10 research outputs found
On-the-fly Historical Handwritten Text Annotation
The performance of information retrieval algorithms depends upon the
availability of ground truth labels annotated by experts. This is an important
prerequisite, and difficulties arise when the annotated ground truth labels are
incorrect or incomplete due to high levels of degradation. To address this
problem, this paper presents a simple method to perform on-the-fly annotation
of degraded historical handwritten text in ancient manuscripts. The proposed
method aims at quick generation of ground truth and correction of inaccurate
annotations such that the bounding box perfectly encapsulates the word, and
contains no added noise from the background or surroundings. This method will
potentially be of help to historians and researchers in generating and
correcting word labels in a document dynamically. The effectiveness of the
annotation method is empirically evaluated on an archival manuscript collection
from well-known publicly available datasets
Learning Surrogate Models of Document Image Quality Metrics for Automated Document Image Processing
Computation of document image quality metrics often depends upon the
availability of a ground truth image corresponding to the document. This limits
the applicability of quality metrics in applications such as hyperparameter
optimization of image processing algorithms that operate on-the-fly on unseen
documents. This work proposes the use of surrogate models to learn the behavior
of a given document quality metric on existing datasets where ground truth
images are available. The trained surrogate model can later be used to predict
the metric value on previously unseen document images without requiring access
to ground truth images. The surrogate model is empirically evaluated on the
Document Image Binarization Competition (DIBCO) and the Handwritten Document
Image Binarization Competition (H-DIBCO) datasets
A fuzzy approach for early human action detection / Ekta Vats
Early human action detection is an important computer vision task with a wide
spectrum of potential applications. Most existing methods deal with the detection of an
action after its completion. Contrarily, for early detection it is essential to detect an action
as early as possible. Therefore, this thesis develops a solution to detect ongoing human
action as soon as it begins, but before it finishes.
In order to perform early human action detection, the conventional classification
problem is modified into frame-by-frame level classification. There exists well-known
classifiers such as Support Vector Machines (SVM), K-nearest Neighbour (KNN), etc. to
perform action classification. However, the employability of these algorithms depends
on the desired application and its requirements. Therefore, selection of the classifier to
employ for the classification task is an important issue to be taken into account. The
first part of the thesis studies this problem and fuzzy Bandler-Kohout (BK) sub-triangle
product (subproduct) is employed as a classifier. The performance is tested for human
action recognition and scene classification. This is a crucial step as it is the first attempt
of using fuzzy BK subproduct for classification.
The second part of this thesis studies the problem of early human action detection.
The method proposed is based on fuzzy BK subproduct inference mechanism and utilizes
the fuzzy capabilities in handling the uncertainties that exist in the real-world for reliable
decision making. The fuzzy membership function generated frame-by-frame from fuzzy
BK subproduct provides the basis to detect an action before it is completed, when a certain
threshold is attained in a suitable way. In order to test the effectiveness of the proposed
framework, a set of experiments is performed for few action sequences where the detector
is able to recognize an action upon seeing �32% of the frames.
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Finally, the proposed method is analyzed from a broader perspective and a hybrid
technique for early anticipation of human action is proposed. It combines the benefits of
computer vision and fuzzy set theory based on fuzzy BK subproduct. The novelty lies
in the construction of a frame-by-frame membership function for each kind of possible
movement, taking into account several human actions from a publicly available dataset.
Furthermore, the impact of various fuzzy implication operators and inference structures
in retrieving the relationship between the human subject and the actions performed is
discussed. The existing fuzzy implication operators are capable of handling only two dimensional
data. A third dimension ‘time’ plays a crucial role in human action recognition
to model the human movement changes over time. Therefore, a new space-time fuzzy
implication operator is introduced, by modifying the existing implication operators to
accommodate time as an added dimension. Empirically, the proposed hybrid technique
is efficiently able to detect an action before completion and outperform the conventional
solutions with good detection rate. The detector is able to identify an action upon viewing
�23% of the frames on an average
Word Recognition using Embedded Prototype Subspace Classifiers on a New Imbalanced Dataset
This paper presents an approach towards word recognition based on embedded prototype subspace classification.The purpose of this paper is three-fold. Firstly, a new dataset for word recognition is presented, which is extractedfrom the Esposalles database consisting of the Barcelona cathedral marriage records. Secondly, different clusteringtechniques are evaluated for Embedded Prototype Subspace Classifiers. The dataset, containing 30 different classesof words is heavily imbalanced, and some word classes are very similar, which renders the classification task ratherchallenging. For ease of use, no stratified sampling is done in advance, and the impact of different data splits isevaluated for different clustering techniques. It will be demonstrated that the original clustering technique based onscaling the bandwidth has to be adjusted for this new dataset. Thirdly, an algorithm is therefore proposed that findskclusters, striving to obtain a certain amount of feature points in each cluster, rather than finding some clustersbased on scaling the Silverman’s rule of thumb. Furthermore, Self Organising Maps are also evaluated as both aclustering and embedding technique
Radial line Fourier descriptor for historical handwritten text representation
Automatic recognition of historical handwritten manuscripts is a daunting task due to paper degradation over
time. Recognition-free retrieval or word spotting is popularly used for information retrieval and digitization of
the historical handwritten documents. However, the performance of word spotting algorithms depends heavily
on feature detection and representation methods. Although there exist popular feature descriptors such as Scale
Invariant Feature Transform (SIFT) and Speeded Up Robust Features (SURF), the invariant properties of these
descriptors amplify the noise in the degraded document images, rendering them more sensitive to noise and complex
characteristics of historical manuscripts. Therefore, an efficient and relaxed feature descriptor is required as
handwritten words across different documents are indeed similar, but not identical. This paper introduces a Radial
Line Fourier (RLF) descriptor for handwritten word representation, with a short feature vector of 32 dimensions. A
segmentation-free and training-free handwritten word spotting method is studied herein that relies on the proposed
RLF descriptor, takes into account different keypoint representations and uses a simple preconditioner-based feature
matching algorithm. The effectiveness of the RLF descriptor for segmentation-free handwritten word spotting
is empirically evaluated on well-known historical handwritten datasets using standard evaluation measures
Broad defects in the energy metabolism of leukocytes underlie immunoparalysis in sepsis
The acute phase of sepsis is characterized by a strong inflammatory reaction. At later stages in some patients, immunoparalysis may be encountered, which is associated with a poor outcome. By transcriptional and metabolic profiling of human patients with sepsis, we found that a shift from oxidative phosphorylation to aerobic glycolysis was an important component of initial activation of host defense. Blocking metabolic pathways with metformin diminished cytokine production and increased mortality in systemic fungal infection in mice. In contrast, in leukocytes rendered tolerant by exposure to lipopolysaccharide or after isolation from patients with sepsis and immunoparalysis, a generalized metabolic defect at the level of both glycolysis and oxidative metabolism was apparent, which was restored after recovery of the patients. Finally, the immunometabolic defects in humans were partially restored by therapy with recombinant interferon-γ, which suggested that metabolic processes might represent a therapeutic target in sepsis