [[Discrete wavelet transform|Discrete wavelet]] frame (DWF) ===
In order to do SCM we have to use discrete wavelet frame (DWF) transformation first to get a series of sub images. The discrete wavelet frames is nearly identical to the standard wavelet transform,<ref>{{cite journal|last1=Kevin|first1=Lund|last2=Curt|first2=Burgess|title=Producing high-dimensional semantic spaces from lexical co-occurrence|journal=Behavior Research Methods|date=June 1996|volume=28|issue=2|pages=203–208}}</ref> except that one upsamples the filters, rather than downsamples the image. Given an image, the DWF decomposes its channel using the same method as the wavelet transform, but without the subsampling process. This results in four filtered images with the same size as the input image. The decomposition is then continued in the LL channels only as in the wavelet transform, but since the image is not subsampled, the filter has to be upsampled by inserting zeros in between its coefficients. The number of channels, hence the number of features for DWF is given by 3 × l − 1.<ref>{{cite journal|last1=Mallat|first1=S.G.|title=A theory for multiresolution signal decomposition: The wavelet representation|journal=IEEE Transactions on Pattern Analysis and Machine Intelligence|volume=11|issue=7|date=1989|pages=674–693|doi=10.1109/34.192463}}</ref>
One dimension discrete wavelet frame decompose the image in this way:
| |||