In general: PNG is lousy for photographic stuff. It will be very large for continuous=20 tone images because it can do little, if any, compression. JPG is lousy for line art stuff. It will generate weird looking artifacts=20 around high contrast areas of the image. Horses for courses. -- Bob Ammerman RAm Systems ----- Original Message -----=20 From: "peter green" To: "Microcontroller discussion list - Public." Sent: Tuesday, April 24, 2012 8:52 PM Subject: Re: [OT] My Raspberry Pi has arrived. > cdb wrote: >> On Wed, 25 Apr 2012 00:37:23 +0100, peter green wrote: >> :: Why the heck were you trying to do that? JPEG is a perfectly >> :: acceptable format >> >> To attach to an email to post here I need it as small as possible, PNG >> tends to do that > Not for photos it doesn't. PNG compression is simply not optimised for > photographic images and tends to produce relatively low compression > ratios on > them. > > If you need to make a photo smaller and still keep it accessible to most > people > you have basically to choices, lower the resoloution or lower the jpeg > quality > setting. >> - doesn't solve th eproblem why Windows Paint, Windows >> Photo Manager all manage to convert jpg to png and manage to make it an >> order or two of magnitude larger. > Doesn't sound too unreasonable for me. You may find different png encoder= s > vary a bit but i'd be very surprised if any of them come close to the > size of the > original JPEG. > --=20 > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist=20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .