[gimp-help] Fix #26 Unsharp slider values listed incorrectly

[Jacob Boerema <jboerema src gnome org>]

commit f7d24ef87d71f354cecee617d684c7c7c3a0acc7
Author: Jacob Boerema <jgboerema gmail com>
Date:   Sun Jul 24 18:00:26 2022 -0400

    Fix #26 Unsharp slider values listed incorrectly
    
    Besides the values of the sliders I also did some slight improvements
    to the text.
    
    (cherry picked from commit b48e4cd52a79283e9040e00a8c97991807eca547)

 src/filters/enhance/unsharp_mask.xml | 61 +++++++++++++++++++-----------------
 1 file changed, 32 insertions(+), 29 deletions(-)
---
diff --git a/src/filters/enhance/unsharp_mask.xml b/src/filters/enhance/unsharp_mask.xml
index ddcc951f2..5359ece97 100644
--- a/src/filters/enhance/unsharp_mask.xml
+++ b/src/filters/enhance/unsharp_mask.xml
@@ -42,28 +42,30 @@
     </figure>
     <para>
       Out-of-focus photographs and most digitized images often need a
-      sharpness correction. This is due to the digitizing process that must
-      chop a color continuum up in points with slightly different colors:
-      elements thinner than sampling frequency will be averaged into an
-      uniform color. So sharp borders are rendered a little blurred. The same
-      phenomenon appears when printing color dots on paper.
+      sharpness correction. This is due to the digitizing process that has
+      to divide a color continuum in points with slightly different colors.
+      Elements smaller than the sampling frequency will be averaged into a
+      uniform color. So sharp borders will be rendered a little blurred. The
+      same phenomenon appears when printing color dots on paper.
     </para>
     <para>
-      The Sharpen filter (old name was Unsharp Mask) sharpens edges of the
+      The Sharpen filter (previously called Unsharp Mask) sharpens edges of the
       elements without increasing noise or blemish. It is the king of the
       sharpen filters.
     </para>
     <tip>
       <para>
         Some imaging devices like digital cameras or scanners offer to sharpen
-        the created images for you. We strongly recommend you disable the
-        sharpening in this devices and use the GIMP filters instead. This way
-        you regain the full control over the sharpening of your images.
+        the created images for you. We strongly recommend you disable this
+        means of sharpening and use <acronym>GIMP</acronym> filters instead.
+        This way you regain the full control over the sharpening of your images.
       </para>
     </tip>
     <para>
-      To prevent color distortion while sharpening, Decompose your image to
-      HSV and work only on Value. Then Compose the image to HSV. Go to
+      To prevent color distortion while sharpening, you can
+      <ulink url="plug-in-decompose">Decompose</ulink> your image to
+      <guilabel>HSV</guilabel> and work only on <guilabel>Value</guilabel>.
+      Go to
       <menuchoice>
         <guimenu>Colors</guimenu>
         <guisubmenu>Components</guisubmenu>
@@ -74,7 +76,9 @@
       image with three layers, one for Hue, one for Saturation, and one for
       Value. (Close the original image so you won't get confused). Select
       the Value layer and apply your sharpening to it. When you are done,
-      with that same layer selected, reverse the process. Go to
+      with that same layer selected, reverse the process by using
+      <ulink url="plug-in-compose">Compose</ulink>.
+      Go to
       <menuchoice>
         <guimenu>Colors</guimenu>
         <guisubmenu>Components</guisubmenu>
@@ -122,10 +126,9 @@
         <term>Radius</term>
         <listitem>
           <para>
-            The slider and input boxes (0.1-120) allow you to set how many
+            The slider and input boxes (0.0-1500.0) allow you to set how many
             pixels on either side of an edge will be affected by sharpening.
-            High resolution images allow higher radius. It is better to always
-            sharpen an image at its final resolution.
+            It is better to always sharpen an image at its final resolution.
           </para>
         </listitem>
       </varlistentry>
@@ -133,7 +136,7 @@
         <term>Amount</term>
         <listitem>
           <para>
-            This slider and input boxes (0.00-5.00) allow you to set
+            This slider and input boxes (0.0-300.0) allow you to set the
             strength of sharpening.
           </para>
         </listitem>
@@ -142,7 +145,7 @@
         <term>Threshold</term>
         <listitem>
           <para>
-            This slider and input boxes (0-255) allow you to set the minimum
+            This slider and input boxes (0.0-1.0) allow you to set the minimum
             difference in pixel values that indicates an edge where sharpen
             must be applied. So you can protect areas of smooth tonal
             transition from sharpening, and avoid creation of blemishes in
@@ -168,7 +171,7 @@
     <para>
       Think of an image with a contrast in some place. The intensity curve of
       the pixels on a line going through this contrast will show an abrupt
-      increase of intensity: like a stair if contrast is perfectly sharp (blue), 
+      increase of intensity: like a stair if contrast is perfectly sharp (blue),
       like an S if there is some blur (yellow).
     </para>
     <mediaobject>
@@ -177,14 +180,14 @@
       </imageobject>
     </mediaobject>
     <para>
-      Now, we have an original image with some blur (black curve) we want to 
-      sharpen. We apply some more blur: the intensity variation will be 
+      Now, we have an original image with some blur (black curve) we want to
+      sharpen. We apply some more blur: the intensity variation will be
       more gradual (green curve).
     </para>
     <para>
-      Let us subtract the difference between blurredness intensity (green 
-      curve) and the intensity of the original image (black curve) to the 
-      intensity of the original image (black curve). We get the red 
+      Let us subtract the difference between blurredness intensity (green
+      curve) and the intensity of the original image (black curve) to the
+      intensity of the original image (black curve). We get the red
       curve, which is more abrupt: contrast and sharpness are increased. QED.
     </para>
     <mediaobject>
@@ -194,14 +197,14 @@
     </mediaobject>
 
     <para>
-      Unsharp mask has first been used in silver photography. The photograph
+      Unsharp mask was first used in silver photography. The photographer
       first creates a copy of the original negative by contact, on a film,
       placing a thin glass plate between both; that will produce a blurred
-      copy because of light diffusion. Then he places both films, exactly
-      corresponding, in a photo enlarger, to reproduce them on paper. The dark
-      areas of the positive blurred film, opposed to the clear areas of the
-      original negative will prevent light to go through and so will be
-      subtracted from the light going through the original film.
+      copy because of light diffusion. Then both films are placed in a photo
+      enlarger, to reproduce them on paper. The dark areas of the positive
+      blurred film, opposed to the clear areas of the original negative will
+      prevent light to go through and so will be subtracted from the light
+      going through the original film.
     </para>
 
     <procedure>