GIMP on PIXLS.US

A Masashi Wakui look with GIMP

Mon, 28 Nov 2016 13:25:21 -0600

This tutorial explains how to achieve an effect based on the post processing by photographer Masashi Wakui . His primary subjects appear as urban landscape views of Japan where he uses some pretty and aggressive color toning to complement his scenes along with a soft ‘bloom’ effect on the highlights. The results evoke a strong feeling of an almost cyberpunk or futuristic aesthetic (particularly for fans of Bladerunner or Akira !).

Highlight Bloom and Photoillustration Look

Wed, 12 Oct 2016 13:47:35 -0500

Over in the forums community member Sebastien Guyader (@sguyader) posted a neat workflow for emulating a photo-illustrative look popularized by photographers like Dave Hill where the resulting images often seem to have a sort of hyper-real feeling to them. Some of this feeling comes from a local-contrast boost and slight ‘blooming’ of the lighter tones in the image (though arguably most of the look is due to lighting and compositing of multiple elements).

A Chiaroscuro Portrait

Wed, 27 Jul 2016 13:16:07 -0500

Introduction (Concept/Theory)

The term Chiaroscuro is derived from the Italian chiaro meaning ‘clear, bright’ and oscuro meaning ‘dark, obscure’. In art the term has come to refer to the use of bold contrasts between light and shadow, particularly across an entire composition, where they are a prominent feature of the work.

This interplay of shadow and light is particularly important in allowing the viewer to extrapolate volume from a flat image. The use of a single light source helps to accentuate the perception of volume as well as adding drama and dynamics to the scene.

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.

Freaky Details (Calvin Hollywood)

Mon, 31 Aug 2015 14:33:50 -0500

German photographer/digital artist/photoshop trainer Calvin Hollywood has a rather unique style to his photography. It’s a sort of edgy, gritty, hyper-realistic result, almost a blend between illustration and photography.

As part of one of his courses, he talks about a technique for accentuating details in an image that he calls “Freaky Details”.

Here is Calvin describing this technique using Photoshop:

In my meandering around different retouching tutorials I came across it a while ago, and wanted to replicate the results in GIMP if possible. There were a couple of problems that I ran into for replicating the exact same workflow:

Color Curves Matching

Tue, 04 Aug 2015 14:10:36 -0500

In my previous post on Color Curves for Toning/Grading , I looked at the basics of what the Curves dialog lets you do in GIMP . I had been meaning to revisit the subject with a little more restraint (the color curve in that post was a little rough and gross, but it was for illustration so I hope it served its purpose).

This time I want to look at the use of curves a little more carefully. You’d be amazed at the subtlety that gentle curves can produce in toning your images. Even small changes in your curves can have quite the impact on your final result. For instance, have a look at the four film emulation curves created by Petteri Sulonen (if you haven’t read his page yet on creating these curves, it’s well worth your time):

Basic Color Curves

Mon, 27 Jul 2015 10:26:49 -0500

Color has this amazing ability to evoke emotional responses from us. From the warm glow of a sunny summer afternoon to a cool refreshing early evening in fall. We associate colors with certain moods, places, feelings, and memories (consciously or not).

Volumes have been written on color and I am in no ways even remotely qualified to speak on it. So I won’t.

Instead, we are going to take a look at the use of the Curves tool in GIMP . Even though GIMP is used to demonstrate these ideas, the principles are generic to just about any RGB curve adjustments.

A Q&A with Photographer Riley Brandt

Wed, 15 Jul 2015 08:47:30 -0500

Riley Brandt is a full-time photographer (and sometimes videographer) at the University of Calgary . He previously worked for the weekly (Calgary) local magazine Fast Forward Weekly (FFWD) as well as Sophia Models International , and his work has been published in many places from the Wall Street Journal to Der Spiegel (and more ).

He recently announced the availability of The Open Source Photography Course . It’s a full photographic workflow course using only free, open source software that he has spent the last ten months putting together.

Basic Landscape Exposure Blending with GIMP and G'MIC

Tue, 09 Jun 2015 10:34:49 -0500

Photographer Ian Hex had previously explored the topic of exposure blending with us by using luminosity masks in darktable . For his first video tutorial he’s revisiting the subject entirely in GIMP and G’MIC .

Have a look and let him know what you think in the forum. He’s promised more if he gets a good response from people - so let’s give him some encouragement!

An Open Source Portrait (Mairi)

Mon, 18 May 2015 12:04:49 -0500

This is an article I had written long ago (originally published in 2013). The material is still quite relevant and the workflow hasn’t really changed, so I am republishing it here for posterity and those that may have missed it the first time around.

The previous post for this article went over the shoot that led to this image.

If you’d like to follow along with the image of Mairi, you can download the files from the links below.

Skin Retouching with Wavelet Decompose

Mon, 20 Apr 2015 11:47:07 -0500

Skin retouching is a delicate art.

Effective skin retouching can feel like a black art.

There have been various methods detailed in the past for ways to “smooth” skin in GIMP . Those methods ranged from disappointing at best to downright ridiculous at worst. The disappointing methods were simply a product of the best methods available at the time. The ridiculous ones seemed to be due to a lack of subtlety.

Digital B&W Conversion (GIMP)

Tue, 16 Sep 2014 13:36:26 -0500

Black and White photography is a big topic that deserves entire books devoted to the subject. In this article we are going to explore some of the most common methods for converting a color digital image into monochrome in GIMP .

What We are Trying to Achieve

There are a few things you should focus on in regards to preparing your images for a B&W conversion. You want to keep in mind that by removing color information you are effectively left with only tonal data (and composition) to convey your intentions.

GIMP on PIXLS.US

A Masashi Wakui look with GIMP

Highlight Bloom and Photoillustration Look

A Chiaroscuro Portrait

Introduction (Concept/Theory)

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

Freaky Details (Calvin Hollywood)

Color Curves Matching

Basic Color Curves

A Q&A with Photographer Riley Brandt

Basic Landscape Exposure Blending with GIMP and G'MIC

An Open Source Portrait (Mairi)

Skin Retouching with Wavelet Decompose

Digital B&W Conversion (GIMP)

What We are Trying to Achieve