问题
I'm working on a C++/Qt image retrieval system based on similarity that works as follows (I'll try to avoid irrelevant or off-topic details):
I take a collection of images and build an index from them using OpenCV functions. After that, for each image, I get a list of integer values representing important "classes" that each image belongs to. The more integers two images have in common, the more similar they are believed to be. So, when I want to query the system, I just have to compute the list of integers representing the query image, perform a full-text search (or similar) and retrieve the X most similar images.
My question is, what's the best approach to permorm such a search? I've heard about Lucene, Lemur and other indexing methods, but I don't know if this kind of full-text searchs are the best way, given the domain is reduced (only integers instead of words). I'd like to know about the alternatives in terms of efficiency, accuracy or C++ friendliness.
Thanks!
回答1:
It sounds to me like you have a vectorspace model, so Lucene or a similar product may work well for you. In general, an inverted-index model will be good if:
- You don't know the number of classes in advance
- There are a lot of classes relative to the number of images
If your problem doesn't fit these criteria, a normal relational DB might work better, as Thomas suggested. If it meets #1 but not #2, you could investigate one of the "column oriented" non-relational databases. I'm not familiar enough with these to tell you how well they would work, but my intuition is that you'll need to replicate a lot of the functionality in an IR toolkit yourself.
Lucene is written in Java and I don't know of any C++ ports. Solr exposes Lucene as a web service, so it's easy enough to access it that way from whatever language you choose.
I don't know much about Lemur, but it looks like it has a similar vectorspace model, and it's written in C++, so that might be easier for you to use.
回答2:
You can take a look at Lucene for image retrieval (LIRE) here: http://www.semanticmetadata.net/2006/05/19/lire-lucene-image-retrieval-04-released/
If I'm mistaken, you are trying to implement a typical bag of words image retrieval am I correct? If so you are probably trying to build an inverted file index. Lucene on its own is not suitable as you probably have already realized as it index text instead of numbers. Using its classes for querying the index would also be a problem as it is not designed to "parse" (i.e. detect keypoints, extract descriptors then vector-quantize them) image into the query vector.
LIRE on the other hand have been modified to index feature vectors. However, it does not appear to work out of the box for bag of words model. Also, I think I've read on the author's website that it currently uses brute force matching rather than the inverted file index to retrieve the images but I would expect it to be easier to extend than Lucene itself for your purposes.
Hope this helps.
来源：https://stackoverflow.com/questions/7394420/best-approach-for-doing-full-text-search-with-list-of-integers-documents