Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: How to calculate the angle between two images?
Replies: 41   Last Post: Dec 8, 2012 11:02 PM

 Messages: [ Previous | Next ]
 khoo Posts: 63 Registered: 8/9/08
Re: How to calculate the angle between two images?
Posted: Apr 6, 2009 1:02 PM

> > > Had you considered that the results just might be right? Think about it - when you rotated the image, do the the actual image boundaries rotate?. You had some almost circular details toward the centre of the image, rotating a circle will generate exactly the same angle image irrespective of the amount of twist. If your image contains aliasing (digital stepping in the image), these will always generate detail usually at 0 and 90 degrees. Remember that your x scale needs to be rescaled such that 0 -> 256 actually maps to 0 ->360 degrees.
> > >
> > > Meanwhile do the other spikes bear any relationship to the actual rotation angle between your images?
> > >
> > > If the zero degree spike offends you why not set it to zero - if you know that the two images do have a valid rotation
> > >
> > > Regards
> > >
> > > Dave Robinson

> >

Bro Dave, i think i ady get the graph i want, but how to take out peak point from the graph?? and how to convert the radian in the graph to the degree??please continue teach me, i dunno how to convert and take the peak radian out....and this is the graph i got...

http://i278.photobucket.com/albums/kk119/khoo011/graph2.jpg

Date Subject Author
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 Dave Robinson
4/3/09 khoo
4/3/09 khoo
4/4/09 khoo
4/4/09 Dave Robinson
4/4/09 khoo
4/4/09 khoo
4/5/09 khoo
4/5/09 Dave Robinson
4/5/09 khoo
4/5/09 khoo
4/5/09 Dave Robinson
4/5/09 khoo
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 Dave Robinson
4/6/09 khoo
4/6/09 khoo
4/6/09 khoo
4/7/09 khoo
4/7/09 khoo
4/7/09 Dave Robinson
12/8/12 Jeff
4/3/09 Skeptic
4/3/09 Dave Robinson
4/3/09 Roger Stafford
4/3/09 khoo
4/3/09 Roger Stafford
4/3/09 ImageAnalyst
4/3/09 khoo
4/4/09 khoo
4/6/09 Matt
4/6/09 khoo
4/6/09 Matt