Likewise the colour management system and settings will be familiar to
those who previously used Photoshop 6 or 7. All of this is good news for
those migrating from earlier versions but colour management and
particularly the plethora of options associated with it can leave many
new users in a state of confusion.
This essay is primarily intended to help new Photoshop users and will
explain how the colour management system within Photoshop CS should be
configured. That said and before getting into the specifics I think it
worth taking a few moments reviewing the underlying principles of colour
Colour Management Primer
Ever since the beginning of colour reproduction, colour management has
existed in one form or another. The basic concept underlying colour
management is to ensure that colour data is processed in a consistent and
predictable way throughout the entire imaging workflow. A typical Imaging
System will consist a wide range of Input and Output Devices, and each
device will reproduce colour differently. This means that a colour
represented by one device will rarely if ever match the same colour
represented on another device. In other words, colour is
device-dependent. So expanding upon our earlier definition we can say
that the purpose of a Colour Management System (CMS) is to maintain the
consistent and accurate appearance of a colour on different devices (e.g.
scanners, monitors, printers, etc.) throughout our imaging workflow.
Components of a Colour Management System
In order that we can achieve the above aims a colour managed system
will require three basic components, namely: -
A device-independent colour space - this is usually referred to as
the Working Space or Reference Colour Space.
ICC/ColorSync device profiles for each device (printer, scanner,
monitor, digital camera, etc.) that describe the colour characteristics
of the specific device.
A Colour Matching Module (CMM) that will interpret the information
contained within a device profile and carry out the instructions on the
way the colour gamut of each device should be treated.
The following diagram demonstrates a typical Colour Managed Workflow
and shows the image being passed along the chain - from scanner/digital
camera - to - computer - to - monitor - and printer with the ICC profiles
ensuring that the colour data from/to each device is correctly described.
Colour Numbers, their Meaning, and
A digital image will comprise pixels each of which is represented by a
number. This number will describe the location of the pixel within the
image and its particular colour value (typically an RGB value). We have
already noted that since colour is device-dependent the appearance of the
each coloured pixel will vary for each device. We also noted that this is
because each device has its own unique way of translating the raw colour
value into visual colour. To minimise the discrepancies that result from
the widely differing colour characteristics of each device we use an ICC
profile to inform the CMM how the colour values produced by that device
should actually appear. This may be on our monitor, in print or on film
output. In simple terms it is the device profile that conveys the meaning
of the raw colour numbers associated with each pixel.
Whilst consumer class film and flatbed scanner software applications
are now ICC/ColorSync aware they tend to be based upon a colour space
known as sRGB, likewise consumer digital cameras. This colour space isnít
generally regarded as appropriate for high quality image editing,
especially when print or film output is required, but is quite often all
we can expect to get. An image delivered into Photoshop by the scanner or
digital camera application software which is already in a
device-independent colour space sRGB/Adobe RGB means that it has already
undergone a considerable amount of data processing and not that itís an
sRGB/Adobe RGB device.
Many Prosumer class scanners and digital printers are now supplied
with some form of generic or "canned" profiles. Whilst these profiles are
useable they are rarely accurate. For truly accurate colour matching you
should seriously consider getting customised profiles for each device
and/or media type. These profiles can be created professionally or by
buying your own profiling software. Sadly very few, if any digital camera
vendors have adopted the "canned" profile approach instead opting process
the images into a device-independent colour space as discussed above.
Device profiles come in two basic forms, i.e. Input and Output. Input
profiles typically describe the colour characteristics of scanners and
digital cameras, whereas Output profiles describe devices such as
monitors, printers and film recorders. Input profiles are often referred
to as one-way since it is only possible to select them as the Source
meaning we can never convert an image into the colour space of our
scanner or digital camera. Output profiles are two-way meaning we can
convert From or To them.
Why bother with Profiles?
Even though colour correction and colour management are not the same
thing they are often confused with each other, especially by the novice
Photoshop user. The colour characteristics of most imaging devices are
such that it is very rare for them to be truly linear (i.e.
R=G=B=Neutral). Sometimes this characteristic is referred to as the
device not being well behaved. Scanners and printers are good examples of
badly behaved devices. Obviously it would be extremely difficult for a
Photoshop user to edit an image where a group of pixels with values of
R=G=B=128 (grey) actually appeared to be non-neutral. In such
circumstances colour correction would an absolute nightmare. To overcome
these discrepancies we usually carry out all our editing in a colour
space that is well behaved. In Photoshop well behaved colour spaces are
more usually referred to as the Working Spaces, and are always
characterised by having R=G=B appearing neutral. Without the aid of
accurate device profiles the accurate translation of the raw colour data
(the numbers) from the scanner/digital camera into the Working Space will
prove very difficult, if not impossible. The translation from the Working
Space into the media specific colour space of a digital printer will
prove equally difficult without the aid of media specific printer
So the main benefit offered by colour management is that the process
of colour correction can be undertaken in the knowledge that the image
displayed on the monitor is an accurate visual representation of the
original subject, and that the final print will accurately reflect the
colours of the displayed image.
Some Photoshop Revision!
Photoshop CS continues to use document/image specific colour settings,
which means that the colour space of each document is independent of
others that may be open on the Photoshop desktop. As with Photoshop 6 and
7 the Working Space defined in Color Settings only has a bearing on three
types of image, viz.: -
Existing images/documents without an embedded ICC profile.
Images/documents with no embedded ICC/ColorSync profile (i.e. untagged
Image or document specific colour means that it's the profile embedded
within an image that determines how the image will be displayed (it's
appearance) and not the Photoshop Working Space. With Photoshop CS we can
have multiple images, each in its own unique Working Space, open at the
same time and each will be displayed accurately. Of course all of this
assumes we're using a calibrated monitor.
Note that except for the obvious difference in user interfaces;
Photoshop CS for Mac OSX and Windows share a virtually identical feature
set. Therefore the Windows based screen shots that follow should be
equally useful to Mac users.
On opening Photoshop CS for the very first time we are presented with
an information dialog (shown below). The purpose of this dialog is to
warn the user that the Photoshop Color Settings will be automatically
configured or to provide access for manual setup. As with Photoshop 6 and
7 there is no wizard to help the user through the process of
configuring the Color Settings. If Photoshop 6 and 7 are anything to go
by many new users will panic at this dialog and accept the defaults only
to realise later that this was only a short-term solution.
For the purpose of this essay I to have chosen the No option
and have therefore accepted the default Photoshop settings. However, I
chose this option for no other reason than to concentrate upon monitor
calibration and characterisation. Once I have discussed calibrating the
monitor we can return to Color Settings.
Part 1 - Monitor
Calibration and Characterisation
Accurately calibrating and characterising the monitor is the probably
the most important aspect of the colour-managed workflow. The aim is to
calibrate and characterise the monitor so that we eliminate unwanted
colour casts and so obtain the best possible display environment for
editing our images. We characterise the monitor by means of creating an
ICC device profile, which is simply a data file that includes a
description of the monitorsí colour handling characteristics. The profile
will then be used by Photoshop to compensate for the colour limitations
of the monitor. Photoshop automatically optimises the display of images
by carrying out an on-the-fly conversion between the image/document
profile (e.g. Adobe RGB, sRGB, ColorMatch) and the monitor profile. This
conversion does not alter the actual image in any way.
Note: Adobe no longer supply Adobe Gamma with the Mac
version of Photoshop although the Apple Display Calibrator Assistant
found within System Preferences offers similar features. A tutorial
describing the process of calibrating a display with the Apple Display
Calibrator Assistant can be found
To calibrate and characterise the monitor Windows users should open
the Adobe Gamma utility or a third party alternative. For many new users
Adobe Gamma is more than sufficient and it's free.
Adobe Gamma is a Control Panel utility that can easiest be accessed
from My Computer > Control Panel. Before running Adobe Gamma, it is best
that the monitor has been switched on for at least 30 minutes. It is also
best to work in subdued lighting when calibrating a monitor using Adobe
Gamma. Another helpful tip is to set the desktop colour to grey.
Control Panel as is appears when using the Windows
When the Adobe Gamma utility is first opened you will be asked
to make a choice between the Step- by- Step (Wizard) and the
Control Panel method. It's probably easier to use the Step-by-Step
Using the Load button choose your monitor profile or pick one
that's close. If in doubt choose the Adobe default monitor profile
or even sRGB, it really makes little difference since all we are
doing is defining the start point.
Before progressing to the next step, be sure to give the profile a
unique description and include the date.
Set your monitor contrast control to maximum and then adjust the
brightness control until the innermost grey square is only just visible
against the black surround. Squinting your eyes helps with this process,
as does keeping the room lighting at a low level or off.
If you're using a manufacturer supplied profile for your specific make
and model of monitor then in all probability the Phosphors will be listed
as Custom. If this is the case leave well alone. If you don't have
a monitor profile choose either Trinitron or P22-EBU. I
keep getting asked -"how do I decide which is appropriate for my
monitor?" You can tell a Trinitron monitor by simply looking at the
display area. A Trinitron type monitor will have two faint lines running
across the display area approximately 1/4 from the top and 1/4 from the
bottom. If your monitor has these lines choose Trinitron, otherwise
Begin by keeping the View Single Gamma selected. However, keep
in mind that this option ONLY allows you to adjust the relative
brightness of the monitor.
Adjust the slider until the inner grey square blends with the outer
frame, squinting slightly can help. Finally, deselect the View Single
This is the step where we neutralise the colour imbalances inherent in
our monitor. Adjust each of the sliders in turn so as to blend the inner
square with its coloured surround. Again squinting is a great help.
Green is usually the most difficult to get right, but persevere. The
closer you get to a perfect match at this point the more accurate your
final profile will be.
Depending upon your computer type choose either the Windows Default
or Mac Default gamma. In reality, this choice is not as important
as it once was and you can choose either in the knowledge that Photoshop
will make the appropriate corrections when necessary. Personally, and
even though most of my work is now done on the Mac platform I choose
Choosing the White Point for your monitor is pretty much a
formality these days. Even the die-hards are in agreement that 6500oK
is probably the best option on most systems.
You should have already set the Hardware white point via the
dials/buttons on the monitor. Most monitors have a native white of
9300oK; so do check what it has been manually set to.
Choosing 6500oK provides the cleanest and brightest
white point and closely matches daylight. If you feel really confident
you could select the Measure option. You can choose 5000oK,
but this usually produces a slightly dimmer and more yellow white point.
Generally, it's better to leave the Adjusted White Point
setting at the default - Same as Hardware. Nevertheless, this
option is used to choose a working white point for monitor if it
differs from the hardware white point set in the last step.
By way of example; if your hardware white point can only be set to
6500oK, but you want to set it at 5000oK
because that most closely represents the environment in which it will
normally be viewed, you can set your Adjusted White Point to
5000oK, and Adobe Gamma will change the monitor display
accordingly: However, choosing this approach will all cause the graphics
card colour LUT to be adjusted quite severely, and depending upon the
graphics card the screen can look quite ugly on some systems. As
indicated above I recommend that you choose Same as Hardware and
thus avoid this problem.
That's it, if all has gone well you will have adjusted the brightness,
contrast and colour settings of your monitor to the optimum values.
Make a quick check using the Before and After radio
button. If you're happy that the screen display now looks more neutral
than before press the Finish button and Save the profile.
Once saved the profile will be available for use by the OS and Photoshop.
22 May 04
Finally you might wish to check that the newly created monitor profile
has been enabled and set as the system default. To do so you should
reopen the Windows Control Panel from My Computer and
double click the icon labelled Display. A dialog called Display
Properties, which will be similar to the following should appear.
Once the Display Properties dialog box appears navigate your
way to the Settings tab and click the Advanced button. The
next dialog box to appear will be labelled to match with the
display/graphics card vendor names and will be similar to that shown
below. The final step is to click the tab labelled Color Management.
All being well you should find that your newly created monitor profile is
listed and set as the default.
Useful Information on location of
Photoshop CS is only compatible with
Windows 2000 and XP on the PC platform and OSX 10.2.x or higher on the
Mac platform. An upside of this change is that the ICC and ColorSync
profiles are more easily found.
Windows 2000 and XP - sub-folder named system32/spool/drivers/color
Mac OSX - ColorSync profiles are located in the
The only advantage of Adobe Gamma (Windows systems) or the
Apple Display Calibrator Assistant (Mac OSX systems) is that they're
both free, whereas the third party products can cost nearly as much if
not more than Photoshop. However, since many third party alternatives use
hardware and not the eyeball for measurement you are generally assured of
much greater accuracy.
Part 2 - Photoshop CS
Now begins the process of configuring Photoshop. This is achieved
through the "Color Settings" dialog (figure 1) found under the "Edit"
menu (Windows) or the Photoshop menu (Mac OSX).
The Color Settings dialog is the control room for the Photoshop CS
colour management system, and like all control rooms it can appear
complicated. The default colour setting is called: North America General
Purpose Defaults, but this certainly isnít the best choice. So if the
default isnít what is, and how do we make the necessary alterations?
I could answer the above question by simply writing US Prepress
Defaults but doing so doesn't really help explain why. Therefore, I will
work my way through each section of the Color Settings dialog in turn.
Note the Description box at the bottom of the dialog. As the mouse is
moved across the various pop-up menus, etc. you should see a short but
informative explanation of what each menu does. Also note the checkbox
labelled Advanced Mode; it's probably best that you select it now. At
least you'll now see everything that the Color Settings has to offer,
even if some are only applicable to the most advanced of Photoshop users.
Figure 1 - Photoshop CS Default Color Settings
The first section is labelled Settings and is a simple pop-up menu
with a list of pre-set Photoshop settings plus any that you may have
saved. You needn't worry too much about this section just yet.
If you are upgrading from Photoshop 6 or 7 it should be a simple
matter of selecting your previous saved setup. Notice that Adobe has
retained the Colour Management Off option for those users who find the
whole subject too complicated. However, whilst I don't recommend choosing
this option I am aware that quite a few new Photoshop users working on
the PC Windows platform find it the easiest to manage.
The next section is labelled Working Spaces (figure 3), and as I
discussed earlier the selections made here will determine the Working
Space of certain types of image/document.
There are four Working Space types in Photoshop: RGB, CMYK, Grey and
Spot (occasionally called Modes because they appear under the Image>Mode
menu). Since configuring the others follows a similar process I will
concentrate mainly on the RGB Working Space.
Also note that the term Working Space should not be confused
with Workspace. The term Workspace is used by Adobe to describe
the layout of palettes, menu bars, etc whereas Working Space relates
specifically to the various colour modes available in Photoshop.
RGB - Working Space
Clicking the RGB pop-up menu with the mouse will produce a list of
options similar to that shown below. I chose Adobe RGB (1998) because
it's the Working Space I settled on when using Photoshop 5. Notice that
Adobe RGB (1998) appears within a group of four Working Spaces, each of
which is device-independent. Typically sRGB will be confined to those
users solely interested in web design, ColorMatch is a favoured choice of
many Mac users and AppleRGB is apparently for Mac web design.
If you look just above the four common Working Spaces you should also
find options for Monitor RGB (green spot in the screenshot), and in the
case of Mac systems ColorSync RGB. Monitor RGB is simply the colour space
of your monitor as created by the Adobe Gamma utility or a 3rd party
It's often claimed that Photoshop CS has no obvious way of informing
the user which monitor profile is actually being used. Well, a quick
check for Monitor RGB in the RGB Working Space pop-up should be enough to
put your mind at rest. If Monitor RGB is showing something other than the
profile you created when calibrating the monitor it is essential that you
investigate the reason and make the appropriate corrections. It is also
possible to select your monitor space as the Photoshop Working Space, but
this is not really a good idea. ColorSync RGB is only available to Mac
users and will reflect the settings chosen as part of the ColorSync
The actual list of options available for selection as Working Spaces
differs depending on whether you activated Advanced Mode, or not. If you
chose to activate Advanced Mode then the list of available RGB profiles
will be quite extensive.
Additionally, if you had previously been using another Working Space
such as BruceRGB then it should also appear as one of the options in this
extended list. If it doesnít you can still create it yourself by choosing
Custom (yellow spot in figure 4 above). The dialog box shown below
appears and you simply type in the data as shown for the Primaries etc,
but remember to give this new Working Space a name and click OK.
Figure 5 - Description of BruceRGB
Bruce Fraser originally developed BruceRGB around the time Photoshop 5
shipped but it has long since fallen out of favour by the majority of
experienced Photoshop users.
CMYK - Working Space
With the exception of the list of available profiles making your
choice of CMYK Working Space isn't that different to RGB. Again, having
Advanced Mode activated gives you a more extensive list. Since desktop
inkjet printers from Epson, Canon and HP actually require RGB data rather
than CMYK and so configuring this particular Working Space will have
little or no influence in their actual workflow.
As mentioned above, the choice for you make is pretty much irrelevant
if using a consumer class inkjet printer. In my case I just picked US.
Web Coated (SWOP) V2. We can also have pick the old Photoshop 4 or 5
default CMYK options, the ColorSync settings (Mac only), or even
customise our own settings.
Greyscale - Working Space
With the Greyscale Working Space we have access to two gamma settings,
a series of five pre-set dot gain curves, the ColorSync Grey Work Space
(Mac only) and the ability to customise the dot gain to our own
requirements. The screenshots below (figures 7 and 8) show the various
options and a typical customised Dot Gain curve.
Note that if you choose to use a Custom Gamma or Dot Gain this will be
the Working Space listed in the Grey Working Space pop-up menu.
A very important point regarding Greyscale is that itís not tied to
the CMYK setup! This is why some legacy greyscale documents might not
look quite the same as they did in Photoshop 5.x (does anyone still use
Spot - Working Space
The Spot pop-up menu is broadly similar to the greyscale, but for spot
colours. The options that we find include a series of five pre-set Dot
Gain options and the facility for customising the Dot Gain curve if
required. In my case I simply selected the standard 20% option.
Colour Management Policies was a new phrase introduced by Adobe with
Photoshop 6 and continues with only minor changes in Photoshop CS. Figure
9 below shows the new default setup, but this hides a lot of important
Figure 9 - Photoshop CS Defaults
This section of the essay is probably the one that will cause most
Photoshop users the greatest difficulty and for that reason the
explanation that I give below will appear quite wordy, but don't be put
Basically each Working Space will have the same set of three options,
although we need not configure each identically. These options are called
Policies and include: -
In simple terms, the Off Policy ensures that Photoshop does as little
as possible when dealing with ICC profiles. In most circumstances it
isn't the ideal choice and certainly not the choice to be made by new
users. The following explanation will give you some idea as to the
behaviour of Photoshop CS when this option is selected.
Choosing Off means that new images/documents will be created and
saved without an embedded ICC profile. We sometimes refer to them as
untagged images because they do not contain an embedded ICC profile.
Opening an existing image that has an embedded ICC profile matching
the current Working Space will mean that Photoshop will honour the
embedded profile and will subsequently be resaved with the image.
The default Pasting behaviour between images is to retain numerical
values (RGB pixel values), not the appearance. This means that no
conversion between colour spaces will take place and will often lead to
the pasted version of the image taking on a radically different colour
appearance to that of the original.
Opening an existing image that has an embedded ICC profile that
does not match the current Working Space (i.e. profile mismatch) will
cause that embedded profile to be stripped out of the image. The image
will subsequently be saved with no embedded profile. With the Off
Policy we find that the profile warning Ask When Opening has not been
activated for Profile Mismatches so a warning similar to the following
(figure 10) will appear.
The problem with this configuration is that the user either accepts
what Photoshop CS dictates or doesn't open the image at all, not much of
a choice. Activating the Don't show again checkbox is generally accepted
as a good move.
(b) Preserve Embedded Profiles (Default)
For most situations this is my preferred colour management policy
since it offers the greatest degree of flexibility. The following should
give you an idea as to the behaviour of Photoshop CS when this policy is
Choosing Preserve Embedded Profiles means that when you open an
existing image into Photoshop which has an embedded ICC profile that
differs from the current Working Space then that image and its
associated profile will be left intact. In other words Photoshop will
make no attempt to convert the image to the current Working Space; the
original embedded profile will be retained and subsequently saved with
the image. Nevertheless, even though the image and Photoshop are no
longer in sync colour space wise the image preview will still be
When opening an existing image with an embedded ICC profile that
matches the current Working Space Photoshop will take no action; the
image is opened and saved as normal.
The default behaviour when pasting either an RGB or Greyscale image
is slightly more complex whereby the appearance of the pasted image
will be preserved but the numbers will change (i.e. the pixel values
will change). In the case of CMYK it is the numbers that will be
retained, not the appearance.
If the image being opened or imported has no embedded ICC profile
(i.e. the image is untagged) then Photoshop will use the current
Working Space for editing and previewing purposes. However, the profile
will not be embedded into the image when it is subsequently saved.
Creating a new document with this policy setting means that the
current Working Space is used for editing, previewing. The associated
profile will eventually be embedded into the file when saved. However,
the default Working Space profile for new documents can be overridden
in the New document dialog.
The following warning (figure 11) will appear if the profile warning
Ask When Opening has not been activated for Profile Mismatches. Again, my
earlier comment about Photoshop imposing its will on proceedings applies.
At first glance the above warning appears virtually identical to that
shown for the OFF Policy, but there is a subtle difference - the embedded
ICC profile is retained rather than discarded. Compare the text of the
two screenshots (figure 10 and 11) if you're in any doubt as to the
differences. Again you may wish to tick the Don't show again checkbox so
as to stop this warning reappearing in the future.
(c) Convert to Working Space
This policy behaves in an almost identical fashion to colour
management Photoshop 5. It's for this reason that many still tend to
favour it. Actually this policy isn't a bad choice but does need to be
treated with care.
If an existing image with no embedded ICC profile is opened or
imported into Photoshop then the current Working Space will be used for
editing and previewing. However, there will be no profile embedded into
the image when it is saved (i.e. the resulting image will be untagged).
If an image is opened or imported and has an embedded ICC profile
which is found to differ from the current Working Space then that image
will be converted into, and subsequently saved in the Working Space.
When the image and the Working Space are matched then Photoshop takes
no action; the image is opened and saved as normal. Newly created
images will be edited, previewed and ultimately saved in the current
Finally, the default pasting behaviour is to convert and thus
preserve the appearance of the image. However, the user will get the
option not to convert the pasted image, hence preserving the numbers if
the pasted image doesn't match with the target image. Overriding the
Default Policy Behaviour
Overriding the Default Policy Behaviour
The previous section described how our choice of Colour Management
Policy determined the default behaviour of Photoshop CS under various
scenarios. However, we need not be confined to these pre-set outcomes. A
much better option would be to configure the Colour Management Policies
as shown in figure 12 below.
Here we can see that each of the checkboxes for Profile Mismatches and
Missing Profiles be set for Ask When Opening or Ask When Pasting as
appropriate. It is only through setting these checkboxes to ON that we
can enable the default behaviour override facility.
Basically the three checkboxes associated with the profile warnings
have the following impact on the Colour Management Policies: -
(i) Profile Mismatches: Ask When Opening
Photoshop has been set to present the user with a warning when the
image being opened or imported has an embedded profile that does not
match the current Working Space. The warning looks like figure 13 below
and contains three options with the pre-set selection being dependent
upon the Colour Management Policy in operation at the time. Noticed that
all the necessary information required to make an informed decision is
The above example is pre-set for how the dialog would appear when the
Colour Management Policy is set for Preserve Embedded Profile. The user
can choose to leave the image as is (default - Use the embedded profile),
allow the conversion (Convert document's colors to the Working Space) or
strip out the embedded profile and switch off colour management (Discard
the embedded profile). Had the policy been Convert to Working Space the
dialog would have looked almost identical except that it would have been
pre-set for Convert document's colours to Working Space. Basically, the
answer to the question: How do you want to proceed? is already decided
for you when the Embedded Profile Mismatch dialog appears. If you KNOW
this answer to be incorrect then by all means make an alternative
selection otherwise leave well alone and click OK.
I think you will agree that the warning in figure 13 is a lot more
user friendly than the one that appears under similar circumstances when
Ask When Opening is unchecked (i.e. figure 10 above). At least with this
option we now have the opportunity to assign an alternative profile to
the image before it opens.
Now that Photoshop CS can read the EXIF colour space information it's
likely that many consumer class digital camera users will be seeing this
particular warning on a regular basis. Since no benefit will be gained by
converting the image from say sRGB to Adobe RGB (1998) the best choice in
such circumstances is to leave the default Use the Embedded Profile
rather than be tempted to choose Convert document's colours to Working
Users of high-end cameras such as the Canon EOS 1 or Nikon D series
have the facility to program the camera so that it processes images into
a colour space such Adobe RGB (1998). In this situation the user will
know that the profile mismatch warning is incorrect and should choose to
either accept the embedded profile or discard it. However, they must then
use the Assign Profile command to assign the correct profile. Both
methods are equally valid. Assign Profile does not change the actual
image only its appearance. Assign Profile and Convert to Profile are
(ii) Missing Profiles: Ask When Opening
Choosing this option means that Photoshop has been set to present the
user with a warning when the image being opened has no embedded ICC
profile. The warning looks similar to the following (figure 14) and again
contains three options. The pre-set or default selection is dependent
upon the Colour Management Policy in operation at the time.
The above example is pre-set for how the dialog would appear when the
Colour Management Policy is set for Preserve Embedded Profile. Since no
profile is embedded Photoshop will try to assign the Working Space
profile to the image. No conversion takes place, just the assignment of
the Working Space profile.
The lower Assign Profile (and the associated and then convert to
working RGB) checkbox is the best choice if you know the source images'
true colour space and you want the image to appear correctly in
Photoshop. Typically, this option will be used for images from a digital
camera or similar device that does not embed a profile in the image file
or provide accurate EXIF colour space information. Note that the source
profile must be known and available to the user before this option can be
(iii) Paste Profile Mismatches: Ask When
Figure 15 below shows the Paste Profile Mismatch warning that appears
in the event of the colour spaces of the two images not matching.
Note that the terms preserve colour appearance and colour numbers
relate to the source image, not the destination.
The various warning dialog boxes shown above are only a sample of
those that may appear as you open or import images that contravene the
defined Colour Management Policy. However, I think that the text messages
included in each should be more than ample to explain what each option
does and will therefore allow you to make the appropriate choice.
This section will only be present in the Color Setting dialog if the
user chooses to activate the Advanced checkbox. Figure 16 shows this
section of the Color Setting dialog in its default configuration.
Engine: this is the name of the engine, which will be used for all
colour space conversions. Unless you have good reason to choose an
alternative your should leave it at the default Adobe ACE setting. ACE is
the direct equivalent of the Built-in engine used in Photoshop 5. Windows
users should NOT be tempted to choose ICM. Mac users should keep in mind
that the option chosen here will override the selection made in the
ColorSync setup. Choosing the ColorSync engine is for Mac users as a bad
a choice as Windows users choosing ICM.
Intent: this pop-up menu allows the user to select from four different
rendering intents, namely Perceptual, Saturation, Relative Colorimetric
and Absolute Colorimetric. Typically, most users will choose between
either Relative Colorimetric or Perceptual. A short description on each
is provided in the Description section of the Colour Settings dialog. A
more comprehensive explanation can be found in the Photoshop on-line help
With Relative Colorimetric it is only those source colours that are
out of gamut (i.e. can't be viewed/printed accurately within the
destination colour space) that will be mapped to the closest in-gamut
colour, the remainder are left unchanged. This means that in the case of
images with lots of out-of-gamut colours the visual relationship between
the colours (after conversion) will almost certainly change. With
Perceptual, all colours of the source colour space will be mapped to the
nearest in-gamut colour of the destination colour space thus maintaining
the visual relationship between colours. In other words, with Perceptual
the whole image colour gamut will be compressed so that it fits within
the new colour space. The Photoshop default and my recommendation is
Use Black Point Compensation: this should be kept checked. Black Point
Compensation ensures that the darkest neutrals of the source colour space
are mapped to the darkest neutrals of the destination colour space. In
most circumstances toggling BPC ON and OFF will result in no obvious
change to the image appearance.
Use Dither (8-bit/channel images): as with Black Point Compensation
this should be kept checked. The description box at the bottom of the
Colour Settings dialog box will give you some clue as to what it does.
As with the Conversion options, this section will only be present in
the Colour Settings dialog if the user chooses to activate the Advanced
checkbox. Figure 17 shows this section of the Colour Settings dialog in
its default configuration.
An explanation on what each of these options do is provided in the
Description box and on-line helps files. The consensus appears to be that
both settings should be left in the default Off condition.
The Desaturate Monitor Colour option is the one that has greatest
potential to cause confusion, as it will result in the image preview to
become progressively less saturated as the percentage is increased. Those
choosing to work in VERY wide colour spaces may find it useful, however,
the majority of Photoshop users should leave it Off.
Saving Out Your Own Default Colour Settings
Select the Save button and give your settings a Name and Description
by which you can call them back in the future, if for some reason you
make a temporary change. Also note that you can have as many different
sets of settings as you wish, although only one can be active at a time.
Figure 18 shows my preferred colour settings. Notice that I have chosen
to use a customised dot gain for the greyscale Working Space; you
shouldn't try to repeat these particular settings since it is specific to
Figure 18 - Customised Color
Part 3 - Soft Proofing
A frequently asked Photoshop questions is: why don't my prints match
the screen? Generally it's down to poor monitor calibration, but on other
occasions it's simply the fact that the user has unrealistically high
expectations of what can be printed or theyíve made the wrong selection
in the Photoshop Print with Preview dialog.
This section will discuss the options and commands associated with the
Photoshop CS Soft Proof feature and should also go some way to answering
the above question. However, you should note that I haven't included any
reference to specific printer driver set-ups as these have been covered
in a dedicated tutorial at: -
Basically soft proofing is nothing more than using your monitor as a
proofing device. However, accurate proofing is dependent upon the quality
and accuracy of the monitor profile that I described in Part 1. Youíll
also need good quality media profiles for each printer/media/ink
In order that we may get Photoshop in a state ready for soft proofing
we must configure the relevant dialogs. This is done via the View > Proof
Setup > Custom menu as shown below.
Proof Setup only affects the current or active image on your desktop.
So if you want to define your own default Proof Setup (as wise move) you
MUST configure the proof setup via the Custom menu option with NO
The various proofing options are:
Working CMYK - soft proofs the image using the current CMYK
working space defined in the Colour Settings dialog.
Working Cyan, Magenta, Yellow and Black Plate or Working CMY
Plates - soft proofs the image using the current CMYK working space
defined in the Colour Settings dialog.
Macintosh RGB and Windows RGB - soft proofs the image using the
standard Mac or Windows monitor profile (i.e. Apple RGB and sRGB
Monitor RGB - soft proofs the image using your actual monitor
profile. If the image look bad when this option is selected you know
that your monitor profile is broken and needs to be recreated as
described in Part 1.
Simulate Paper White - provides a preview of the shade of white
for the paper based upon the active soft proof profile . This option
requires a very accurate profile otherwise the whites of the image can
appear significantly more blue/yellow than it should.
Simulate Ink Black - provides a preview of the dynamic range of
the image based upon the active soft proof profile.
The screenshot below shows a typical view of the Proof Setup dialog
for an Epson inkjet printer simulation. From this dialog we can easily
select, configure and save our own customised soft proofing setup for any
number of different printer profiles. Remember; make sure you have NO
images/documents open when going through the process of defining your own
default Soft Proof profile.
We begin the process by choosing the Profile; in the example shown
above I have selected the Epson profile for Premium Glossy paper. This
choice will be the profile for the media that we want to simulate on the
Preserve Colour Numbers
This option will only be available if the image and profiles are in
sync, i.e. both are RGB or both are CMYK. Selecting the Preserve Colour
Numbers checkbox will usually result in a quite awful looking display,
this is how it should be. Basically we are simulating how the
document/image will appear if it is not converted to the actual device
One use of this option is to enable you to see how the image would
print if the media profile had not been selected in the Profile pop-up
menu. There are apparently others, but these all well beyond my
understanding. Normally it is best the leave the checkbox unchecked.
Use Black Point Compensation
I described Use Black Point Compensation previously when discussing
the Conversion Engines. Typically, it will be best to keep it checked.
Intent is the setting that appears to cause most confusion and it's
generally worth trying both Relative Colorimetric and Perceptual.
Typically Relative Colorimetric will be best but some highly saturated
images may benefit from choosing Perceptual.
There are two options (or checkboxes) shown in this section of the
Proof Setup dialog. The first Paper White allows you to simulate, on the
monitor, the shade/colour of the paper white. The second Ink Black will
enable you to simulate, on your monitor, the dynamic range defined by
the media profile (i.e. how dark black will appear on the media you are
printing to). Note that selecting the Paper White checkbox will cause
the Ink Black to be selected and greyed out. Not all profiles will
support both options.
The resulting soft proof display can be quite disconcerting in that
the overall tone of the image may tend to look compressed or slightly
colour shifted (e.g. white takes on a blue cast). This can often occur
when using scanner derived printer profiles. In such circumstances it
may be best to ignore the use of the Paper White and Ink Black since it
is VERY unlikely that they are in fact providing an accurate soft proof.
No doubt things will improve as the suppliers of the profiling software
update their programs to be compatible with this Photoshop feature.
To save your customised proof setup simply choose the Save button and
give the soft proof profile a name that clearly indicates the
printer/media combination for which it should be used. The name of a
saved soft profile will be appended onto the bottom of the list
immediately below Simulate Ink Black.
The saved soft proof profiles are saved to the following locations:
Windows - Program Files/Common
Mac OSX - ~Library/Application
A comprehensive tutorial describing the technique of soft proofing is
Part 4 - Managing
Image/Document Colour Space
On the Colour Space conversion and profile-embedding front we find
that little has changed from Photoshop 6 and 7. Without the tools that
follow it would be virtually impossible for the user to maintain a fully
As with previous versions of Photoshop the Assign Profile command is
accessed via the Image > Mode menu and allows the user to assign any
profile of their choosing to an image. The command itself was designed
for only a few limited uses, typically with images that have been scanned
into Photoshop using a Twain module or a scanner package that has no
means of embedding an ICC profile. It will also be useful handling images
from digital cameras that have no embedded profile or incorrect EXIF
colour space information.
Assuming that the colour management policy is not set to off then an
image imported into Photoshop with NO embedded profile will be assigned,
previewed and subsequently saved using the current Photoshop Working
Space. Obviously, this may not be the most appropriate colour space in
which to edit or save the image; so assuming the user has the correct
source profile they can make Assign the correct profile.
Itís important to note that assigning a profile does NOT convert the
image (will not change the numbers; i.e. RGB pixel values). Assign simply
provides Photoshop with a description of the actual colour space that you
wish to edit and view the image in. In other words it changes the image
appearance or meaning of the numbers.
The Don't Colour Manage this Document: option is used to instruct
Photoshop to remove an existing embedded profile (sometimes referred to
The Working RGB: option tags the image with the current default
working space profile as defined in Colour Settings.
The Profile: popup option allows us to assign a profile other than
the default Working RGB profile. In the above example I chose to assign
a customised profile for a digital camera.
Other potential uses for Assign Profile include the removal of an
embedded profile (i.e. don't colour manage the image). The example
screenshot shows a case where I chose to assign a customised profile for
my digital camera to an image.
Convert to Profile
The Convert to Profile command found under the Image > Mode menu is
basically an enhanced version of the old Photoshop 5 Profile-to-Profile
command. With Profile-to-Profile we were able to define the source colour
space (and probably get it wrong) whereas in Photoshop CS this cannot be
done since the source profile for the image is locked. The only way that
this source profile can be changed is via the Assign Profile command
In the example above I show an image with an embedded profile (Source
Space = Canon EOS D30 ..........NSC) being converted to Adobe RGB (1998)
(i.e. the Destination Space). Whenever we make this conversion it will be
the profile for the destination space that is embedded within the image
file when saved. Convert to Profile changes the numbers (i.e. pixel
values). The inclusion of the Preview checkbox allows the user to compare
the conversion with and without Black Point Compensation, Dithering and
any one of the four rendering Intents. The ability to preview the
conversion is a real boon and shouldn't be ignored, use it to your
Notice that the Intent is set to Relative Colorimetric, as this was
the default Intent chosen by me when configuring the Color Settings.
However, as with many Photoshop setting the Intent is "sticky", which
means that if I had chosen Perceptual instead then the next time I chose
Convert to Profile the Intent would be set to Perceptual. The moral being
- always check the actual value before clicking OK.
Last but not least, the Save As dialog throws up a host of useful
features. The Embed Profile checkbox is very important and will reflect
your choice of Colour Management Policy. You switch it ON or turn it OFF
as you please, the latter option being a bad idea in most instances.
Notice that the dialog even informs us which profile is being embedded.
The screenshot shown below is how the dialog appears on a Windows 2000
system; the Mac OSX version of Photoshop CS will look slightly different,
but are functionally identical.
The other save options present in the dialog are those associated with
Layers, Alpha Channels, Annotations, etc. Again, we can choose to uncheck
them and so save the image without the layers, etc. The Save As a Copy
feature is engaged by default as soon as you uncheck Layers; this
prevents you trashing a lot of hard work.
Part 5 - Print with Preview
Whilst printing from within Photoshop is discussed in
tutorial it's still worth providing a brief overview to round off
this essay on colour management.
The screenshot shown below shows the colour management
features within the Print with Preview dialog box although it is
first necessary to turn them on via the Show More Options
checkbox. The various colour management options enable you to define the
source and destination (target) colour spaces and the rendering intent
used to convert the image between the two.
Source Space: Document - this denotes the actual colour space
of the source image/document to be printed. The above example shows Adobe
RGB (1998), but it could be any number of user specified alternatives
(e.g. sRGB, ProPhoto, ColorMatch, etc.). If the image has already been
converted (using the Photoshop Convert to Profile command) to a
printer/media profile its name will be reflected here.
Source Space: Proof - tells Photoshop to convert the
image/document from the source colour space to the ICC profile specified
in the Proof Setup dialog (see: Photoshop View menu).
Print Space: Profile - is where you choose the preferred method
of managing the colour output from Photoshop. We have three different
options - each has its own specific configuration in the printer driver
so avoid a mix and match approach, as it will end in tears. The following
discussion should help you understand the differences between each.
Same as source: Photoshop simply passes the image/document
straight to the printer driver without making any print space
conversions. This option is effectively telling Photoshop to not colour
manage the printing of the image/document.
Printer Colour Management: choosing this options tells
Photoshop that the image/document should be sent to printer driver with
the profile listed against Source Space: embedded within it. By
embedding the profile Photoshop is providing the printer driver with
all the necessary information required to ensure accurate colour
rendering. Image/document colour management is handled the printer
ICC Profile: this last option is where we choose a specific
profile that is compatible with our printer. Notice that once an ICC
profile is selected the Intent and Use Black Point
Compensation (BPC) facilities are activated.
Hopefully the material presented in this essay has been
helpful and improved your understanding of Photoshop's approach to
managing colour. As noted throughout the essay there is vast body of
material to be found all over the internet. A simple search using "google.com"
and the keys words color management is all that is required.