John Joyce wrote:
>
> On Jul 18, 2007, at 7:28 PM, Tim Hunter wrote:
>
>>>
>> Yes, you'll need to composite the scaled image on top of the 
>> background of your desired size. See  my article "Alpha Compositing - 
>> Part 1" [http://rmagick.rubyforge.org/src_over.html]. If you're 
>> making a lot of thumbnails you might also be interested in  "Making 
>> Thumbnails with RMagick" 
>> [http://rmagick.rubyforge.org/resizing-methods.html], which compares 
>> the performance of all the RMagick resizing methods.
>>
>> Also if you'll tell me which parts of the documentation are lacking 
>> in clear examples I'll see what I can do to fix it. You can always 
>> open a documentation bug in the RMagick bug tracker on RubyForge.
>>
>> -- 
>> RMagick OS X Installer [http://rubyforge.org/projects/rmagick/]
>> RMagick Hints & Tips 
>> [http://rubyforge.org/forum/forum.php?forum_id=1618]
>> RMagick Installation FAQ [http://rmagick.rubyforge.org/install-faq.html]
>>
>>
> Hey Mr. Hunter,
> I'm using RMagick semi-successfully now, in a dumb Rails app, works 
> like a charm with jpg files, but png files give me a Corrupt image 
> `path/to/image.png' while using the same set of code as with jpg files:
>
>     img = Image.read(image_to_alter)[0]
>
>
> This is the line called out with the error.
>
> Is it possible, since this was created with Photoshop CS2, that the 
> png is somehow different from what RMagick expects to read? or is 
> there something I'm missing with the fact that it contains a 
> transparency?
>
> Regards,
> John Joyce
>
Can you read the image with ImageMagick? Try

identify path/to/image.png


-- 
RMagick OS X Installer [http://rubyforge.org/projects/rmagick/]
RMagick Hints & Tips [http://rubyforge.org/forum/forum.php?forum_id=1618]
RMagick Installation FAQ [http://rmagick.rubyforge.org/install-faq.html]