[Rabbit-dev] Questions about the RabbIT

[Robert Olofsson]

On Tue, 10 Nov 2009 17:13:52 -0700
Samat K Jain <lists at samat.org> wrote:

> On Tuesday 10 November 2009 03:35:43 pm, Robert Olofsson wrote:
> > Did you have any time to try out the java based image converter? 
> > With 4.3-pre-5 it even has some type of memory usage protection. 
> > I have been running with the java based conversion for some time
> > and it seems to work ok for my usage, but what do I know. 
> > 
> > Anyone else that can see any difference in speed/cpu usage/image
> > quality/<other>?
> 
> I've been using it for about a week and a half.
> 
> I haven't noticed any differences in speed or CPU usage, but it feels like image quality is lower (I haven't quantitatively tested). With 4.3-pre-2 there was also some issue where certain images would recompress with a strong red tint (fixed in recent builds).

Ok, since I wanted to know I wrote a small benchmarking program
that times image conversion. 
The results are not really what I expected.
The java based converter is _much_ faster on my machine. 

Small image 6550 bytes: 
ImageMagick convert took 160112 millis, on average: 160.112 millis
JavaConvert convert took 2320 millis, on average: 2.32 millis

Medium sized image 112326 bytes:
ImageMagick convert took 172001 millis, on average: 172.001 millis
JavaConvert convert took 73231 millis, on average: 73.231 millis

Medium sized image, 160928 bytes:
ImageMagick convert took 199568 millis, on average: 199.568 millis
JavaConvert convert took 33531 millis, on average: 33.531 millis

Big image, 3066439 bytes:
ImageMagick convert took 979269 millis, on average: 979.269 millis
JavaConvert convert took 504584 millis, on average: 504.584 millis

The output is reasonably similar, the java based converter tend to 
output slightly larger files (.c = convert, .j = java based) 

-rw-r--r-- 1 robo robo 3066439 2009-11-14 16:10 big.jpg
-rw-r--r-- 1 robo robo  123766 2009-11-14 16:11 big.jpg.c
-rw-r--r-- 1 robo robo  170232 2009-11-14 16:11 big.jpg.j
-rw-r--r-- 1 robo robo  112326 2009-11-14 15:38 kreml.jpg
-rw-r--r-- 1 robo robo   12759 2009-11-14 15:45 kreml.jpg.c
-rw-r--r-- 1 robo robo   12237 2009-11-14 15:42 kreml.jpg.j
-rw-r--r-- 1 robo robo  160928 2009-11-14 16:10 pa030039.jpg
-rw-r--r-- 1 robo robo   15601 2009-11-14 15:54 pa030039.jpg.c
-rw-r--r-- 1 robo robo   18226 2009-11-14 15:50 pa030039.jpg.j
-rw-r--r-- 1 robo robo    6550 2009-11-14 15:07 ps.jpg
-rw-r--r-- 1 robo robo    1317 2009-11-14 15:40 ps.jpg.c
-rw-r--r-- 1 robo robo    1801 2009-11-14 15:37 ps.jpg.j

Running GraphicsMagick I see a much better times, small image: 
GraphicsMagick convert took 13039 millis, on average: 13.039 millis
JavaConvert convert took 2486 millis, on average: 2.486 millis

Medium image 1: 
GraphicsMagick convert took 32332 millis, on average: 32.332 millis
JavaConvert convert took 73218 millis, on average: 73.218 millis

Medium image 2: 
GraphicsMagick convert took 44901 millis, on average: 44.901 millis
JavaConvert convert took 35046 millis, on average: 35.046 millis

The red tint most probably comes from transparent backgrounds, 
I have made no changes to handle it better. 

So as it is now, I would probably suggest running graphicsmagick.
The java based converter is probably faster for small to medium
sized images, but image quality may be a bit worse and image sizes
are a bit bigger, so in all graphicsmagick looks like the win for
now.

/robo