34 research outputs found
Evaluation of accurate eye corner detection methods for gaze estimation
Accurate detection of iris center and eye corners appears to be a promising approach for low cost gaze estimation. In this paper we propose novel eye inner corner detection methods. Appearance and feature based segmentation approaches are suggested. All these methods are exhaustively tested on a realistic dataset containing images of subjects gazing at different points on a screen. We have demonstrated that a method based on a neural network presents the best performance even in light changing scenarios. In addition to this method, algorithms based on AAM and Harris corner detector present better accuracies than recent high performance face points tracking methods such as Intraface
Computational Anatomy for Multi-Organ Analysis in Medical Imaging: A Review
The medical image analysis field has traditionally been focused on the
development of organ-, and disease-specific methods. Recently, the interest in
the development of more 20 comprehensive computational anatomical models has
grown, leading to the creation of multi-organ models. Multi-organ approaches,
unlike traditional organ-specific strategies, incorporate inter-organ relations
into the model, thus leading to a more accurate representation of the complex
human anatomy. Inter-organ relations are not only spatial, but also functional
and physiological. Over the years, the strategies 25 proposed to efficiently
model multi-organ structures have evolved from the simple global modeling, to
more sophisticated approaches such as sequential, hierarchical, or machine
learning-based models. In this paper, we present a review of the state of the
art on multi-organ analysis and associated computation anatomy methodology. The
manuscript follows a methodology-based classification of the different
techniques 30 available for the analysis of multi-organs and multi-anatomical
structures, from techniques using point distribution models to the most recent
deep learning-based approaches. With more than 300 papers included in this
review, we reflect on the trends and challenges of the field of computational
anatomy, the particularities of each anatomical region, and the potential of
multi-organ analysis to increase the impact of 35 medical imaging applications
on the future of healthcare.Comment: Paper under revie
A straightforward method of measuring MPRT using LC test cells
A simple method based on integration over time to measure motion-picture response time (MPRT) has been developed. Liquid-crystal response time (LCRT) alone cannot express the motion blur perceived by the observer; one must also take into account the transition between intermediate gray levels and the sample-and-hold effect. The method shows similar results to other previously reported methods based on temporal integration, while being simpler and more straightforward. Indeed, just monopixel test cells are required for measuring MPRT. This method can be used for comparison between different materials, alignments surfaces, or other manufacturing details with no need of fabricating the whole LCD structure. Nevertheless, the method could also be used for characterization of commercial displays with major changes. A comparison of MPRT values for three different liquid-crystal materials is presented in this work. The behavior of the MPRT parameter in the case of an ideal liquid-crystal material with an LCRT equal to zero has also been studied. The results obtained for this material have been used as a reference to establish comparisons with real materials