[gimp-web/testing] Add Focus Group tutorial

[Pat David <patdavid src gnome org>]

commit ebd56345be423c2919dbee053d858acabb33673f
Author: Pat David <patdavid gmail com>
Date:   Sun Jul 15 10:22:33 2018 -0500

    Add Focus Group tutorial

 content/tutorials/Focus_Group/Singapore_Final.jpg  | Bin 0 -> 238197 bytes
 .../tutorials/Focus_Group/Singapore_Final_Blur.jpg | Bin 0 -> 218219 bytes
 content/tutorials/Focus_Group/Singapore_Focus.jpg  | Bin 0 -> 452777 bytes
 content/tutorials/Focus_Group/Singapore_Layers.jpg | Bin 0 -> 22714 bytes
 content/tutorials/Focus_Group/Singapore_Mask.jpg   | Bin 0 -> 18459 bytes
 .../tutorials/Focus_Group/Singapore_Original.jpg   | Bin 0 -> 467826 bytes
 content/tutorials/Focus_Group/Singapore_Sepia.jpg  | Bin 0 -> 451261 bytes
 content/tutorials/Focus_Group/Storm_After.jpg      | Bin 0 -> 257159 bytes
 content/tutorials/Focus_Group/Storm_Final.jpg      | Bin 0 -> 229971 bytes
 content/tutorials/Focus_Group/Storm_Layers.JPG     | Bin 0 -> 18133 bytes
 content/tutorials/Focus_Group/Storm_Original.jpg   | Bin 0 -> 239439 bytes
 content/tutorials/Focus_Group/TehTarik_Final.jpg   | Bin 0 -> 354656 bytes
 content/tutorials/Focus_Group/TehTarik_Layers.jpg  | Bin 0 -> 22417 bytes
 content/tutorials/Focus_Group/TehTarik_Mask.jpg    | Bin 0 -> 21871 bytes
 .../tutorials/Focus_Group/TehTarik_Multiply.jpg    | Bin 0 -> 553773 bytes
 .../tutorials/Focus_Group/TehTarik_Original.jpg    | Bin 0 -> 652274 bytes
 content/tutorials/Focus_Group/TehTarik_Screen.jpg  | Bin 0 -> 591437 bytes
 content/tutorials/Focus_Group/index.md             | 365 +++++++++++++++++++++
 content/tutorials/index.md                         |   8 +-
 19 files changed, 370 insertions(+), 3 deletions(-)
---
diff --git a/content/tutorials/Focus_Group/Singapore_Final.jpg 
b/content/tutorials/Focus_Group/Singapore_Final.jpg
new file mode 100644
index 00000000..376d8e91
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Final.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Final_Blur.jpg 
b/content/tutorials/Focus_Group/Singapore_Final_Blur.jpg
new file mode 100644
index 00000000..a09a05cc
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Final_Blur.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Focus.jpg 
b/content/tutorials/Focus_Group/Singapore_Focus.jpg
new file mode 100644
index 00000000..3062fe95
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Focus.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Layers.jpg 
b/content/tutorials/Focus_Group/Singapore_Layers.jpg
new file mode 100644
index 00000000..dbd5e4cf
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Layers.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Mask.jpg 
b/content/tutorials/Focus_Group/Singapore_Mask.jpg
new file mode 100644
index 00000000..980822c2
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Mask.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Original.jpg 
b/content/tutorials/Focus_Group/Singapore_Original.jpg
new file mode 100644
index 00000000..8e394f9a
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Original.jpg differ
diff --git a/content/tutorials/Focus_Group/Singapore_Sepia.jpg 
b/content/tutorials/Focus_Group/Singapore_Sepia.jpg
new file mode 100644
index 00000000..58ac4585
Binary files /dev/null and b/content/tutorials/Focus_Group/Singapore_Sepia.jpg differ
diff --git a/content/tutorials/Focus_Group/Storm_After.jpg b/content/tutorials/Focus_Group/Storm_After.jpg
new file mode 100644
index 00000000..1d80d43a
Binary files /dev/null and b/content/tutorials/Focus_Group/Storm_After.jpg differ
diff --git a/content/tutorials/Focus_Group/Storm_Final.jpg b/content/tutorials/Focus_Group/Storm_Final.jpg
new file mode 100644
index 00000000..2730e8a6
Binary files /dev/null and b/content/tutorials/Focus_Group/Storm_Final.jpg differ
diff --git a/content/tutorials/Focus_Group/Storm_Layers.JPG b/content/tutorials/Focus_Group/Storm_Layers.JPG
new file mode 100644
index 00000000..1ddf6c3f
Binary files /dev/null and b/content/tutorials/Focus_Group/Storm_Layers.JPG differ
diff --git a/content/tutorials/Focus_Group/Storm_Original.jpg 
b/content/tutorials/Focus_Group/Storm_Original.jpg
new file mode 100644
index 00000000..22fa256f
Binary files /dev/null and b/content/tutorials/Focus_Group/Storm_Original.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Final.jpg 
b/content/tutorials/Focus_Group/TehTarik_Final.jpg
new file mode 100644
index 00000000..b4d73a2a
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Final.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Layers.jpg 
b/content/tutorials/Focus_Group/TehTarik_Layers.jpg
new file mode 100644
index 00000000..7b93489f
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Layers.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Mask.jpg b/content/tutorials/Focus_Group/TehTarik_Mask.jpg
new file mode 100644
index 00000000..59f2c9d6
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Mask.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Multiply.jpg 
b/content/tutorials/Focus_Group/TehTarik_Multiply.jpg
new file mode 100644
index 00000000..30a29e5d
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Multiply.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Original.jpg 
b/content/tutorials/Focus_Group/TehTarik_Original.jpg
new file mode 100644
index 00000000..2b732193
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Original.jpg differ
diff --git a/content/tutorials/Focus_Group/TehTarik_Screen.jpg 
b/content/tutorials/Focus_Group/TehTarik_Screen.jpg
new file mode 100644
index 00000000..168aa8fe
Binary files /dev/null and b/content/tutorials/Focus_Group/TehTarik_Screen.jpg differ
diff --git a/content/tutorials/Focus_Group/index.md b/content/tutorials/Focus_Group/index.md
new file mode 100644
index 00000000..c32b98ea
--- /dev/null
+++ b/content/tutorials/Focus_Group/index.md
@@ -0,0 +1,365 @@
+Title: Focus Group
+Date: 2018-07-15T08:57:27-06:00
+Author: John Brewer
+Template: page_author
+Status: Published
+
+## Teh Tarik
+
+This tutorial was written using Gimp version 2.10.2
+When I visited a Malaysian island cafe and ordered my usual 'Teh
+Tarik' in which tea and condensed milk are mixed by pouring them
+repeatedly from a height. I quickly snapped the action using a
+small point-and-shoot with a flash and, when I viewed the photo
+I was underwhelmed to say the least.
+
+<figure>
+<img src="{attach}TehTarik_Original.jpg" alt="Tarik_Original"
+width="1000" height="1333">
+</figure>
+
+Was this to be consigned to the dustbin or was it a challenge?
+
+<figure>
+<img src="TehTarik_Final.jpg" alt="Tarik_Final" width="723"
+height="1092">
+</figure>
+
+I saved it by dropping the background illumination and a crop.
+I dropped the background illumination on a layer set to Multiply
+blend mode. I then returned the figure and stream of tea to
+about normal via a masked layer set to Screen blend mode.
+
+To achieve this, I duplicated the original layer twice. I set
+the lower new layer to a blend mode of Screen in order to set a
+light colour to aid the masking operation later. On the upper
+new layer, set a layer mask to black. 
+I chose a hard-edged brush, zoomed in to the stream of tea using
+Ctrl and my mouse wheel, adjusted my brush diameter using the
+square-angle-bracket keys until it fitted within the tea stream,
+clicked on the layer mask icon to select that as a target and
+painted white on the mask, starting with the stream of tea and
+continuing around the perimeter of the person, panning the
+image by clicking and dragging my mouse wheel. Because the layer
+below is in blend mode Screen, the layer mask painting showed up
+brighter. If I made a mistake and painted over the background, I
+pressed the X key to swap colours to black, and painted over the
+mistake.
+Once I had the outline painted I Alt-clicked the layer mask to
+view it and filled the perimeter with white using the bucket
+fill tool and a brush. I also chose to fade-out the white below
+his waist by painting with the soft-edged airbrush with a low
+flow.
+
+<figure>
+<img src="TehTarik_Mask.jpg" alt="TehTarik_Mask" width="401"
+height="616">
+</figure>
+
+Once I was satisfied with the masking of the person and tea, I
+changed the layers to be as in the image below:
+
+<figure>
+<img src="TehTarik_Layers.jpg" alt="Layers" width="290"
+height="325">
+</figure>
+
+The second layer, which was blend mode Screen to aid in mask
+painting, now became blend mode Multiply. The layer with the
+mask now became blend mode Screen.
+
+<figure>
+<img src="TehTarik_Multiply.jpg" alt="Tarik_Multiply"
+width="1000" height="1333">
+</figure>
+
+Multiply ignores white and makes dark things darker. The
+Multiply layer gives a darkened background in order that it is
+less noticeable.
+
+<figure>
+<img src="TehTarik_Screen.jpg" alt="Tarik_Screen" width="1000"
+height="1333">
+</figure>
+
+The Screen layer has a mask that shows only the person and the
+tea. While Multiply ignores white and makes dark things
+darker, Screen ignores black and makes light pixels get lighter.
+Accordingly the person and the tea returned somewhat to normal
+but with a slight lightening in the brighter pixels.
+Should you wish to have the figure even brighter, you may
+duplicate the masked layer, although this was not needed in this
+case. Duplicating this layer is also needed if you wish to try
+various other blend modes or treatments in order to adjust the
+colour, contrast or tone of the figure.
+
+Now all that is needed is a crop and you're finished. 
+
+<figure>
+<img src="TehTarik_Final.jpg" alt="Tarik_Final" width="723"
+height="1092">
+</figure>
+
+A handy rescue!
+
+## Singapore
+The next photo calls for a similar masking technique to the
+previous - On a festival day in Singapore, outside a Chinese
+temple, I was watching a devout woman with her children and
+rapidly took a photograph before moving on to some other scene.
+When I eventually looked at the resulting photo I could see it
+did not reflect what I saw due to the confusion of people in the
+scene. 
+
+<figure>
+<img src="Singapore_Original.jpg" alt="Singapore_Original"
+width="1000" height="750">
+</figure>
+
+In my mind's eye, I had seen the woman and her children as a
+focal group and the others faded into the background - thus the
+need to re-create what I had seen in my mind's eye. 
+This technique is to treat my chosen group differently to what I
+choose to be my background.
+
+<figure>
+<img src="Singapore_Final.jpg" alt="Singapore_Final" width="696"
+height="571">
+</figure>
+
+Above is the simplest of these techniques, where my crop lessens
+the number of people and the woman and children are in
+heightened contrast to my background which has less colour and
+less saturation.
+To achieve this result, I am firstly going to change the
+appearance of a layer to serve as the background then isolate
+the focal group in the layers above this. I will eventually have
+a stack of layers, from the bottom up, the original, a
+background and two of the focal group at the top of the stack.
+
+<figure>
+<img src="Singapore_Layers.jpg" alt="Layers" width="291"
+height="290">
+</figure>
+
+To make a start, forget about the two upper layers at this
+stage, they'll come later. I duplicated the original layer and
+renamed layer two Background. I now had two layers in my image.
+Now I played around with various ways of introducing a
+difference in order to have this layer recede into the
+background or, in some way, be differentiated from the focal
+group.
+I tried Colours &gt; Hue-Chroma with the Hue set to 30 and the
+Chroma to -6, Hue introducing a yellowish tinge and the
+reduction in Chroma lead to a desaturation.
+I tried Brightness-Contrast and lowered the Contrast.
+I tried Colours &gt; Colorize and set the colour to bf9740 then
+reduced the opacity of the layer to 50% allowing the original
+layer beneath to partially show through.
+As one experiment, below, I chose Colours &gt; Desaturate &gt;
+Sepia and used a strength of 0.5 then lowered the opacity to 70%
+to allow the original, below, to show through.
+
+<figure>
+<img src="Singapore_Sepia.jpg" alt="Singapore_Sepia"
+width="1000" height="750">
+</figure>
+
+This subdued the colours of the whole scene quite well.
+To introduce the focal group I duplicated the original layer and
+moved it to the top and gave it a layer mask coloured black.
+With the black layer mask the top layer makes no difference
+until you paint with white onto the layer mask so, with a
+soft-edged brush of a diameter that covered the woman's right
+arm, I clicked on the layer mask icon to select it as a target
+and painted over the perimeter of the focal group in white: The
+woman, and the two children. I chose a small diameter hard-edged
+brush for the incense sticks, clicking once at the base and
+shift-clicking once at the top for each.
+I then Alt-clicked the layer mask to make it show, then
+filled-in the perimeter with white using the bucket fill tool
+and then a paintbrush.
+
+<figure>
+<img src="Singapore_Mask.jpg" alt="Singapore_Mask" width="437"
+height="556">
+</figure>
+
+If you blend a layer with itself in either Overlay mode or the
+softer Soft Light mode, you effect an increase in contrast. The
+lights become lighter and the darks become darker. To make the
+focal group even more prominent, I duplicated the top-most layer
+and set the top layer to a blend mode of Soft Light to increase
+contrast and set its opacity to 50% to lessen the effect.
+Alternatively, I could have applied a mild S curve to the focal
+group layer, but adding a Soft Light layer gave me the
+opportunity of adjusting the effect (via opacity) later. 
+
+<figure>
+<img src="Singapore_Focus.jpg" alt="Singapore_Focus"
+width="1000" height="750">
+</figure>
+
+The final thing to do was to apply a suitable crop which further
+reduced the confusion of people in the shot leading the viewer
+to the focal group of the composition.
+
+<figure>
+<img src="Singapore_Final.jpg" alt="Singapore_Final" width="696"
+height="571">
+</figure>
+
+### Foreground Alternatives
+I tried sharpening the focal group layer: I duplicated the focal
+group layer and applied the High Pass filter and changeded the
+blend mode to Soft Light, Overlay or Grain Merge but, as I was
+working on an image less than the original size for this
+tutorial, I didn't leave this layer in as it emphasised the
+pixellation too much.
+
+### Background Alternatives
+There are so many different ways of treating the background
+layer that I'm sure some will spend quite some time coming up
+with schemes that better suit them.
+In Filters &gt; Artistic there is Soft Glow and another may be
+to turn the background into a coloured pencil-style sketch using
+G'MIC B&amp;W &gt; Pencil combined with Colors &gt; Sepia and
+adjusting the gamma then fading this into the background using a
+layer mask.
+
+<figure>
+<img src="Singapore_Final_Blur.jpg" alt="Singapore_Final_Blur"
+width="717" height="580">
+</figure>
+
+One classic alternative is to blur the background. The
+background, above, was blurred in G'MIC-Qt using Repair &gt;
+Smooth Median with a radius of 4 and Threshold of 0 and seems to
+me to bring the focal group to the fore.
+Having the background and focal group as separate layers allows
+you to experiment further as you discover new ways to change
+images. Happy experimenting!
+
+## Blend Modes
+In these two photos we have seen the use of three blend modes,
+Screen, Multiply and Soft Light, a soft version of Overlay.
+These are the three most basic blend modes of the three most
+important blend mode groups which we may as well explore a
+little. Identify these three blend modes in Gimp's menu. I've
+taken the following comments from my notes which may be a
+paraphrase from the person I learned from, Dan Margulis,
+apologies Dan.
+
+**Screen** is the basic representative of the lighten group
+which includes about 4 others. If you want to lighten something,
+start with Screen. Screen ignores Black. Light pixels get
+lighter, dark pixels are ignored. It's like aiming two
+projectors at the same screen.
+
+**Multiply** is part of the darken group which includes about
+four others and is the opposite of Screen. If you want to darken
+something, start with Multiply. It ignores white and makes
+things darker. If you have any bright pixels Multiply blend mode
+just ignores them. It's like sandwiching two 35 mm slides
+together (if you are familiar with slides).
+
+**Overlay** is the representative of the contrast group along
+with its milder counterpart, Soft Light and about 5 others, and
+is a combination of Screen and Multiply. It ignores 50% grey,
+makes light things lighter and dark things darker thus
+increasing contrast. 
+
+The blend modes that go together with these three, such as Dodge
+and Burn may be thought of as variations of these three basic
+representatives and all have their own specific characters and
+functions which are definitely worth exploring. 
+Screen, Multiply and Overlay will not cause clipping but some
+blend modes, for example: Dodge, Addition, Burn, do cause
+clipping and should be watched for in light or dark areas.
+Clipping or blowing-out means taking a pixel colour or tone
+value to pure black or white. This isn't good as pure black or
+white parts of an image contain no detail.
+
+## Storm
+During a break in rain during a storm at our local beach in
+Bunbury Western Australia, the sun briefly showed and I took a
+shot of the sea by the rocks in the storm's winds. The usual
+story is my photo did not reflect what I had experienced taking
+it - it all looked a bit subdued. Following our theme for this
+tutorial, the idea is to mask and apply a blend mode but this
+time two layer masks to accommodate two different blend modes.
+Here is the 'Before':
+
+<figure>
+<img src="Storm_Original.jpg" alt="Storm_Original" width="1000"
+height="747">
+</figure>
+
+Here is the 'After':
+
+<figure>
+<img src="Storm_After.jpg" alt="Storm_After" width="1000"
+height="747">
+</figure>
+
+I began by duplicating the layer and running through a range of
+blend modes by selecting one mode then pressing the down arrow
+key to go to the next, looking at what each mode did to the sky
+and to the sea and land.
+
+What I found was that Overlay did not work for the sky by did so
+beautifully for the land, bringing out the texture of the rocks
+against the sand and heightening the white of the spray. I also
+found that Multiply worked well for the sky, darkening it into
+the glowering sky I remembered.
+
+I then left the blend mode of the duplicated layer at Multiply
+(in order to provide a visual difference when masking), added a
+white layer mask and began painting black onto the mask to cover
+the sea. I began at one side and painted a line under the
+horizon by choosing a small enough brush, clicking once, moving
+the brush a few centrimetres then Shift-clicking under the
+horizon again. This procedure draws straight lines between the
+two clicks as long as Shift is down. I renamed this layer Sky. I
+then duplicate this layer and renamed it Sea. I clicked the
+layer mask, went to Colours and chose Invert and this inverted
+the layer mask so the black portion covered the sky.
+
+I set the Sea layer to Overlay. 
+
+I noted that, at the horizon, I had a strip of lighter tone
+which drew attention to itself. Experimenting, I found that I
+could adjust the mask of the sky to remove it and did so.
+I then adjusted each of the layers above the original to 80%
+opacity as this gave me the intensity of effect I wished.
+
+<figure>
+<img src="Storm_Layers.JPG" alt="Storm_Layers" width="285"
+height="307">
+</figure>
+
+The final cropped photo of the storm:
+
+<figure>
+<img src="Storm_Final.jpg" alt="Storm_Final" width="1000"
+height="621">
+</figure>
+
+I do hope you benefited from these tutorials, I wish you well.
+
+<small><em>Tutorials for Gimp</em> by John Brewer
+</small>
+
+<small>
+<a rel="license"
+href="http://creativecommons.org/licenses/by-sa/4.0/";><img
+alt="Creative Commons License" style="border-width:0"
+src="https://i.creativecommons.org/l/by-sa/4.0/88x31.png";></a>
+<span xmlns:dct="http://purl.org/dc/terms/"; property="dct:title">FocusGroup</span>
+by <span xmlns:cc="http://creativecommons.org/ns#";
+property="cc:attributionName">John Brewer</span> is licensed
+under a <a rel="license"
+href="http://creativecommons.org/licenses/by-sa/4.0/";>Creative
+Commons Attribution-ShareAlike 4.0 International
+License</a>.
+</small>
diff --git a/content/tutorials/index.md b/content/tutorials/index.md
index 7f06c7ec..429c0ea9 100644
--- a/content/tutorials/index.md
+++ b/content/tutorials/index.md
@@ -50,13 +50,15 @@ Detailed conversion tutorial for generating a B&W result from a color image.
 Using multiple layer masks to isolate specific tones in your image for editing.
 
 [Tone Mapping with 'Colors/Exposure'][]  
-Using high bit depth GIMP's 'Colors/Exposure' operation to add exposure compensation to shadows 
-and midtones while retaining highlight details.
+Using high bit depth GIMP's 'Colors/Exposure' operation to add exposure compensation to shadows and midtones 
while retaining highlight details.
+
+[Focus Group][]  
+Layer masking and creative filter applications.
 
 [Digital B&W Conversion]: {filename}Digital_Black_and_White_Conversion/index.md
 [Luminosity Masks]: {filename}Luminosity_Masks/index.md
 [Tone Mapping with 'Colors/Exposure']: {filename}Tone_Mapping_Using_GIMP_Levels/index.md
-
+[Focus Group]: {filename}Focus_Group/index.md
 
 
 ## Programming