Strange results with display profile created with Eye One Display

Discussion in 'Photoshop Tutorials' started by Greg, Jan 20, 2004.

  1. Greg

    Greg Guest

    I've just received my Eye One Display, and have calibrated my display for
    D65, gamma 2.2.

    If I open a greyscale wedge in Photoshop 7.01, and assign it the sRGB
    profile, it looks fine.

    If I now assign this profile a D50 profile (ColorMatch), again, it looks
    fine.

    If I now do a soft proof, selecting my display profile as the proof profile,
    with an absolute intent,
    it does *not* look ok - the colour barely shifts at all. It *should* turn
    slightly yellow. (this is what
    happens when I use another D65 display profile, such as sRGB)

    Anyone else notice this kind of behaviour?

    I'm using Eye One Match V2.03A.

    I've double checked that there's no other display lookup table loader
    running, or residing in my Startup folder.

    Greg.
    p.s Will contact Eye One support as well.
     
    Greg, Jan 20, 2004
    #1
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  2. Greg

    Greg Guest

    This *might* be a bug in the Eye One Match software. According to an ICC
    profile inspector utility,
    the profiles always seem to have a white point which appears to be close to
    D50, regardless of the
    white point I selected in Eye One Match.

    As further evidence, if I assign the greyscale wedge sRGB, and do an
    absolute proof to my D65 display,
    it turns blue. All this is starting to add up - the D50 wedge didn't change
    because the white point
    matches the display white point - i.e - both a relative conversion and an
    absolute conversion will appear
    to be identical.

    I am using the Advanced mode of Eye One Match.

    This isn't a good first impression of Eye One Display, assuming that I'm not
    doing something wrong.

    Greg.
     
    Greg, Jan 20, 2004
    #2
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  3. Greg

    Greg Guest

    More evidence:
    I've now tried the beta Little CMS profiler, which actually supports the Eye
    One Display puck.
    This profiler is extremely basic at the moment - it merely profiles the
    display in it's current settings.
    I.e, it does not force the user to adjust brightness, contrast, and try to
    hit a whitepoint target - it
    measures how the display is currently set, and just creates a profile. It
    reports a whitepoint which is
    very close to the whitepoint I entered in to Eye One Match. This means that
    Eye One Match *is*
    allowing me to *calibrate* my monitor correctly - the only problem is in the
    creation of the ICC file
    afterwards. ;^)

    The problem is present in both the version of software I received (V2.0.1),
    and the current version
    available for download (V2.0.3A).

    I have *not* yet tried the "easy" mode of Eye One Match.

    Greg.
     
    Greg, Jan 20, 2004
    #3
  4. Greg

    Greg Guest

    This is what seems to be the case, after speaking with others, and having
    done some more testing:
    1. The Eye One Display profiles comply with the V4 ICC specification, which
    mandates that the whitepoint be exactly D50 for
    displays.
    2. The profiles are entirely usable for normal display
    3. It seems highly likely that the profiles are working fine for Photoshop's
    soft proofing as well. (the appearance matches that of
    a traditional monitor profile, overall.)
    4. At the moment, the profiles do *not* seem to be usable in Photoshop for
    absolute intent conversions, if the monitor is
    calibrated/profiled for a whitepoint other than D50. As an example, if
    one converts from ColorMatch to the non-D50 monitor
    profile, using absolute intent, incorrect pixel values will result.

    Point 3 (soft proofing) was the one which I was most concerned about, and
    I'm really glad that this does seem to work ok.
    I'm not too happy about 4, but it's not nearly as important to me, and I
    suspect, most of us.

    Greg.
     
    Greg, Jan 25, 2004
    #4
  5. Greg

    Flycaster Guest

    If you've found a practical use for absolute colormetric rendering, my hat's
    off to you; with no white point reference, it's been useless to me.

    I hope you're not going through all of this just to get a decent
    screen-printer match. I've built dozens of profiles using Eye-One,
    calibrate my monitor with it, and have zero problems...so I guess I'm just
    really puzzled by your efforts. What are you trying to achieve that has
    practical application?
     
    Flycaster, Jan 25, 2004
    #5
  6. The http://www.color.org/ICC1-V41_ForPublicReview.pdf does not mandate
    that at all.

    You possibly have confused with the whitepoint of the Profile
    Connection Space (PCS) that is completely another issue, it has to be
    D50 and this requirement has been there from the start.

    Color-space conversions are made through the PCS and the requirement
    of the D50 PCS whitepoint does not make any requirements for the
    device whitepoint (mediaWhitePointTag in case the monitor) that is
    just what it measurably is.

    Timo Autiokari
     
    Timo Autiokari, Jan 25, 2004
    #6
  7. Greg

    Greg Guest

    I quote, from that document:
    6.4.25 mediaWhitePointTag

    Tag Type: XYZType

    Tag Signature: 'wtpt' (77747074h)

    This tag, which is used for generating ICC-absolute colorimetric intent,
    specifies the XYZ tristimulus values

    of the media white point. If the media is measured under an illumination
    source which has a chromaticity

    other than D50, the measured values must be adjusted to D50 using the
    chromaticAdaptationTag matrix

    before recording in the tag. For reflecting and transmitting media, the tag
    values are specified relative to

    the perfect diffuser (which is normalized to a Y value of 1,0) for
    illuminant D50. For displays, the values

    specified must be those of D50 (i.e. 0,9642, 1,0 0,8249) normalized such
    that Y = 1,0.

    See Annex A for a more complete description of the use of the media white
    point.

    Greg.
     
    Greg, Jan 25, 2004
    #7
  8. Greg

    Greg Guest

    Flycaster,
    As you probably now understand, I was mainly concerned about soft proofing.
    I thought that a soft proof involved an absolute intent conversion as the
    final step,
    from the output profile (printer profile, being proofed), to the monitor
    profile.
    As far as I can tell, Photoshop doesn't do this. (I don't yet understand
    fully what it
    does do, but I think I understand the *result* of what it does, now)

    Other than that, though, I use absolute intent for testing purposes. For
    example,
    when I printed the two test patches for that monitor gamut experiment that
    you and
    I did together, I use absolute intent, because I wanted to print these
    colours *exactly*, without
    a whitepoint shift. (this wasn't an absolute intent conversion to the
    monitor, of
    course - it was from Lab space to printer space). I have also needed
    absolute
    intent for other tests, which have been from the document space to the
    monitor
    space. I needed it just recently in fact, and it served me very well. I
    could not
    use my Eye One Display monitor profile for this - I had to use a traditional
    monitor profile

    If the Eye One monitor profiles really are entirely to spec, then it seems
    that
    either a) Photoshop has a problem with them, or b) the V4 ICC spec has
    removed
    functionality. In the latter case, I'm not sure why it was felt necessary to
    do this.

    I stress though that I did probably exaggerate this issue. I'm a lot more
    comfortable
    than I was initially.

    Greg..
     
    Greg, Jan 25, 2004
    #8
  9. Greg

    Greg Guest

    Note that this subject is also being discussed at dpreview.com.
    This message seems key:
    http://forums.dpreview.com/forums/read.asp?forum=1003&message=7347365
    but I still don't understand it. :) Perhaps others here will benefit more
    from that post.
    In that post there is a further link, to a forum on imagingrevue.com. I
    don't have an
    account on that site, so I can't access it.

    Greg.
     
    Greg, Jan 25, 2004
    #9
  10. the quote is OK but you need to understand it a little more.

    In case of the CRT, the media whitepoint is the CRT screen itself when
    driven with 255,255,255.

    What the quote instructs is that the actual measured hardware
    whitepoint of the CRT has to specified (as D50) XYZ value in that
    profile tag. It does NOT require that the actual hardware whitepoint
    of the CRT should be set to D50. Or you could set the media whitepoint
    tag to D50 and set the chromatic adaptation tag in such way that it
    converts the media whitepoint tag that holds the D50 to the actual
    hardware whitepoint, the result is the same and does NOT require that
    the actual hardware whitepoint of the CRT should be set to D50.

    What you say is the very same as to require that the users of what
    ever printed matter should "set" the actual paper surface of the
    prints to D50 chromaticity. Pretty hard thing to do.

    Timo Autiokari http://www.aim-dtp.net
     
    Timo Autiokari, Jan 25, 2004
    #10
  11. Greg

    Greg Guest

    Again, understood/agreed, and I never said this.
    The media whitepoint tag *must* be set to D50. It's not correct to say that
    "you could".
    It *must* be.
    But you are putting words into my mouth.

    All I'm saying is this:
    1. Eye One Match created profiles do, always, have a media whitepoint tag of
    D50 (very very close, anyway). This is regardless of the hardware whitepoint
    I calibrate to, and regardless of the whitepoint I enter into the profiling
    software. The software definitely caters for different hardware
    whitepoints. The fact that Eye One Match always writes a media whitepoint
    tag of D50 is to the V4 specification.

    2. The profiles are usable for most things, including Photoshop soft
    proofing.

    3. The profiles are *not* usable for absolute colorimetric conversions from
    the document space to the monitor space, *if* the hardware whitepoint is not
    D50.

    4. I simply don't know whether there is something wrong with the profiles,
    or something wrong with Photoshop, or whether the V4 ICC specification
    itself has a problem. All I know is that I do not know how to use these
    profiles for absolute colorimetric conversions, in Photoshop 7.01 (or
    Photoshop CS), on Windows XP. I think something is broken, somewhere.

    Greg.
     
    Greg, Jan 25, 2004
    #11
  12. Greg

    Greg Guest

    Just by the way, the profiles do not have a chromatic adaption tag.
    ('chad'). Could that be the problem?

    Greg.
     
    Greg, Jan 25, 2004
    #12
  13. Greg

    Greg Guest

    Unfortunately, vastly different soft proofing results are obtained in
    Picture Window Pro, when using
    Eye One Display profiles, vs traditional monitor profiles. I'm reasonably
    certain Picture Window Pro
    does in fact do an absolute colorimetric conversion from the proofing
    profile to the monitor profile,
    and that would explain the difference.

    Greg.
     
    Greg, Jan 25, 2004
    #13
  14. You said:

    Quote: "1. The Eye One Display profiles comply with the V4 ICC
    specification, which mandates that the whitepoint be exactly D50 for
    displays."

    I understood the above like: ...mandates that the whitepoint of
    display devices should be (set) exactly to D50.

    Particularly the word exactly seem to refer to the hardware
    whitepoint, in case of numbers in the profile we rarely say that some
    value has to be entered exactly as D50, instead we just say the value
    has to be D50..

    So, we agree that ICC spec does not mandate to adjust the monitor to
    any particular hardware whitepoint.

    Timo Autiokari
     
    Timo Autiokari, Jan 25, 2004
    #14
  15. The chromatic adaptation tag is rather new, older profilers do not
    include that tag.

    Color managed SW should perform correctly with older and new ICC
    profiles. Especially Photoshop should since Adobe is a member of the
    International Color Con Sortium who publish the ICC spec.

    Timo Autiokari
     
    Timo Autiokari, Jan 25, 2004
    #15
  16. Greg

    Greg Guest

    Definitely.

    Greg.
     
    Greg, Jan 25, 2004
    #16
  17. Greg

    Greg Guest

    Soft proofing *to* the Eye One Display profiles may not be yielding proper
    gamut warning results. (I do this to see
    whether the colours in my image are out of gamut of my monitor, sometimes)

    I did the following:
    - Profile/calibrate monitor to D65 using Eye One Display.
    - Profile the monitor in the same calibration state with the Little CMS
    beta 3 monitor profiler, using the Eye One Display puck.
    - Open Photoshop 7.01, and create a blue patch (0,0,255) and assign
    ColorMatch RGB.

    - View | Proof Setup | Custom, proofing profile the i1 profile, intent
    relative, blackpoint compensation off
    - View | Gamut warning (enable). Observe that image is out of gamut.
    - Image | Adjust | Hue Saturation, adjust saturation until gamut warning
    disappears. Adjust value required: -41%

    Repeat these three steps, using the Little CMS profile: Hue adjustment
    required: -11%

    Repat these steps using sRGB: Hue adjustment required: -15%

    I have trouble believing that the gamut warning for the i1 profile
    represents reality.

    Greg.
     
    Greg, Jan 25, 2004
    #17
  18. Greg

    Greg Guest

    (yes, I did reset the image to 0,0,255) inbetween each proof - always the
    same starting point before
    doing the saturation reduction)
     
    Greg, Jan 26, 2004
    #18
  19. Greg

    Flycaster Guest

    Understood. However, with respect to your first paragraph,

    "As you probably now understand, I was mainly concerned about soft proofing.
    I thought that a soft proof involved an absolute intent conversion as the
    final step,
    from the output profile (printer profile, being proofed), to the monitor
    profile. As far as I can tell, Photoshop doesn't do this. [snip]"

    It does, if you toggle the AbCol rendering intent. The soft-proof dialogue
    will allow you to select whatever rendering intent you want, as will the
    final Print Space selection.
     
    Flycaster, Jan 28, 2004
    #19
  20. Greg

    Greg Guest

    It converts from the document space to the *proofing* profile using the
    selected intent.
    As far as I can see, it does *not* convert from the proofing profile back to
    the monitor's space using
    absolute intent, regardless of whether "simulate paper white" is enabled or
    not. I thought it did.
    I believe the Microsoft CMM does, and my experiments in Picture Window Pro
    3.5 support
    this.

    Greg.
     
    Greg, Jan 28, 2004
    #20
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