From: ara.t.howard@...
Date: 2005-12-29T11:17:42+09:00
Subject: Re: Real-time image processing in Ruby

On Thu, 29 Dec 2005, Ron M 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.

absolutely.  unless you start looping... this is the tradeoff for high-level
languages.

>
> 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).

and a combination of NArray and RubyInline and/or ruby dl would make for very
rapid prototyping indeed.

-a
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