Changes + some indication of timing for a non-representative image

* Base version 2:52    (1024x1024, with 80% or so lot of transparent pixels)
* Print only the row number 2:31
* Do not perform superfluous checks 2:32    (also drops math.sqrt)
* Factor subtraction out 1:41
* Iterate over the palette directly 1:17

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

diff --git a/convertor_v4.py b/convertor_v4.py
--- a/convertor_v4.py
+++ b/convertor_v4.py
@@ -48,11 +48,12 @@ def rgb2palette(inputImage, frameNumber)
 
 
   for y in range (0, i.height):
+    print("row {}".format(y))
     for x in range (0, i.width):
       winnerDistance = 100000000
       winnerID = 0
 
-      pixelNumber = x + (y * i.width)
+      #pixelNumber = x + (y * i.width)
       pix = i.getpixel((x,y))
       pixRed = pix[0]
       pixGreen = pix[1]
@@ -63,49 +64,45 @@ def rgb2palette(inputImage, frameNumber)
       if pixAlpha < 128:
         finalAlpha = 0
         colorOffset = 0
-      if pixAlpha >= 128 and pixAlpha < 178:
+      elif pixAlpha < 178:
         finalAlpha = 255
         colorOffset = 1
-      if pixAlpha >= 178 and pixAlpha < 230:
+      elif pixAlpha < 230:
         finalAlpha = 255
         colorOffset = 2
-      if pixAlpha >= 230:
+      else:
         finalAlpha = 255
         colorOffset = 0
 
       if pixAlpha >= 128:
-        for z in range(0, 255):
-          colorArray = p[z]
+        for z, (cr, cg, cb) in enumerate(p):
           #print("current z is ..." + str(colorArray) )
-          paletteR = colorArray[0]
-          paletteG = colorArray[1]
-          paletteB = colorArray[2]
-          distance = math.sqrt( ((pixRed-paletteR)*(pixRed-paletteR)) + ((pixGreen-paletteG)*(pixGreen-paletteG)) + ((pixBlue-paletteB)*(pixBlue-paletteB) ))
+          dr = pixRed - cr
+          dg = pixGreen - cg
+          db = pixBlue - cb
+          distance = dr*dr + dg*dg + db*db
           #print("Pixel " + str(pixelNumber) + ": " + str(distance) + " ,Alpha: " + str(pixAlpha) )

           #taking the distance and comparing it to previous "round"
-          temporaryDistance = distance
-          temporaryID = z
-          #print("temporaryID is ..." + str(temporaryID) )
-          if temporaryDistance < winnerDistance:
-            winnerDistance = temporaryDistance
-            winnerID = temporaryID
+          if distance < winnerDistance:
+            winnerDistance = distance
+            winnerID = z
             #print("new winner is ..." + str(winnerID) + "!!!")

       #colorOffset changes based on Value of the input

       if pixRed >= pixGreen and pixRed >= pixBlue:
         highestValue = pixRed
-      if pixGreen >= pixRed and pixGreen >= pixBlue:
+      elif pixGreen >= pixRed and pixGreen >= pixBlue:
         highestValue = pixGreen
-      if pixBlue >= pixRed and pixBlue >= pixGreen:
+      else:
         highestValue = pixBlue

       if highestValue < 128:
         negation = -1
         colorOffset = colorOffset * negation

-      print("colorOffset is ... " + str(colorOffset) )
+      #print("colorOffset is ... " + str(colorOffset) )
       finalColor = p[winnerID - colorOffset]

       finalR = finalColor[0]
@@ -114,7 +111,7 @@ def rgb2palette(inputImage, frameNumber)
       #finalAlpha taken from the if output above

       imageOutput.putpixel((x,y),(finalR,finalG,finalB,finalAlpha))
-      print("Pixel " + str(pixelNumber) + ": R= " + str(finalR) + ", G= " + str(finalG) + ", B= " + str(finalB) + ", A= "  + str(finalAlpha)   )
+      #print("Pixel " + str(pixelNumber) + ": R= " + str(finalR) + ", G= " + str(finalG) + ", B= " + str(finalB) + ", A= "  + str(finalAlpha)   )