Simple improvement of the gradient operator

Greg J. Reese

doi:10.1117/12.211966

16 June 1995 Simple improvement of the gradient operator

Greg J. Reese

Proceedings Volume 2488, Visual Information Processing IV; (1995) https://doi.org/10.1117/12.211966
Event: SPIE's 1995 Symposium on OE/Aerospace Sensing and Dual Use Photonics, 1995, Orlando, FL, United States

Abstract

The gradient operator is frequently used for detecting edges in digital images. Although it does enhance edges well, it also enhances noise well, making edge detection difficult, especially for computer vision systems. This paper introduces a simple improvement of the gradient operator called gradient propagation. The standard method of detecting edges with a gradient operator is to calculate the gradient at each pixel and then threshold the magnitude of that gradient. Gradient propagation does exactly the same thing except that before thresholding, it adds copies of the gradient vector at each pixel to an output gradient image along a line perpendicular to the gradient vector. The gradient sums turn out to be large along edges and small noise. After thresholding, strong image edges processed by gradient propagation come out as good as those from the gradient operator but weak edges are detected better and with substantially less noise. The paper compares the results of the Sobel operator and equivalent edges. Both techniques produce little noise when detecting strong edges, but for weak edges, gradient propagation shows substantially less noise.

Citation Download Citation

Greg J. Reese "Simple improvement of the gradient operator", Proc. SPIE 2488, Visual Information Processing IV, (16 June 1995); https://doi.org/10.1117/12.211966

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available