[vtkusers] Zooming an Image

[David Gobbi]

Note that in order for Zoom() to work, you will need to display the
image with a vtkImageActor, not a vtkImageMapper, since Zoom only
impacts the appearance of 3D actors.

Also, rather than Zoom, it is better to do this:
camera->ParallelProjectionOn()
camera->SetParallelScale(imagesize/zoom)

For viewing images (as opposed to viewing 3D scenes), parallel projection
is better than perspective projection.

 - David

On Mon, 18 Oct 2004, Charles Moad wrote:

> vtkRenderer.GetActiveCamera().Zoom()
>
> Messing with the camera should have no overhead.
>
> - Charlie
>
> On Mon, 2004-10-18 at 11:40, Beau Sapach wrote:
> > Hello everyone,
> >
> > I'm using vtkImageMapper and vtkActor2D to display an time-series of images
> > as a movie.  I want to be able to zoom in on a given frame and continue
> > playing the series at that zoom setting, when I use vtkImageMagnify the
> > program gets VERY slow, this is seems very CPU intensive.  Is there a better
> > way to zoom?  Thanks!
> >
> > Beau
> >
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