14 Replies Latest reply: Feb 24, 2012 2:16 PM by Keith Barkley
BPWMorro Level 1 Level 1 (70 points)

Hello,

 

A friend, with iPhoto 9.1, imports images from a Panasonic camera and when he exports to burn to a CD they have a Camera RGB Color Profile -- which then displays lousy on a projector in a club competition.

 

When I import images from my Panasonic into iPhoto 9.2.1 and export they have an sRGB profile -- which displays nearly perfectly.

 

I cannot figure out how to help my friend assign an sRGB profile to his images. Any suggestions?

 

(PS -- I also have Aperture and Adobe CS, but my sRGB profile appears on my images without every opening Aperture or CS.)

 

Thanks,


Mac OS X (10.7.3)
  • 1. Re: Color Profile in iPhoto
    LarryHN Level 9 Level 9 (56,695 points)

    Camera RGB and sRGB should be very close to each other

     

    As to assigining sRGB you can do it in Preview

     

    LN

  • 2. Re: Color Profile in iPhoto
    Old Toad Level 10 Level 10 (115,715 points)

    Use the Colorsync Utility to compare the sRGB profile to the Camera RGB profile. With my camera the two profiles are very close together.

     

    sRGB IEC61966=2.1

    ColorSync Utility002.jpg

    Camera RGB Profile

    ColorSync Utility001.jpg

     

    See if your two profiles are close or not.  I have a couple of Automator workflows and an Applescript that can change the color profile to the sRGB profile.  You can get them from Old Toad's Cellar. You will have to apply the workflow to the photos outside of iPhoto and reimport them.

     

    OT

  • 3. Re: Color Profile in iPhoto
    BPWMorro Level 1 Level 1 (70 points)

    Larry,

     

    Thank you. I agree; from my reading the two profiles should be very close -- but, in actuallity, the converted to sRGB profile displayed nearly perfectly on the same computer & projector that last month displayed a Camera RGB in a washed out situation. Granted, it was four different pictures, but I cannot explain why other than the computer assigned sRGB profile might somehow handshake with how the projector is configured better....I know it has been operator "adjusted" somehow....this is actually far more technical than I care to be involved, but...he's a friend.

     

    Please take a look at Old Toad's response and my Reply to him. I ask an additional question that you might have some interest in addressing.

  • 4. Re: Color Profile in iPhoto
    BPWMorro Level 1 Level 1 (70 points)

    OLD TOAD!!! Great to see/read you again; I have not been in these forums lately...

     

    A Continuing Question:  Yes, I look at the graphics of your two profiles and they appear very similar -- no difference to the naked eye -- BUT -- the sRGB shows it has 3144 bytes and the Camera RGB 1352.  While the two diagrams display as the same size, isn't the content of the sRGB 2 1/4 times that of the Camera? Aren't the bytes a measure of content?

     

    Continuing, please address my simplistic illustration of how this works with a projector:

              Assume you are going to paint two identical walls that are currently photogrey, each is 8' high by 10' wide.

              On the first wall you use two quarts of red.

              On the second wall you use only 1 pint of the identical same red.

              Won't the second wall be less ... intense....than the first?

         If we translate this to images, consider a projector displaying a full size 8MB image, one that has not been image resized ("resampled") and also displaying the same image that has been resized (reduced) to one-quarter the size (from 8MB to only 2MB) -- wouldn't we expect the reduced image to display with less intensity, the same as the painted wall?

     

    As I told Larry, above, this is far more technical than I care to be involved, but your help with answers will be appreciated.

  • 5. Re: Color Profile in iPhoto
    LarryHN Level 9 Level 9 (56,695 points)

    And did you try Old Toad's Applescript to change the color profile to sRGB?

     

    Did it help?

     

    LN

  • 6. Re: Color Profile in iPhoto
    BPWMorro Level 1 Level 1 (70 points)

    Larry,

    No -- I used Adobe Photoshop Elements 8; I was guided to how to change to sRGB with it before Old Toad posted. Same effect -- but, yes, the sRGB converted profile displayed far superior this month to the old Camera RGB did last month.   So I have a solution to the problem that I can use -- but I'm asking those of you who know more than I "why?" -- as in my Reply to Old Toad.

    Continued Thanks.

  • 7. Re: Color Profile in iPhoto
    Keith Barkley Level 5 Level 5 (5,260 points)

    It really sounds like the profile used is much closer to AdobeRGB than CameraRGB.  It could be that the Panasonic just attaches a profile tag  instead of the profile and that the Panasonic Profile is actually far away from sRGB.

  • 8. Re: Color Profile in iPhoto
    Keith Barkley Level 5 Level 5 (5,260 points)

    I don't know if this is true, but I saw in a post on dpreview that Camera RGB expects a Gamma of 1.8. If the projector is at 2.2, that could throw things off.

     

    ETA:

    Terrence as usual has the answer:

    https://discussions.apple.com/thread/1458772?start=0&tstart=0

     

    Since mac's use 2.2 gamma these days, there doesn't seem to be much point.

  • 9. Re: Color Profile in iPhoto
    BPWMorro Level 1 Level 1 (70 points)

    Keith,

    I think you're leading me on the correct path. I've stumbled on Terrence's comments, also...but this is really over my head:  However, I'm willing to bet that projector was set to use 2.2 and these older iMacs (SnowLeopard) are using 1.8 gamma....QUERY: do you have a quick & dirty answer as to when Macs switched to 2.2?

  • 10. Re: Color Profile in iPhoto
    Terence Devlin Level 10 Level 10 (123,865 points)
  • 11. Re: Color Profile in iPhoto
    BPWMorro Level 1 Level 1 (70 points)

    Terence, and Old Toad and LarryN and Keith,

     

    Thanks to all of you for your support and guidance. This is far more detailed than I ever wanted to get into but each of you have contributed to my understandings. The Apple KB HT3712 was extremely illuminating with the clarifications regarding the Gamma -- whatever a gamma is, I'm sure it is the problem!

     

    (Now, if any of you wish to address my paint can illustration, that I posted in response to Old Toad, I'd still appreciate that!)

  • 13. Re: Color Profile in iPhoto
    Terence Devlin Level 10 Level 10 (123,865 points)

    On the first wall you use two quarts of red.

              On the second wall you use only 1 pint of the identical same red.

              Won't the second wall be less ... intense....than the first?

     

    No it won't. The red is the red. There's no difference in the intensity. What might differ is the coverage - there's a greater risk of the old colour showing through, but that don't change the intensity of the red.

     

    If we translate this to images, consider a projector displaying a full size 8MB image, one that has not been image resized ("resampled") and also displaying the same image that has been resized (reduced) to one-quarter the size (from 8MB to only 2MB) -- wouldn't we expect the reduced image to display with less intensity, the same as the painted wall?

     

    We might expect it but it wouldn't necessarily be true. The compression involved in jpegs is very complex and it is quite possible that the two images will appear the same. For instance, if you follow your logic,  wouldn’t the blacks in the shot become grey?

     

    And, if my recollection of schoolboy physics is correct (and remember in my schooldays chalk was considered a new invention) colour produced by light works very differently than colour produced by pigment - one of the reasons it's so difficult to get a print that matches what you see on the screen. This might help explain the difference between additive and subtractive colour

     

    http://en.wikipedia.org/wiki/Additive_color

     

     

    Regards

     

     

    TD

  • 14. Re: Color Profile in iPhoto
    Keith Barkley Level 5 Level 5 (5,260 points)

    wouldn't we expect the reduced image to display with less intensity, the same as the painted wall?

     

    Each pixel in the projector is independent*. If a particular pixel in the image is displyed red, it will be displayed red. It does not matter if it is surrounded by more red or blue - it might appear a different color because of the surrounding pixels, but that is your eye's fault, not the projector.

     

    When you resample, it works the same way. The resulting image has no memory of the previous image. If you down-sample a perfectly sharp checkerboard pattern the inside of the pattern will maintain the same color, though it will be at a lower resolution. The edges might have pixels that are in-between the two colors, but again that is not really what we are talking about here.

     

    *Of course in a poor projector, some pixel's may bleed into others, but I don't think that is what we are talking about here.