R help - Jan 2006 - Display an Image on a Plane

Hi,

 

I am new to R and I would like to display an image on a plane in a 3D plot,
i.e. I would like to be able to specify a theta and a phi parameters like in
the function persp to display a 2D image on an inclined plane.

 

Regards,

 

vincent


	[[alternative HTML version deleted]]

Labbe, Vincent (AEREX <Vincent.Labbe.AEREX <at> drdc-rddc.gc.ca>
writes:
> 
> Hi,
> 
> I am new to R and I would like to display an image on a plane in a 3D plot,
> i.e. I would like to be able to specify a theta and a phi parameters like
in
> the function persp to display a 2D image on an inclined plane.
> 
> Regards,
> 
> vincent
> 
   can't think of an easy way to do this: what do you mean by
"image"
exactly?  A bitmapped image from a file?  Or something like the
output of image()?  If the latter, you may be able to cobble together something
using the trans3d() function (i.e., manually recreating an image()
by drawing colored squares, but transforming each of the to the 3D
perspective).  If the former, you might be able to do something with
the pixmap package ...

  Ben Bolker

Thanks to all for the answers.

I needed something quickly for a report so I used Gimp (as proposed by
Fran??ois Pinard) but I will look at the links given by Barry Rowlingson if I
want something more fancy. Thanks also to Ben Bolker.

Vincent


-----Original Message-----
From: Fran??ois Pinard [mailto:pinard at iro.umontreal.ca] 
Sent: Friday, January 20, 2006 6:31 PM
To: Barry Rowlingson
Cc: Ben Bolker; R-help; Labbe, Vincent (AEREX)
Subject: Re: [R] [Rd] Display an Image on a Plane

[Barry Rowlingson]
>[Ben Bolker]
>> [Labbe, Vincent]
>>>I am new to R and I would like to display an image on a plane in a
>>>3D plot, i.e. I would like to be able to specify a theta and a phi
>>>parameters like in the function persp to display a 2D image on an
>>>inclined plane.
>> what do you mean by "image" exactly?
>I think once you get into doing fancy visualisations like this then you
>may find a solution outside of R. [good referrences deleted]
Bonjour, Vincent.

I'm not fully sure I understand your request, what I get is that you 
want to transform an image on a plane as if one was looking at it in 
space, from an angle.   If I had this problem, I would probably produce 
the image using regular R machinery for this like png() or postscript(), 
then interactively process the result within Gimp, using trapezoidal 
deformations (I think they call it "Perspective transformation").  For
example, I used this simple trick in the following picture:

   http://pinard.progiciels-bpi.ca/plaisirs/dessins/cd-back.jpg

for the KWIC listing being part of the composition.  However, if 
I needed a precise phi and theta for transformations beyond what 
trans3d() can offer, I would likely use Python or R for computing the 
projection of the rectangle enclosing the image, than PIL (Python 
Imaging Library) for producing that precise trapezoidal deformation.  
Just sharing ideas, of course.  Much likely that if I knew R better, 
I would use it more fully -- but that's a tautology! :-)

-- 
Fran??ois Pinard   http://pinard.progiciels-bpi.ca