Jump to content
WnSoft Forums

P2E and Calibrated Monitors


smb804

Recommended Posts

Is P2E ignoring the colour calibration when we have ATI graphics cards is the question?

It looks therefore that P2E is ignoring the calibration data.

Its not that PTE is ignoring the calibration data ... its that the current ATI graphic card drivers are ignoring the calibration data for some reason in the fullscreen Direct 3D mode of the ATI card.

previously from Igor:

Unfortunately it's a bug in ATI drivers for Windows XP. And my headache. ATI ignores color gamma settings in fullscreen mode which you adjusted for desktop.

In several words: slide shows created in PicturesToExe 5 use fullscreen Direct 3D mode and ATI drivers for Windows XP in this mode ignore color calibration which adjusted for desktop.

Ed has basically hit the nail on the head with his "afterthought " ... if you dont use the 3D hardware acceleration checkbox in your slideshow ... your show wont use the fullscreen Direct 3D mode of the ATI card.

Link to comment
Share on other sites

It is definitely the bug in ATI drivers for Windows XP (all is OK in drivers for Windows Vista). I'm sorry, but we only can wait when ATI will fix it (they promissed me). The problem that ATI mistakenly considers DirectX and 3D acceleration as thing intended for games, not for serious purpose. In fact, ATI ignores an important specification - Windows Color Management which should works equally in both modes - desktop and 3D fullscreen mode. I like NVIDIA video cards which perfectly follow by Color management standards.

You may wonder, why ATI video card supports color calibrated display in Windows Vista and doesn't under XP? The answer is simple. Vista uses DirectX and 3D fullscreen mode for the desktop. Because of this ATI had to write correctly their drivers for Windows Vista.

I could feel better and not so tired, if ATI wrote better drivers.

As small consolation, no so many people use color calibration of their displays, usually professional photographers.

Link to comment
Share on other sites

Hi Jeff,

Just a quick reply to your Post above, I apologise for the delay...

Jeff you said:-...."So are you saying - "Don't buy SpyderPro but get the Nokia Test Card program instead? If so, does this depend on adjusting your monitor visually? Because, if so, I have tried that and it is a very subjective adjustment which I was not satisfied with. Also it will not deal with the projector problem".....

Now Jeff I did not say that, nor did I in any way allude to your 'deduction' quoted above...What I said was:- Members are wasting their time with Colour Adjustments if the "Grey Scale" is not calibrated in the 1st instance prior to any other Colourmetric adjustment's. I also said that the PTE Show must be made to a very high quality standard suitable for Projector Usage, which means that Colour Standards must be implimented and 'personal viewing preferences' must be abandoned in order to achieve those Standards for that usage...

Confusion cleared, I hope..

Brian.Conflow.

Link to comment
Share on other sites

Sounds like there are at least two reasons why you may not get the colors from PTE that you expect:

When you use a puck and its software on your display, the software guides you to adjust display settings such as brightness and contrast and it creates a profile file for the display. The profile contains two classes of data: global settings (such as gamma values) to be loaded into your video adapter and tables, coefficients, etc. that programs can use to map colors from an image's color space to the color space of your display. To get the most accurate colors possible on a display, you need to:

1. Run the puck's software to set the display's settings to the right values and create a profile

2. Arrange that the global settings in the profile will be loaded into your video adapter hardware. (The puck's software will typically do this. On Macs, it just has to set the profile as the default profile for the display. On WinXP, it sets up a program to run at startup to do it -- that is why you may see your display color change at some point during startup.) Of course, this assumes that if you load the settings into the video adapter, it will use them. Evidently, some ATI adapters ignore the settings for some or all of the 3D operations that PTE uses. This is the first reason that PTE may not give the colors you expect. As noted in other posts in this thread, turning off 3D can be used to see if this is happening for you.

3. Arrange that when an image is displayed, the RGB values are mapped from the image's color space to the display's color space. That is, for each pixel in the image, a color engine uses the profile that defines the image's color space and the profile that defines the display's color space to map the pixel's RGB value in the image to the RGB value that will produce the same color on the display.

The easy way to achieve #3 is to use a color management aware (CMA) program, such as Photoshop, which is aware of the color spaces of the image and the display and does the mapping on-the-fly whenever it sends the image to the display. Unfortunately, most programs are color management naive (CMN) -- they just send the RGB values from the image to the display. In order to see as-accurate-as-possible colors with a CMN program, you have no choice except to convert the image to the display's profile _before_ presenting it to the program (e.g. make a copy of the image, use Photoshop's Convert To Profile command on it, then give it to the CMN program).

From empirical tests, I have determined that PTE is CMN. (Igor: please correct me if I am wrong.) Thus, the second potential reason that people don't get the colors they expect is that they don't realize that PTE is CMN. For example, you have an AdobeRGB image that looks right when viewed in PS, but not in PTE. The workaround is to convert the image to the display's color space as described above. Similarly for the photo club projector issue: if you are using PTE for your presentation, you should generate a copy of the presentation from images that you converted to the _projector's_ color space. Note: this is what you should do to display the most accurate colors. In practice, just having the display or projector calibrated (that is, the display's settings are properly set and the global settings from the profile are loaded into the video adapter) will often result in acceptable colors. Of course, it depends on how similar the image's color space is to the display's color space.

I hope that a future version of PTE will be CMA so that we will no longer need to have multiple copies of our images.

A third reason you may not get the color you expect is out-of-gamut colors. This is especially likely in the projector case since typically projects have smaller gamuts than computer displays.

Well, I've rambled on enough for now....

Cheers

Karl

Link to comment
Share on other sites

Steve, after upgrading my NVidia video card (7600 GT) and display (23" ACD) my desktop computer calibration works perfectly with PTE 5.0. Still a problem with my laptop ATI card and calibration.

While I do not do photo editing on my laptop, I have this problem only when using video projector used to present the show. Display calibration would be meaningless for video projector anyway. On the other hand, modern projectors have many opportunities to have "internal calibration" via menu.

Link to comment
Share on other sites

Hi Jeff,

Just a quick reply to your Post above, I apologise for the delay...

Jeff you said:-...."So are you saying - "Don't buy SpyderPro but get the Nokia Test Card program instead? If so, does this depend on adjusting your monitor visually? Because, if so, I have tried that and it is a very subjective adjustment which I was not satisfied with. Also it will not deal with the projector problem".....

Now Jeff I did not say that, nor did I in any way allude to your 'deduction' quoted above...What I said was:- Members are wasting their time with Colour Adjustments if the "Grey Scale" is not calibrated in the 1st instance prior to any other Colourmetric adjustment's. I also said that the PTE Show must be made to a very high quality standard suitable for Projector Usage, which means that Colour Standards must be implimented and 'personal viewing preferences' must be abandoned in order to achieve those Standards for that usage...

Confusion cleared, I hope..

Brian.Conflow.

Hi Brian,

Sorry to misunderstand you. Your comments on setting the grey scale and using a colour card, just made me think that you were not in favour of using devices like Spyder2, just when I thought I had got some really good practical advice from Ed. I have been mulling over the whole topic of colour management for ages. Read the books, (sometimes twice) but, until now, have been short on real practical application methods. Calibrating/profiling monitors has been tried in our club before with poor results. Thus there is strong resistance to going down that route which I need to overcome by demonstrating that it really works and is essential if we are to have consistent presentations.

Anyway Brian, thanks as always for your excellent contributions and help you have given me generally. This is a great forum.

Jeff

Link to comment
Share on other sites

Hi Brian,

Sorry to misunderstand you. Your comments on setting the grey scale and using a colour card, just made me think that you were not in favour of using devices like Spyder2, just when I thought I had got some really good practical advice from Ed. I have been mulling over the whole topic of colour management for ages. Read the books, (sometimes twice) but, until now, have been short on real practical application methods. Calibrating/profiling monitors has been tried in our club before with poor results. Thus there is strong resistance to going down that route which I need to overcome by demonstrating that it really works and is essential if we are to have consistent presentations.

Anyway Brian, thanks as always for your excellent contributions and help you have given me generally. This is a great forum.

Jeff

Jeff,

I absolutely agree with you ~ it ain't easy to get this thing right ~ I spent many sleepless nights wrestling with it but eventually got it down to the 'Grey Scale Tests' ~ if they ain't right forget it. However this is dependent on all other things being equal and for those unfortunates who own an ATI Video Card ~ throw it out ~ they won't fix it, they will simply bring out a New Model which remedies the hardware issues.

Had that been a 'Software Fault' they would have created a new 'Driver Set' a long time ago ~ need I say more ??

As to the expertise available on this Forum, it's phenomenal ~ ranging from Software Developers, Program Writers, Pro-Photographers & Musicians to PC Application Engineers and Systems Engineers like myself and all types of Professionals apart from the general body of Forum Members ~ we are a really lucky bunch....

Brian.Conflow.

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...