fix misspellings

README.md

@@ -127,7 +127,7 @@ gift.New().DrawAt(dstImage, fgImage, image.Pt(100, 100), gift.OverOperator)
     - Sepia(percentage float32)
     - Sigmoid(midpoint, factor float32)
     - Sobel()
-    - UnsharpMask(sigma, amount, thresold float32)
+    - UnsharpMask(sigma, amount, threshold float32)
 
 
 ### FILTER EXAMPLES

convolution.go

@@ -380,19 +380,19 @@ func GaussianBlur(sigma float32) Filter {
 }
 
 type unsharpMaskFilter struct {
-	sigma    float32
-	amount   float32
-	thresold float32
+	sigma     float32
+	amount    float32
+	threshold float32
 }
 
 func (p *unsharpMaskFilter) Bounds(srcBounds image.Rectangle) (dstBounds image.Rectangle) {
 	dstBounds = image.Rect(0, 0, srcBounds.Dx(), srcBounds.Dy())
 	return
 }
 
-func unsharp(orig, blurred, amount, thresold float32) float32 {
+func unsharp(orig, blurred, amount, threshold float32) float32 {
 	dif := (orig - blurred) * amount
-	if absf32(dif) > absf32(thresold) {
+	if absf32(dif) > absf32(threshold) {
 		return orig + dif
 	}
 	return orig
@@ -424,10 +424,10 @@ func (p *unsharpMaskFilter) Draw(dst draw.Image, src image.Image, options *Optio
 				pxOrig := pixGetterOrig.getPixel(x, y)
 				pxBlur := pixGetterBlur.getPixel(x, y)
 
-				r := unsharp(pxOrig.R, pxBlur.R, p.amount, p.thresold)
-				g := unsharp(pxOrig.G, pxBlur.G, p.amount, p.thresold)
-				b := unsharp(pxOrig.B, pxBlur.B, p.amount, p.thresold)
-				a := unsharp(pxOrig.A, pxBlur.A, p.amount, p.thresold)
+				r := unsharp(pxOrig.R, pxBlur.R, p.amount, p.threshold)
+				g := unsharp(pxOrig.G, pxBlur.G, p.amount, p.threshold)
+				b := unsharp(pxOrig.B, pxBlur.B, p.amount, p.threshold)
+				a := unsharp(pxOrig.A, pxBlur.A, p.amount, p.threshold)
 
 				pixelSetter.setPixel(dstb.Min.X+x-srcb.Min.X, dstb.Min.Y+y-srcb.Min.Y, pixel{r, g, b, a})
 			}
@@ -439,7 +439,7 @@ func (p *unsharpMaskFilter) Draw(dst draw.Image, src image.Image, options *Optio
 // The sigma parameter is used in a gaussian function and affects the radius of effect.
 // Sigma must be positive. Sharpen radius roughly equals 3 * sigma.
 // The amount parameter controls how much darker and how much lighter the edge borders become. Typically between 0.5 and 1.5.
-// The thresold parameter controls the minimum brightness change that will be sharpened. Typically between 0 and 0.05.
+// The threshold parameter controls the minimum brightness change that will be sharpened. Typically between 0 and 0.05.
 //
 // Example:
 //
@@ -449,11 +449,11 @@ func (p *unsharpMaskFilter) Draw(dst draw.Image, src image.Image, options *Optio
 //	dst := image.NewRGBA(g.Bounds(src.Bounds()))
 //	g.Draw(dst, src)
 //
-func UnsharpMask(sigma, amount, thresold float32) Filter {
+func UnsharpMask(sigma, amount, threshold float32) Filter {
 	return &unsharpMaskFilter{
-		sigma:    sigma,
-		amount:   amount,
-		thresold: thresold,
+		sigma:     sigma,
+		amount:    amount,
+		threshold: threshold,
 	}
 }
 

convolution_test.go

@@ -322,10 +322,10 @@ func TestGaussianBlur(t *testing.T) {
 func TestUnsharpMask(t *testing.T) {
 
 	testData := []struct {
-		desc                    string
-		sigma, amount, thresold float32
-		srcb, dstb              image.Rectangle
-		srcPix, dstPix          []uint8
+		desc                     string
+		sigma, amount, threshold float32
+		srcb, dstb               image.Rectangle
+		srcPix, dstPix           []uint8
 	}{
 		{
 			"unsharp mask (0.3, 1, 0)",
@@ -397,7 +397,7 @@ func TestUnsharpMask(t *testing.T) {
 		src := image.NewGray(d.srcb)
 		src.Pix = d.srcPix
 
-		f := UnsharpMask(d.sigma, d.amount, d.thresold)
+		f := UnsharpMask(d.sigma, d.amount, d.threshold)
 		dst := image.NewGray(f.Bounds(src.Bounds()))
 		f.Draw(dst, src, nil)