From: Ron M <rm_rails@...>
Date: 2005-12-29T10:06:25+09:00
Subject: Re: Real-time image processing in Ruby

Ilmari Heikkinen wrote:
> On 12/29/05, John Koschwanez <ishkaprog@gmail.com> wrote:
  >
>>- Is anyone using pure Ruby to process images real-time?  RMagick is too
>>limited for my applications.  I doubt Ruby would match the speed of C,
>>but it might be fun to try.
> 
> Correct me if I'm wrong, but image processing is one of those things
> that plays directly into the weaknesses of the current Ruby
> implementation.

I disagree.   Image processing is an area where even in Java/C#/C/etc
you're probably better off using highly tuned matrix libraries than
rewriting such basic operations from scratch; and Ruby has a pretty
good matrix library (NArray).

And under the assumption that regardless of the language most of
the CPU time will be used inside such a matrix library, the
overhead of the language wrapping it shouldn't matter much.



If you do find yourself writing ruby loops to touch large sets
of individual pixels, however, you should probably consider
extending NArray in C instead - hopefully with some pretty
general purpose function so many ruby algorithms could make
use of the same extensions.  (for example, I'm not sure if
NArray has a nice way of specifying a mask to only process
part of an image).

- R