Author Topic: Embedding Color Space tags.  (Read 1363 times)

keithsnell

  • Administrator
  • Hero Member
  • *****
  • Posts: 1407
Embedding Color Space tags.
« on: April 20, 2011, 02:03:16 PM »
For those of you that are using photoshop to process your images, here's a quick tutorial on how to embed a color space in your images so that they display properly in color managed applications.

Most cameras give you the option of selecting a color space in the camera menu.  You should understand that if you are shooting raw, this selection is just a "tag" that tells the raw processing software what color space to use when rendering the image.  You can easily change this color space selection in the raw processor with no loss of quality, since the conversion isn't applied until the image is rendered from raw and saved in another format (i.e. JPEG or TIFF).  If you are shooting JPEGs in camera, then this setting tells the in-camera processing engine what color space to use when rendering the JPEG.  If you select sRGB then you will be discarding much of the color information available from the sensor, and converting to Adobe RGB (a wider color space) later in the processing flow cannot bring any of this information back.

Most of you are shooting raw, so I'll continue on by primarily addressing that workflow.  If you are using the raw processing software supplied by the camera manufacturer then it will read the color space tag in the image file and use that as the "default" target color space when rendering the file.  If you are using Adobe Camera Raw (ACR) as part of Photoshop, then you set your preferred color space by clicking on the link at the bottom of the ACR window, here:


These ACR settings are "sticky" and will be applied to all images in the future until you change them again.

You should also ensure your color management settings are correct in Photoshop by accessing them through the Edit menu and selecting "Color Settings" at the bottom of the drop down menu.


In the Color Settings dialog box you should select your "working" RGB color space (don't worry about the settings for CMYK, Gray or Spot for now, the defaults are fine).  Use the drop down arrow to the right of the RGB box and select a working color space.  Adobe RGB is a good compromise.  (We can talk about why, if you are interested, but in a nutshell this color space contains most of the "real world" colors you are likely to deal with in your images without any of the issues associated with super-wide color spaces like ProPhoto.)


In the Color Management Policies section you should select Preserve Embedded Profiles for all three boxes.  This will preserve any choices you have already made in the raw processing software.  You should also check both boxes following Profile Mismatches (Ask When Opening and Ask When Pasting) and check the box labeled "Ask When Opening" under Missing Profiles.  

From this point on, whenever you open a file in Photoshop it will check to make sure that the embedded color space matches your working color space.  If it does not, (or there is no color space tag in the file) then a warning dialog will pop up asking you how you want to handle the mismatch.  (Usually selecting the "Use embedded Color Space" option is the best selection.)

If, after you have worked on an image you want to save it in a different color space (for example saving it in sRGB for display on the web) then you can convert the color space by selecting that option under the Edit menu.  (Don't use the "Assign" option.)

Finally, you need to ensure the option to embed the color space in the file is selected in the Save dialog, like this:


If you have any questions, please don't hesitate to ask!

Keith


« Last Edit: April 20, 2011, 02:12:44 PM by keithsnell »