--- a/Depth24Image.st	Tue Aug 29 15:39:48 2017 +0200
+++ b/Depth24Image.st	Tue Aug 29 15:39:49 2017 +0200
@@ -182,10 +182,14 @@
 !
 
 rgbValueAtX:x y:y
-    "retrieve a pixels rgb value at x/y; return a 24bit rgbValue (rrggbb, red is MSB).
-     Pixels start at 0@0 for upper left pixel, end at (width-1)@(height-1) for lower right pixel."
+    "retrieve a pixel's rgb value at x/y; 
+     return a 24bit rgbValue (rrggbb, red is MSB).
+     Pixels start at 0@0 for the upper left pixel, 
+     and end at (width-1)@(height-1) for the lower right pixel."
 
     ^ self pixelAtX:x y:y.
+
+    "Modified (comment): / 29-08-2017 / 14:35:01 / cg"
 !
 
 rowAt:y putAll:pixelArray startingAt:startIndex
@@ -2639,7 +2643,15 @@
 !
 
 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
@@ -2664,19 +2676,27 @@
     srcIndex := 1 + (((width * y) + x1) * 3).
 
     x1 to:x2 do:[:x |
-	r := bytes at:(srcIndex).
-	g := bytes at:(srcIndex + 1).
-	b := bytes at:(srcIndex + 2).
-	srcIndex := srcIndex + 3.
-	aBlock value:x value:(((r bitShift:16) bitOr:(g bitShift:8)) bitOr:b)
+        r := bytes at:(srcIndex).
+        g := bytes at:(srcIndex + 1).
+        b := bytes at:(srcIndex + 2).
+        srcIndex := srcIndex + 3.
+        aBlock value:x value:(((r bitShift:16) bitOr:(g bitShift:8)) bitOr:b)
     ]
 
-    "Created: 7.6.1996 / 19:09:40 / cg"
+    "Created: / 07-06-1996 / 19:09:40 / cg"
+    "Modified (comment): / 29-08-2017 / 14:53:14 / 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,
@@ -2768,8 +2788,8 @@
         srcIndex := srcNext.
     ].
 
-    "Modified: 11.7.1996 / 20:06:47 / cg"
-    "Created: 11.7.1996 / 20:08:11 / cg"
+    "Created: / 11-07-1996 / 20:08:11 / cg"
+    "Modified (comment): / 29-08-2017 / 14:45:54 / cg"
 ! !
 
 !Depth24Image methodsFor:'image manipulations'!