1 May 2011 02:18
Png vs Jpg
Tom Davies <tomdavies04 <at> yahoo.co.uk>
2011-05-01 00:18:33 GMT
2011-05-01 00:18:33 GMT
Hi :) Yes, true. Png is 'lossless compression' whereas Jpg is lossy but Png is still compressed and Gimp can set the compression rate. Jpg often introduces strange artifacts (like ripples or the wake from a boat) which can inflate file-size! You see this a lot on badly done logos or images that have been manipulated while being jpgs (eg heavily cropped and re-sized), I have seen Pngs suffer a little at extreme rates of compression but Jpg compression is far worse even at low levels of compression. There are some clever ways of reducing Png sizes so that they can compete favourably with Gifs for things like logos and simple stylised images. I've seen very light Pngs that have very low colour range. say only 2 or 3 colours and no shading or blending. The corresponding jpgs have been very much heavier and looked messy whereas the png stayed clean. Regards from Tom :) ________________________________ From: Isaac Hummel <isaac <at> daedaleus.com> To: users <at> libreoffice.org Sent: Sat, 30 April, 2011 21:04:55 Subject: Re: [libreoffice-users] exported PDF file size On 04/30/2011 03:33 PM, Tom Davies wrote: > PS. Png is also set to take over from Jpg as it also handles larger images > better and again Jpg is a proprietary format (i think).(Continue reading)
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