slavio

You are very right. I was actually not arguing in favor of more complicated compression, but instead for more efficient access to data. Certainly, iterating though array and map items to get to the next element is not efficient.

I agree. I think CBOR trades off a bit too much efficiency of in-place data access for compactness of representation.

Any JSON object encoding format would greatly benefit from compression. It does not have to be complicated: even something as simple as using a dictionary array of "symbols" whose indices can be used instead of repeating string values.

Sparse matrices or not? You could look into OpenCV's Mat and SparseMat here: http://docs.opencv.org/modules/core/doc/basic_structures.htm...