[gimp-web/testing] Modified — to remove whitespace from around the element.

[Pat David <patdavid src gnome org>]

commit 0abecb82a236ea37d3bc3d8bc9667d91579b1543
Author: Pat David <patdavid gmail com>
Date:   Mon May 2 16:53:01 2016 -0500

    Modified &mdash; to remove whitespace from around the element.
    
    This element usually appears with either no, or a hairline, space
    surrounding it. ty ankh and houz for pointing it out!

 .../Tone_Mapping_Using_GIMP_Levels/index.md        |   16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)
---
diff --git a/content/tutorials/Tone_Mapping_Using_GIMP_Levels/index.md 
b/content/tutorials/Tone_Mapping_Using_GIMP_Levels/index.md
index 1f76d65..344ce98 100644
--- a/content/tutorials/Tone_Mapping_Using_GIMP_Levels/index.md
+++ b/content/tutorials/Tone_Mapping_Using_GIMP_Levels/index.md
@@ -25,7 +25,7 @@ A very common editing problem is how to lighten the shadows and midtones of an i
 
 A very common editing problem is how to lighten the shadows and midtones of an image without blowing out the 
highlights, which problem is very often encountered when dealing with photographs of scenes lit by direct 
sunlight. Precanned algorithms for accomplishing this task are often referred to as "shadow recovery" 
algorithms. But really these algorithms are special-purpose tone-mapping algorithms, which sometimes work 
pretty well, and sometimes not so well, depending on the algorithm, the image, and your artistic intentions 
for the image.
 
-This step-by-step tutorial shows you how to use GIMP's unbounded floating point Levels operations to recover 
shadow information &mdash; that is, add one or more stops of positive exposure compensation to an image's 
shadows and midtones &mdash; without blowing out or unduly compressing the image highlights. The procedure is 
completely "hand-tunable" using masks and layers, and is as close as you can get to non-destructive image 
editing using high bit depth GIMP 2.9/2.10.
+This step-by-step tutorial shows you how to use GIMP's unbounded floating point Levels operations to recover 
shadow information&mdash;that is, add one or more stops of positive exposure compensation to an image's 
shadows and midtones&mdash;without blowing out or unduly compressing the image highlights. The procedure is 
completely "hand-tunable" using masks and layers, and is as close as you can get to non-destructive image 
editing using high bit depth GIMP 2.9/2.10.
 
 <figure>
 <img src='power-lines.jpg' alt='power-lines'>
@@ -87,16 +87,16 @@ This worked example provides a sample image and is broken down into five steps,
 2. **Open tree.png and convert it to 32-bit floating point linear precision**: Go to "Image/Precision", 
select "32-bit floating point", and when the Dither dialog pops up, select "Linear light".
 
 <li markdown=1> 
-Make a copy of the "tree.png" layer, and label it "Levels: +1 stop exp. comp". Then **use Levels to add one 
stop of positive exposure compensation** &mdash; Figure 3 below shows the proper settings for the Levels 
dialog, and Figure 4 shows the result:
+Make a copy of the "tree.png" layer, and label it "Levels: +1 stop exp. comp". Then **use Levels to add one 
stop of positive exposure compensation**&mdash;Figure 3 below shows the proper settings for the Levels 
dialog, and Figure 4 shows the result:
 
 <figure>
 <img src="levels-add-one-stop-positive-exposure-compensation.jpg" 
alt="levels-add-one-stop-positive-exposure-compensation" >
 <figcaption>
-Using Levels to add one stop of positive exposure compensation &mdash; <i>make sure the "Gamma hack" box is 
checked!</i>
+Using Levels to add one stop of positive exposure compensation&mdash;<i>make sure the "Gamma hack" box is 
checked!</i>
 </figcaption>
 </figure>
 
-When using Levels to add one stop of positive exposure compensation, make sure the image really is at 
floating point precision, because integer precision will clip the highlights. Also make sure the "Gamma hack" 
box is checked &mdash; <a title="GIMP bug report: Curves and Levels should operate by default on linear RGB 
and present linear RGB Histograms." href="https://bugzilla.gnome.org/show_bug.cgi?id=757444";>otherwise the 
Levels operation will operate on perceptually uniform RGB</a>, despite the fact that the image is at "Linear 
light" precision. Trying to add one stop of positive exposure compensation using RGB values encoded using the 
sRGB TRC would require moving the upper right Levels Value slider to the entirely unobvious and nonintuitive 
value of 73.53, and in the process the shadow and midtone tonalities would be distorted because the sRGB TRC 
is not a true gamma TRC. (An easier alternative might be to use the GEGL Exposure operation: 
"Colors/Exposure", which always 
 operates on linearized RGB).
+When using Levels to add one stop of positive exposure compensation, make sure the image really is at 
floating point precision, because integer precision will clip the highlights. Also make sure the "Gamma hack" 
box is checked&mdash;<a title="GIMP bug report: Curves and Levels should operate by default on linear RGB and 
present linear RGB Histograms." href="https://bugzilla.gnome.org/show_bug.cgi?id=757444";>otherwise the Levels 
operation will operate on perceptually uniform RGB</a>, despite the fact that the image is at "Linear light" 
precision. Trying to add one stop of positive exposure compensation using RGB values encoded using the sRGB 
TRC would require moving the upper right Levels Value slider to the entirely unobvious and nonintuitive value 
of 73.53, and in the process the shadow and midtone tonalities would be distorted because the sRGB TRC is not 
a true gamma TRC. (An easier alternative might be to use the GEGL Exposure operation: "Colors/Exposure", 
which always op
 erates on linearized RGB).
 
 <figure>
 <img width="772" src="one-stop-positive-exposure-compensation-added.jpg" 
alt="one-stop-positive-exposure-compensation-added" >
@@ -111,13 +111,13 @@ If you had used integer precision instead of floating point, the highlights real
 </li>
 
 <li><img style='float: right;' src="add-inverse-grayscale-mask.jpg" alt="add-inverse-grayscale-mask" >
-<b>Add an inverse grayscale layer mask</b>: Right-click on the layer and select "Layer/Mask/Add Layer Mask", 
and when the "Add a mask to the Layer" dialog pops up, choose "Grayscale copy of layer" and check the "Invert 
mask" box. <p>As shown in Figure 5 below, at this point the highlights will be brought back into the display 
range, meaning all RGB channel values are between 0.0f and 1.0f. But the image will probably look a little 
odd (sort of cloudy and flat), and depending on the image, the brightest highlights might actually have dark 
splotches &mdash; don't worry! this is temporary.</p>
+<b>Add an inverse grayscale layer mask</b>: Right-click on the layer and select "Layer/Mask/Add Layer Mask", 
and when the "Add a mask to the Layer" dialog pops up, choose "Grayscale copy of layer" and check the "Invert 
mask" box. <p>As shown in Figure 5 below, at this point the highlights will be brought back into the display 
range, meaning all RGB channel values are between 0.0f and 1.0f. But the image will probably look a little 
odd (sort of cloudy and flat), and depending on the image, the brightest highlights might actually have dark 
splotches&mdash;don't worry! this is temporary.</p>
 
  
 <figure >
 <img width="772" src="inverse-grayscale-mask-added.jpg" alt="inverse-grayscale-mask-added" >
 <figcaption>Result of adding an inverse grayscale layer mask to bring the highlights back into the display 
range.<br>
-Adding an inverse grayscale layer mask brings the highlights back into the display range, but at this point 
most images will look flat and cloudy, and some images will have dark splotches in the highlights. The next 
step &mdash; "Auto Stretch Contrast" performed on the mask &mdash; will take care of this problem.
+Adding an inverse grayscale layer mask brings the highlights back into the display range, but at this point 
most images will look flat and cloudy, and some images will have dark splotches in the highlights. The next 
step&mdash;"Auto Stretch Contrast" performed on the mask&mdash;will take care of this problem.
 </figcaption>
 </figure>
 </li>
@@ -238,7 +238,7 @@ For the "Power lines" picture shown in Figure 8 above, after doing "Color/Auto/S
 </li>
 
 
-<li>An essential component of the procedure for using Levels to add positive exposure compensation to images 
with dark shadows and midtones needs to be explicitly mentioned: Not only is the high bit depth GIMP's Levels 
operation unbounded at floating point precision &mdash; <a title="GIMP bug report: Some filters / operations 
provide float values superior to 1.0." href="https://bugzilla.gnome.org/show_bug.cgi?id=737925";>layer masks 
are also unbounded</a>. <p>If the inverted grayscale masks were summarily clipped (as is the case when 
editing at integer precision), then the procedure described in this tutorial wouldn't work. However, if you 
are trying this procedure in a floating point image editor that doesn't allow for retaining out of display 
range values on a layer mask, you can make an inverse grayscale mask from the base layer, auto-stretch the 
resulting mask, turn it into a selection, add it to the "Levels positive exposure compensation" copy of the 
base layer, and then
  delete or disable the mask on the base layer.</p></li>
+<li>An essential component of the procedure for using Levels to add positive exposure compensation to images 
with dark shadows and midtones needs to be explicitly mentioned: Not only is the high bit depth GIMP's Levels 
operation unbounded at floating point precision&mdash;<a title="GIMP bug report: Some filters / operations 
provide float values superior to 1.0." href="https://bugzilla.gnome.org/show_bug.cgi?id=737925";>layer masks 
are also unbounded</a>. <p>If the inverted grayscale masks were summarily clipped (as is the case when 
editing at integer precision), then the procedure described in this tutorial wouldn't work. However, if you 
are trying this procedure in a floating point image editor that doesn't allow for retaining out of display 
range values on a layer mask, you can make an inverse grayscale mask from the base layer, auto-stretch the 
resulting mask, turn it into a selection, add it to the "Levels positive exposure compensation" copy of the 
base layer, and then d
 elete or disable the mask on the base layer.</p></li>
 
 </ol>
 
@@ -254,6 +254,8 @@ For the "Power lines" picture shown in Figure 8 above, after doing "Color/Auto/S
 
 <!-- END ARTICLE -->
 
+The original tutorial this was adapted from can be [found on Elle's 
site](http://ninedegreesbelow.com/photography/gimp-tone-map-with-levels.html).
+
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