Related Experiment Video
Updated: Jun 8, 2026
13:44
Detection of Architectural Distortion in Prior Mammograms via Analysis of Oriented Patterns
Published on: August 30, 2013
Invariant pattern recognition using angular signature functions.
Applied Optics
|September 11, 2010
Summary
This study introduces a novel invariant pattern recognition method using object contour information. The technique achieves shift, orientation, and scale invariance for enhanced pattern recognition applications.
Area of Science:
- Computer Vision
- Pattern Recognition
- Image Processing
Background:
- Object recognition is crucial in computer vision.
- Existing methods often struggle with variations in scale, orientation, and position.
- Invariant pattern recognition aims to overcome these limitations.
Purpose of the Study:
- To present a new concept for invariant pattern recognition.
- To utilize object contour information for recognition.
- To achieve invariance to shift, angular orientation, and quasi-invariance to scale.
Main Methods:
- Extracting an angular signature from object contours using nonlinear 2D directional convolutions.
- Normalizing the angular signature by area or energy for scale quasi-invariance.
- Comparing signatures using a 1D correlation for an angular similarity measure.
Main Results:
- The proposed method demonstrates invariance to object shift.
- The method exhibits invariance to angular orientation.
- Numerical experiments confirm quasi-invariance to scale.
Conclusions:
- The novel approach effectively uses object contour information for invariant pattern recognition.
- The method provides a robust solution for recognizing patterns despite transformations.
- This technique offers a promising direction for advanced computer vision systems.
Related Concept Videos
01:21Angular Momentum
Angular momentum characterizes an object's rotational motion and is defined as the moment of its linear momentum about a specified point O. When a particle moves along a curved path in the x-y plane, the scalar formulation calculates the magnitude of its angular momentum, utilizing the moment arm (d), representing the perpendicular distance from point O to the line of action of the linear momentum. Despite being scalar in formulation, angular momentum is inherently a vector quantity. Its...
01:11Angular Momentum about an Arbitrary Axis
Imagine a rigid body with a mass denoted as 'm', which has its center of mass at point G and is rotating around an inertial reference frame. The angular momentum at an arbitrary point P can be calculated by taking the cross product of the position vector and linear momentum vector for each individual mass element.
The velocity of a mass element comprises its translational velocity and the relative velocity instigated by the body's rotation. Substituting the velocity equation into the angular...
The velocity of a mass element comprises its translational velocity and the relative velocity instigated by the body's rotation. Substituting the velocity equation into the angular...
01:09Angular Momentum and Principle Axes of Inertia
The concept of angular momentum for a solid structure is illustrated as the cumulative result of the cross-product of the position vector of the mass element and the cross-product of the body's angular velocity with the position vector.
To put this equation into simpler terms, it can be reconfigured using rectangular coordinates. This involves choosing an alternative set of XYZ axes that are arbitrarily inclined with respect to the reference frame. The process of deriving the rectangular...
To put this equation into simpler terms, it can be reconfigured using rectangular coordinates. This involves choosing an alternative set of XYZ axes that are arbitrarily inclined with respect to the reference frame. The process of deriving the rectangular...
01:18Conservation of Angular Momentum: Application
A system's total angular momentum remains constant if the net external torque acting on the system is zero. Examples of such systems include a freely spinning bicycle tire that slows over time due to torque arising from friction, or the slowing of Earth's rotation over millions of years due to frictional forces exerted on tidal deformations. However in the absence of a net external torque, the angular momentum remains conserved. The conservation of angular momentum principle requires a change...
01:03IR Frequency Region: Fingerprint Region
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1.
The...
The...
01:25Relative Motion Analysis using Rotating Axes
Consider a component AB undergoing a linear motion. Along with a linear motion, point B also rotates around point A. To comprehend this complex movement, position vectors for both points A and B are established using a stationary reference frame.
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in...
However, to express the relative position of point B relative to point A, an additional frame of reference, denoted as x'y', is necessary. This additional frame not only translates but also rotates relative to the fixed frame, making it instrumental in...