BUGFIX: Modified reconstruct_background to access correct frame range

[wingillis]

A bug in reconstruct_background has a bug in it, where reconstructing the background in each batch neuron using a frame range of batch_neuron.reconstruct_background([1 size(C_raw, 2)]); will cause the same background to be reconstructed from the first batch neuron, for every batch neuron. This bug fix allows each batch neuron to sample from the correct frame range to reconstruct the background.

See line 1265 in Sources2D.m

Please disregard all the white-space changes, that's an artifact of my code editor.

[zhoupc]

thanks, @wingillis ! good catch.
I think we also have to consider the 'ELSE' case in the IF statement (line 1263). There is always a shift in relative to obj.frame_range(1) and we should correct this shift for extracting obj.C, & obj.f.

I sent another pull request for fixing the bug https://github.com/zhoupc/CNMF_E/pull/24/files. I will merge it to the master branch if you think it fixes the bug. thanks for your great feedback.

Best,
Pengcheng