GIF can do graphics and photographs very well. It can even do animation.
JPEG gets better compression on photographs but it is much more complex and
with 8-bit paletted screens it is even more complex. However, it seems clear
that photographs and better compression is in demand, so JPEG will probably
get some hardware assist in the future (if not already).
-jim munro
-----Original Message-----
From: David Davies [mailto:david@intadev.com]
Sent: Thursday, October 18, 2001 10:22 PM
To: keitai-l@appelsiini.net
Subject: (keitai-l) Re: iMode on GIF
On Friday, 19 October 2001 12:26 PM Nick May wrote:
>> >Can anyone tell me why DoCoMo decided to go with GIF format with
iMode
>> >as opposed to JPEG or PNG? There seems little sense in this, either
>> >technically or economically.
>>
>> Possibilities:
>>
>> 1) smaller files size (for icons and limited/flat colour files) than
jpeg.
>> 2) they can be made to flash/move. Horribly, but that is what many
here want.... .png could not (at launch time, at least)
>> 3) They had no idea the service would be such a success and did not
envisage colour screens, high bandwidth availability, etc...
>> 4) take less time to display on the original low cpu speed
handsets......
>> (???)
>> 5) Take less firmware code to process - again maybe relevant on the
original handsets....
>> 6) .png was still not mainstream when the service was launched.
4 and 5 are very significant,
The code to uncompress and display [non-animated]GIFs (in C/Assembler at
least) is much smaller (about 2-3x) and faster than that for JPG. PNG
is somewhere between.
Regards,
David Davies
http://www.intadev.com
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Received on Fri Oct 19 11:08:56 2001