Histogram equalization apparatus for contrast enhancement of moving image and method therefor
US6259472A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 22, 1998 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Apr 22, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T5/92
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A histogram equalization apparatus for contrast enhancement of a moving image includes a CDF calculator for counting the number of pixels having a gray level from the minimum to the maximum or less with respect to an input image in a frame unit to calculate a cumulative distribution function (CDF) value of each gray level, and a look-up table for updating histogram-equalized level corresponding to each gray level of the input moving image in a frame unit based on the CDF value of each gray level, and outputting a corresponding histogram-equalized level according to a level of the input moving image. Therefore, the histogram equalization apparatus can perform real-time histogram equalization on a moving image with a simple hardware, without using a frame memory, a probability density function (PDF) calculator and dividers for a cumulative density function (CDF) calculation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.