--- a/Depth8Image.st	Tue Aug 29 15:39:47 2017 +0200
+++ b/Depth8Image.st	Tue Aug 29 15:39:48 2017 +0200
@@ -1,5 +1,3 @@
-"{ Encoding: utf8 }"
-
 "
  COPYRIGHT (c) 1993 by Claus Gittinger
 	      All Rights Reserved
@@ -1938,7 +1936,15 @@
 !
 
 valuesAtY:y from:xLow to:xHigh do:aBlock
-    "perform aBlock for each pixelValue from x1 to x2 in row y.
+    "WARNING: this enumerates pixel values which need photometric interpretation
+     Do not confuse with #rgbValuesAtY:from:to:do:
+
+     Perform aBlock for each pixelValue from x1 to x2 in row y.
+
+     Notice the difference between rgbValue and pixelValue: rgbValues are always
+     the rgb bytes; pixelvalues depend on the photometric interpretation, and may be
+     indices into a colormap or be non-byte-sized rgb values.
+
      The block is passed the pixelValue at each pixel.
      This method allows slighly faster processing of an
      image than using valueAtX:y:, since some processing can be
@@ -1963,11 +1969,19 @@
 
     "Created: / 07-06-1996 / 19:09:47 / cg"
     "Modified: / 30-01-2017 / 18:54:15 / stefan"
+    "Modified (comment): / 29-08-2017 / 14:52:56 / cg"
 !
 
 valuesFromX:xStart y:yStart toX:xEnd y:yEnd do:aBlock
-    "perform aBlock for each pixel in the rectangle
-     yStart..yEnd / xStart..xEnd.
+    "WARNING: this enumerates pixel values which need photometric interpretation
+     Do not confuse with #rgbValuesAtY:from:to:do:
+
+     Perform aBlock for each pixelValue in a rectangular area of the image.
+
+     Notice the difference between rgbValue and pixelValue: rgbValues are always
+     the rgb bytes; pixelvalues depend on the photometric interpretation, and may be
+     indices into a colormap or be non-byte-sized rgb values.
+
      The block is passed the pixelValue at each pixel.
      This method allows slighly faster processing of an
      image than using individual valueAtX:y: accesses,
@@ -2004,6 +2018,7 @@
     "Created: / 11-07-1996 / 20:08:11 / cg"
     "Modified: / 30-01-2017 / 19:04:05 / stefan"
     "Modified (format): / 31-01-2017 / 12:44:04 / stefan"
+    "Modified (comment): / 29-08-2017 / 14:46:03 / cg"
 ! !
 
 !Depth8Image methodsFor:'image manipulations'!