Minor optimisations

Former-commit-id: 29042a39cda4cf3e8b50d66292c877db2fda8c2d
Former-commit-id: b133abc88402677d2b65df54be481f9d8197c32c
Former-commit-id: 7edec27867e0850ccd5bd8d3537c6479b694ada4

src/ImageProcessor/Samplers/Resampler.cs

@@ -277,7 +277,7 @@ namespace ImageProcessor.Samplers
                             Weight[] horizontalValues = this.horizontalWeights[x].Values;
 
                             // Destination color components
-                            Color destination = new Color(0, 0, 0, 0);
+                            Color destination = new Color();
 
                             foreach (Weight yw in verticalValues)
                             {
@@ -371,7 +371,7 @@ namespace ImageProcessor.Samplers
                         }
 
                         // Normalise the values
-                        if (Math.Abs(sum) > 0.00001f)
+                        if (sum > 0 || sum < 0)
                         {
                             builder.ForEach(w => w.Value /= sum);
                         }