621 research outputs found
Deep-FExt: Deep Feature Extraction for Vessel Segmentation and Centerline Prediction
Feature extraction is a very crucial task in image and pixel (voxel)
classification and regression in biomedical image modeling. In this work we
present a machine learning based feature extraction scheme based on inception
models for pixel classification tasks. We extract features under multi-scale
and multi-layer schemes through convolutional operators. Layers of Fully
Convolutional Network are later stacked on this feature extraction layers and
trained end-to-end for the purpose of classification. We test our model on the
DRIVE and STARE public data sets for the purpose of segmentation and centerline
detection and it out performs most existing hand crafted or deterministic
feature schemes found in literature. We achieve an average maximum Dice of 0.85
on the DRIVE data set which out performs the scores from the second human
annotator of this data set. We also achieve an average maximum Dice of 0.85 and
kappa of 0.84 on the STARE data set. Though these datasets are mainly 2-D we
also propose ways of extending this feature extraction scheme to handle 3-D
datasets.Comment: 9 page
Multitemporal Fusion for the Detection of Static Spatial Patterns in Multispectral Satellite Images--with Application to Archaeological Survey
We evaluate and further develop a multitemporal fusion strategy that we use to detect the location of ancient settlement sites in the Near East and to map their distribution, a spatial pattern that remains static over time. For each ASTER images that has been acquired in our survey area in north-eastern Syria, we use a pattern classification strategy to map locations with a multispectral signal similar to the one from (few) known archaeological sites nearby. We obtain maps indicating the presence of anthrosol – soils that formed in the location of ancient settlements and that have a distinct spectral pattern under certain environmental conditions – and find that pooling the probability maps from all available time points reduces the variance of the spatial anthrosol pattern significantly. Removing biased classification maps – i.e. those that rank last when comparing the probability maps with the (limited) ground truth we have – reduces the overall prediction error even further, and we estimate optimal weights for each image using a non-negative least squares regression strategy. The ranking and pooling strategy approach we propose in this study shows a significant improvement over the plain averaging of anthrosol probability maps that we used in an earlier attempt to map archaeological sites in a 20,000 km2 area in northern Mesopotamia, and we expect it to work well in other surveying tasks that aim at mapping static surface patterns with limited ground truth in long series of multispectral images.Anthropolog
Efficient Algorithms for Moral Lineage Tracing
Lineage tracing, the joint segmentation and tracking of living cells as they
move and divide in a sequence of light microscopy images, is a challenging
task. Jug et al. have proposed a mathematical abstraction of this task, the
moral lineage tracing problem (MLTP), whose feasible solutions define both a
segmentation of every image and a lineage forest of cells. Their branch-and-cut
algorithm, however, is prone to many cuts and slow convergence for large
instances. To address this problem, we make three contributions: (i) we devise
the first efficient primal feasible local search algorithms for the MLTP, (ii)
we improve the branch-and-cut algorithm by separating tighter cutting planes
and by incorporating our primal algorithms, (iii) we show in experiments that
our algorithms find accurate solutions on the problem instances of Jug et al.
and scale to larger instances, leveraging moral lineage tracing to practical
significance.Comment: Accepted at ICCV 201
Spatio-Temporal Video Segmentation with Shape Growth or Shrinkage Constraint
We propose a new method for joint segmentation of monotonously growing or shrinking shapes in a time sequence of noisy images. The task of segmenting the image time series is expressed as an optimization problem using the spatio-temporal graph of pixels, in which we are able to impose the constraint of shape growth or of shrinkage by introducing monodirectional infinite links connecting pixels at the same spatial locations in successive image frames. The globally optimal solution is computed with a graph cut. The performance of the proposed method is validated on three applications: segmentation of melting sea ice floes and of growing burned areas from time series of 2D satellite images, and segmentation of a growing brain tumor from sequences of 3D medical scans. In the latter application, we impose an additional intersequences inclusion constraint by adding directed infinite links between pixels of dependent image structures
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