Richard, you’re correct, the higher the number, the better the quality and the larger the file size. With respect to the comparison between a 10 and a 12, you won’t be able to see it on the screen; you might be able to see it on a print. A further caution: what makes the file size differ in JPEG’s is the amount of compression that the file undergoes; the more compression, the smaller the file – and the more likely that the image will degrade if you open it, edit it, and then save it again as a JPEG. Recommendation here is to save your edited images in PSD or TIF format while the editing process is ongoing.
Hope that helps.
Chuck
Check this out>> from my XP booklet;
PNG; This is a relatively new file format that is becoming more and more popular on the internet ( although it’s still not supported by all browsers). It’s a versatile format that can be used with both sim[ple drawings and photos. PNG supporst compression to keep images relatively small and unlike JPEG the PNG compression doesn’t reduce the quality of the image.
SO WHY AREN’T WE ON THE PNG BANDWAGON YET !!!!!!
??????????????????????????????
Jodi, the contention that PNG compresses but doesn’t reduce image quality sounds like a dose of snake oil…..
🙂
Well, that is just it….does it or doesn’t it. Seems the world is stuck on JPEG for web and we don’t hear anything about the future of PNG. You say my book by Paul McFedries lies ?
I’ll be off for a little while…but I’ll be back…I’d like to get to the bottom of this !
there.
Well, Jodi….maybe it’s for real:
PNG is a lossless image compression format. Simply put, when you compress an image using this format the compressed image retains the same quality of the original. Using the PNG format has several advantages over using GIF. PNG images are richer than GIF because it supports more colors than GIF and it also supports a more complex image transparency method. PNG compressed images also contain authoring platform information. This means that viewing software on different hardware platforms (i.e. IBM compatible PC, Macintosh) will render the image correctly. Since SitePen strives to create cross-platform compatible Web solutions, we prefer technologies that help us meet this goal -the PNG format, as it is supported by nearly all recent Web browser versions, is one such technology.
(from sitepen.com)
A ha ! So … perhaps we can get the ball rolling by having our challenge images sent to Grant in PNG format ??? …Just to see if everyone can view…that would be a step in the right direction. yes ?
wrote in message
our challenge images sent to Grant in PNG format
Jodi
I will spank you if I can catch you! Bite your tongue for such an evil suggestion.
g.
Grant, be careful!
Some people seem to love spanking.
😉
Leen
Leen
I thought that was only a British thing, with all the public schooling! Then again the Dutch are marvellously open minded individuals. Fore me I don’t
knock anything I haven’t tried so I will keep quiet on this subject.
g.
oh I’m sorry Grant. I guess your proggy wont take PNG will it ?
Jodi, I think Grant is telling us that PNG is NFG…
What ? No %$#@*&^ good ? Chuck, is that the mouth you drink with ?
Grant, pleeze esplane.
Jodi, how COULD you misinterpret my acronym?? NFG is Not For Grant…
😉
OK Chuck, you managed to crawl out of that one real good. I’ll give it to you. What does that say about me ? Oh gosh. Cabin fever is not good.
Meanwhile, back at the ranch, I’ve been running some numbers. I took a simple diagonal (orange to yellow) gradient on a 1600×1200 canvas, then used PSE2 to save same in a bunch of different formats. PSE2’s "Save as …" JPEG options are not set up the same way as the "Save for WEB …" JPEG options (go figure!).
13045 1_web_10.jpg
13377 1_web_30.jpg
30578 1_web_60.jpg
46813 1_web_80.jpg
50494 1_03.jpg
50731 1_05.jpg
79781 1_08.jpg
93243 1_10.jpg
170672 1_web_100.jpg
307075 1_12.jpg
1058204 1_ZIP.tif
1120762 1.png
1152756 1_LZW.tif
3243196 1.pct
3263246 1.psd
5776272 1.tif
JPEG degradation was noticable at anything below 50% or Medium quality.
Kyle
Edit: 1.psd was the original file
K
Jodi
Oh I have no trouble with PNG it is just all those browsers out there will not be able to see the image. Well not all but the majority of them. PNG is a good idea who’s time has not come and maybe its time will never come as not all good ideas fly. Fore me to receive anything but a JPG or GIF requires me to do more work.
g.
