Poster
Extracting regions of interest from biological images with convolutional sparse block coding
Marius Pachitariu · Adam M Packer · Noah Pettit · Henry Dalgleish · Michael Hausser · Maneesh Sahani

Sun Dec 8th 02:00 -- 06:00 PM @ Harrah's Special Events Center, 2nd Floor #None

Biological tissue is often composed of cells with similar morphologies replicated throughout large volumes and many biological applications rely on the accurate identification of these cells and their locations from image data. Here we develop a generative model that captures the regularities present in images composed of repeating elements of a few different types. Formally, the model can be described as convolutional sparse block coding. For inference we use a variant of convolutional matching pursuit adapted to block-based representations. We extend the K-SVD learning algorithm to subspaces by retaining several principal vectors from the SVD decomposition instead of just one. Good models with little cross-talk between subspaces can be obtained by learning the blocks incrementally. We perform extensive experiments on simulated images and the inference algorithm consistently recovers a large proportion of the cells with a small number of false positives. We fit the convolutional model to noisy GCaMP6 two-photon images of spiking neurons and to Nissl-stained slices of cortical tissue and show that it recovers cell body locations without supervision. The flexibility of the block-based representation is reflected in the variability of the recovered cell shapes.

Author Information

Marius Pachitariu (Gatsby Unit, UCL)
Adam M Packer (UCL)
Noah Pettit (UCL)
Henry Dalgleish (UCL)
Michael Hausser (UCL)
Maneesh Sahani (Gatsby Unit, UCL)

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