The following images was converted with Adobe ImageReady from the original
PNG-output from POV-Ray.
I just want to show the difference in size from the 24-bit PNG to the
"Medium quality" JPG.
Give or take some decimals the PNG is 209 KiB and the "Medium" JPG is 37,4
KiB.
That is roughly a 82% reduction in size with only a slight loss in quality.
You could even go for the
no loss quality (HIGH, 100 or whatever setting your program has) and still
get a 42% reduction.
Let's say we post a 100 images and 1000 people download them. With no
compression
that is, with my example above, that is something like 20 GiB. Compress and
you will get
3.5 GiB. Worth the trouble, isn't it?

Of course this is image dependent with nature type of images suffering less
than others.
The "Low quality" JPG was posted just as a reference but even here I have
problems with spotting
any severe compression artefacts.

What I'm really after here is that it's not necessary to post a high quality
image when you want to
show a WIP. I can accept a full size image when it's finished but not
before.

I use a 2Mbit connection so I don't really have a problem, but I think it's
for everyones good to reduce the size.
Like mentioned earlier in the thread, not only it reduces the space on the
server but it also cuts down traffic.


/Stefan

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Attachments:
Download 'light_test_png_24_800x600.png' (210 KB) Download 'light_test_jpg_q30_800x600.jpg' (21 KB) Download 'light_test_jpg_q60_800x600.jpg' (38 KB) Download 'light_test_jpg_no_loss_800x.jpg' (123 KB)

Preview of image 'light_test_png_24_800x600.png'

Preview of image 'light_test_jpg_q30_800x600.jpg'

Preview of image 'light_test_jpg_q60_800x600.jpg'

Preview of image 'light_test_jpg_no_loss_800x.jpg'