The importance of 8-bit vs 16-bit per channel

[Klaus Nordby]

It seems that all too few digital people understand the crucial difference between working in 8-bit vs 16-bit per channel - hence this simple little test, to conclusively demonstrate it.

This image (in max. JPG quality - no artifacts) shows four layers of overlapping gradations, from white to light gray, set to merge in Multiply mode. The top version is done in Picture Publisher 10 in 16-bit grayscale mode - the combined gradations are smooth as silk. But the bottom version is done in Photoshop 6 in 8-bit grayscale mode - and the combined gradations shows very bad banding. But while PS6 does allow for working with 16-bit files, it does NOT allow for using layers - hence ALL layering work in Photoshop is doomed to be plagued by such banding problems! The same goes for XaraX and all other programs which are only 8-bit per channel. (Working in 24-bit color does not change this one iota: it's the bit depth of the channels which count.)

Thank goodness for PictPub 10!

At a time when every $100 scanner now can scan in high-bit mode, almost all our software is still mired in the ancient, crude 8-bit world! I shout in despair at the heavens: WHEN are the software companies going to address this grave problem?!?!?

K
www.xaraxone.com/FeaturedArt/kn/
www.klausnordby.com/xara

[Klaus Nordby]

It seems that all too few digital people understand the crucial difference between working in 8-bit vs 16-bit per channel - hence this simple little test, to conclusively demonstrate it.

This image (in max. JPG quality - no artifacts) shows four layers of overlapping gradations, from white to light gray, set to merge in Multiply mode. The top version is done in Picture Publisher 10 in 16-bit grayscale mode - the combined gradations are smooth as silk. But the bottom version is done in Photoshop 6 in 8-bit grayscale mode - and the combined gradations shows very bad banding. But while PS6 does allow for working with 16-bit files, it does NOT allow for using layers - hence ALL layering work in Photoshop is doomed to be plagued by such banding problems! The same goes for XaraX and all other programs which are only 8-bit per channel. (Working in 24-bit color does not change this one iota: it's the bit depth of the channels which count.)

Thank goodness for PictPub 10!

At a time when every $100 scanner now can scan in high-bit mode, almost all our software is still mired in the ancient, crude 8-bit world! I shout in despair at the heavens: WHEN are the software companies going to address this grave problem?!?!?

K
www.xaraxone.com/FeaturedArt/kn/
www.klausnordby.com/xara

[photoman]

If you select the option of dithering when making your gradients, the banding will not be as bad. Now on the other hand if you add just a little noise on top of that. It will elimate the effect of banding. That's if you select the dithering option before hand. I have made many different gradients this way with layer and without and do not have this problem like your having. Just my 2 cents worth.

[img]/infopop/emoticons/icon_smile.gif[/img]

Wait I'm not done yet! Ok, now I'm done.

[Klaus Nordby]

Photoman, I know, I know all about dithering and noise - that is how I have always semi-managed to circumvent my 8-bit banding woes. But there are many other 8-bit problems which can not be overcome in this way. My post is meant to ***pinpoint*** this problem - to show the general unsatisfactoriness of the 8-bit world. And also to praise PictPub - a much-underrated program - for letting me finally overcome this problem.

K
www.xaraxone.com/FeaturedArt/kn/
www.klausnordby.com/xara

[photoman]

Have you written Adobe about this problem? Maybe there working on the issue. I was not trying to criticize your statement, just trying to offer a remedy to the problem you were having. That's all I was trying to say. [img]/infopop/emoticons/icon_smile.gif[/img]

Wait I'm not done yet! Ok, now I'm done.

[mike engles]

Hello

Yes Picture Publisher was always very good.
That is up to version 5.
Since then it was downhill. The main problem was that it's objects could not act as layers.
In Photoshop you can lock/unlock the layer transparency,giving it huge flexibility.
PP never managed this. I beta tested PP8 and remember asking the development manager for a layer ability in PP. They never managed it.
CorelPaint originally worked just like PP, but they managed to give it both object and layer abilities.

PP is now to all intents an purposes dead, taken over by Corel.

PP was never were able to compete with Photoshop, even though it was very innovative.

Very sad.

Mike Engles

[Klaus Nordby]

The "objects" largely work like "layers" - I have no problems with them, especially since PP10 both reads and writes PS6 PSD files (though the PS Layer Effects are not supported). Yes, it would be said if the Corel deal would totally kill off PicPub - but even if it does, owning this version will help me a LOT!


K

K
www.xaraxone.com/FeaturedArt/kn/
www.klausnordby.com/xara

[s.winders]

Klaus its official there will be no 16 bit functionality in PS 7 [img]/infopop/emoticons/icon_rolleyes.gif[/img]


Here is a reply to the question of 16 bit layers from Jeff Schewe on the Adobe users group.


------------------------------------------------------------------------
Jeff Schewe - 09:15am Feb 24, 2002 Pacific (#5 of 52)

Jim,

Nothing more for 16 bit this version I'm afraid, but tons of new workflow capability. The Healing Brush does work in 16 bit as well as the new Auto Color command (which actually works rather well).

Those of us who really want more 16 bit functionality need to make a lot of noise about more functionality in future versions. But believe me when I say the engineers where very busy on the 7.0 feature set as it was, so we'll just need to keep asking till they hear us.

---------------------------------------------------------------


Stu.

[gidgit]

Just a thought...doing the grey thing in 24 bits and saving as png is a smaller file size as well the gradient is smooth...trry it, you'll love it, in fact this is the prefered file for all things gradient yes? [img]/infopop/emoticons/icon_smile.gif[/img]

Of course I could be way off base here in what you are looking for and this would not be a first for me... [img]/infopop/emoticons/icon_smile.gif[/img] [img]/infopop/emoticons/icon_smile.gif[/img]

[Klaus Nordby]

Gidgit, I fear you're way off base here! But, luckily, you have practice. :-)

K
www.xaraxone.com/FeaturedArt/kn/
www.klausnordby.com/xara