1,256 research outputs found
Reconstructive Sparse Code Transfer for Contour Detection and Semantic Labeling
We frame the task of predicting a semantic labeling as a sparse
reconstruction procedure that applies a target-specific learned transfer
function to a generic deep sparse code representation of an image. This
strategy partitions training into two distinct stages. First, in an
unsupervised manner, we learn a set of generic dictionaries optimized for
sparse coding of image patches. We train a multilayer representation via
recursive sparse dictionary learning on pooled codes output by earlier layers.
Second, we encode all training images with the generic dictionaries and learn a
transfer function that optimizes reconstruction of patches extracted from
annotated ground-truth given the sparse codes of their corresponding image
patches. At test time, we encode a novel image using the generic dictionaries
and then reconstruct using the transfer function. The output reconstruction is
a semantic labeling of the test image.
Applying this strategy to the task of contour detection, we demonstrate
performance competitive with state-of-the-art systems. Unlike almost all prior
work, our approach obviates the need for any form of hand-designed features or
filters. To illustrate general applicability, we also show initial results on
semantic part labeling of human faces.
The effectiveness of our approach opens new avenues for research on deep
sparse representations. Our classifiers utilize this representation in a novel
manner. Rather than acting on nodes in the deepest layer, they attach to nodes
along a slice through multiple layers of the network in order to make
predictions about local patches. Our flexible combination of a generatively
learned sparse representation with discriminatively trained transfer
classifiers extends the notion of sparse reconstruction to encompass arbitrary
semantic labeling tasks.Comment: to appear in Asian Conference on Computer Vision (ACCV), 201
Almost thermal operations: inhomogeneous reservoirs
The resource theory of thermal operations explains the state transformations
that are possible in a very specific thermodynamic setting: there is only one
thermal bath, auxiliary systems can only be in corresponding thermal state
(free states), and the interaction must commute with the free Hamiltonian (free
operation). In this paper we study the mildest deviation: the reservoir
particles are subject to inhomogeneities, either in the local temperature
(introducing resource states) or in the local Hamiltonian (generating a
resource operation). For small inhomogeneities, the two models generate the
same channel and thus the same state transformations. However, their
thermodynamics is significantly different when it comes to work generation or
to the interpretation of the "second laws of thermal operations".Comment: 9 pages, 5 figures. Supersedes submission arXiv:1806.0810
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