144 research outputs found
Three-dimensional morphanalysis of the face.
The aim of the work reported in this thesis was to determine the extent to which orthogonal two-dimensional morphanalytic (universally relatable) craniofacial imaging methods can be extended into the realm of computer-based three-dimensional imaging. New methods are presented for capturing universally relatable laser-video surface data, for inter-relating facial surface scans and for constructing probabilistic facial averages. Universally relatable surface scans are captured using the fixed relations principle com- bined with a new laser-video scanner calibration method. Inter- subject comparison of facial surface scans is achieved using inter- active feature labelling and warping methods. These methods have been extended to groups of subjects to allow the construction of three-dimensional probabilistic facial averages. The potential of universally relatable facial surface data for applications such as growth studies and patient assessment is demonstrated. In addition, new methods for scattered data interpolation, for controlling overlap in image warping and a fast, high-resolution method for simulating craniofacial surgery are described. The results demonstrate that it is not only possible to extend universally relatable imaging into three dimensions, but that the extension also enhances the established methods, providing a wide
range of new applications
Visual ageing of human faces in three dimensions using morphable models and projection to latent structures
We present an approach to synthesising the effects of ageing on human face images using three-dimensional modelling. We extract a set of three dimensional face models from a set of two-dimensional face images by fitting a Morphable Model. We propose a method to age these face models using Partial Least Squares to extract from the data-set those factors most related to ageing. These ageing related factors are used to train an individually weighted linear model. We show that this is an effective means of producing an aged face image and compare this method to two other linear ageing methods for ageing face models. This is demonstrated both quantitatively and with perceptual evaluation using human raters.Postprin
FFD:Fast Feature Detector
Scale-invariance, good localization and robustness to noise and distortions
are the main properties that a local feature detector should possess. Most
existing local feature detectors find excessive unstable feature points that
increase the number of keypoints to be matched and the computational time of
the matching step. In this paper, we show that robust and accurate keypoints
exist in the specific scale-space domain. To this end, we first formulate the
superimposition problem into a mathematical model and then derive a closed-form
solution for multiscale analysis. The model is formulated via
difference-of-Gaussian (DoG) kernels in the continuous scale-space domain, and
it is proved that setting the scale-space pyramid's blurring ratio and
smoothness to 2 and 0.627, respectively, facilitates the detection of reliable
keypoints. For the applicability of the proposed model to discrete images, we
discretize it using the undecimated wavelet transform and the cubic spline
function. Theoretically, the complexity of our method is less than 5\% of that
of the popular baseline Scale Invariant Feature Transform (SIFT). Extensive
experimental results show the superiority of the proposed feature detector over
the existing representative hand-crafted and learning-based techniques in
accuracy and computational time. The code and supplementary materials can be
found at~{\url{https://github.com/mogvision/FFD}}
A Wide Area Multiview Static Crowd Estimation System Using UAV and 3D Training Simulator
Crowd size estimation is a challenging problem, especially when the crowd is spread over a significant geographical area. It has applications in monitoring of rallies and demonstrations and in calculating the assistance requirements in humanitarian disasters. Therefore, accomplishing a crowd surveillance system for large crowds constitutes a significant issue. UAV-based techniques are an appealing choice for crowd estimation over a large region, but they present a variety of interesting challenges, such as integrating per-frame estimates through a video without counting individuals twice. Large quantities of annotated training data are required to design, train, and test such a system. In this paper, we have first reviewed several crowd estimation techniques, existing crowd simulators and data sets available for crowd analysis. Later, we have described a simulation system to provide such data, avoiding the need for tedious and error-prone manual annotation. Then, we have evaluated synthetic video from the simulator using various existing single-frame crowd estimation techniques. Our findings show that the simulated data can be used to train and test crowd estimation, thereby providing a suitable platform to develop such techniques. We also propose an automated UAV-based 3D crowd estimation system that can be used for approximately static or slow-moving crowds, such as public events, political rallies, and natural or man-made disasters. We evaluate the results by applying our new framework to a variety of scenarios with varying crowd sizes. The proposed system gives promising results using widely accepted metrics including MAE, RMSE, Precision, Recall, and F1 score to validate the results
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Skin texture and colour predict perceived health in Asian faces
Facial skin texture and colour play an important role in observers' judgments of apparent health and have been
linked to aspects of physiological health, including fitness, immunity and fertility. However, most studies have
focused on Caucasian populations. Here, we report two studies that investigate the contribution of skin texture
and colour to the apparent health ofMalaysian Chinese faces. In Study 1, homogenous skin texture, as measured
by wavelet analysis, was found to positively predict ratings of apparent health of Asian faces. In study 2, homogenous skin texture and increased skin yellowness positively predicted rated health of Malaysian Chinese faces. This finding suggests that skin condition serves as an important cue for subjective judgements of health in Malaysian Chinese faces
Social Preference in Preschoolers: Effects of Morphological Self-Similarity and Familiarity
Adults prefer to interact with others that are similar to themselves. Even slight facial self-resemblance can elicit trust towards strangers. Here we investigate if preschoolers at the age of 5 years already use facial self-resemblance when they make social judgments about others. We found that, in the absence of any additional knowledge about prospective peers, children preferred those who look subtly like themselves over complete strangers. Thus, subtle morphological similarities trigger social preferences well before adulthood
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