Color-Management on PIXLS.US

Display Color Profiling on Linux

Thu, 09 Jun 2016 16:50:08 -0600

This article by Pascal de Bruijn was originally published on his site and is reproduced here with permission. —Pat

Attention: This article is a work in progress, based on my own practical experience up until the time of writing, so you may want to check back periodically to see if it has been updated.

This article outlines how you can calibrate and profile your display on Linux, assuming you have the right equipment (either a colorimeter like for example the i1 Display Pro or a spectrophotometer like for example the ColorMunki Photo). For a general overview of what color management is and details about some of its parlance you may want to read this before continuing.

Users Guide to High Bit Depth GIMP 2.9.2, Part 2

Wed, 02 Dec 2015 12:00:00 -0600

This is Part 2 of a two-part guide to high bit depth editing in GIMP 2.9.2 with Elle Stone. The first part of this article can be found here: [*Part 1*](/articles/users-guide-to-high-bit-depth-gimp-2-9-2-part-1/).

Using GIMP 2.9.2 for radiometrically correct editing

<ol>
<li><a href="#linearized-srgb-channel-values-and-radiometrically-correct-editing">Linearized sRGB channel values and radiometrically correct editing</a></li>
<li><a href="#using-the-linear-light-option-in-the-image-precision-menu">Using the “Linear light” option in the “Image/Precision” menu</a></li>
<li><a href="#a-note-on-interoperability-between-krita-and-gimp">A note on interoperability between Krita and GIMP</a></li>
</ol>

GIMP 2.9.2’s unbounded floating point ICC profile conversions (handle with care!)

Using GIMP 2.9.2’s floating point precision for unclamped editing

<ol>
<li><a href="#high-bit-depth-gimp-s-unclamped-editing-a-whole-realm-of-new-editing-possibilities">High bit depth GIMP’s unclamped editing: a whole realm of new editing possibilities</a></li>
<li><a href="#if-the-thought-of-working-with-unclamped-rgb-data-is-unappealing-use-integer-precision">If the thought of working with unclamped RGB data is unappealing, use integer precision</a></li>
</ol>

Looking to the future: GIMP 3.0 and beyond

Radiometrically correct editing

Linearized sRGB channel values and radiometrically correct editing

One goal for GIMP 2.10 is to make it easy for users to produce radiometrically correct editing results. "Radiometrically correct editing" reflects the way light and color combine out there in the real world, and so requires that the relevant editing operations be done on linearized RGB.

Users Guide to High Bit Depth GIMP 2.9.2, Part 1

Sun, 01 Nov 2015 12:00:00 -0600

Introduction: high bit depth GIMP 2.9.2

    <ol>
    <li><a href="#purpose-of-this-guide">Purpose of this guide</a></li>
    <li><a href="#useful-links-the-official-gimp-website-builds-for-windows-and-mac-building-gimp-on-linux">Useful links: the official GIMP website, builds for Windows and MAC, building GIMP on Linux</a></li>
    <li><a href="#editing-in-srgb-vs-editing-in-other-color-spaces">Editing in sRGB vs editing in other color spaces</a></li>
    <li><a href="#a-note-about-the-gamma-hack-that-s-provided-for-many-editing-operations">A note about the “Gamma hack” that’s provided for many editing operations</a></li>
    </ol></li>

<li><a href="#new-high-bit-depth-precision-options">New high bit depth precision options</a>

    <ol>
    <li><a href="#menu-for-choosing-the-image-precision">Menu for choosing the image precision</a></li>
    <li><a href="#which-precision-should-you-choose-for-editing-">Which precision should you choose for editing?</a></li>
    <li><a href="#using-the-image-precision-options-when-exporting-an-image-to-disk">Using the image precision options when exporting an image to disk</a></li>
    </ol></li>

<li><a href="#new-color-management-options">New color management options</a>

    <ol>
    <li><a href="#gimp-2-9-2-automatically-detects-camera-dcf-information">GIMP 2.9.2 automatically detects camera DCF information</a></li>
    <li><a href="#black-point-compensation">Black point compensation</a></li>
    </ol></li>

<li><a href="#new-and-updated-algorithms-for-converting-to-luminance-lab-and-lch">New and updated algorithms for converting to Luminance, LAB, and LCH</a>

    <ol>
    <li><a href="#converting-srgb-images-from-color-to-black-and-white-using-luma-and-luminance">Converting sRGB images from Color to Black and White using Luma and Luminance</a></li>
    <li><a href="#decomposing-from-srgb-to-lab">Decomposing from sRGB to LAB</a></li>
    <li><a href="#lch-the-actually-usable-replacement-for-the-entirely-inadequate-color-space-known-as-hsv-">LCH: the actually usable replacement for the entirely inadequate color space known as “HSV”</a></li>
    </ol></li>

Introduction: high bit depth GIMP 2.9.2

Purpose of this guide

As announced on the GIMP users and developers mailing lists, the recent (November 26, 2015) GIMP 2.9.2 release is the first development release in the GIMP 2.9.x series leading to GIMP 2.10. The release announcement summarizes the many code changes that were made to port the old GIMP code over to GEGL’s high bit depth processing.

Color-Management on PIXLS.US

Display Color Profiling on Linux

Users Guide to High Bit Depth GIMP 2.9.2, Part 2

Contents

Radiometrically correct editing

Linearized sRGB channel values and radiometrically correct editing

Users Guide to High Bit Depth GIMP 2.9.2, Part 1

Contents

Introduction: high bit depth GIMP 2.9.2

Purpose of this guide