added path from go image to opencv image and back.

opencv/cxcore.go

@@ -114,6 +114,39 @@ 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(x), C.int(y))
+	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(x), C.int(y), C.int(z))
+	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(x), C.int(y), (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(x), C.int(y), C.int(z), (C.CvScalar)(value))
+}
+
 /* GetMat returns the matrix header for an image.*/
 func (img *IplImage) GetMat() *Mat {
 	var null C.int
@@ -155,6 +188,11 @@ 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() {
@@ -275,6 +313,21 @@ 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 {
-	rv := C.cvScalar(C.double(b), C.double(g), C.double(r), C.double(0))
+func NewScalar(b, g, r, a float64) Scalar {
+	rv := C.cvScalar(C.double(b), C.double(g), C.double(r), C.double(a))
 	return (Scalar)(rv)
 }
 

opencv/goimage.go

@@ -0,0 +1,57 @@
+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(buf, CV_LOAD_IMAGE_UNCHANGED)
+}
+
+/* From Image converts a go image.Image to an opencv.IplImage. */
+func FromImage(img image.Image) *IplImage {
+	b := img.Bounds()
+	model := color.NRGBAModel
+	dst := CreateImage(
+		b.Max.Y-b.Min.Y,
+		b.Max.X-b.Min.X,
+		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.NRGBA)
+
+			value := NewScalar(float64(c.B), float64(c.G), float64(c.R), float64(c.A))
+			dst.Set2D(x, y, value)
+		}
+	}
+
+	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/highgui.go

@@ -399,11 +399,11 @@ func SaveImage(filename string, image *IplImage, params int) int {
 }
 
 /* decode image stored in the buffer */
-func DecodeImage(buf unsafe.Pointer, iscolor int) *IplImage {
+func DecodeImage(buf *Mat, iscolor int) *IplImage {
 	rv := C.cvDecodeImage((*C.CvMat)(buf), C.int(iscolor))
 	return (*IplImage)(rv)
 }
-func DecodeImageM(buf unsafe.Pointer, iscolor int) *Mat {
+func DecodeImageM(buf *Mat, iscolor int) *Mat {
 	rv := C.cvDecodeImageM((*C.CvMat)(buf), C.int(iscolor))
 	return (*Mat)(rv)
 }