Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Conservative Vector Fields

Conservative Vector Fields

A conservative vector field describes a force or field in which the work done between two points depends only on the initial and final positions. For a ball moving in Earth’s gravitational field, gravity performs work determined by the difference in height, regardless of whether the ball moves vertically or follows a curved trajectory.A vector field is conservative if it can be expressed as the gradient of a scalar potential function, f. In two dimensions, this is written...

Vector Algebra: Method of Components

Vector Algebra: Method of Components

It is cumbersome to find the magnitudes of vectors using the parallelogram rule or using the graphical method to perform mathematical operations like addition, subtraction, and multiplication. There are two ways to circumvent this algebraic complexity. One way is to draw the vectors to scale, as in navigation, and read approximate vector lengths and angles (directions) from the graphs. The other way is to use the method of components.
In many applications, the magnitudes and directions of...

Vector Representation of Complex Numbers

Vector Representation of Complex Numbers

Complex numbers, represented in Cartesian coordinates, can also be visualized as vectors. These vectors can be expressed in polar form, emphasizing their magnitude and angle. When a complex number is input into a function, the output is another complex number, highlighting the function's zero point from which the vector representation can originate.
Consider a function defined as the product of the complex factors in the numerator divided by the product of the complex factors in the denominator.

Cartesian Vector Notation

Cartesian Vector Notation

Cartesian vector notation is a valuable tool in mechanical engineering for representing vectors in three-dimensional space, performing vector operations such as determining the gradient, divergence, and curl, and expressing physical quantities such as the displacement, velocity, acceleration, and force. By using Cartesian vector notation, engineers can more easily analyze and solve problems in various areas of mechanical engineering, including dynamics, kinematics, and fluid mechanics. This...

Vector Components in the Cartesian Coordinate System

Vector Components in the Cartesian Coordinate System

Vectors are usually described in terms of their components in a coordinate system. Even in everyday life, we naturally invoke the concept of orthogonal projections in a rectangular coordinate system. For example, if someone gives you directions for a particular location, you will be told to go a few km in a direction like east, west, north, or south, along with the angle in which you are supposed to move. In a rectangular (Cartesian) xy-coordinate system in a plane, a point in a plane is...

Gradient Vectors and Their Applications

Gradient Vectors and Their Applications

Every point on a topographical map corresponds to a particular elevation, so the landscape can be modeled as a surface whose height depends on horizontal position. From any given location, a hiker may face infinitely many directions, but only one direction produces the fastest possible increase in elevation. This unique route is called the direction of steepest ascent, and in multivariable calculus, it is represented by the gradient vector of the elevation function.The gradient vector points...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Non-inertial lift induced migration for label-free sorting of cells in a co-flowing aqueous two-phase system.

The Analyst·2019

Same author

Carcinoid of the Appendix.

The Indian medical gazette·2017

Same author

A Case of Reticulum-Cell Sarcoma.

The Indian medical gazette·2017

Same author

Primary Carcinoma of the Liver.

The Indian medical gazette·2017

Same author

Pharmacognostical and physicochemical characteristics of roots of lesser known medicinal plant caesalpinia digyna rottl.

Ancient science of life·2012

Same author

Anxiogenic activity of isatin, a putative biological factor, in rodents.

Journal of psychopharmacology (Oxford, England)·2012

Search research articles

Related Experiment Videos

Image-adaptive vector quantization in an entropy-constrained framework.

M Lightstone¹, S K Mitra

¹Chromatic Res. Inc., Sunnyvale, CA.

IEEE Transactions on Image Processing : a Publication of the IEEE Signal Processing Society

|January 1, 1997

Summary

This summary is machine-generated.

This study introduces an adaptive vector quantization (VQ) method for efficient image compression. The novel approach optimizes codebooks for better rate-distortion performance, achieving significant gains in peak signal-to-noise ratio (PSNR).

Related Experiment Videos

Area of Science:

Digital Image Processing
Data Compression
Information Theory

Background:

Variable-rate source coding is crucial for efficient image data transmission.
Existing vector quantization (VQ) methods often lack adaptability to specific image statistics.
Codebook transmission in VQ introduces rate-distortion trade-offs that need careful consideration.

Purpose of the Study:

To develop an adaptive VQ scheme for variable-rate image source coding.
To explicitly account for codebook transmission costs in the rate-distortion optimization.
To improve the rate-distortion performance of image compression algorithms.

Main Methods:

An entropy-constrained Lagrangian framework is employed for adaptive VQ.
An iterative algorithm generates an operational codebook C(0) adapted to image statistics.
The design explicitly considers rate-distortion trade-offs for updated code vectors.

Main Results:

The proposed algorithm guarantees improved or equal rate-distortion performance compared to initial codebooks.
Coding the Barbara image demonstrated gains up to 3 dB in peak signal-to-noise ratio (PSNR) across all rates.
Substantial rate-distortion improvements were achieved even with a single pass of the algorithm.

Conclusions:

The adaptive VQ scheme offers superior rate-distortion performance for image compression.
The method effectively balances compression efficiency with codebook adaptation costs.
Encoding complexity can be managed by limiting iterations without significant performance loss.