Employing pixel density to detect a spam image
US7882177B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 2007 |
| Grant date | Feb 1, 2011 |
| Priority date | — |
| Expiry date | Sep 13, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L51/212
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A network device and method are directed towards detecting and blocking image spam within a message by performing statistical analysis on differences in edge pixel distribution patterns. An image spam detection component receives a message with an image attachment. Physical characteristics of the image are examined to determine whether the image is a candidate for further analysis. If so, then the image may be converted to a grayscale image, and then performing edge detection, followed by the elimination of non-maxima and thresholding of weak edges. Edge pixels and then employed to determine a normalized pixel density distribution (PDD). Various statistical analyses are applied to the resulting normalized PDD to determine a likelihood that the image is spam. A signature based exemption may be applied to images improperly identified as spam, based on trusted user feedback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.