--- a/Depth16Image.st	Thu Jul 11 16:47:03 2019 +0200
+++ b/Depth16Image.st	Fri Jul 12 14:49:42 2019 +0200
@@ -204,6 +204,38 @@
     "return the number of bytes in one scanline of the image"
 
     ^ width * 2.
+!
+
+valueFromRGB:rgb
+    "given a color as rgb-value, with 8 bits per component, 
+     return the corresponding pixel value.
+     The red component is in the high 8 bits.
+     Non-representable colors return nil."
+
+    |pixel redBits greenBits blueBits r g b a|
+
+    b := rgb bitAnd:16rFF.
+    g := (rgb bitShift:-8) bitAnd:16rFF.
+    r := (rgb bitShift:-16) bitAnd:16rFF.
+    a := 255.
+
+    photometric == #rgb ifTrue:[
+        samplesPerPixel >= 3 ifTrue:[
+            "/ rrrrrrrrggggggggbbbbbbbb -> rrrrrgggggbbbbb
+            "/ r,g,b  r in hi bits, b in low bits 
+            redBits := bitsPerSample at:1.
+            greenBits := bitsPerSample at:2.
+            blueBits := bitsPerSample at:3.
+            r := r bitShift:(redBits-8).
+            g := g bitShift:(greenBits-8).
+            b := b bitShift:(blueBits-8).
+            pixel := (((r bitShift:greenBits) + g) bitShift:blueBits) + b.
+            ^ pixel
+        ]
+    ].
+    ^ super valueFromRGB:rgb
+
+    "Created: / 12-07-2019 / 14:48:31 / Stefan Reise"
 ! !
 
 !Depth16Image class methodsFor:'documentation'!