[TAG] Image size vs. file size

[Ben Okopnik]

On Wed, Sep 29, 2010 at 03:13:13AM +0100, Jimmy O'Regan wrote:
> On 29 September 2010 03:09, Ben Okopnik <ben at linuxgazette.net> wrote:
> > which presents a GIMP plugin called "save_for_web" [laugh]. Someone
> > there actually asked about changing color subsampling, and the author
> > mentioned that it's in the works! Awesome stuff for the future, then.
> 
> I think my last answer must have passed yours on the street and
> neglected to wave :)

I hope you'll speak to it sternly. :)

> ImageMagick supports changing colour subsampling,
> and it makes quite a difference.

Yeah, looks that way. Applying it without any reduction in quality cuts
the file size by more than 2/3rds:

``
ben at Jotunheim:/tmp$ convert -sampling-factor 4:1:1 bahama20__1.jpg bahama20__1-ss411.jpg
ben at Jotunheim:/tmp$ ls -l baha*
-rw-r--r-- 1 ben ben 1725638 2010-09-28 14:37 bahama20__1.jpg
-rw-r--r-- 1 ben ben  573111 2010-09-28 22:49 bahama20__1-ss411.jpg
''

THAT is great coolness. Thanks, Jimmy!


-- 
* Ben Okopnik * Editor-in-Chief, Linux Gazette * http://LinuxGazette.NET *