Re: [help-GIFT] gift features

[David Squire]

Wolfgang Müller wrote:

> Hi,
>
>  
>
> > If you do not omit the lowest frequency band of the Gabor filters (which
> > might be the default in gift) you end up with 30720 Gabor blocks and 120
> > features for the histogram which gives a total of 87446 features.
> >    
>
> Line 495 from gift-add-collection.pre-pl tells me that we write out 
> InvertedFileFeatureDescription.db using the gift-write-feature-desc command 
> whose source you can find in FeatureExtraction/write_feature_descs.c .
> This command should use the exact same settings as are used for the feature 
> extraction. If I am not mistaken the original author of that file (as of the 
> feature extraction code) is David Squire. Is there anything to add (or to 
> change in the code), David?
>  
Yes, that's me.... quite some time ago now. Some of this has changed 
since the papers in 1999, but not in any really important way. 
Differences in total numbers of features are most probably (I haven't 
looked) due to a choice to include features for the lowest energy bands 
of the Gabor responses (after all, a "flat" texture is still a texture).

I am very busy at present (2 weeks from end of semester). If anything is 
urgent, please email me directly. I'm afraid that I can't guarantee a 
fast response at present though.

Some of the stuff in the feature extraction code is a quick a dirty hack 
that has persisted for years by virtue of being adequate, not optimal :(

Cheers,

David


--
Dr. David McG. Squire, Postgraduate Research Coordinator (Caulfield),
Computer Science and Software Engineering, Monash University, Australia
http://www.csse.monash.edu.au/~davids/