From: Timothy Hunter <cyclists@...>
Date: 2005-04-07T10:34:41+09:00
Subject: Re: RMagick question

Joe Van Dyk wrote:
> Hi,
> 
> I'd like to generate a thumbnail of an image.  The thumbnail should
> have curved corners (corners colored a specified color).  Any ideas on
> what functions I could use?
> 
> Thanks,
> Joe
> 
> 
You might try this approach. Start by making a thumbnail from your image 
with #resize or #thumbnail. Use Image.new to construct a second image 
the same size as the thumbnail. Specify the color you want as the 
background color. Use #roundrectangle in the Draw class to draw a 
rounded rectangle on the image. Specify the stroke and fill colors as 
"none" or "transparent". Use #composite with the Magick::OverCompositeOp 
argument to composite this image over the thumbnail.

Give me a shout if you want and I'll see if I can put together an 
example that does this.

If you want the corners to be transparent instead of some specific 
color, check out the vignette example in the examples/ subdirectory or 
the "Add transparency with a mask" example in the RMagick portfolio at 
http://rmagick.rubyforge.org.