Tuesday, November 17, 2015

Calibrate your Monitor with these Open Source Tools


What is seen on your display and what the image should look like can be two quite different things.
If you value image quality and accuracy, calibration of your monitor will be important. Anyone involved in digital photography, graphic design or artwork will recognise the importance that their monitor is producing the best results, showing true colors and black levels. The objective when calibrating a monitor is to ensure the monitor has color references known by everyone (humans and software). This will mean the colours are represented accurately on your monitor.
Generally speaking, using a color measurement instrument to calibrate your display will result in a better calibration compared to a visual calibration. The following open source tools are invaluable for anyone looking for accurate color reproduction. The first one is dispcalGUI.


dispcalGUI in action
dispcalGUI is an open source graphical user interface for display calibration and profiling using ArgyllCMS.
This tool calibrates and characterizes display devices using a hardware sensor.
dispcalGUI is written in Python and uses NumPy, demjson (JSON library) and wxPython (GUI toolkit). It also makes extensive use of several Argyll CMS utilities.
Features include:
  • Display calibration using one of many supported hardware sensors
  • Profile verification and measurement report: Check the quality of profiles and 3D LUTs via measurements. Also supports custom CGATS files (e.g. FOGRA, GRACoL/IDEAlliance, SWOP) and using of reference profiles to obtain test values
  • 3D LUT generation
  • Profile inspection
  • Test chart editor: Create charts with any amount of color patches, easy copy & paste from CGATS, CSV files (only tab-delimited) and spreadsheet applications
  • Support for multi-display setups
  • Variety of available settings such as customizable whitepoint, luminance, tone response curve as well as the option to create matrix and look-up-table ICC profiles, with optional gamut mapping, as well as some proprietary 3D LUT formats
  • Support of colorimeter correction for different screens via correction matrices or calibration specral sample files (the latter only for specific colorimeters i.e. i1 Display Pro, ColorMunki Display and Spyder 4/5)
  • Create synthetic ICC (matrix) profiles with custom primaries, white- and blackpoint as well as tone response
  • All instruments supported by Argyll CMS are supported by dispcalGUI
  • Website: dispcalgui.hoech.net
  • Developer: Florian Hoech
  • License: GNU GPL v3
  • Version Number:


ArgyllCMS is an open source ICC compatible color management system. It supports accurate ICC profile creation for scanners, CMYK printers, film recorders and calibration and profiling of displays. Spectral sample data is supported, allowing a selection of illuminants observer types, and paper fluorescent whitener additive compensation.
Profiles can also incorporate source specific gamut mappings for perceptual and saturation intents. Gamut mapping and profile linking uses the CIECAM02 appearance model, a unique gamut mapping algorithm, and a wide selection of rendering intents.
It also includes code for the fastest portable 8 bit raster color conversion engine available anywhere, as well as support for fast, fully accurate 16 bit conversion. Device color gamuts can also be viewed and compared using a VRML viewer. Comprehensive documentation is provided for each major tool, and a general guide to using the tools for typical color management tasks is also available.
Features include:
  • Command line only collection of tool
  • Covers a wide range of needs from source or output characterization to monitor LUT loading and more
  • Supports many common (commercial and do-it-yourself) color meters such as the X-Rite i1 Display Pro and ColorMunki Display colorimeters
  • Suppport for ColorVision Spyder to produce an ICC monitor profile
  • Experimental support for ColorHug - an open colorimeter
  • Website: www.argyllcms.com
  • Developer: Graeme Gill
  • License: Affero GNU v3
  • Version Number: 1.8.3

Gnome Color Manager

GNOME Color Manager in action
GNOME Color Manager is a set of open source graphical utilities for color management to be used in the GNOME desktop. With the help of ArgyllCMS, it can create and apply display ICC color profiles. This gives a consistent color to an image or document, wherever it is output.
Features include:
  • Generate, install and manage device colors on a GNOME desktop
  • Uses International Color Consortium (ICC) profiles to map device color characteristics onto a standard color space used by the GNOME desktop
  • Website: apps.ubuntu.com
  • Developer: The Gnome Project
  • License: GNU GPL v2
  • Version Number: -


LPROF in action
LPROF is a color profiler that creates ICC compliant profiles for devices such as cameras, scanners, and monitors. These profiles provide color consistency across devices. They can be used in color profile-aware software such as The Gimp and Scribus.
Camera and scanner profiles are built by using a thing known as "IT8 target". IT8 targets are just a photo with a set of color patches. There are known colorimetric measurements for each of these patches. There is also a standard way to specify these measurements, the IT8/CGATS file format. Each IT8 target comes with a IT8/CGATS file that contains the colormetric measurements for that target.
Features include:
  • Easy to use graphical interface
  • ICC version 2 compliant
  • Use with software that utilizes the color profile in calibration
  • Website: lprof.sourceforge.net
  • Developer: Klas Kalass, Marti Maria
  • License: GNU GPL v2
  • Version Number:

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