[Live-demo] osgeo live image sizes

[Cameron Shorter]

Ah, it seems the attached images from my last email were too big for the 
email list.
Sending again without the images...

On 4/01/2015 12:22 pm, Cameron Shorter wrote:
>
> Angelos noticed that the size of the images within our docs directory 
> seems to have increased recently as quickstarts are getting updated.
> In our recent IRC meeting, it was suggested that maybe we could reduce 
> image sizes, either by compressing png images (without loss of 
> quality) or by switching to jpg images (with minimal loss of quality).
>
> So I've done some tests of the image directory under a few different 
> scenarios, using the command-line imagemagic to convert images. 
> Command used:
> convert -resize 800x600 -quality 85 tilemill_projectinfo.png 
> tilemill_projectinfo.jpg; rm tilemill_projectinfo.png
>
> Directory sizes as below.
>
> My conclusions:
> * Yes, we can save some space from converting PNG to JPG, but it would 
> result in degradation of image quality, so we should keep source 
> images in original PNG format.
> * For the docs copied onto the ISO image, we could write a script 
> which converts png->jpg (with reduced quality), but keep high quality 
> images on our website at http://live.osgeo.org . (This shouldn't be 
> our first choice, as ideally our website and iso should have the same 
> docs, and we should try to keep the docs on the iso at best quality 
> available).
>
> du -sh trunk/doc/images*
> 161M  images-osgeolive8.0 (Not sure why last release was so big)
> 90M    images-osgeolive8.5a3 (current osgeolive8.5a3 directory)
> 89M    images_optipng (compress png to png. Not much to save. using 
> optipng -o5)
> 64M    images_jpg (png to jpg, no compression)
> 34M    images_50jpg (png to jpg, 50% compression)
> 52M    images_85jpg (png to jpg, 85% compression)
> 45M    images_85jpg800x600 (png to jpg, 85% compression, resize 
> 1024x768 screenshots to 800x600)
>
> The level of image degradation from compression seems to vary between 
> screen shots.
> The GeoNetwork images don't look too good when compressed:
>
> Original PNG image:
> <image>
>
> Compressed 85% JPG:
> <image>
>
> Compressed 50% JPG:
> <image>
>
> The GRASS images seem to compress better:
> Original PNG:
> <image>
>
>
> Compressed 85% JPG:
> <image>
>
>
> Compressed 50% JPG:
> <image>
>
>
>
> -- 
> Cameron Shorter,
> Software and Data Solutions Manager
> LISAsoft
> Suite 112, Jones Bay Wharf,
> 26 - 32 Pirrama Rd, Pyrmont NSW 2009
>
> P +61 2 9009 5000 <tel:%2B61%202%209009%205000>,  W www.lisasoft.com 
> <http://www.lisasoft.com>,  F +61 2 9009 5099 
> <tel:%2B61%202%209009%205099>

-- 
Cameron Shorter,
Software and Data Solutions Manager
LISAsoft
Suite 112, Jones Bay Wharf,
26 - 32 Pirrama Rd, Pyrmont NSW 2009

P +61 2 9009 5000,  W www.lisasoft.com,  F +61 2 9009 5099

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