[ptx] SIFT patent reference

[Littlefields - Rik, Janis, Kyle & Peter]

Here is a patent that looks like SIFT.  Full text and images
are available from www.uspto.gov .

(The search string is for Inventor contains "Lowe" and
Assignee contains "Columbia",as in Univ.of...)

--Rik

http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=0&f=S&l=50&TERM1=LOWE&FIELD1=INZZ&co1=AND&TERM2=COLUMBIA&FIELD2=ASNM&d=ptxt 
<http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2Fsearch-bool.html&r=0&f=S&l=50&TERM1=LOWE&FIELD1=INZZ&co1=AND&TERM2=COLUMBIA&FIELD2=ASNM&d=ptxt>

United States Patent    6,711,293      
Lowe    March 23, 2004 

Method and apparatus for identifying scale invariant features in an 
image and use of same for locating an object in an image

Abstract

A method and apparatus for identifying scale invariant features in an 
image and a further method and apparatus for using such scale invariant 
features to locate an object in an image are disclosed. The method and 
apparatus for identifying scale invariant features may involve the use 
of a processor circuit for producing a plurality of component subregion 
descriptors for each subregion of a pixel region about pixel amplitude 
extrema in a plurality of difference images produced from the image. 
This may involve producing a plurality of difference images by blurring 
an initial image to produce a blurred image and by subtracting the 
blurred image from the initial image to produce the difference image. 
For each difference image, pixel amplitude extrema are located and a 
corresponding pixel region is defined about each pixel amplitude 
extremum. Each pixel region is divided into subregions and a plurality 
of component subregion descriptors are produced for each subregion. 
These component subregion descriptors are correlated with component 
subregion descriptors of an image under consideration and an object is 
indicated as being detected when a sufficient number of component 
subregion descriptors (scale invariant features) define an aggregate 
correlation exceeding a threshold correlation with component subregion 
descriptors (scale invariant features) associated with the object.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.email-lists.org/pipermail/ptx/attachments/20040504/da99529c/attachment.htm