[magick-users] displacement map question

[Timothy Hunter]

On Sep 16, 2006, at 8:03 AM, Anthony Thyssen wrote:

> Timothy Hunter on  wrote...
> | > As all you are doing is a slight bend in the picture. then
> | > you can just use -wave.
> | >
> | > However -wave only works in the displacement in the Y direction.
> | > And in your case can add lots of extra space.
> | >
> | > To fix, rotate your picture 90 degrees (no loss of quality)
> | > run it through wave (some quality loss, to be expected)
> | > crop the unwanted space, and rotate back (or visa-versa).
> | >
> | Thanks, Anthony. I thought about wave but I was afraid that the two
> | rotations would cause me to end up with a bad-looking image. I'm  
> glad
> | to hear that it won't.
>
> Enjoy.. let me know how you go and your final usage.

I figured out how to get the effect I was shooting for and wrote an  
article it.  Per your advice it uses wave to put the bend in the  
image. The article is here: http://rmagick.rubyforge.org/Polaroid/ 
polaroid.html. I used Ruby and RMagick. I'm sure there's a command- 
line-only approach as well, but it's beyond my shell-scripting skills.