27th December 2004, 11:58 PM
Assign Profile or Convert to Profile?
Hey guys, what is the difference between "Assign Profile" and "Convert to Profile" in Photoshop Image adujustments?
Been reading up the Photoshop help files and I'm not really sure what it means.
"When using the Assign Profile command, you may see a shift in color appearance as color numbers are mapped directly to the new profile space. Convert to Profile, however, shifts color numbers before mapping them to the new profile space, in an effort to preserve the original color appearances."
So what does that mean for me? Which should I use? Thanks in advance.
27th December 2004, 11:59 PM
Eh... I got no idea. Muahahah...
I set PS to use my monitor profile default. So when I open my files it uses the profile and when I save, the monitor profile is embedded into the file.
28th December 2004, 12:03 AM
Assign profile is done before editing. Convert to profile is done before saving.
28th December 2004, 12:05 AM
Originally Posted by espn
Thank you for the fast response. What is your monitor's profile? I dont' see any monitor profiles listed as a choice in the profile list. Does that mean you don't process your photos in either AdobeRGB or SRGB?
28th December 2004, 12:15 AM
most of our images should already have a profile like srgb... in most cases u shld convert profiles to other profiles... unless the image did not have a profile in the first place, then assign first.
Dont think should convert image's profile to your monitor profile. By right PS should detect your monitor's profile (you can see it by: edit->color settings. Then click on drop down menu of "working space"->RGB. Somewhere at the top of the list, you shld be able to find "monitor rgb" together w the corresponding profile name.) and will map the colors appropriately.
28th December 2004, 12:30 AM
I've read somewhere that everytime you change a profile. You lose image information, I would like to confirm if that's true.
Originally Posted by r52lanc
28th December 2004, 01:16 AM
Assign profile should only be used if you have an image that doesn't have a colour profile attached.
Convert profile is used when you are attempting to match the gamut of an output destination.
Moniter profiles are automatically used by PS-CS if they are set as the system defaults.
Profile conversions do cause information losses. However, the more important point should be to not mess with profiles if you are unsure of what you are doing.
28th December 2004, 01:47 AM
aiyoh, this is really one of the most confusing digital photography topics around. hmm a few things...
agree with zerstorer, that assign profile is used for images that don't have a profile attached.
convert profile is when you have an image with one colour profile, eg adobe rgb or your camera's own colour profile, and you want to change it to another profile for a certain use, eg srgb
you get a monitor profile when you caliberate your monitor, using stuff like adobe gamma or spyder or eye one etc... this should appear in your photoshop colour settings (edit -> colour settings) next to the words "monitor RGB" in the working space:rgb pulldown menu.
should not set your photoshop rgb colourspace to monitor profile: leave it as either adobe rgb or srgb, depending on which you prefer to work in. (hehe as for which one does what and which one to use, wah i not going to even try to talk about this, but i personally use srgb for convenience lah)
and i think probably shouldn't attach your own monitor profile to your files. since your monitor is different from every other monitor, it's not a common standard.
if want to read something by someone who seems to know what he's talking about, go here:
28th December 2004, 10:01 AM
My monitor's profile is based on what I calibrate and saved the ICC file. Eg I saved it as Monitor_Profile.icc, NC4, PS CS, and my display will now use "Monitor_Profile.icc" as the profile.
Originally Posted by Gosu_John
My images are taken in sRGB mode and processed only in sRGB mode. I don't do Adobe or CYMK.
28th December 2004, 10:20 AM
In PS, you get a "Convert" profile msg box when your image's embedded profile does not match the working space set in PS. You can check your PS's working space by pressing CTRL-SHIFT-K. Mine's set to Adobe RGB cos I like the greater gamut it provides.
My cam shoots in sRGB, so when I open files in PS, I get the "Embedded Profile Mismatch" msg box which gives me the option to use the embedded profile, convert or discard.
If for some reason, the image does not have an embedded profile, PS will then give you the "Missing Profile" msg box where you can then leave it as it is, assign a working space or assign another profile (like your monitor profile for example).
Bottom line: Convert-ing and Assign-ing profiles are used under different cirumstances
28th December 2004, 10:21 AM
One other use of convert profile is for output devices that do not understand color profile, like the Fuji Frontier machine. Before I save my jpg file, I always convert it to srgb. This way I ensure what I see on my monitor is close to what is printed out from the photo labs.