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caleb5
Known Participant
May 24, 2018
Answered

How to Convert an Embedded sRGB Color Profile Image to an 8-Bit Gray-Scale Image

  • May 24, 2018
  • 3 replies
  • 3142 views

I have a .TIF image that has an Embedded sRGB Color Profile and I want to convert it to an 8-Bit Gray-Scale .TIF image.  Would anyone know how to do this in Photoshop CS3?  Can I do this by the Image > Mode > Grayscale menu?

Thanks in advance.

    This topic has been closed for replies.
    Correct answer JJMack

    Yes

    When you open your tiff that has and embedded sRGB color profile in Photoshop.  It will open as a three channel document the is in SRGB Color space.  If you use menu Image Mode Grayscale the document will be converted to s single channel Grayscale image and convert to a Dot Gain 20%  profile.

    Photoshop is a document editor not a file editor your Tiff file on disk is still  a sRGB Color image.   The document in Photoshop is not.  When you save a file for the document the File will have A grayscale  image Profile Dot Gain 20%.  I added gray to the document name when I save that tiff file or PSD or PNG.  Whatever you use in Save AS.

    I use  a newer Photoshop I no longer have CS3 installed.  Photoshop has not changed in that area

    3 replies

    D Fosse
    Community Expert
    Community Expert
    May 25, 2018

    You're mixing things up here. The bit depth is something else entirely, not related at all.

    Again, to make a true grayscale file, "Convert to Profile". If you don't know which grayscale profile to choose, I'd recommend Gray Gamma 2.2. This removes all color information and leaves only a single channel.

    Completely separate from that, you can convert from 16 bit depth to 8 bit depth, or vice versa. This is a separate menu item under Image > Mode.

    caleb5
    caleb5Author
    Known Participant
    May 25, 2018

    Sorry for the mix up.  I'm kinda new to Photoshop.

    Thanks, I wasn't able to locate the 8-bit option under Image > Mode, that's what I needed to know.

    Thanks a lot!

    JJMack
    Community Expert
    JJMackCommunity ExpertCorrect answer
    Community Expert
    May 24, 2018

    Yes

    When you open your tiff that has and embedded sRGB color profile in Photoshop.  It will open as a three channel document the is in SRGB Color space.  If you use menu Image Mode Grayscale the document will be converted to s single channel Grayscale image and convert to a Dot Gain 20%  profile.

    Photoshop is a document editor not a file editor your Tiff file on disk is still  a sRGB Color image.   The document in Photoshop is not.  When you save a file for the document the File will have A grayscale  image Profile Dot Gain 20%.  I added gray to the document name when I save that tiff file or PSD or PNG.  Whatever you use in Save AS.

    I use  a newer Photoshop I no longer have CS3 installed.  Photoshop has not changed in that area

    JJMack
    caleb5
    caleb5Author
    Known Participant
    May 25, 2018

    Thanks for the replies everyone.  So if I want to convert my image file to an 8-bit grayscale file (not just the way the image looks when viewed in Photoshop, but change the file) Photoshop is not the right tool for that Job.

    Thanks everyone.

    D Fosse
    Community Expert
    Community Expert
    May 25, 2018

    caleb5  wrote

    So if I want to convert my image file to an 8-bit grayscale file (not just the way the image looks when viewed in Photoshop, but change the file) Photoshop is not the right tool for that Job.

    That's the exact opposite of what I was trying to say. Photoshop is exactly the right tool for that job - not only that; it's pretty much the only application you can use to convert RGB into grayscale. Very few applications can do that.

    You just need to consider which grayscale profile you want. If your reference is screen, the safest choice is probably gray gamma 2.2.

    Grayscale support everywhere else is mostly non-existent. In almost any application you can think of, it will most likely not be printed or displayed correctly. Photoshop is the only widespread raster image editor that I know of that will treat grayscale correctly.

    D Fosse
    Community Expert
    Community Expert
    May 24, 2018

    Convert to Profile. Image Mode does the same thing, but doesn't give you a choice - it converts to whatever you have set up as working gray. That's fine if you know that's the profile you want.

    Grayscale works just like any other color spaces. It's just one channel instead of 3 or 4. The icc profile defines the values.

    Personally I try to avoid grayscale, because support in other applications is very poor. To my knowledge only Photoshop and Acrobat treat grayscale correctly, by honoring the embedded profile and converting correctly for display or printed output. In all other applications, all bets are off, and there's a high likelihood of random tonal shifts. Even Illustrator and InDesign are lacking here.

    If I have to use grayscale for offset print on the black plate only, I prepare a CMYK file (using the appropriate CMYK profile) with CMY empty and all content in the K channel. Such a CMYK file is displayed accurately in Photoshop and always treated correctly on press.

    JJMack
    Community Expert
    Community Expert
    May 24, 2018

    Yes Grayscale is not used much.   There are many ways to convert a color image to Black a White and you have more tools to control the conversion process.

    https://www.google.com/search?q=adobe+photoshop+convert+color+picture+to+black+and+white&oq=Photoshop+Tutorial+convert+C…

    JJMack