Focus Assessment Method of Gaze Tracking Camera Based on ε-Support Vector Regression
نویسندگان
چکیده
In order to capture an eye image of high quality in a gaze-tracking camera, an auto-focusing mechanism is used, which requires accurate focus assessment. Although there has been previous research on focus assessment in the spatial or wavelet domains, there are few previous studies that combine all of the methods of spatial and wavelet domains. Since all of the previous focus assessments in the spatial or wavelet domain methods have disadvantages, such as being affected by illumination variation, etc., we propose a new focus assessment method by combining the spatial and wavelet domain methods for the gaze-tracking camera. This research is novel in the following three ways, in comparison with the previous methods. First, the proposed focus assessment method combines the advantages of spatial and wavelet domain methods by using ε-support vector regression (SVR) with a symmetrical Gaussian radial basis function (RBF) kernel. In order to prevent the focus score from being affected by a change in image brightness, both linear and nonlinear normalizations are adopted in the focus score calculation. Second, based on the camera optics, we mathematically prove the reason for the increase in the focus score in the case of daytime images or a brighter illuminator compared to nighttime images or a darker illuminator. Third, we propose a new criterion to compare the accuracies of the focus measurement methods. This criterion is based on the ratio of relative overlapping amount (standard deviation of focus score) between two adjacent positions along the Z-axis to the entire range of focus score variety between these two points. Experimental results showed that the proposed method outperforms other methods.
منابع مشابه
Online multiple people tracking-by-detection in crowded scenes
Multiple people detection and tracking is a challenging task in real-world crowded scenes. In this paper, we have presented an online multiple people tracking-by-detection approach with a single camera. We have detected objects with deformable part models and a visual background extractor. In the tracking phase we have used a combination of support vector machine (SVM) person-specific classifie...
متن کاملCalibration-Free Eye Gaze Direction Detection with Gaussian Processes
In this paper we present a solution for eye gaze detection from a wireless head mounted camera designed for children aged between 6 months and 18 months. Due to the constraints of working with very young children, the system does not seek to be as accurate as other state-of-the-art eye trackers, however it requires no calibration process from the wearer. Gaussian Process Regression and Support ...
متن کامل2D Gaze Estimation Based on Pupil-Glint Vector Using an Artificial Neural Network
Abstract: Gaze estimation methods play an important role in a gaze tracking system. A novel 2D gaze estimation method based on the pupil-glint vector is proposed in this paper. First, the circular ring rays location (CRRL) method and Gaussian fitting are utilized for pupil and glint detection, respectively. Then the pupil-glint vector is calculated through subtraction of pupil and glint center ...
متن کاملSupport vector regression based on data shifting
In this article, we provide some preliminary theoretical analysis and extended practical experiments of a novel regression method proposed recently which is based on representing regression problems as classification ones with duplicated and shifted data. The main results regard partial equivalency of Bayes solutions for regression problems and the transformed classification ones, and improved ...
متن کاملEstimating Gaze Direction from Low-Resolution Faces in Video
In this paper we describe a new method for automatically estimating where a person is looking in images where the head is typically in the range 20 to 40 pixels high. We use a feature vector based on skin detection to estimate the orientation of the head, which is discretised into 8 different orientations, relative to the camera. A fast sampling method returns a distribution over previously-see...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Symmetry
دوره 9 شماره
صفحات -
تاریخ انتشار 2017