Re: Speeding up thumbnail generation (like multi threaded). Thoughts please.

[Mark <markg85 gmail com>]

On Wed, Sep 30, 2009 at 3:27 PM, Philip Van Hoof <spam pvanhoof be> wrote:
> On Fri, 2009-08-28 at 22:11 +0200, Mark wrote:
>
>>
>> Now for the results:
>>
>> Glib
>> ----------------------
>> 1927 images thumbnailed in 2.29 minutes. That is roughly 0.07 seconds
>> per thumbnail
>>
>> GraphicsMagick
>> ----------------------
>> 1927 images thumbnailed in 3.08 minutes. That is roughly 0.09 seconds
>> per thumbnail
>>
>> FreeImage
>> ----------------------
>> 1927 images thumbnailed in 5.45 minutes. That is roughly 0.17 seconds
>> per thumbnail
>
> You want to override GdkPixbuf's support for Jpeg and thumbnail all JPEG
> images using EPeg. It'll beat GdkPixbuf by 5 times or something.
>
> That's because afaik does EPeg use libjpeg in a way that it skips rows
> and columns, and that way performs better on both I/O (having to read
> less of the original), memory (same reason) and CPU (having to
> decompress less, having to scale less or nothing).
>
> We are already using EPeg for this on the Maemo Fremantle platform, by
> the way. Scaling truly large JPEG images goes magically fast with it.
>
>
> --
> Philip Van Hoof, freelance software developer
> home: me at pvanhoof dot be
> gnome: pvanhoof at gnome dot org
> http://pvanhoof.be/blog
> http://codeminded.be
>
>

sounds interesting.
A few questions for that lib:
- Where can it be downloaded (i only found the documentation of it)
- Can it be used on it's own without a need of including other
dependencies other then libjpeg?
- Are there any benchmarks existing? preferably compared to GdkPixbuff

and beating it by 5 times is unlikely. My threaded test took ~30
seconds that would mean with epeg it can take just 6 seconds.. i just
doubt that's possible for my 1927 image test.

Thanx,
Mark