Code refactoring

process.go

@@ -8,13 +8,17 @@ import (
 	"io"
 	"os"
 	"image/jpeg"
+	"github.com/pkg/errors"
 )
 
+// SeamCarver is an interface that Carver uses to implement the Resize function.
+// It takes an image and the output as parameters and returns the resized image.
+type SeamCarver interface {
+	Resize(*image.NRGBA) (image.Image, error)
+}
+
 // Processor options
-type Carver struct {
-	Width          int
-	Height         int
-	Points         []float64
+type Processor struct {
 	SobelThreshold int
 	BlurRadius     int
 	NewWidth       int
@@ -22,20 +26,84 @@ type Carver struct {
 	Percentage     bool
 }
 
+
 // Implement the Resize method of the Carver interface.
 func Resize(s SeamCarver, img *image.NRGBA) (image.Image, error) {
 	return s.Resize(img)
 }
 
+// This is the main entry point which takes the source image
+// and encodes the new, rescaled image into the output file.
+func (p *Processor) Resize(img *image.NRGBA) (image.Image, error) {
+	var c *Carver = NewCarver(img.Bounds().Dx(), img.Bounds().Dy())
+
+	resize := func() {
+		width, height := img.Bounds().Max.X, img.Bounds().Max.Y
+		c = NewCarver(width, height)
+		c.ComputeSeams(img, p)
+		seams := c.FindLowestEnergySeams()
+		img = c.RemoveSeam(img, seams)
+	}
+
+	if p.Percentage {
+		// Calculate new sizes based on provided percentage.
+		nw := c.Width - int(float64(c.Width) - (float64(p.NewWidth)/100 * float64(c.Width)))
+		nh := c.Height - int(float64(c.Height) - (float64(p.NewHeight)/100 * float64(c.Height)))
+		// Resize image horizontally
+		for x := 0; x < nw; x++ {
+			resize()
+		}
+		// Resize image vertically
+		img = c.RotateImage90(img)
+
+		// Needs to update the slice width & height because of image rotation.
+		c.Width = img.Bounds().Dx()
+		c.Height = img.Bounds().Dy()
+		for y := 0; y < nh; y++ {
+			resize()
+		}
+		img = c.RotateImage270(img)
+	} else if p.NewWidth > 0 || p.NewHeight > 0 {
+		if p.NewWidth > 0 {
+			if p.NewWidth > c.Width {
+				err := errors.New("new width should be less than image width.")
+				return nil, err
+			}
+			for x := 0; x < p.NewWidth; x++ {
+				resize()
+			}
+		}
+
+		if p.NewHeight > 0 {
+			if p.NewHeight > c.Height {
+				err := errors.New("new height should be less than image height.")
+				return nil, err
+			}
+			img = c.RotateImage90(img)
+
+			// Needs to update the slice width & height because of image rotation
+			// otherwise the new image will be cut off.
+			c.Width = img.Bounds().Dx()
+			c.Height = img.Bounds().Dy()
+			for y := 0; y < p.NewHeight; y++ {
+				resize()
+			}
+			img = c.RotateImage270(img)
+		}
+	}
+	return img, nil
+}
+
 
 // Process is the main entry point for the image resize operation.
-func (c *Carver) Process(file io.Reader, output string) (*os.File, error) {
+func (p *Processor) Process(file io.Reader, output string) (*os.File, error) {
 	src, _, err := image.Decode(file)
 	if err != nil {
 		return nil, err
 	}
 	img := imgToNRGBA(src)
-	res, err := Resize(c, img)
+	//sobel := SobelFilter(Grayscale(img), float64(p.SobelThreshold))
+	res, err := Resize(p, img)
 	if err != nil {
 		return nil, err
 	}