Merge pull request #17 from sprungknoedl/golang-image

added path from go image to opencv image and back.

opencv/cv.go

@@ -20,6 +20,7 @@ func init() {
 const (
 	CV_BGR2GRAY  = C.CV_BGR2GRAY
 	CV_BGR2BGRA  = C.CV_BGR2BGRA
+	CV_RGBA2BGRA = C.CV_RGBA2BGRA
 
 	CV_BLUR = C.CV_BLUR
 

opencv/cxcore.go

@@ -57,6 +57,11 @@ func CreateImage(w, h, depth, channels int) *IplImage {
 	return (*IplImage)(img)
 }
 
+/* SetData assigns user data to the image header */
+func (img *IplImage) SetData(data unsafe.Pointer, step int) {
+	C.cvSetData(unsafe.Pointer(img), data, C.int(step))
+}
+
 /* Releases (i.e. deallocates) IPL image header */
 func (img *IplImage) ReleaseHeader() {
 	img_c := (*C.IplImage)(img)
@@ -69,6 +74,10 @@ func (img *IplImage) Release() {
 	C.cvReleaseImage(&img_c)
 }
 
+func (img *IplImage) Zero() {
+	C.cvSetZero(unsafe.Pointer(img))
+}
+
 /* Creates a copy of IPL image (widthStep may differ) */
 func (img *IplImage) Clone() *IplImage {
 	p := C.cvCloneImage((*C.IplImage)(img))
@@ -114,6 +123,39 @@ func (img *IplImage) Reshape(channels, rows, _type int) *Mat {
 	return (*Mat)(n)
 }
 
+/* Get1D return a specific element from a 1-dimensional matrix. */
+func (img *IplImage) Get1D(x int) Scalar {
+	ret := C.cvGet1D(unsafe.Pointer(img), C.int(x))
+	return Scalar(ret)
+}
+
+/* Get2D return a specific element from a 2-dimensional matrix. */
+func (img *IplImage) Get2D(x, y int) Scalar {
+	ret := C.cvGet2D(unsafe.Pointer(img), C.int(y), C.int(x))
+	return Scalar(ret)
+}
+
+/* Get3D return a specific element from a 3-dimensional matrix. */
+func (img *IplImage) Get3D(x, y, z int) Scalar {
+	ret := C.cvGet3D(unsafe.Pointer(img), C.int(z), C.int(y), C.int(x))
+	return Scalar(ret)
+}
+
+/* Set1D sets a particular element in the image */
+func (img *IplImage) Set1D(x int, value Scalar) {
+	C.cvSet1D(unsafe.Pointer(img), C.int(x), (C.CvScalar)(value))
+}
+
+/* Set2D sets a particular element in the image */
+func (img *IplImage) Set2D(x, y int, value Scalar) {
+	C.cvSet2D(unsafe.Pointer(img), C.int(y), C.int(x), (C.CvScalar)(value))
+}
+
+/* Set3D sets a particular element in the image */
+func (img *IplImage) Set3D(x, y, z int, value Scalar) {
+	C.cvSet3D(unsafe.Pointer(img), C.int(z), C.int(y), C.int(x), (C.CvScalar)(value))
+}
+
 /* GetMat returns the matrix header for an image.*/
 func (img *IplImage) GetMat() *Mat {
 	var null C.int
@@ -155,6 +197,11 @@ func (mat *Mat) InitHeader(rows, cols, type_ int, data unsafe.Pointer, step int)
 	)
 }
 
+/* SetData assigns user data to the matrix header. */
+func (mat *Mat) SetData(data unsafe.Pointer, step int) {
+	C.cvSetData(unsafe.Pointer(mat), data, C.int(step))
+}
+
 /* Releases CvMat header and deallocates matrix data
    (reference counting is used for data) */
 func (mat *Mat) Release() {
@@ -179,6 +226,10 @@ func (mat *Mat) Clone() *Mat {
 	return (*Mat)(mat_new)
 }
 
+func (mat *Mat) Zero() {
+	C.cvSetZero(unsafe.Pointer(mat))
+}
+
 /*
 Reshape changes shape of the matrix without copying data. A value of `0` means
 that channels or rows remain unchanged.
@@ -275,6 +326,21 @@ func (m *Mat) Get3D(x, y, z int) Scalar {
 	return Scalar(ret)
 }
 
+/* Set1D sets a particular element in them matrix */
+func (m *Mat) Set1D(x int, value Scalar) {
+	C.cvSet1D(unsafe.Pointer(m), C.int(x), (C.CvScalar)(value))
+}
+
+/* Set2D sets a particular element in them matrix */
+func (m *Mat) Set2D(x, y int, value Scalar) {
+	C.cvSet2D(unsafe.Pointer(m), C.int(x), C.int(y), (C.CvScalar)(value))
+}
+
+/* Set3D sets a particular element in them matrix */
+func (m *Mat) Set3D(x, y, z int, value Scalar) {
+	C.cvSet3D(unsafe.Pointer(m), C.int(x), C.int(y), C.int(z), (C.CvScalar)(value))
+}
+
 /* GetImage returns the image header for the matrix. */
 func (m *Mat) GetImage(channels int) *IplImage {
 	tmp := CreateImage(m.Cols(), m.Rows(), m.Type(), channels)

opencv/cxtype.go

@@ -602,8 +602,8 @@ const (
 
 type Scalar C.CvScalar
 
-func NewScalar(b, g, r int) Scalar {
+func NewScalar(b, g, r, a float64) Scalar {
-	rv := C.cvScalar(C.double(b), C.double(g), C.double(r), C.double(0))
+	rv := C.cvScalar(C.double(b), C.double(g), C.double(r), C.double(a))
 	return (Scalar)(rv)
 }
 

opencv/goimage.go

@@ -0,0 +1,77 @@
+package opencv
+
+import (
+	"image"
+	"image/color"
+	"unsafe"
+)
+
+/* DecodeImageMem decodes an image from an in memory byte buffer. */
+func DecodeImageMem(data []byte) *IplImage {
+	buf := CreateMatHeader(1, len(data), CV_8U)
+	buf.SetData(unsafe.Pointer(&data[0]), CV_AUTOSTEP)
+
+	return DecodeImage(unsafe.Pointer(buf), CV_LOAD_IMAGE_UNCHANGED)
+}
+
+/* FromImage converts a go image.Image to an opencv.IplImage. */
+func FromImage(img image.Image) *IplImage {
+	b := img.Bounds()
+	model := color.RGBAModel
+	dst := CreateImage(
+		b.Max.X-b.Min.X,
+		b.Max.Y-b.Min.Y,
+		IPL_DEPTH_8U, 4)
+
+	for y := b.Min.Y; y < b.Max.Y; y++ {
+		for x := b.Min.X; x < b.Max.X; x++ {
+			px := img.At(x, y)
+			c := model.Convert(px).(color.RGBA)
+
+			value := NewScalar(float64(c.B), float64(c.G), float64(c.R), float64(c.A))
+			dst.Set2D(x, y, value)
+		}
+	}
+
+	return dst
+}
+
+/* FromImageUnsafe create an opencv.IplImage that shares the buffer with the
+go image.RGBA image. All changes made from opencv might affect go! */
+func FromImageUnsafe(img *image.RGBA) *IplImage {
+	b := img.Bounds()
+	buf := CreateImageHeader(
+		b.Max.X-b.Min.X,
+		b.Max.Y-b.Min.Y,
+		IPL_DEPTH_8U, 4)
+	dst := CreateImage(
+		b.Max.X-b.Min.X,
+		b.Max.Y-b.Min.Y,
+		IPL_DEPTH_8U, 4)
+
+	buf.SetData(unsafe.Pointer(&img.Pix[0]), CV_AUTOSTEP)
+	CvtColor(buf, dst, CV_RGBA2BGRA)
+	buf.Release()
+
+	return dst
+}
+
+/* ToImage converts a opencv.IplImage to an go image.Image */
+func (img *IplImage) ToImage() image.Image {
+	out := image.NewNRGBA(image.Rect(0, 0, img.Width(), img.Height()))
+	if img.Depth() != IPL_DEPTH_8U {
+		return nil // TODO return error
+	}
+
+	for y := 0; y < img.Height(); y++ {
+		for x := 0; x < img.Width(); x++ {
+			s := img.Get2D(x, y).Val()
+			b, g, r, a := s[2], s[1], s[0], s[3]
+
+			c := color.NRGBA{uint8(r), uint8(g), uint8(b), uint8(a)}
+			out.Set(x, y, c)
+		}
+	}
+
+	return out
+}

opencv/goimage_test.go

@@ -0,0 +1,96 @@
+package opencv
+
+import (
+	"image"
+	_ "image/jpeg"
+	_ "image/png"
+	"os"
+	"reflect"
+	"testing"
+)
+
+func TestFromImage(t *testing.T) {
+	fh, err := os.Open("../images/pic5.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	img, _, err := image.Decode(fh)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ocv := FromImage(img)
+	if ocv == nil {
+		t.Fatal("failed to convert image")
+	}
+
+	width := img.Bounds().Max.X - img.Bounds().Min.X
+	height := img.Bounds().Max.Y - img.Bounds().Min.Y
+	if ocv.Width() != width || ocv.Height() != height {
+		t.Fatalf("loaded image has wrong dimensions: got %dx%d, expected %dx%d", ocv.Width(), ocv.Height(), width, height)
+	}
+
+	ex := [4]float64{98, 139, 26, 255}
+	px := ocv.Get2D(50, 90).Val()
+	if !reflect.DeepEqual(px, ex) {
+		t.Fatalf("wrong color @50,90: got %v, expected %v", px, ex)
+	}
+}
+
+func TestFromImageUnsafe(t *testing.T) {
+	fh, err := os.Open("../images/pic5.png")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	img, _, err := image.Decode(fh)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	rgba, ok := img.(*image.RGBA)
+	if !ok {
+		t.Fatal("image is no RGBA image")
+	}
+
+	ocv := FromImageUnsafe(rgba)
+	if ocv == nil {
+		t.Fatal("failed to convert image")
+	}
+
+	width := img.Bounds().Max.X - img.Bounds().Min.X
+	height := img.Bounds().Max.Y - img.Bounds().Min.Y
+	if ocv.Width() != width || ocv.Height() != height {
+		t.Fatalf("loaded image has wrong dimensions: got %dx%d, expected %dx%d", ocv.Width(), ocv.Height(), width, height)
+	}
+
+	ex := [4]float64{98, 139, 26, 255}
+	px := ocv.Get2D(50, 90).Val()
+	if !reflect.DeepEqual(px, ex) {
+		t.Fatalf("wrong color @50,90: got %v, expected %v", px, ex)
+	}
+}
+
+func BenchmarkFromImage(b *testing.B) {
+	fh, _ := os.Open("../images/pic5.png")
+	img, _, _ := image.Decode(fh)
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		ocv := FromImage(img)
+		ocv.Release()
+	}
+}
+
+func BenchmarkFromImageUnsafe(b *testing.B) {
+	fh, _ := os.Open("../images/pic5.png")
+	img, _, _ := image.Decode(fh)
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		rgba := img.(*image.RGBA)
+		ocv := FromImageUnsafe(rgba)
+		ocv.Release()
+	}
+}