> On 01/07/2011 10:12 PM, H. Karsten wrote:
>> Invisible<voi### [at] devnull> wrote:
>>> It baffles me that in this day and age, people still use images with
>>> dithering. I mean, how long have the display technologies and file
>>> formats for true 24-bit colour been around?
At least 1994, common by 1997.
>>
>> When I'm saving images not to show beauty but content, I always try to
>> make them
>> small.
>
> You realise that /not/ dithering it down to 256 colours would probably
> make the file drastically /smaller/, right?
Without dithering and using a custom optimisez palete, you need white, 2 
blues, red, red-green mix, black and 2 grays, the rest can be used for 
the greens (leaving 248 shades of green to chose from...).
The current image only use 76 colours.
>
>

My experience on that mather:
I started with a true colours JPG file about 16K.
I converted it as GIF using dithering and optimised palete. The result 
was rather poor, and the file size jumped to around 150K! Almost the 
same as the 24 bits BMP version...

Yeah! Right, dithering plays havok on compression. It introduce 
non-compressible noise, most of it is essentialy random.


Alain

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