This paper introduces an affine invariant of trapezia, and the explicit constraint equation between the intrinsic matrix of a camera and the similarity invariants of a trapezium are established using the affine invariant. By this constraint, the inner parameters, motion parameters of the cameras and the similarity invariants of trapezia can be linearly determined using some prior knowledge on the cameras or the trapezia. The proposed algorithms have wide applicability since parallel lines are not rare in many scenes. Experimental results validate the proposed approaches. This work presents a unifying framework based on the parallelism constraint, and the previous methods based on the parallelograms or the parallelepipeds can be integrated into this framework.
Key words: invariant parallelism constraint camera calibration 3D reconstruction
Mobile phones are constantly decreasing in size, thereby complicating the acoustical
functionality. Signal processing methods can be used to partially mitigate
this problem. In this paper we suggest a method which uses multiple spectral
subtraction functions and two microphones, introducing only a short signal delay.
There are many different (and often confusing) terms associated
with clock-based devices. This application note attempts
to clarify these terms, and hence serves as a comprehensive
reference on clock terminology. This application note can be
divided into two sections. The first section describes and distinguishes
between various clock sources available today.
The second section defines and distinguishes between various
parameters used to describe clocks. This section also provides methods of measuring some of these parameters.
Jitter is extremely important in systems using PLL-based
clock drivers. The effects of jitter range from not having any
effect on system operation to rendering the system completely
non-functional. This application note provides the reader
with a clear understanding of jitter in high-speed systems. It
introduces the reader to various kinds of jitter in high-speed
systems, their causes and their effects, and methods of reducing
jitter. This application note will concentrate on jitter in PLL-based frequency synthesizers.
This C++ example demonstrates how to create multimedia messages using the
CMmsClientMtm API. Notice that some methods have changed between S60 2nd and 3rd Edition.
The Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG are finalising a new standard for
the coding (compression) of natural video images. The new standard [1] will be known as H.264 and
also MPEG-4 Part 10, “Advanced Video Coding”. This document describes the methods of filtering
reconstructed blocks in an H.264 CODEC. Note that the H.264 draft standard is not yet finalised and
so readers are encouraged to refer to the latest version of the standard.
The Joint Video Team (JVT) of ISO/IEC MPEG and ITU-T VCEG are finalising a new standard for
the coding (compression) of natural video images. The new standard [1,2] will be known as H.264 and
also MPEG-4 Part 10, “Advanced Video Coding”. This document describes the methods of predicting
intra-coded macroblocks in an H.264 CODEC.
Aiming at the application of passive trackinn based on sensor array, a new passive trackinn usinn sensor array
based on particle filter was proposed. Firstly, the“fake points" could be almost entirely and exactly deleted with the aids of the
sensor array at the expense of an additional sensor. Secondly, considered the fact that the measurements notten from each array
were independent in passive trackinn system, a novel sequential particle filter usinn sensor array with improved distribution was proposed. At last, in a simulation study we compared this approach a壇orithm with traditional trackinn methods. The simulation re-sups show that the proposed method can nreatly improve the state estimation precision of sensor array passive trackinn system.
An unsatisfactory property of particle filters is that they
may become inefficient when the observation noise is low.
In this paper we consider a simple-to-implement particle filter,
called ‘LIS-based particle filter’, whose aim is to overcome
the above mentioned weakness. LIS-based particle
filters sample the particles in a two-stage process that uses
information of the most recent observation, too. Experiments
with the standard bearings-only tracking problem indicate
that the proposed new particle filter method is indeed
a viable alternative to other methods.
The need for accurate monitoring and analysis of sequential data arises in many scientic, industrial
and nancial problems. Although the Kalman lter is effective in the linear-Gaussian
case, new methods of dealing with sequential data are required with non-standard models.
Recently, there has been renewed interest in simulation-based techniques. The basic idea behind
these techniques is that the current state of knowledge is encapsulated in a representative
sample from the appropriate posterior distribution. As time goes on, the sample evolves and
adapts recursively in accordance with newly acquired data. We give a critical review of recent
developments, by reference to oil well monitoring, ion channel monitoring and tracking
problems, and propose some alternative algorithms that avoid the weaknesses of the current
methods.
