If you want a dramatic visual of the effect Noel, set the blend mode of the "all black" layer to Vivid Light and place a color fill layer beneath. Something like this:

Paulo

Noel,

Indeed, the effect on your system is much weaker. I also see no pattern in the unadjusted image .

Strange!

Paulo

Two pieces of information I failed to mention previously: The transparency visibility problem occurs on my system (PC, Nvidia, CS6) with either Normal or Advanced GP drawing modes enabled. It does not occur with the Basic mode setting. Using the same system but running CS4, the problem does not present.

Paulo

Chris Cox wrote:

 

You're showing low bit errors -- that is a minor problem, made visible only by extreme adjustments.

We'll get that fixed when we can.

 

This topic is talking about a major problem that makes low bit errors visible on some GPUs when they should not be visible.

We need to get a reproducable case of this so we can figure out where the bug is (in Photoshop, in the driver, etc.) and get it fixed.

OK, I didn't realise that you'd already determined that some resampling is creating errors in low bits of transparency values in 16-bit mode. That's why I presented an extreme adjustment of the transparency values extracted to an image.

Yes, here the transparency errors are visible without adjustment when affected layer dark pixels are viewed over a bright Transparency Grid. I'll get more info together.

Chris, just as an FYI A see the same issue with the Intel 4000 driver latest but not the Beta Version. I do not see the "suit" but the same artifacts in the second image as shown in Post 38.

Hope this helps you track the issue

Cheers

MK

Noel Carboni wrote:

 

Paulo or anyone experiencing the visibility of the transparency glitch...  Does transparency otherwise seem to work normally?

 

It's almost hard to picture how it could, but I'm guessing it must or more major problems than this would be reported.  It's almost as though the LS byte inaccuracy is getting combined into the MS byte.

 

-Noel

Yes, transparency is normally OK. The glitch seems only to be a display artefact involving blending of the Transparency Grid with partially transparent image pixels.

Noel Carboni wrote:

 

...  Does transparency otherwise seem to work normally?

 

 

Noel,

A qualified yes! That is, nothing has presented itself that suggests any other problem with transparency. On the other hand, I have not run through a series of tests looking specifically for transparency problems.  Also, I have seen no transparency issues, including the one that is the subject of this thread, in CS4 on the same hardware with the same drivers.

I may take a closer look if time permits.

Paulo

FYI, I've just updated to ATI Catalyst 12.6 released drivers, and now I see the slight transparency glitch expressed without extreme enhancement.

Summarizing:  Catalyst 12.2 did NOT do this, 12.6 DOES do this.

-Noel

There seems to be yet another problem, or a related one, with the 16-bit mode in CS6. Rather than put this observation into

a new thread it will remain in this one as I happened across it while dealing with the transparency issue discussed above.

I have been visualizing the problem in the transparency channel using layer blending modes rather than by using extreme adjustment layers - not for any good reason other than it seemed a bit easier for me to do.  My recent favorite procedure to create and visualize the problems of16-bit interpolation artifacts and those artifacts spilling into the transparency channel  has been to create a 100x100 pixel document and fill it with 50% gray. Using the image size  command the document is upsampled to 550x550 pixels and that larger image looks normal to the unaided eye - uniform medium gray.. That layer is then duplicated (Ctrl+J) and its blending mode is changed to hard mix. Voila, you have a dramatic rendering of the 16-bit mode problems. as shown here

The new problem is that I do not think that the layer math should be revealing the problem.  If I execute the same process in 8-bit mode I get an all-white result, which is what I expect it to be. To eliminate the interpolation and transparency issues I made a new document 550x550 pixels, filled it with 50% gray, did NO scaling, duplicated it and changed the duped layer's blend mode to hard mix. The result is an all black image - again, not what one would expect.  If I look at each of three component channels they are each all white, but the composite channel view is black. What's that all about ?

So the 16-bit mode in cs6 has interpolation problems, transparency channel problems and blend mode problems.  I am not going to search for any other issues nor will I just happen upon any other malfunctions as I am now finished using 16-bit mode in CS6 until these issues are resolved, hopefully in the first update.

Paulo

Erickellerman,

Good, it's always good to know one's results are not unique .

Paulo

Since the problem resolves by going to 8 bit, and since I deliver my work to the client as 8 bits, it doesn't make a whit of difference. Also, printing is still 8 bit so I don't see any problems there either.

I did generate the pattern as outlined by the OP. I am running an Sapphire 7750, driver vers 12.6. I can see the problem clearly just eyeballing it at 100% The quality of the artifacts appears to be related to the Straighten angle; at 16.8°, it appears as an interferometer pattern. Changing to 8 bits clears it up, and turning off the GPU in Prefs also eliminates the problem.

I know that there are still driver problems or at least the driver seems to be able to be corrupted if I use Sleep Mode. That has been fixed by reinstalling the driver and turning off Sleep. (It is a desktop, not a laptop).

There seems to be no difference between 12.2 and any other driver for this card, afaik, at this time.

I am eyeballing the black image only at this time. No tweaks to exaggerate the patterns.

Edit: FYI, I'm running a PC, Win7 64 Ultimate.

The PC consists of a Asus M4A77TD mobo, Athlon IIx4 630, cpu stock speed,12G Ram

Video Driver version atiumdag 8.98.0.0

Message was edited by: Hudechrome

8 or 16 bits, Lawrence?

Was the fill color 128, 128, 128?

-Noel

Are you using Bicubic or Bicubic Automatic for the resampling?

If Bicubic Automatic, I guess I need to get one o them new fangled 7000 series video cards then. 

-Noel

I've actually got my eye on the 7850, Lawrence. 

-Noel

I finally got around to dealing with your posting Noel, sorry for the delay.

For the example I presented you have found a good workaround in choosing bicubic for resampling. My goal, of course, is not to find work arounds but to generate more information to help Adobe fix any related issues. Also, if I changed the example process from scaling up the mid-gray square to let's say transforming the square to a 45 degree rotation of itself (everything else being the same) then the problem is present even with bicubic resampling for the transformation.

Changing the cache levels to 1 is not  that good a work around for me as it completely turns off caching and thus affects the performance of other operations. It's a good piece of diagnostic information that you have uncovered and I hope it quickens an adobe repair. In the meantime I remain wary of using 16-bit mode in CS6.

Paulo