--- a/Depth4Image.st	Tue Aug 29 15:39:26 2017 +0200
+++ b/Depth4Image.st	Tue Aug 29 15:39:45 2017 +0200
@@ -847,7 +847,15 @@
 !
 
 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
@@ -887,6 +895,7 @@
 
     "Created: / 07-06-1996 / 19:09:45 / cg"
     "Modified (format): / 30-01-2017 / 20:41:31 / stefan"
+    "Modified (comment): / 29-08-2017 / 14:53:04 / cg"
 ! !
 
 !Depth4Image methodsFor:'magnification'!