JPEG: Difference between revisions

Revision as of 21:27, 16 December 2008

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-JPEG is [http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=18902 international image stadard]. It's lossy standard good for photographs. You can reduce image size many times without apparent quality loss!
-Since OLPC has limited storage it looks like a good to use JPEG whereever poossible. But in reality it's pretty dumb idea. When you are saving JPEG you are choosing between <u>good quality, medium-sized files</u> and <u>poor quality, small files</u>. You <b>can not</b> open and resave JPEG without quality loss (there are no loseless JPEG unless we are talking about [[JPEG 2000]]) - except in a few special cases. So it's not a good idea to use this format for intermediate images! Use [[PNG]] or [[JPEG 2000]] instead. Also it's not a good idea to put artwork in JPEG files (you can always overlay artwork with usage of [[SVG]]).
-Authors of OLPC should use JPEG for photographs - and usully just for photographs. Use [[SVG]] and [[PNG]] for artwork, [[PNG]] and [may be] [[JPEG 2000]] for intermediate images.
-There is a page on [[choosing image formats]] that will help you to understand the differences and how to know which format will be best for the intended use.
-More info can be found on [http://en.wikipedia.org/wiki/JPEG Wikipedia].
-[[Category:File formats]]