scaler: support Stretch

config.go

@@ -12,6 +12,7 @@ const (
 
 	FitOutside AspectFormat = 80 // Pad out with black bars to dimensions
 	FitInside  AspectFormat = 82 // Crop to dimensions
+	Stretch    AspectFormat = 83 // Doesn't preserve aspect ratio
 
 	NearestNeighbour ScaleFormat = 120
 	BilinearFast     ScaleFormat = 121

scaler.go

@@ -52,6 +52,10 @@ func (this *DirectThumbnailer) scaleImage(src image.Image) (image.Image, error)
 		srcCopyPosition = image.Rect(offsetX, offsetY, srcSmallestDim+offsetX, srcSmallestDim+offsetY)
 		destCopyPosition = image.Rect(0, 0, this.cfg.Width, this.cfg.Height)
 
+	case Stretch:
+		srcCopyPosition = src.Bounds()
+		destCopyPosition = image.Rect(0, 0, this.cfg.Width, this.cfg.Height)
+
 	default:
 		return nil, ErrInvalidOption
 	}