Added interface and test for sharpen

options.go

@@ -100,6 +100,15 @@ type GaussianBlur struct {
 	MinAmpl float64
 }
 
+type Sharpen struct {
+	Radius  int
+	X1 float64
+	Y2 float64
+	Y3 float64
+	M1 float64
+	M2 float64
+}
+
 // Supported image transformation options
 type Options struct {
 	Height         int
@@ -129,4 +138,5 @@ type Options struct {
 	Interpolator   Interpolator
 	Interpretation Interpretation
 	GaussianBlur   GaussianBlur
+	Sharpen        Sharpen
 }

resize.go

@@ -149,7 +149,7 @@ func shouldTransformImage(o Options, inWidth, inHeight int) bool {
 }
 
 func shouldApplyEffects(o Options) bool {
-	return o.GaussianBlur.Sigma > 0 || o.GaussianBlur.MinAmpl > 0
+	return o.GaussianBlur.Sigma > 0 || o.GaussianBlur.MinAmpl > 0 || o.Sharpen.Radius > 0 && o.Sharpen.Y2 > 0 || o.Sharpen.Y3 > 0 
 }
 
 func transformImage(image *C.VipsImage, o Options, shrink int, residual float64) (*C.VipsImage, error) {
@@ -202,8 +202,15 @@ func applyEffects(image *C.VipsImage, o Options) (*C.VipsImage, error) {
 		}
 	}
 
-	debug("Effects: gaussSigma=%v, gaussMinAmpl=%v",
-		o.GaussianBlur.Sigma, o.GaussianBlur.MinAmpl)
+	if o.Sharpen.Radius > 0 && o.Sharpen.Y2 > 0 || o.Sharpen.Y3 > 0 {
+		image, err = vipsSharpen(image, o.Sharpen)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	debug("Effects: gaussSigma=%v, gaussMinAmpl=%v, sharpenRadius=%v",
+		o.GaussianBlur.Sigma, o.GaussianBlur.MinAmpl, o.Sharpen.Radius)
 
 	return image, nil
 }

resize_test.go

@@ -168,6 +168,23 @@ func TestGaussianBlur(t *testing.T) {
 	Write("fixtures/test_gaussian.jpg", newImg)
 }
 
+func TestSharpen(t *testing.T) {
+	options := Options{Width: 800, Height: 600, Sharpen: Sharpen{Radius: 1, X1: 1.5, Y2: 20, Y3: 50, M1: 1, M2: 2}}
+	buf, _ := Read("fixtures/test.jpg")
+
+	newImg, err := Resize(buf, options)
+	if err != nil {
+		t.Errorf("Resize(imgData, %#v) error: %#v", options, err)
+	}
+
+	size, _ := Size(newImg)
+	if size.Height != options.Height || size.Width != options.Width {
+		t.Fatalf("Invalid image size: %dx%d", size.Width, size.Height)
+	}
+
+	Write("fixtures/test_sharpen.jpg", newImg)
+}
+
 func TestConvert(t *testing.T) {
 	width, height := 300, 240
 	formats := [3]ImageType{PNG, WEBP, JPEG}

vips.go

@@ -473,3 +473,14 @@ func vipsGaussianBlur(image *C.VipsImage, o GaussianBlur) (*C.VipsImage, error)
 	}
 	return out, nil
 }
+
+func vipsSharpen(image *C.VipsImage, o Sharpen) (*C.VipsImage, error) {
+	var out *C.VipsImage
+	defer C.g_object_unref(C.gpointer(image))
+
+	err := C.vips_sharpen_bridge(image, &out, C.int(o.Radius), C.double(o.X1), C.double(o.Y2), C.double(o.Y3), C.double(o.M1), C.double(o.M2))
+	if err != 0 {
+		return nil, catchVipsError()
+	}
+	return out, nil
+}

vips.h

@@ -341,3 +341,12 @@ vips_gaussblur_bridge(VipsImage *in, VipsImage **out, double sigma, double min_a
 	return vips_gaussblur(in, out, sigma, NULL, "min_ampl", min_ampl, NULL);
 #endif
 }
+
+int
+vips_sharpen_bridge(VipsImage *in, VipsImage **out, int radius, double x1, double y2, double y3, double m1, double m2) {
+#if (VIPS_MAJOR_VERSION == 7 && VIPS_MINOR_VERSION < 41)
+	return vips_sharpen(in, out, radius, x1, y2, y3, m1, m2, NULL);
+#else
+	return vips_sharpen(in, out, "radius", radius, "x1", x1, "y2", y2, "y3", y3, "m1", m1, "m2", m2, NULL);
+#endif
+}