docs: Fix some typos and add missing oiiotool expression explanations (…

…AcademySoftwareFoundation#4169)

Signed-off-by: Larry Gritz <lg@larrygritz.com>

src/doc/oiiotool.rst

@@ -136,8 +136,8 @@ contents of an expression may be any of:
     `ImageDescription`, or `width`)
   * `filename` : the name of the file (e.g., `foo.tif`)
   * `file_extension` : the extension of the file (e.g., `tif`)
-  * `full_geom` : the "full" or "display" size)
-  * `geom` : the pixel data size in the form `640x480+0+0`)
+  * `full_geom` : the "full" or "display" size
+  * `geom` : the pixel data size in the form `640x480+0+0`
   * `nativeformat` : the pixel data type from the file.
   * `MINCOLOR` : the minimum value of each channel over the entire image
     (channels are comma-separated)
@@ -221,6 +221,14 @@ contents of an expression may be any of:
     retrieved by `OIIO::getattribute(name, ...)`. The `name` may be enclosed
     in single or double quotes or be a single unquoted sequence of characters.
     (Added in OIIO 2.3.)
+  * `var(name)` : returns the user variable of the give name. (Added in OIIO
+    2.4.)
+  * `eq(a,b)` : returns 1 if `a` is equal to `b`, 0 otherwise. (Added in OIIO
+    2.4.)
+  * `neq(a,b)` : returns 1 if `a` is not equal to `b`, 0 otherwise. (Added in
+    OIIO 2.4.)
+  * `not(val)` : returns 1 if `val` is a false value, 0 if `val` evaluates
+     to a true value. (Added in OIIO 2.4.)
 
 
 To illustrate how this works, consider the following command, which trims

src/include/OpenImageIO/imagebufalgo.h

@@ -1763,15 +1763,15 @@ enum NonFiniteFixMode
     NONFINITE_BLACK = 1,    ///< Replace non-finite values with 0.0.
     NONFINITE_BOX3 = 2,     ///< Replace non-finite values with the average
                             ///< value of any finite pixels in a 3x3 window.
-    NONFINITE_ERROR = 100,  ///< EReturn false (error), but don't change any
+    NONFINITE_ERROR = 100,  ///< Return false (error), but don't change any
                             ///< values, if any nonfinite values are found.
 };
 
 /// `fixNonFinite()` returns in image containing the values of `src` (within
-/// the ROI), while repairing  any non-finite (NaN/Inf) pixels. If
-/// pixelsFixed is not nullptr, store in it the number of pixels that
+/// the ROI), while repairing any non-finite (NaN/Inf) pixels. If
+/// `pixelsFixed` is not nullptr, store in it the number of pixels that
 /// contained non-finite value.  It is permissible to operate in-place (with
-/// `src` and  `dst` referring to the same image).
+/// `src` and `dst` referring to the same image).
 ///
 /// How the non-finite values are repaired is specified by one of the `mode`
 /// parameter, which is an enum of `NonFiniteFixMode`.