Profile Inspector

Overview Tab

Device and Profile Connection Colorspace

The box area on the left of the Overview Tab summarizes the information regarding the device colorspace of the profile.

The box on the right summarizes the information regarding the Profile Connection Space (PSC) of the profile.

Color Tabs

For device profiles, the color tabs in the overview represent the colors of the primaries of the device as they were read when the profile was made. The white bar at the bottom of each tab can be clicked to reveal the Lab values of the colors.

For device link profiles the tabs show a representation of how colors will be modified by the profile. As no colorimetric information is contained in device link profiles, default RGB and CMYK profiles are used to display colors to screen. If the link profiles refer to color spaces other than CMYK, RGB, Lab or XYZ, there are no standard profiles available via ColorSync and color tabs will not be displayed. When available, the tabs will open to show device settings. Please refer to the Tutorials section of this manual for an example of evaluating a device link profile.

The Lab and XYZ tabs represent the Profile Connection Space (PCS) and are for illustration only. They cannot be dragged for graphing or other purposes.

Device Link Profiles

Device Link Profiles are used exclusively to convert from one set of device colors to another and as a result, contain no colorimetric information. To display CMYK or RGB colors on screen, the default RGB and CMYK profiles set in the ColorSync control panel are used.

Named Color Profiles

Monitor Profiles

Monitor profiles will display the measured white point in Kelvin.

Gamut Volume

The gamut volume number here represents cubic Lab values. This provides a reasonable approximation of the number of uniquely perceptible colors contained in a device's color gamut. This is intended for relative comparison purposes only.

Header Fields

The header fields in an ICC profile contain information and settings that apply to all ICC profile types. Most of these fields are for information purposes only but some can be edited:

Preferred CMM

This setting is typically used in applications or printer drivers that do not allow the setting of the desired CMM (Color Management Module). CMM selection and arbitration is a complex issue that takes into consideration the available CMM’s, the ability of the selected CMM to perform the desired operation and other factors. Change the setting with the popup menu and then save the profile using “FileSave” for the change to take effect.

The CMM used in ColorThink 4 is "LCMS" (littleCMS).

This CMM also enables ColorThink to offer the same module for both Windows and Mac platforms. For those who need consistency between operating systems, this ensures that you will get the same numbers on both systems (for example, when calculating profile gamut volume.)

Default Rendering Intent

This setting is typically used in applications or printer drivers that do not allow the setting of the desired rendering intent. Change the setting with the popup menu and then save the profile using “FileSave” for the change to take effect.

A diamond will appear next to the profile icon showing the profile has been altered and the change has not yet been saved.

Device Information

Device Information represents data bits that are available as part of the ICC specification. In practical usage, these bits have been very rarely even used in the industry, either from the profile creation side, or from the software that would use profiles. Most profiles will show these bits at 0.

Tag Table

The tag table in an ICC profile contains a series of data fields that are variable length and contain many different types of information. Text, color, device settings, descriptions and other information are contained in tags. The ICC profile specification requires some tags to be supplied in each type of profile. Additional “private” tags can be supplied by the profile creation software or editing applications and may be used by CMM’s to render color differently.

ColorThink recognizes all ICC-approved tags and a descriptive explanation is given for each of these tag types.

Name

The name (also known as the tag signature) is the official name as specified in the ICC specification.

Type

The type describes the different functions of the tag as defined by the ICC.

• Examples include "text" "desc" "mft2". Click on a tag for more information including where in the profile the tag resides and a summary of the tag's contents.

• “Text” data types can be exported as text files and opened in text editors, spreadsheet programs like Excel, or even opened into the Color Worksheet. Some profile-building applications embed the original measurement and reference data in the profile in the form of “Text” tags. These lists can be exported as text files and also re-opened into the Color Worksheet for analysis or graphing. (Click the "Open in Worksheet" button.)

• Color tags are shown in several different coordinate systems and a color tab displays the color for viewing or graphing.

Columns in this table can be re-ordered according to alphabetical order by clicking on the column heading. Once re-ordered, the Profile Inspector must be reopened in order to return to the original sort order. It is not possible to save a profile with a customized sort order of its tag table.

NEW!

Editing

A new feature of ColorThink 4 is the ability to edit color tags. The editing of the white point tab can be useful in many situations.

• A white point tag can be edited to reflect a different white point.

• Some colorant tags can be edited to make working space matrix profiles larger or smaller as desired.

• Values can be entered manually in XYZ, Lab or CCT data fields.

• The CCT (Correlated Color Temperature) value represents the equivalent white point in Kelvin temperature values.

• A list of colors, or a different profile can be dropped into the editor, and the white point will be automatically extracted.

• As ColorThink 4 supports measuring instruments, a measurement can be taken to be used to edit a tag definition. A “one-spot target” definition reference is included in ColorThink’s built-in targets for this purpose.

Private Tags

Private tags are unique to the profile creator or editor. Some private tags are recognized by ColorThink. Private, unrecognized tags are marked as such. If a profile manufacturer is willing to make their private tag information available to CHROMiX, we will consider writing tag interpreters for their tags into future versions of ColorThink. Please contact us for more information.

Try out the "Compare Profile Structures" procedure in the ColorSmarts Guide to compare the tag list of two different profiles.

Altering Profile Tags

Warning! The following procedures can render a profile useless if used incorrectly. Always save a backup copy of your profiles before making any changes.

Deleting tags

A tag can be deleted from the tag table by highlighting the tag and clicking the Backspace key (Delete on some keyboards).

Possible purposes for deleting tags:

• This can be useful in eliminating extraneous tags when repurposing profiles.

• If the profile will be publicly distributed, you may want to eliminate unused tags to avoid confusion and shrink the profile size.

• Some color data sets do not allow public distribution, so deleting these from the profile is required for compliance.

It is possible to delete tags that are required by the ICC specification and therefore render the profile useless. Be careful! See the http://www.color.org/for more information.

Copying tags from profile to profile

Tags can be swapped from one profile to another by clicking and dragging a tag from one open profile inspector window to another.

In most cases, the profile must be saved (File > Save As...) in order for the changes to be updated when altering tags.

Curves

The Curves tab gives a 2D graph of the either the neutral rendering curves or (if you have the Pro license), TVI / dot gain curves.

Neutral Rendering Curves

The Curves indicate what the profile needs to do, all along the spectrum of white to black, in order to produce neutral gray.

CMYK

When viewing a CMYK profile, four thin colored lines are shown running from bottom left to top right. These represent the process colors which would closely resemble the actual "curves" that are used to adjust color on a press or other CMYK device.

• The left axis, labeled 0 to 100, (bottom to top) represents the ink output values.

• The bottom axis, labeled 100 to 0, (left to right) represents the luminance (L*) input values for CMYK.

• The bottom axis would be labeled 0 to 100, left to right when referring to the density line. (To avoid confusion this labeling is left off of the graph for the density line.)

• Change the rendering intent that is graphed by clicking the drop-down box next to "Rendering Intent."

RGB

Since an RGB profile represents additive primary colors, the Curves tab will represent three thin lines of Red, Green and Blue running from upper left to bottom right. In other words, the upper left corner will start out white, with all of the RGB values combining to make black at the bottom right.

New!

The background behind the colored ramps can be changed from black to white merely by clicking anywhere in the graph.

Gray line

The thick gray line running from top left to bottom right represents the gray level reproduced by the profile. This line is color-accurate, so if the profile produces off-color neutrals, this tint will be reflected in this gray line.

The number scale on the left of the graph indicates RGB values from 0 to 255. So, at the upper left starting point, the paper is white. The line represents how much density is presented in relation to how much ink of any color is being laid down.

• The bottom axis, labeled 100 to 0, (left to right) represents the luminance (L*) input values for RGB.

• The bottom axis would be labeled 0 to 100, left to right when referring to the density line. (To avoid confusion this labeling is left off of the graph for the density line.)

• Change the rendering intent that is graphed by clicking the drop-down box next to "Rendering Intent."

Chroma Window

The Chroma window identifies at what point (in Lab space) is the neutral axis of the profile, for any given L (lightness) value. It is as if you were looking down the center of the profile and seeing where the grays differ from the center of Lab. The numbers on top of the Chroma bullseye window are the "a" and "b" values. The Chroma value below the windows tells how many Chroma values away from Lab neutral that point is. The concentric rings in the Chroma window are one delta E apart.

So, in this illustration: at an L value of 8, the a value would be -1.1 and the b value would be -1.2. This is a slightly cyan point approximately 1.6 delta E away from neutral.

This window is not necessarily an indication of how accurate your profile is, but is a good gauge of how much work your profile is doing to get your color into shape.

Dot Gain Curves

These dot gain curves are calculated using the XYZ method of dot gain calculation. To see an explanation of this calculation, check the Bruce Lindbloom website: http://www.brucelindbloom.com/index.html?Eqn_DotGain.html

One of the advantages of this method is that it allows ColorThink to calculate dot gains from profiles even when there is no measurement data available (for example, when the measurement data is not embedded in the profile.) Other means of calculating dot gain depend on using original measurement data.

Calculation of dot gain is only relevant to CMYK profiles. The dot gain option is not available for RGB profiles.

The XYZ method of dot gain calculation is only applicable to cyan, magenta, yellow and black inks, and may not give accurate results for multicolor profiles using other inks.

Try out the "Evaluate Device Dot Gain" procedure in the ColorSmarts Guide to see this function in practice.

Statistics

The Statistics table provides information comparing the current profile with the solid ink color required in the ISO 12647-2 standard.

The gamut volume number here represents cubic Lab values. This provides a reasonable approximation of the number of uniquely perceptible colors contained in a device's color gamut. This is intended for relative comparison purposes only. This is the same number shown on the Overview tab.

ColorThink 4 will recognize if the data used to create the profile is embedded in the profile. (For example, the reference and measurement information exists in the tag table.) If so, Training Data Available will indicate: "Yes."

In some cases, the ColorSmarts Guide can automatically extract this data for some tests.

For example, when running the "Evaluate Profile Proofing" procedure in the ColorSmartsGuide, if you have "training data available", then the measurement and reference data will be populated automatically by merely clicking and dragging your profile into place in the Guide.

Inking Statistics

This is a summary of the ink information found in the Curves tab. This information can confirm that the profile is using ink properly. For example, a CMYK profile, built using 350% total ink limit, would not be expected to be using more than 350% total ink here. The total ink limit shown here may fall below that requested when building the profile, but if it exceeds the TIL of the profile then it is an indication that the profiling software made a poor profile.

The black start numbers listed here are taken from the cyan percentage for that rendering intent.

Ink Color / ISO 12647-2 Compliance

This represents a quick comparison of this profile to the popular offset lithography standard.

Errors/Warnings tab

If any errors or warnings are discovered as the profile is opened, a caution or stop icon will appear in the “Errors and Warnings” tab to alert of the problem. All errors and warnings will be summarized in this tab. Click the Profile Medic button to perform the necessary fixes on the profile.

Quick Access Buttons

These icons provide a quick way to perform many useful tasks.

Edit white point

This button will instantly open up the White point tag in the Tag Table to make it available for editing.

Rename Profile

This will allow the editing of both the internal name (the name displayed by Photoshop), and the external name (as viewed by file browsers).

• To copy the Internal Name down to the File Name, click the down arrow and vice versa.

• If the names are the same, the "lock" button will be checked.

• Check the lock button at any time to synchronize the names.

• If the Lock button is checked, all changes are made in the upper (Internal Name) box and are reflected in both edit boxes.

• "Allow” “Remove” “Add” Suffix explained:

By default a suffix such as .icc, .icm or .pf is allowed to exist on the filename. It will not be copied into the internal name and any changes made will keep the suffix (unless you explicitly delete it.)

• ColorThink will only allow the addition of the “.icc” suffix - as the “.icm” and “.pf” suffixes are unnecessary and easily cause user confusion.

• Selecting "Change Prefs..." will save the new preference for use in the Color Medic, Profile Inspector, and Profile Manager.

• File names are limited to 31 characters in some operating systems. If you wish the internal and external names to be the same (this is recommended), then locking the internal name to the external file name may limit how many characters can be used.

Clicking "Rename" will save any changes made to either name.