From: Timothy Hunter <TimHunter@...>
Date: 2006-11-17T07:16:19+09:00
Subject: Re: Another IO.popen question ...

Adam Groves wrote:
> Hi,
>
> I'm wanting to create thumbnails of pdfs in png format and send them off 
> to be saved. I've come up with this so far:
>
>     IO.popen("curl #{some_uri} | convert -resize 700x700 pdf:-[0] 
> png:-") {|f| do_something_with_this_file}
>
> Which works a treat. (In case you didn't know, convert is a command line 
> tool for ImageMagick).
>
> What I'd really like to do though is pass on a File object to convert:
>
> file = File.open("mypdf.pdf")
>
>     IO.popen("#{file} | convert -resize 700x700 pdf:-[0] png:-") {|f| 
> do_something_with_this_file}
>
> This obviously doesn't work but I hope illustrates what I'm wanting to 
> acheive - namely to pass 'file' to convert it to a png which is read 
> back into ruby and uploaded to my file repository on S3.
>
> By the way, this IS for a rails application, but it seems basically like 
> a pure ruby question to me.
>
>
> Regards
>
> Adam
>
>   
Consider RMagick: http://rmagick.rubyforge.org

The Magick::Image.read method accepts an open Ruby file object as an 
argument.

http://www.simplesystems.org/RMagick/doc/image1.html#read