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Rotating an Image

  • To: mathgroup at smc.vnet.net
  • Subject: [mg104348] Rotating an Image
  • From: "Ernst H.K. Stelzer" <stelzer at embl.de>
  • Date: Wed, 28 Oct 2009 04:09:37 -0500 (EST)
  • References: <hc38kb$i9r$1@smc.vnet.net> <200910271000.FAA05828@smc.vnet.net>

Hi,

I need to rotate an image, i.e. a 2D Matrix, about an arbitrary angle.
I would like to maintain the image size.
I would like to have full control over the interpolation process.

I know about ImageRotate.  ImageRotate is really fast, but it is not very
well documented and in particular its Methods are not described at all.
Maintaining the image size could be accomplished by a subsequent application
of ImageRotate and ImageCrop but this does not settle the interpolation
issue.

The function in the Digital Image Processing package is not an option since
it is not really well supported in version 7 but it comes very close to what
I need.

I have an implementation in Mathematica but it is dreadfully slow,
therefore, I wonder if somebody has generated an efficient implementation I
could take advantage of or is aware of a Mathematica function I have
overlooked.

In the long term I am actually interested in rotating a 3D volume/matrix
around an arbitrary axis by an arbitrary angle.  Such functions exist for
graphics objects but not for image/volume/matrix data.  Or am I wrong?

Sincerely

	E. Stelzer





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