14,243 research outputs found
Efficiently computing and registering digitally reconstructed radiographs
Generation of digitally reconstructed radiographs (DRRs) is computationally expensive and has been cited as the rate-limiting step in the execution time of intensity-based two-dimensional/three-dimensional registration algorithms. This paper considers the problem of generating DRRs by conventional ray tracing. Experiments confirm that good quality reconstructions can be obtained using this approach in a few seconds. We evaluate the approach for automatic patient setup prior to radiotherapy treatment by performing intensity based 2D-3D registration using normalized cross correlation. Preliminary results using a pelvic CT data set show the method is accurate to about ±2 pixels (i.e. ±0.3 mm)
End-to-end Learning of Driving Models from Large-scale Video Datasets
Robust perception-action models should be learned from training data with
diverse visual appearances and realistic behaviors, yet current approaches to
deep visuomotor policy learning have been generally limited to in-situ models
learned from a single vehicle or a simulation environment. We advocate learning
a generic vehicle motion model from large scale crowd-sourced video data, and
develop an end-to-end trainable architecture for learning to predict a
distribution over future vehicle egomotion from instantaneous monocular camera
observations and previous vehicle state. Our model incorporates a novel
FCN-LSTM architecture, which can be learned from large-scale crowd-sourced
vehicle action data, and leverages available scene segmentation side tasks to
improve performance under a privileged learning paradigm.Comment: camera ready for CVPR201
LSUN: Construction of a Large-scale Image Dataset using Deep Learning with Humans in the Loop
While there has been remarkable progress in the performance of visual
recognition algorithms, the state-of-the-art models tend to be exceptionally
data-hungry. Large labeled training datasets, expensive and tedious to produce,
are required to optimize millions of parameters in deep network models. Lagging
behind the growth in model capacity, the available datasets are quickly
becoming outdated in terms of size and density. To circumvent this bottleneck,
we propose to amplify human effort through a partially automated labeling
scheme, leveraging deep learning with humans in the loop. Starting from a large
set of candidate images for each category, we iteratively sample a subset, ask
people to label them, classify the others with a trained model, split the set
into positives, negatives, and unlabeled based on the classification
confidence, and then iterate with the unlabeled set. To assess the
effectiveness of this cascading procedure and enable further progress in visual
recognition research, we construct a new image dataset, LSUN. It contains
around one million labeled images for each of 10 scene categories and 20 object
categories. We experiment with training popular convolutional networks and find
that they achieve substantial performance gains when trained on this dataset
SkipNet: Learning Dynamic Routing in Convolutional Networks
While deeper convolutional networks are needed to achieve maximum accuracy in
visual perception tasks, for many inputs shallower networks are sufficient. We
exploit this observation by learning to skip convolutional layers on a
per-input basis. We introduce SkipNet, a modified residual network, that uses a
gating network to selectively skip convolutional blocks based on the
activations of the previous layer. We formulate the dynamic skipping problem in
the context of sequential decision making and propose a hybrid learning
algorithm that combines supervised learning and reinforcement learning to
address the challenges of non-differentiable skipping decisions. We show
SkipNet reduces computation by 30-90% while preserving the accuracy of the
original model on four benchmark datasets and outperforms the state-of-the-art
dynamic networks and static compression methods. We also qualitatively evaluate
the gating policy to reveal a relationship between image scale and saliency and
the number of layers skipped.Comment: ECCV 2018 Camera ready version. Code is available at
https://github.com/ucbdrive/skipne
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