We describe ongoing work at JPL in two fields: autonomous navigation for terrestrial vehicles, and prioritized progressive transmission for deep space communications. While such applications may seem rather disparate,...
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ISBN:
(纸本)076951183X;0769511848
We describe ongoing work at JPL in two fields: autonomous navigation for terrestrial vehicles, and prioritized progressive transmission for deep space communications. While such applications may seem rather disparate, the), have in common the need for autonomous reasoning about visual information. We first review a number of techniques currently, under development that make use of data from color and infrared cameras, multispectral sensors, and laser rangefinder for estimating properties of the terrain cover in outdoor vegetated terrain. We then discuss how onboard visual analysis mechanisms for Mars rovers can be used for prioritizing the data to be transmitted to Earth, in order to maximize the science return of a mission.
The proceedings contains 95 papers from the SPIE 2001 conference on visualcommunications and imageprocessing. The topics discussed include: image coding;image analysis;video coding algorithms;stereo and multiview pr...
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The proceedings contains 95 papers from the SPIE 2001 conference on visualcommunications and imageprocessing. The topics discussed include: image coding;image analysis;video coding algorithms;stereo and multiview processing;video coding implementations;motion estimation;error-resilent coding;image sequencing analysis;face tracking and recognition and wireless video.
An image sequence stabilization system that removes translational jitter while preserving intentional camera pan is presented. The video sequence is processed to acquire global camera translations from frame to frame ...
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ISBN:
(纸本)0819439886
An image sequence stabilization system that removes translational jitter while preserving intentional camera pan is presented. The video sequence is processed to acquire global camera translations from frame to frame (global interframe motion vectors) by motion estimation. The resulting motion vectors an accumulated to construct an absolute frame position vs. frame number signal. This signal is low-pass filtered to remove high frequency components caused by jitter, and retain low frequency parts representing the intentional camera pan. Correction vectors for image frames are obtained by subtracting the absolute frame position from the low-pass filtered value, and stabilization is achieved by the corresponding translation of image frames.
This paper presents a regularized smoothing algorithm for 3D reconstruction from image sequence. Depth data estimated from a stereo pair or multiple image frames can easily be corrupted by various types of noise such ...
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ISBN:
(纸本)0819439886
This paper presents a regularized smoothing algorithm for 3D reconstruction from image sequence. Depth data estimated from a stereo pair or multiple image frames can easily be corrupted by various types of noise such as quantization and imperfect matching. We propose a regularized image restoration algorithm which enhances the surface of depth maps based on spatially adaptive image fusion. We can also enhance the resolution of the surfaces and preserve discontinuities.
In this paper we investigate the use of a fully rate scalable wavelet codec known as SAMCoW (Scalable Adaptive Motion Compensated Wavelet) for use in robust video streaming. We develop a theory based on the notion of ...
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ISBN:
(纸本)0819439886
In this paper we investigate the use of a fully rate scalable wavelet codec known as SAMCoW (Scalable Adaptive Motion Compensated Wavelet) for use in robust video streaming. We develop a theory based on the notion of additive temporal distortion to predict the performance of the bit stream under error conditions. Due to the regular nature of SAMCoW a closed-form solution is found and compared experimentally to a SAMCoW stream in a simulated channel.
Block-based disparity compensation is an efficient prediction scheme for encoding multi-view image data. Available scene geometry can be used to further enhance prediction accuracy In this paper, three different strat...
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ISBN:
(纸本)0819439886
Block-based disparity compensation is an efficient prediction scheme for encoding multi-view image data. Available scene geometry can be used to further enhance prediction accuracy In this paper, three different strategies are compared that combine prediction based on depth maps and 3-D geometry. Three real-world image sets are used to examine prediction performance for different coding scenarios. Depth maps and geometry models are derived from the calibrated image data. Bit-rate reductions up to 10% are observed by suitably augmenting depth map-based with geometry-based prediction.
Under the typical video communication configuration in which a camera is placed on top or at lateral side of a monitor, the face-to-face video communication has an inherent difficulty of poor eye contacts since the us...
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ISBN:
(纸本)0819439886
Under the typical video communication configuration in which a camera is placed on top or at lateral side of a monitor, the face-to-face video communication has an inherent difficulty of poor eye contacts since the users stare at the monitor screen rather than directly seeing the camera lens. In this paper, me propose an image warping technique for gaze-correction which performs 3D warping of face object in the given image by a certain correction angle. The correction angle which is the angle between the direction of eye gaze and that to the camera is estimated in an unsupervised way by using eye tracking technique. Experimental result with real image data shows much enhanced naturalness which the face-to-face video communication has to offer.
A novel fidelity constraint to the image enhancement problem is presented. With this constraint, we exploit the motion vectors of a compressed video bit-stream. These vectors establish a correspondence between image p...
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ISBN:
(纸本)0780370414
A novel fidelity constraint to the image enhancement problem is presented. With this constraint, we exploit the motion vectors of a compressed video bit-stream. These vectors establish a correspondence between image pixels across a series: of frames, and we guarantee that processing the decoded sequence does not violate this correspondence. We develop the constraint within the context of MPEG-2 and incorporate the constraint into a regularized enhancement algorithm. Simulations are then performed. Quantitative and qualitative results illustrate an improvement in visual quality.
In this work we present some image coding models based on adaptive approximation techniques. The image coding models presented are based on Matching Pursuit and High Resolution Pursuit, which are the most popular adap...
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ISBN:
(纸本)0819439886
In this work we present some image coding models based on adaptive approximation techniques. The image coding models presented are based on Matching Pursuit and High Resolution Pursuit, which are the most popular adaptive approximation techniques. These models have a similar computational complexity and structure. The models expands an image along an overcomplete dictionary. The dictionary was selected according to a best basis metric or a training strategy. From such expansion, the model selects the coefficients that correspond to the most important image structures. Selected coefficients are quantized just when they are chosen, in order to minimize error propagation along the process. These coefficients represent an optimal image decomposition, or a reduced image representation. This representation, in some way, corresponds to a coded image with a high compression rate. A simple reconstruction algorithm recovers the original image with a high visual quality.
In this paper, we propose the fractal-based gradient match vector quantizers (FGMVQs) and the fractal-based side match vector quantizers (FSMVQs) for the image coding framework. The proposed schemes are based upon the...
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ISBN:
(纸本)0819439886
In this paper, we propose the fractal-based gradient match vector quantizers (FGMVQs) and the fractal-based side match vector quantizers (FSMVQs) for the image coding framework. The proposed schemes are based upon the noniterative fractal block coding (FBC) technique and the concepts of the gradient match vector quantizers (GMVQs) and the side match vector quantizers (SMVQs). Unlike the ordinary GMVQs and SMVQs, the super codebooks in the proposed FGMVQs and FSMVQs are generated from the affine-transformed domain blocks in the non-iterative FBC technique. The codewords in the state codebook are dynamically extracted from the super codebook with the side-match and gradient-match criteria. The redundancy in affine-transformed domain blocks is greatly reduced and tile compression ratio can be significantly increased. Our simulation results show that about 10% - 20% bit rates in tile non-iterative FBC techniques are saved by using the proposed FGMVQs and FSMVQs.
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