Episode 199: G’MIC

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G’MIC is a lot of things that do stuff with images. You have a stand alone program with a complete image manipulation and analysis programming language, an online service and a GIMP plugin that gives easy access to (nearly) the whole package. Don’t get G’MIC from other sources than their pages – the update cycle is so fast that package maintainers can’t keep up. The version recorded in the video is already outdated twice at the time of the publication.

G’MIC is mostly developed by Dr. David Tschumperlé of the GREYC, an institute at the University of Caen in France that is also part of the Centre National de la Recherche Scientifique (National Center for Scientific Research). So definitely no hobbyist project.

I met David and his friend and colleague Jérôme – also a scientist AKA Dr. Jérôme Boulanger – at the LGM in Leipzig. Very nice guys! See Pat David’s wonderful blog post for more images and a report.

You can find information about G’MIC at their site in the very good and complete manual, at YouTUBE from G’MIC and David, at Pat David’s Blog and all over the Internets.

The second part of the video is a promotion for Ramón Miranda‘s very good training DVD “Muses”. It goes through the whole process of learning Krita – a graphics program under Linux and Windows, which is much better for painters than GIMP – up to finishing a real digital painting. You can buy the DVD at the Krita shop, 32.50€ is comparable to other kinds of such DVDs and the proceeds support the Krita Foundation.

I got this one for free – and I will give it away! If you want to have it, write a comment to this blog post before Episode 200 is published. Get your mail address right (it will only be visible to me) and mention that you want the DVD. After the deadline I’ll have some supposedly innocent children draw a winner.

The TOC

00:00:00 Start of video
00:01:10 Installing the G’MIC Plugin for GIMP
00:03:00 Installing and using G’MIC as a stand alone program
00:10:00 G’MIC Online service
00:10:40 Using the G’MIC GIMP Plugin
00:13:40 Pencil Drawing emulation as an example
00:18:10 Film emulations and grain as an example
00:25:15 Spectral filters – Fourrier included
00:26:20 Plotting Graphs with G’MIC
00:26:50 Conclusion
00:29:20 Ramon Miranda’s Krita tutorial DVD
00:33:10 EOF

Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 4.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 197: The LGM 2014 Group Photo

LGM 2014 Group PhotoDownload the Video! (37:06, 124 MB)

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I went to the Libre Graphics Meeting 2014 in Leipzig to get either a boost for my motivation or to find an end for this project. It turned out to be a booster.

It was a really good time – even with missing the first day and the (for me) most interesting talks because I had to work that day. Another day was spent at the Zoo with Pat David and his wife, more time in the coffee room, Milchbars and restaurants. All the time having good conversations and learning a lot.

And then I got the honors of shooting the traditional group image. I assume it was not my track record of famous group pictures but the 36 megapixel resolution of my D800 that led to that decision.

In this episode I cover the post processing of the image and how I blended my previously taken image into the group.

The TOC

00:00:00 Intro
00:01:14 The LGM Group Photo
00:04:05 Rotating the image
00:06:05 Adjusting contrast and brightness with the curves tool
00:09:23 Getting myself into the image
00:10:54 Registering the layers
00:14:38 Merging with a layer mask
00:17:55 Ways to change the brush size
00:18:50 Cleaning up the layer mask
00:20:38 Curves adjustments on a selection
00:24:28 Cropping the image
00:25:58 Sampling a fill colour out of the image
00:27:14 Sharpening with wavelets
00:31:12 Adding the SVG logo
00:34:04 Scaling down and exporting
00:36:38 Good bye!
00:37:06 EOF

Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 4.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 196: ENIAC and Me

ENIAC and MeDownload the Video! (42:02, 140 MB)

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Some timing issues pushed this video back and back again in time – and now it’s Christmas! Have nice Holidays!

In this video I try to change history and put myself in an old image of the first electronic computer, the ENIAC.

The original image is an US ARMY Photo under Public Domain, downloaded from Wikimedia.

As this is intended to be the base for a class project, I don’t go into the depth of GIMP but try to cover a lot of ground on a beginners level. And of course I make some mistakes…..

Links and Notes:

Episode 163 – Curves
Episode 094 – Curves
Episode 083 – Grit and Grain
Episode 073 – Layers

Our Wiki also covers Layers and Curves.

The nice image of the Rolleiflex has been made bay Rid Sevilla from Hawaii Camera Style

The image in this post has been altered a bit more with the GIMP filter “Old Photo” under /Filters/Decor/Old Photo.

The TOC

00:00:00 Intro
00:02:04 Opening an image from the Web
00:03:02 Loading an image from disk and some mistakes to avoid when making your image
00:03:55 Getting an image into another one
00:04:30 Measure Tool
00:05:00 Scaling to the proper size
00:05:25 Copy and Paste between images
00:06:10 RGB- and Grayscale Mode
00:06:30 Save the image in XCF format!
00:07:54 Isolate the person from the background with a layer mask, the Free Hand Selection and a brush
00:10:10 Free Hand Selection
00:11:30 Undo
00:12:15 Tedious paint work
00:17:30 “Optimizing” the mask with the curves tool and a blur
00:19:30 Finding the right position and scaling a layer
00:22:15 Adding the Curves Tool to the Toolbox
00:23:20 The Curves Tool
00:26:30 Adding grit and grain by extracting the grain from the image
00:30:00 Bucket fill tool
00:31:08 Try stuff with a layer copy
00:33:06 Adding light and shadows
00:38:15 Summary
00:40:20 Move a stack of layers, keeping them aligned
00:41:10 Saving and exporting the image
00:42:02 EOF

Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 195: Whose RGB?

rgb
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Colo(u)r ist the topic this time. You are in for a ride from the electromagnetic spectrum to the biology of color vision and the infamous Mantis Shrimp. (Link to the fabulous Oatmeal!)

Grassmann’s Law gives a clue how to create a color sensation in the brain by mixing up some wavelengths out of the spectrum. The CIE finally defines what is visible for a “Standard Observer” and Microsoft & HP (sRGB) and Adobe (Adobe RGB) build their color spaces on that foundation.

Elle Stone, Bruce Lindbloom and Cambridge in Colour help along the way, passing a Black Body emitting radiation according to Planck’s Law at 6500K just to give us a White Point.

Then I organize a shootout between sRGB and Adobe RGB – and I’ll stick to sRGB for the forseeable future.

Finally I cover the question of Intent while converting between different color spaces – Perceptual or Relative Colorimetric?

Links

Elle’s fine writeup about All the Colors.

The Color Space Viewer (at the bottom of the page)

Pascal’s tutorials about color management on Linux – really hands on:

https://encrypted.pcode.nl/blog/2012/01/29/color-management-on-linux/
https://encrypted.pcode.nl/blog/2013/11/24/display-color-profiling-on-linux/
https://encrypted.pcode.nl/blog/2013/04/14/display-profiles-generated-from-edid/

The TOC

00:00:00 Intro
00:00:15 Submit to GIMP Magazine
00:00:50 Light as part of the electromagnetic spectrum
00:01:43 Biology of color vision
00:06:14 World Champion of Color Vision: The Mantis Shrimp!
00:06:40 Grassmann’s Law – mixing colors from spectral primes
00:07:22 CIE 1931 Color Space – the standard observer
00:09:00 Elle Stone’s blog – a lot about color!
00:09:50 sRGB
00:11:40 D65 – the White Point for sRGB
00:11:56 Black Body Radiation and White Points
00:13:44 Bruce Lindbloom has a Color Space viewer
00:14:30 Adobe RGB (1998)
00:15:50 Why not ProPhoto RGB?
00:16:20 Preparing some test shots in the lab
00:16:59 Comparing sRGB and Adobe RGB camera setting
00:18:42 Conclusion – stick to sRGB
00:19:34 Converting between color spaces
00:20:06 Intent: relative colorimetric or perceptual?
00:21:14 Consequences
00:23:10 Winding down
00:24:09 EOF

Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 193: A Mondrian UI

193Download the Video! (11:50, 41.3 MB)

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After a too long summer break I give you a preview of one feature in the next version of GIMP – the unified transformation tool. It combines the tools for moving, rotating, scaling, shearing and for changing the perspective in one tool with a nice and sleek user interface.

The UI design has been done mostly by Peter Sikking.  He has also had his hands in the nice free selection tool design.

This unified transformation tool shall be used with visual feedback on the canvas. The old tool will stay around for work where numbers are important.  So this is not a replacement but an addition.

You can read a bit more in the developers mailing list and on the GUI wiki page.

The TOC

00:00:00 General rumblings
00:01:20 GIMPMagazine 4
00:02:26 GIMP 2.9
00:02:26 The Transform Tools of 2.8
00:04:00 Loss of sharpness – unavoidable with transformation
00:04:35 The new Unified Transform Tool UI
00:07:50 Better results due to only one calculation
00:09:00 Peter Sikking, UI architect
00:10:20 The UI design determines your work flow
00:10:41 No replacement for the traditional tools
00:11:33 Final words
00:11:50 End of video

Image credits for the Autobahn sign: Wikimedia, User Mediatus.
Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 192: Look Down! – A Challenge

192Download the Video! (45:45, 86.9 MB)

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Download the template! (0.06 MB)
Download my sidewalk images! ( 18.1 MB)

There was no show for quite some time – and there will be a gap until the end of summer. I move back to Bremen – and that takes a lot of time and creativity away. But in Bremen I will have nearly 2 hours more time each day, because I can walk to school and don’t need to ride the famous Berlin S-Bahn Ring Line.

In the meantime I have a challenge for you! Present the place where you live to us – but look down on the sidewalk for that! The best results will be published in the GIMP Magazine #5 and of course here on the blog. The exact rules are below.

This Challenge is a perfect rip off from a challenge by Andrés (Twitter) (Website), an illustrator from Buenos Aires, in the now closed forum of Tips from the Top Floor. Make a mosaik of images of the sidewalks in your city and try to transport the atmosphere.
Rolf's Example
This is my take on the Silvio-Meier-Strasse around the corner from my flat in Berlin.

The Rules

  1. Make a mosaic of at least 3×3 images.
  2. All images have to be shot straight down
  3. All images are in the same scale, use the same distance to the ground and the same focal length.
  4. All images have to be linked to each other in their theme by being from one city, one journey …..
  5. Publish your image online and post a link to it before September 1st in the comments to this blog post.
  6. License your image as CC-BY or better and allow this site and the GIMP Magazine to publish your image under CC-BY (here) or CC-BY-SA (GIMP Magazine).
  7. Rules 1 to 4 may be broken, 5, 6 and 7 have to be followed exactly.

You may download the template for my version from above or build your own one. You are free to make other forms than a square – circles or a spiral anyone?

There will be hopefully a discussion in our forum.

The TOC

The video uses chapter marks, you can jump between TOC entrys!

00:00:00 Pause until end of August
00:02:05 A contest for you – introduction
00:03:42 The contest rules
00:04:50 My example
00:06:04 Selecting the images
00:08:00 Scaling down and exporting in Shotwell
00:08:40 Calculating the image size
00:09:30 Create the file
00:10:20 Save as XCF.gz – compressed to save space
00:11:05 Creating a “Contact Sheet” for reference with Imagemagick
00:13:00 Make a movable layer mask with “multiply mode”
00:16:00 Building a stack of layer groups and fill it with images
00:23:00 Filling images into the layer stack
00:26:45 Isolate the layer groups with “lighten only mode”
00:27:55 What do these layer modes do? Blackboard explanation
00:33:08 The last image – a Memory to Edith and Tina Wolff
00:34:30 Fine tuning the mosaic – exchange images
00:36:08 Adjusting contrast between the images with the curves tool
00:39:20 THE CHALLENGE
00:41:05 Variations: Soften the borders between fields
00:43:08 Final words about the Challenge
00:44:15 Exporting and scaling down for publication
00:45:45 End of video

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 191: PNG or JPG – The Big Fight

This is a PNG in JPG lookDownload the Video! (26:07 49.7MB)

In the last Episode I looked under the hood of JP(E)G and PNG. This time it gets a bit more practical – which is better for what?

I tackle two examples from the GIMP Magazine web site and test, if they would be better saved as JPG or PNG. The Plugin “Save for Web” is really usefull for this task.(The image for this blog entry is a PNG by the way, showing JPG compression artifacts. As a JPG it would be five times the size. )

I “developed” a method for comparing two layers – just set the top layer mode to “difference”, make a new layer from visible and check that with the threshold tool for pixels, that are not completely black. After locating the problematic zones in an image with this tool, one can decide what settings are “good enough”.

Conclusion: It depends. It depends on the file, your use case, your level of “good enough” and your compassion for people on a mobile device in EDGE-Hell.

The show starts with a little extension of the last show, Pascal mentioned some options for saving a JPG file that I had overlooked.

The TOC

00:00:00 Start of video
00:01:00 Progressive mode in JPEG
00:04:09 Progressive mode is not fully supported by browsers
00:04:23 Optimized mode
00:05:56 Baseline?
00:06:17 The quality setting
00:07:09 GIMPMagazine and MTG header image – PNG or JPG?
00:09:23 Checking for quality loss in JPG
00:10:03 Comparing two layers with difference mode
00:10:48 Using the histogram for analysis of the amount of difference
00:11:25 Locating the differences
00:13:50 Trying 85, 75 and 90 as quality settings
00:16:13 When in doubt, compare different settings
00:16:36 Save your work as XCF.GZ
00:17:12 Second example – a drawing
00:19:56 Conclusion
00:23:19 Stay at 4:4:4 for subsampling with photos
00:25:16 Final words of wisdom
00:26:07 End of video

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

GIMP Team gives in to constant nagging!

mtc-logoAs the usually well informed Steve Czajka from the GIMP Magazine reports in a special issue, the GIMP Team has started to rebrand the project. The name GIMP wasn’t professional sounding enough to reach the self defined goal of building a program that fulfills the demands of graphic professionals.

The GIMP Magazine has already changed it’s design. I will follow when I have secured the new domain names, implemented the name server changes and updated the web server for the former GIMP Magazine and Meet the ???????.

They could have announced that a bit earlier…..

Episode 189: Currywurst for Beginners

189Download the Video! (53:45 107MB)

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This is an episode completely in “Beginners Level”, some of you have asked for such a thing. I go through the editing of an image and cover a lot of topics. Nothing really in depth, but you should be able to work your way through other material after viewing this one.

I start with a short tour through the user interface of GIMP, you find more about that in the GIMP documentation and other places. In between there is a bit about saving vs. exporting an image – without the nasty and pointless discussion.

The image itself has to be rotated a bit, cropped, treated with a bit of curves, burned, and dodged, given more omphh with a layer in overlay mode that of course has to be modified with a layer mask.  Finally the image will be scaled down, sharpened and exported as a JPEG while the original XCF file is conserved. Quite a tour – so I needed nearly an hour.

(I’ll update the links here later.)

The TOC

00:00:00 Intro
00:00:56 Comments about the GAP problems
00:01:43 This episode is for beginners
00:02:58 Currywurst and Friedrichshain
00:04:18 The user interface – a short tour
00:04:35 The window header and saving into XCF
00:05:30 Exporting an image as JPG or PNG
00:06:50 Fullscreen and single window mode
00:07:20 Menues, Toolbox, Docks, Tabs
00:09:23 The image area with the canvas, rulers, sliders and buttons
00:10:20 Moving around in the image and zooming
00:12:00 Single window mode vs. multi window mode
00:13:01 TAB to switch the Toolbox and Docks on and off
00:13:32 The image – back story
00:15:30 What has to be done – making a plan
00:16:40 Rotate the image to straighten it
00:19:17 Cropping to a 3:2 aspect ratio
00:19:57 Inside Out Cropping
00:22:50 Make a backup layer
00:23:20 Curves Tool for contrast changes
00:27:30 Burning and Dodging with a layer in Soft Light Mode for local brightness changes
00:30:50 An extra layer for notes
00:33:30 Burning and Dodging
00:38:00 The Smudge Tool
00:41:27 Increasing contrast with a layer copy in Soft Light Mode
00:43:30 Adding a layer mask to apply the effect selectively
00:45:50 Softening the layer mask with a Gaussian Blur
00:47:45 Saving the image
00:48:03 Reducing the size for the Web
00:49:30 Sharpening
00:51:38 Exporting to JPEG
00:53:45 End of video

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.

Episode 187: Cleaning Up

187Download the Video! (35:45 68.1MB)

The last episode got a lot of comments – thank you all for them! And in this episode I try to follow all of the tips you gave me. I remember layer groups and drop shadows, see that Alpha to selection is really better and fight with Copy&Paste in the text tool.

I got a present too – a fine script in Scheme for generating the title screen. Of course that has to be explored. Did you know that you can export the content of a selection as a new image by key stroke? I found out about SHIFT-CTRL-V. Saul’s script gets also a first analytical look – Scheme looses its terror if you come close.

Matthias pointed to an other Colour Design site and the GIMP Magazine will publish a new issue next week.

And finally I take a good look at the “Blender Master Class”, a very fine book about the 3D software Blender.

The TOC

00:00:00 Intro
00:00:40 Using chapter marks in the video
00:01:30 Layer groups
00:05:23 Alpha to Selection – better than selecting by color
00:09:00 Drop shadow filter
00:10:10 Copy and Paste with the text tool is a bit broken
00:13:37 A script in Scheme
00:14:12 Exporting selections from GIMP as graphic image files / Create from clipboard
00:15:20 Exporting vs. saving – don’t discuss, just follow your orders! 😉
00:16:30 Installing a Scheme (.scm) script
00:17:30 Testing the script
00:18:45 Comparing the results
00:19:30 Analyzing the script
00:25:40 Thanks to Saul Goode
00:26:16 Another Color Design website
00:26:45 GIMP Magazine launch ahead
00:27:30 Book review: Blender Master Class, Ben Simonds
00:35:45 End of video

Creative Commons License
Meet the GIMP Video Podcast by Rolf Steinort is licensed under a Creative Commons Attribution 3.0 Unported License.
Permissions beyond the scope of this license may be available at http://meetthegimp.org.