I have a large number of pictures that I would like to use LDA on. However, it requires too much memory, so I was wondering if it would be possible to make the learning incremental, using a sklearn implementation, or maybe another library?
Yes, you can. Instead of using
lda.fit_transfrom(...) you basically just need to call
lda.partial_fit(...). Here you take a mini-batch to update your model.
See this link for more information.
The scikit-learn library does not support incremental learning. The scikit-multiflow library does support incremental learning. However, scikit-multiflow does not have a Linear Discriminant Analysis (LDA) implementation.