Question about JPEG compression...

[Feynman]

I will be putting up 800x600 and 1600x1200 pics on my web site.

I made tests with Photoshop 7 and Advanced JPEG Compressor.

I find that the Photoshop 7 "Save for Web" gives very similar results than AJC, unless I tweak it to death, and then, I get about 1-2% less size.

For the 800x600, I get sizes ranging from 48k to 97k depending on the quantity of details that there is in the picture.

For 1600x1200, I get approx 143-250Kb

(photoshop 7 save-for-web settings: quality 20, optimize)

I'm wondering if there is not a way to get better compressors without loosing image quality.

What are your prefered file size for images of size:
800 x 600 :
1024 x 768 :
1600 x 1200:
2048 x 1536:


Suggestions / comments anyone ?

[Mister X]

I don't think you are going to get any better results than you will get with photoshop without spending 5 mins to save each picture. I usually am happy if the size for 800x600 is somewhere in the 80 to 100 k range. For 1024 pics I'm happy with 120 k or so. Mostly I think there's a point where the bandwidth savings are going to be outweighed by the manpower used to get those savings. You can't reliably use batch processing on jpegs unless you use fairly generic settings or you end up with some pretty shit quality pics at times. Most of the pics I use on our sites are resized in Arles when I build the galleries. I review them beforehand and dump the bad pics and do the rotating in acdsee or compupic and then let arles do the rest. It does a good job of watermarking, resizing and making the thumbs and html all in one and saves me a shitload of time. In Arles I use a setting of 80 and don't use any of the filters and end up with good quality and decent filesize.

[GOD]

20 Quality on a full size pic ?? :eek: Good me Man !!

A JPEG image quality of anything less than 60 on a full size pic is just SACRELIGIOUS !! :(

Like MisterX says ... the man hours sacrificed for 1-2% better filesize is definately NOT worth it ! You'd be much better using that time on more productive tasks.

[wsjb78]

I normally use ThumbsPlus to create thumbs and I'm content with file size / quality

[EZKash-charlie]

http://www.spinwave.com/crunchers.html

i use the crunchers.. cheap and work great

[Feynman]

Originally posted by Mister X
I don't think you are going to get any better results than you will get with photoshop without spending 5 mins to save each picture. I usually am happy if the size for 800x600 is somewhere in the 80 to 100 k range. For 1024 pics I'm happy with 120 k or so.

Yup. I made extensive tests, compared many images side by side, using Advanced JPEG Compressor (you can tweak just about *anything*) and PS7 and I got to the conclusion that PS7 gives more consistent results, with only a very slight quality penalty.

I also use ACDSee 6 for quick viewing (image selection) and batch renaming.

I do all my batch color correction, resizing and all in ThumbPlus 4.5 (my fave of all time, except for batch renaming and convenience of display).

I did my cropping in Photoshop because I wanted to stick to the 4:3 ratio, but I decided to change that for the new upcoming picsets because I'll be moving more toward glamour than stock porn images.

Either I'll crop to whatever ratio the pic requires, of I won't crop at all.


My camera shoots in the 3:2 ratio and I found it rather annoying to have to crop thousand of pics, AND to shoot them with the future cropping in mind, so now, I'll push mostly 3:2 pics and I'm shooting with the finished product in mind. What I see in the viewfinder is what they'll get.

Another thing. My pics were too sharp, thus generating too large a file size.

I compared my images side by side with the industry's reference in sharpness, Suze Randall, and I found that I was pushing overly sharp pictures for nothing. So I increased the blur to 0.15 to .2 in PS7 Save-for-Web and file size/quality ratio got more acceptable (less artefacts).

Thanks for your comments.

As for God, where is He with *unequivocal* and *practical* knowledge when I need him ?

I've been looking for him for days and days and never found him.


Mind you... More probably, I'd have him at my kitchen table, passing him the milk for the morning cereals and I'd not even recognize him...

I'm faithless. :D

[Carrie]

Feyn I did tests like that amongst a bunch of different programs as well and the one I like best is Arles Image Web Creator - especially the thumbs. Super crisp but still small file size. Only thing that was better at the same level of compression was Paint Shop Pro as far as picture quality goes, but the file size was much higher.