Re: [help-GIFT] Fwd: Big database on GIFT. gift-generate-inverted-file error.

[David Squire]

Wolfgang Müller wrote:

> > 1. imagemagick convert to generated thumbnail and ppm files.
> > 2. gift-extract-features and gift-write-feature-descs to get features
> > and creat .fts files.
> > 3. gift-generate-inverted-file to generate InvertedFile.db.
> >    
>
> Yes, and things do not need to remain that way. In fact, David McG. Squire 
> (founder of the Viper project) who wrote the feature extraction had his 
> "home-made" PPM routines and used them for feature extraction. I did not 
> really want to touch his code, so I wrote the perl wrapper around that which 
> uses image magick convert. In fact, much of the time the feature extraction 
> takes is due to startup of convert and startup of gift-feature-extraction. 
> Both of these programs have to be started for each image. The're both C, so 
> dynamic linking is fast compared to c++, but it still takes non-negligible 
> time of the whole feature extraction process.
>
> If you're interested in speed, I would suggest you to extend 
> gift-feature-extraction such that you combine with the libmagick library. I 
> had some stuff doing that (among other things) for my thesis, but I never 
> released it due to feature creep and due to libhell (I had so many pluggable 
> components that things became a maintenance nightmare. Nice to work with at 
> home, but you needed real practice to install it and due to my new job I did 
> not have the time to get it ready for other people.)
>  
Yep. It would certainly make an enormous amount of sense to link with 
libmagick. This is an example of a quick and dirty prototype making it 
into the product because it worked "well enough". I should use it in my 
software engineering class :)

On the topic of features, I am fishing for an honours student to work on 
this this year. I am thinking of a complete redesign, where the 
fundamental element is a segment rather than an image.

Cheers,

David

PS. We might even get into the DAG stuff, Wolfgang...

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