Papers by Carlos Morimoto
International Conference on Pattern Recognition, 1996
: This paper presents an automatic digital image stabilization system thatis able to handle large... more : This paper presents an automatic digital image stabilization system thatis able to handle large image displacements. The system has been implemented in aparallel pipeline image processing hardware (Datacube Max Video 200) connectedto a SUN SPARCstation 20/612 via a VME bus adaptor. Our technique is based ona two-dimensional feature-based multi-resolution motion estimation algorithm, thattracks a small set of features to
... tures were tracked automatically throughout the image sequence based on a spatio-temporal app... more ... tures were tracked automatically throughout the image sequence based on a spatio-temporal approach. ... The mid-level representation de-scribes the observed facial changes at each frame ... a low level (in image space), allowing an easier way to incorporate semantic knowledge ...
In this chapter we look at a passive eye monitoring system, or simply eye tracker (ET), as a mono... more In this chapter we look at a passive eye monitoring system, or simply eye tracker (ET), as a mono-camera system that measures the position and orientation of the subject’s eye. The most common image based ET technique is known as the pupil-corneal reflection (PCR) technique, because it uses a reflection on the surface of the cornea (the first Purkinje image)
Remote gaze estimation using a single non-calibrated camera, simple user calibration or calibrati... more Remote gaze estimation using a single non-calibrated camera, simple user calibration or calibration free, and robust to head movements are very desirable features of eye tracking systems. Because cross-ratio (CR) is an invariant property of projective geometry, gaze estimation methods that rely on this property have the potential to provide these features, though most current implementations rely on a few
This paper describes an academic research project in com- puter vision and distance learning curr... more This paper describes an academic research project in com- puter vision and distance learning currently under development in Brazil, and it can be roughly classified in the 1st workshop area, about com- puter vision research that addresses educational problems in developing regions. In particular, we describe our experience in developing two com- puter vision tools for distance learning (eLearning) applications.
Eye Tracking Research & Application, 2010
Traditional cross-ratio methods (TCR) project a light pattern and use invariant properties of pro... more Traditional cross-ratio methods (TCR) project a light pattern and use invariant properties of projective geometry to estimate the gaze position. Advantages of the TCR methods include robustness to large head movements and in general requires just a one time per user calibration. However, the accuracy of TCR methods decay significantly for head movements along the camera optical axis, mainly due
Resumo: Os constantes avanços em poder de processamento, capacidade de armazenamento, e largura d... more Resumo: Os constantes avanços em poder de processamento, capacidade de armazenamento, e largura de banda tornaram possível ao usuário de com- putadores o acesso, manipulação e edição de imagens e vídeos digitais. Nesse tutorial, vamos descrever alguns algoritmos de visão computacional para a seg- mentação, indexação e recuperação de vídeo utilizando o OpenCV para que, ao final do tutorial, você
Proceedings of 13th International Conference on Pattern Recognition, 1996
This paper explores the use of Hidden Markov Models (HMMs) for th e recognition of head gestures.... more This paper explores the use of Hidden Markov Models (HMMs) for th e recognition of head gestures. A gesture corresponds to a particular pattern of head movement. The facial plane is tracked using a parameterized model and the temporal sequence of three image rotation parameters are used to describe four gestures. A dynamic vector quantization scheme was implemented to transform the parameters into suitable input data for the HMMs.
1995 International Conference on Acoustics, Speech, and Signal Processing, 1995
Proceedings of the 2006 symposium on Eye tracking research & applications - ETRA '06, 2006
... In previous experiments investigating motor control in a Time-To-Contact task [Morya et al ..... more ... In previous experiments investigating motor control in a Time-To-Contact task [Morya et al ... To better understand the factors involved in these observations, gaze was sistematically recorded ... Dynamics of visual feedback in a laboratory simulation of a penalty kick Journal of Sports ...
Proceedings of the Symposium on Eye Tracking Research and Applications - ETRA '12, 2012
Remote gaze estimation using a single non-calibrated camera, simple user calibration or calibrati... more Remote gaze estimation using a single non-calibrated camera, simple user calibration or calibration free, and robust to head movements are very desirable features of eye tracking systems. Because cross-ratio (CR) is an invariant property of projective geometry, gaze estimation methods that rely on this property have the potential to provide these features, though most current implementations rely on a few simplifications that compromise the performance of the method. In this paper, the CR method for gaze tracking is revisited, and we introduce a new method that explicitly compensates head movements using a simple 3 parameter eye model. The method uses a single non-calibrated camera and requires a simple calibration procedure per user to estimate the eye parameters. We have conducted simulations and experiments with real users that show significant improvements over current state-of-the-art CR methods that do not explicitly compensate for head motion.
2006 19th Brazilian Symposium on Computer Graphics and Image Processing, 2006
... A lot of the image processing was facilitated by the use of the OpenCV library. ... [7] DH Yo... more ... A lot of the image processing was facilitated by the use of the OpenCV library. ... [7] DH Yoo and MJ Chung. A novel non-intrusive eye gaze estimation using cross-ratio under large head motion. Com-put. ... Non-contact eye gaze tracking system by mapping of corneal reflections. ...
Proceedings of International Conference on Image Processing, 1997
We propose a novel video coding scheme to improve the performance of established block-based moti... more We propose a novel video coding scheme to improve the performance of established block-based motion compensation codecs such as MPEG, H261, and H263. The proposed method is a hybrid scheme which introduces model-based global motion compensation as a pre-processing step to the basic block-based motion compensation technique. Performance evaluation tests show that the new method is capable of achieving higher
2008 XXI Brazilian Symposium on Computer Graphics and Image Processing, 2008
Page 1. People detection under occlusion in multiple camera views Thiago T. Santos and Carlos H. ... more Page 1. People detection under occlusion in multiple camera views Thiago T. Santos and Carlos H. Morimoto Institute of Mathematics and Statistics University of Sao Paulo Rua do Matao, 1010 - 05508-090 Sao Paulo, Brazil {thsant, hitoshi}@ime.usp.br Abstract ...
International Conference on Pattern Recognition, 1996
We present a fast implementation of an electronic digital image stabilization system that is able... more We present a fast implementation of an electronic digital image stabilization system that is able to handle large image displacements. The system has been implemented in a parallel pipeline image processing hardware (Datacube Max Video 200) connected to a SUN SPARCstation 20/612. Our technique is based on a 2D feature-based multi-resolution motion estimation algorithm, that tracks a small set of
Page 1. 6 Free Head Motion Eye Gaze Tracking Techniques Carlos H. Morimoto and Flávio L. Coutinho... more Page 1. 6 Free Head Motion Eye Gaze Tracking Techniques Carlos H. Morimoto and Flávio L. Coutinho ... The fovea is a very small region, about 1 ◦ in diameter, and is about 5 ◦ off Page 3. 6 Free Head Motion Eye Gaze Tracking Techniques 135 the LoG. ...
Modeling natural phenomena is a problem that has been studied for a long time in Computer Graphic... more Modeling natural phenomena is a problem that has been studied for a long time in Computer Graphics. A problem that currently arises is how to render and animate realistically natural phenomena in real-time. This paper presents a technique to model underbrush with fast and realistic animation. Pre-computations and a simplified physically based model were developed to achieve the work's proposal.
The authors present a fast electronic image stabilization system that compensates for 3D rotation... more The authors present a fast electronic image stabilization system that compensates for 3D rotation. The extended Kalman filter framework is employed to estimate the rotation between frames, which is represented using unit quaternions. A small set of automatically selected and tracked feature points are used as measurements. The effectiveness of this technique is also demonstrated by constructing mosaic images from
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Papers by Carlos Morimoto