Accession Number:

ADA053843

Title:

Digital Image Processing by Use of Local Statistics.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s):

Report Date:

1978-03-01

Pagination or Media Count:

14.0

Abstract:

Computational techniques involving contrast enhancement and noise filtering on two-dimensional image arrays were developed, based on their local mean and variance. These algorithms are nonrecursive and do not require a transform. They share the same characteristics in that each pixel is processed independently. Consequently, this approach has an obvious advantage when used in real-time digital image processing applications and where parallel processors can be used. For both the additive and multiplicative cases, the a priori mean and variance of each pixel is derived from its local mean and variance. Then, the minimum mean-square-error estimator in its simplest form is applied to obtain the noise-filtering algorithms. For multiplicative noise a statistical optimal linear approximation is made. Experimental results show that such an assumption yields a very effective filtering algorithm. Examples on images containing 256 x 256 pixels are given. Results show that in most cases the techniques developed in this report are readily adaptable to real-time image processing. Author

Subject Categories:

  • Human Factors Engineering and Man Machine Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE