Color profiles play a crucial role in ensuring your PDFs look exactly as intended, whether they’re viewed on-screen or printed. Without proper color management, what you see on your monitor might not match the final output—leading to dull colors, unexpected shifts, or print inaccuracies.  

Color profiles are based on the specification created by the International Color Consortium (ICC) in 1993 to govern color and color management across all operating systems, platforms, and software and hardware and software systems. A color profile is usually expressed as a file included in the software or driver for an installed printer, scanner, or other hardware device, or in software used to edit a file that is to be displayed or printed. A profile provides a set of data that describes an input or output device. A color profile file can also be embedded in a PDF document. Here are the different elements of color profiles as used by PDF Optimizer:

enabled: Enables PDF Optimizer to convert colors in a PDF document using a target profile.

convert-profile: The profile used to convert colors in the PDF document.

lab-d50: L*a*b color specification with a D50 white point. The Lab color space is based on the CIE XYZ color space, but it includes a dimension L, for lightness, along with a and b coordinates, to define the color. This is Adobe Systems’ standard Lab profile.

srgb: Standard RGB, the default profile for Windows monitors.

apple-rgb: Apple RGB, the default profile for Mac monitors

color-match-rgb: Color Match RGB. This is a simpler version of the Radius ColorMatch RGB space, without the non-zero black point.

gamma-18: Gray Gamma 1.8, grayscale display profile, used for content viewed on a monitor

gamma-22: Gray Gamma 2.2

dot-gain-10: Grayscale printer profile, with dot gain 10%. Dot gain is commonly used in offset printing to define the increase in size in halftone dots in the printing process, making a printed document look darker than intended.

dot-gain-15: Dot gain 15%

dot-gain-20: Dot gain 20%

dot-gain-25: Dot gain 25%

dot-gain-30: Dot gain 30%

monitor-rgb: RGB Monitor, referring to a monitor that requires separate signals for the three primary colors.

acrobat5-cmyk: Adobe Reader 5 CMYK

acrobat9-cmyk: Adobe Reader 9 CMYK

The above list of options represents the standard list of color profiles provided with PDF Optimizer. These color profiles are in the form of .icc profile files, and these files are stored in this directory after the product is installed:
PDF Optimizer\Resources\Color\Profiles

If you enter one of these options, PDF Optimizer can find the correct color profile file. If you want to use your own custom color profile file, provide the full path name where the file is stored. We recommend that you put your color profile file in the same \Resources directory where the other color profile files are stored, but you can store it wherever you like.

If you want to apply your own color profile, the convert-profile section of the JSON profile file might look like this:
"color-conversion": {
"enabled": "on",
"color-convert-action": "convert",
"convert-intent": "profile-intent",
"convert-profile": "C:\Datalogics\PDF Optimizer\Resources\Color\ Profiles\custom_profile.icc"
},

color-convert-action: The type of color conversion. The values available include convert and decalibrate. The decalibrate setting means that PDF Optimizer will decalibrate calibrated color spaces in the PDF document.

If a color profile file is assigned to a PDF document, or to a feature in that PDF document, such as an image, the document or image is referred to as “calibrated.” This color profile will be used when rendering colors for that document. If a color profile is not assigned to the document, a default color profile is used instead, usually installed on the local device or on a printer. So, if you select decalibrate as the color-conversion-option, you can remove the ICC profile file stored in the PDF document, and thus reduce the size of the PDF output file.

convert-intent: Use this setting to specify the color translation method for colors that are outside the gamut of the color profile. The intent lets the software determine how to substitute a color that can be written to the file. You can select from a list of standard strategies to apply when converting the colors in that original PDF document. The conversion intent is used to describe how the destination device for the document reproduces the colors in the document. Thus, when you print or display the PDF output file, the colors in the output file will match as closely as possible the original color found in the source PDF document.

perceptual-intent: Generally used for photography. This method does not map colors one for one but estimates to match colors. Hence it often provides the most pleasing result but not necessarily the most accurate.

relative-colorimetric-intent: Generally used for photography. The relative method uses an algorithm to select the closest possible color map to be true to the specified color.

saturation-intent: Commonly used in charts and diagrams with a limited palette of colors where hue is not as important.

absolute-colorimetric-intent: Often used to select a specific color or set of colors for drawings or designs. Absolute serves to reproduce the exact colors provided in the original PDF document. A common reason for using absolute would be to reproduce the color used in a corporate logo such as IBM Blue. The color is changed by selecting a defined match. This method does not use a conversion algorithm to select the closest color available.

profile-intent: If you specify a color profile in the convert-profile option the intent value defaults to that profile. In that case software will use the rendering intent provided with the ICC color profile currently in use for that PDF document. For example, the Adobe RGB 1998 color profile uses Relative Colormetric as its rendering intent. So if you specify Adobe RGB 1998 (srgb) as the color profile, and profile-intent is selected here, the PDF Optimizer software will use relative.

object-type: Use this setting to specify what type of objects are included in the color conversion process. This allows for more granular control over what types of objects are included or not during conversion.

all: Include all object types (images, text, line-art, and shading) during color conversion.

images: Include images during color conversion.

text: Include text during color conversion.

line-art: Include line-art during color conversion.

shading: Include smooth shadings during color conversion.

Simplify PDF Color Management

With PDF Optimizer, managing color profiles and conversions is straightforward. By fine-tuning these settings, you can achieve high-quality, color-accurate PDFs while optimizing file size for efficient sharing and storage. Optimize your PDF colors today by starting a free trial!