DIRTY LENS DETECTION DEVICE AND DIRTY LENS DETECTION METHOD

Title:

DIRTY LENS DETECTION DEVICE AND DIRTY LENS DETECTION METHOD

Document Type and Number:

WIPO Patent Application WO/2015/011998

Kind Code:

A1

Abstract:

It is possible to consider an image as a composite wave that is the result of layering a plurality of waves (of variable density) having differing periods and amplitudes. An image having a water droplet attached thereto (in other words, an image captured via a lens having a water droplet attached thereto) has a higher occurrence of changes such as image blur than an image that does not have a water droplet attached thereto, which means that this type of change in an image results in changes in the composite wave thereof as well. Provided is a dirty lens detection device that suitably determines whether a lens is dirty without being affected by a background image by: focusing on the occurrence of large changes in the composite wave of an image that accompany an increase in the dirtiness of a camera lens (for example, when the amount of water droplets that are attached to a lens increases); extracting each of the image frequency components that constitute the composite wave; and analyzing changes in the magnitude relation between the frequency components (in other words, the distribution of image frequency power).

Inventors:

AKIYAMA YASUHIRO (JP)
NAKAMURA KATSUYUKI (JP)
IRIE KOTA (JP)

Application Number:

PCT/JP2014/064986

Publication Date:

January 29, 2015

Filing Date:

June 05, 2014

Export Citation:

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Assignee:

CLARION CO LTD (JP)

International Classes:

H04N5/225; H04N5/232

Foreign References:

JP2005515565A	2005-05-26
JP2003259211A	2003-09-12
JP2009130700A	2009-06-11
JP2007282106A	2007-10-25
JP2013115625A	2013-06-10
JP2006254206A	2006-09-21

Other References: