1 2 3 Previous Next 114 Replies Latest reply: Sep 3, 2012 6:19 PM by Hudechrome Go to original post RSS
      • 40. Re: Weird Crop tool behaviour with 16-bit files
        Chris Cox Adobe Employee

        And byte order reversal was actually my guess as to the cause - but I need to reproduce it and then figure out where in the pipeline it gets messed up.

        • 41. Re: Weird Crop tool behaviour with 16-bit files
          Paulo Skylar Community Member

          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:Capture4.PNG

          Paulo

          • 42. Re: Weird Crop tool behaviour with 16-bit files
            Noel Carboni Community Member

            Good trick.  But here, no red.

             

            NoRed.jpg

             

            Only with extreme enhancement does the issue show.

            SomeRed.jpg

             

            -Noel

            • 43. Re: Weird Crop tool behaviour with 16-bit files
              Paulo Skylar Community Member

              Noel,

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

              Strange!

               

              Paulo

              • 44. Re: Weird Crop tool behaviour with 16-bit files
                Noel Carboni Community Member

                Summarizing the two (or more) issues...

                 

                Problem root: 

                 

                • In 16 bits/channel mode, something in the pixel math during an arbitrary canvas rotation appears to be causing a loss of precision in the transparency mask for a layer, resulting in fully opaque pixel values (0x8000) being changed for some pixels to be one or several levels smaller.

                 

                • The error/inaccuracy appears as a repeating noise-like pattern or something that looks a bit like suit pin-stripes (on different systems).

                 

                • It's not a certainty that the noise-like pattern and the pin-stripes pattern are one and the same issue, but it seems likely.

                 

                 

                Visibility of miniscule transparency differences:

                 

                • On some systems, but not all, the slight inaccuracy in the transparency mask becomes visible, where it clearly shouldn't be seen.  It needs to be verified whether transparency works otherwise normally on such systems.

                 

                • It's interesting that we've heard from ATI users and nVidia users, Mac users and PC users.  Amongst the ATI PC users, some see it and some don't (possibly a video driver version issue).

                 

                -Noel

                • 45. Re: Weird Crop tool behaviour with 16-bit files
                  erickellerman Community Member

                  This is fascinating, but has actually become too technical for me. My question is, is this now a Photoshop problem that needs solving, or is it just my and others' bad luck?

                  • 46. Re: Weird Crop tool behaviour with 16-bit files
                    Noel Carboni Community Member

                    The first of the two is almost certainly a Photoshop problem.  The other may be rooted in how Photoshop is using particular video cards, or maybe a bug in your display driver that may be able to be solved by seeking an updated version and downloading/installing it from the web site of the maker of your video card.  It certainly seems that some people have display subsystems that don't show the problem.

                     

                    In either case you have the attention of one of the more senior Adobe engineers, so there's not much else you need to do to get Adobe working on it.

                     

                    Something to try as a test:  Go into your Preferences - Performance dialog, select the [Advanced Settings...] button, change the Drawing Mode to Basic, then quit and restart Photoshop.  Do you still see the problem, and do you still have all your GPU-accelerated functions?

                     

                    -Noel

                    • 47. Re: Weird Crop tool behaviour with 16-bit files
                      erickellerman Community Member

                      Thanks for all your trouble, Noel. And thanks to Chris too.

                       

                      I did your test, and find that I do not get gentlemen's suiting patterns using Basic Mode.

                      • 48. Re: Weird Crop tool behaviour with 16-bit files
                        Noel Carboni Community Member

                        Hm, that may imply that the GPU-resident color-management code is the place for Adobe to look for the root of the bug.

                         

                        -Noel

                        • 49. Re: Weird Crop tool behaviour with 16-bit files
                          Chris Cox Adobe Employee

                          I'm more worried about the GPU transparency visibility issue than the small errors in interpolation (which we'll get to later).

                           

                          But I'm running the same machine, video card and OS as one of the users, and can't reproduce the problem.  What are we missing?

                          • 50. Re: Weird Crop tool behaviour with 16-bit files
                            Noel Carboni Community Member

                            Chris Cox wrote:

                             


                            But I'm running the same machine, video card and OS as one of the users, and can't reproduce the problem.  What are we missing?

                             

                            Advanced Photoshop GPU settings? Different display resolution (a stretch, I admit)?

                             

                            I was going to say double check the display driver version, but assuming you're talking about a Mac, that's covered by the OS version being the same.

                             

                            -Noel

                            • 51. Re: Weird Crop tool behaviour with 16-bit files
                              Paulo Skylar Community Member

                              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

                              • 52. Re: Weird Crop tool behaviour with 16-bit files
                                Noel Carboni Community Member

                                FYI, I've been testing in Advanced mode and don't see the problem.

                                 

                                -Noel

                                • 53. Re: Weird Crop tool behaviour with 16-bit files
                                  Chris Cox Adobe Employee

                                  OK, that means that the issue is related to the color transform shaders in OpenGL. (converting from document colorspace to display colorspace)

                                  • 54. Re: Weird Crop tool behaviour with 16-bit files
                                    conroy Community Member

                                    There seems to be a problem with transparency in relation to image resampling. Not only image rotation is affected. Up-sizing is, too.

                                     

                                    Up-sizing 16-bit images with Bicubic Smoother (or Bicubic Sharper) and Bicubic Automatic (which will use Smoother when up-sizing, of course) causes a grid pattern in the transparency of the layers' pixels (except Background which has no transparency, of course).

                                     

                                    The Info panel's Opacity readout is in whole percentage units, so it is no aid in examining this phenomenon. Use "Layer > Layer Mask > From Transparency" then copy the mask's pixels and paste as a new layer. That'll provide the transparency values as an examinable and adjustable image.

                                     

                                    Invert that transparency image then boost exposure, e.g. +16, to see the pattern clearly.

                                     

                                    Different scaling factors produce different patterns. The example below was up-sized to 900%.

                                     

                                    Background isn't affected, of course, since it never has transparency.

                                     

                                    Screen-shot-2012-06-30-at-16.23.53.png

                                    • 55. Re: Weird Crop tool behaviour with 16-bit files
                                      Chris Cox Adobe Employee

                                      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.

                                      • 56. Re: Weird Crop tool behaviour with 16-bit files
                                        Noel Carboni Community Member

                                        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

                                        • 57. Re: Weird Crop tool behaviour with 16-bit files
                                          conroy Community Member

                                          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.

                                          • 58. Re: Weird Crop tool behaviour with 16-bit files
                                            Chris Cox Adobe Employee

                                            Try changing the GPU level in preferences, I'll bet the artifacts disappear in basic but show up in normal or advanced (posts 51 and 53).

                                             

                                            Then we need to know your GPU and make sure you're using the latest driver.

                                            Then from that we can try to reproduce the error.

                                            • 59. Re: Weird Crop tool behaviour with 16-bit files
                                              MikeKPhoto Community Member

                                              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

                                              • 60. Re: Weird Crop tool behaviour with 16-bit files
                                                conroy Community Member

                                                Chris Cox wrote:

                                                 

                                                Try changing the GPU level in preferences, I'll bet the artifacts disappear in basic but show up in normal or advanced (posts 51 and 53).

                                                 

                                                Then we need to know your GPU and make sure you're using the latest driver.

                                                Then from that we can try to reproduce the error.

                                                 

                                                That's right, the tiny transparency errors do not result in visible artefacts when the GPU level is "basic".

                                                 

                                                GPU is NVIDIA GeForce 320M in a mid-2010 Mac Mini running OS X 10.6.8 Snow Leopard with whatever driver is the most recently provided by Apple for that system.

                                                • 61. Re: Weird Crop tool behaviour with 16-bit files
                                                  conroy Community Member

                                                  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.

                                                  • 62. Re: Weird Crop tool behaviour with 16-bit files
                                                    Chris Cox Adobe Employee

                                                    It's weird that the error shows up in multiple GPU brands, but not with all driver versions.

                                                    It still seems to be in the shaders that convert color for the display, but I'll have to check with the GPU guys to see why it is so hit and miss.

                                                    • 63. Re: Weird Crop tool behaviour with 16-bit files
                                                      Paulo Skylar Community Member

                                                      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

                                                      • 64. Re: Weird Crop tool behaviour with 16-bit files
                                                        conroy Community Member

                                                        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 get the glitch in both CS6 and CS5.1 (Ps 12.1).

                                                        • 65. Re: Weird Crop tool behaviour with 16-bit files
                                                          Noel Carboni Community Member

                                                          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

                                                          • 66. Re: Weird Crop tool behaviour with 16-bit files
                                                            Chris Cox Adobe Employee

                                                            >> Catalyst 12.2 did NOT do this, 12.6 DOES do this.

                                                             

                                                            Two steps forward, one step back. Sigh.

                                                            • 67. Re: Weird Crop tool behaviour with 16-bit files
                                                              Paulo Skylar Community Member

                                                              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

                                                              16_cs6_hm.png

                                                               

                                                              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

                                                              • 68. Re: Weird Crop tool behaviour with 16-bit files
                                                                erickellerman Community Member

                                                                I can confirm your finding, Paulo.

                                                                • 69. Re: Weird Crop tool behaviour with 16-bit files
                                                                  Paulo Skylar Community Member

                                                                  Erickellerman,

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

                                                                   

                                                                  Paulo

                                                                  • 70. Re: Weird Crop tool behaviour with 16-bit files
                                                                    Noel Carboni Community Member

                                                                    I think that's because the new Photoshop default for resampling is Bicubic Automatic.  Worst idea Adobe ever came up with.

                                                                     

                                                                    Try changing your default upsampling scheme to just plain Bicubic, Paulo.  The problem goes away entirely.

                                                                     

                                                                    Bicubic.png

                                                                     

                                                                    As to why the channels show white instead of black, it's pretty clear they're using a cache level because they're so small, which causes the math to switch to 8 bit for layer compositing.  You want to eliminate THAT disparity, change the cache levels to 1 and GPU mode to Basic, which causes all layer compositing for displays to be done in the full 16 bits.

                                                                     

                                                                    -Noel

                                                                    • 71. Re: Weird Crop tool behaviour with 16-bit files
                                                                      Hudechrome Community Member

                                                                      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

                                                                      • 72. Re: Weird Crop tool behaviour with 16-bit files
                                                                        Hudechrome Community Member

                                                                        Looks like I am the contrarian here.

                                                                         

                                                                        Paolo, I cannot reproduce your effects. The image here is the 550px upsample with the settings shown superimposed over the black supposedly crosshatched set to fill screen.

                                                                         

                                                                        I've run the test over and over with no difference in outcome. Use Graphics Processor is checked, Advanced Mode . Cache set at 4. Paolo test.JPG

                                                                        • 73. Re: Weird Crop tool behaviour with 16-bit files
                                                                          Noel Carboni Community Member

                                                                          8 or 16 bits, Lawrence?

                                                                           

                                                                          Was the fill color 128, 128, 128?

                                                                           

                                                                          -Noel

                                                                          • 74. Re: Weird Crop tool behaviour with 16-bit files
                                                                            Hudechrome Community Member

                                                                            Interesting.

                                                                             

                                                                            1) 16 bit

                                                                             

                                                                            2 ) Fill color set to 50 using LAB, corresponding to 100, 100,100.

                                                                             

                                                                            However RGB in Color Settings set to ProPhoto

                                                                             

                                                                            If I set it to sRGB and use RGB to set gray, at 128 128 128, now I get pure white.

                                                                             

                                                                            In fact, I get pure white with a variety of RGB settings except for 100 100 100, where it is pure black, ProPhoto or sRGB. The correspondence to L in Lab changes, depending on the Color Settings.

                                                                             

                                                                            You can check this easily by selecting each fill layer  Thumbnail on the layers palette and  proceed to change both layers to the same value. It's interesting to set each layer differently as well, but the only outcome to be pure black has 100 100 100 in either layer. IOW, if 100,100,100 is set on only one layer, the other can be anything and I get black.

                                                                             

                                                                            The bottom line is I get wither pure white or pure black. No crosshatch.

                                                                             

                                                                            ???

                                                                            • 75. Re: Weird Crop tool behaviour with 16-bit files
                                                                              Noel Carboni Community Member

                                                                              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

                                                                              • 76. Re: Weird Crop tool behaviour with 16-bit files
                                                                                Hudechrome Community Member

                                                                                It would be interesting to see if you validate my results after doing so.

                                                                                 

                                                                                Tom's HW gives it a best buy and it doesn't require aux pwr connection. Runs at about 55W full throttle.

                                                                                • 77. Re: Weird Crop tool behaviour with 16-bit files
                                                                                  Noel Carboni Community Member

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

                                                                                   

                                                                                  -Noel

                                                                                  • 78. Re: Weird Crop tool behaviour with 16-bit files
                                                                                    Hudechrome Community Member

                                                                                    I did too, even the 7950, but then I saw the price....

                                                                                     

                                                                                    I paid $109 for the 7750.

                                                                                    • 79. Re: Weird Crop tool behaviour with 16-bit files
                                                                                      Paulo Skylar Community Member

                                                                                      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