func main() {
// Some GraphicsMagick boilerplate
C.InitializeMagick(nil)
defer C.DestroyMagick()
C.GetExceptionInfo(&exceptionInfo)
imageInfo = C.CloneImageInfo(nil)
defer C.DestroyExceptionInfo(&exceptionInfo)
defer C.DestroyImageInfo(imageInfo)
// main OMIT
Show("./cgo/armed_gopher.jpg")
img, err := Read("./cgo/armed_gopher.jpg")
if err != nil {
fmt.Println(err)
return
}
if img, err = Resize(img, 200, 800); err != nil {
fmt.Println("resize error:", err)
return
}
if err = Save(img, "./cgo/resized_gopher.jpg"); err != nil {
fmt.Println("save error:", err)
return
}
Show("./cgo/resized_gopher.jpg")
}
// Composite modifies the image, drawing the draw Image argument at offset
// (x, y) using the c Composite operation.
func (im *Image) Composite(c Composite, draw *Image, x int, y int) error {
op, err := im.compositeOperator(c)
if err != nil {
return err
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var data C.CompositeData
data.composite = C.int(op)
data.draw = draw.image
data.x = C.int(x)
data.y = C.int(y)
res, err := im.applyDataFunc("compositing", C.ImageDataFunc(C.compositeImage), &data)
// res.image will be != than im.image when im is a non
// coalesced animation
if res.image != im.image {
unrefImages(im.image)
initializeRefCounts(res.image)
refImages(res.image)
im.image = res.image
dontFree(res)
}
return err
}
func (im *Image) fn(what string, f C.ImageFunc) (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
res := C.bridge_image_func(f, im.image, &ex)
return checkImage(res, nil, &ex, what)
}
func (im *Image) Roll(xoffset, yoffset int) (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
rolled := C.RollImage(im.image, magickLong(xoffset), magickLong(yoffset), &ex)
return checkImage(rolled, nil, &ex, "rolling")
}
// FloatMatrix returns an Image in the GRAY colorspace as FloatMatrix,
// where each pixel represents an element of the matrix. Each element
// is normalized to the [0,1] range.
func (im *Image) FloatMatrix() (FloatMatrix, error) {
if im.Colorspace() != GRAY {
return nil, fmt.Errorf("FloatMatrix() is available only for GRAY images, this one is in %s", im.Colorspace())
}
width := im.Width()
height := im.Height()
ptrs := make([]*C.double, width)
for ii := range ptrs {
ptrs[ii] = allocDoublePtr(height)
}
defer func() {
for _, p := range ptrs {
freeDoublePtr(p)
}
}()
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
C.image_matrix(im.image, (**C.double)(unsafe.Pointer(&ptrs[0])), &ex)
if ex.severity != C.UndefinedException {
return nil, exError(&ex, "generating float matrix")
}
m := make([][]float64, width)
for ii := range m {
m[ii] = doublePtrToFloat64Slice(ptrs[ii], height)
}
return FloatMatrix(m), nil
}
func (im *Image) NColors() (int, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
val := C.GetNumberColors(im.image, nil, &ex)
if ex.severity != C.UndefinedException {
return 0, exError(&ex, "getting colors")
}
return int(val), nil
}
// ChannelDepth returns the depth of the given channel.
func (im *Image) ChannelDepth(ch Channel) (uint, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
ret := C.GetImageChannelDepth(im.image, C.ChannelType(ch), &ex)
if ex.severity != C.UndefinedException {
return 0, exError(&ex, "getting channel info")
}
return uint(ret), nil
}
func (im *Image) IsPalette() (bool, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
b := C.IsPaletteImage(im.image, &ex)
if ex.severity != C.UndefinedException {
return false, exError(&ex, "getting isPalette")
}
return int(b) != 0, nil
}
func (im *Image) statistics() (*Statistics, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var stats C.ImageStatistics
C.GetImageStatistics(im.image, &stats, &ex)
if ex.severity != C.UndefinedException {
return nil, exError(&ex, "getting statistics")
}
return newStatistics(&stats), nil
}
// Clone returns a copy of the image. If the image
// has multiple frames, it copies all of them. To
// Clone just one frame use im.Frame(i).Clone().
func (im *Image) Clone() (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var image *C.Image
if im.parent == nil {
image = C.CloneImageList(im.image, &ex)
} else {
image = C.CloneImage(im.image, magickSize(0), magickSize(0), 1, &ex)
}
return checkImage(image, nil, &ex, "cloning")
}
func (im *Image) applyFunc(what string, f C.ImageFunc) (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
res := C.apply_image_func(f, im.root(), unsafe.Pointer(im.parent), btoi(im.coalesced), &ex)
if res == nil {
return nil, exError(&ex, what)
}
ret := newImage(res, nil)
ret.coalesced = true
return ret, nil
}
func (im *Image) applyDataFunc(what string, f C.ImageDataFunc, data interface{}) (*Image, error) {
p := unsafe.Pointer(reflect.ValueOf(data).Pointer())
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
res := C.apply_image_data_func(f, im.root(), p, unsafe.Pointer(im.parent), btoi(im.coalesced), &ex)
if res == nil {
return nil, exError(&ex, what)
}
ret := newImage(res, nil)
ret.coalesced = true
return ret, nil
}
func (im *Image) statistics() (*Statistics, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
stats := C.GetImageChannelStatistics(im.image, &ex)
if stats != nil {
defer freeMagickMemory(unsafe.Pointer(stats))
}
if stats == nil || ex.severity != C.UndefinedException {
return nil, exError(&ex, "getting statistics")
}
return newStatistics(stats), nil
}
func decodeData(data []byte, try int) (*Image, error) {
if len(data) == 0 {
return nil, ErrNoData
}
info := C.CloneImageInfo(nil)
defer C.DestroyImageInfo(info)
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
im := C.BlobToImage(info, unsafe.Pointer(&data[0]), C.size_t(len(data)), &ex)
if im == nil && try < maxGifTries && ex.severity == C.CorruptImageError && looksLikeGif(data) {
return fixAndDecodeGif(data, try)
}
return checkImage(im, nil, &ex, "decoding")
}
// Composite modifies the image, drawing the draw Image argument at offset
// (x, y) using the c Composite operation.
func (im *Image) Composite(c Composite, draw *Image, x int, y int) error {
op, err := im.compositeOperator(c)
if err != nil {
return err
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var data C.CompositeData
data.composite = C.int(op)
data.draw = draw.image
data.x = C.int(x)
data.y = C.int(y)
_, err = im.applyDataFunc("compositing", C.ImageDataFunc(C.compositeImage), &data)
return err
}
// Supported formats returns a list with the names
// of all supported image formats. This varies depending
// on the backend and the compile options that have been
// used while building IM or GM.
func SupportedFormats() ([]string, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
infos, p := supportedFormats(&ex)
if infos == nil {
return nil, exError(&ex, "getting supported formats")
}
var formats []string
for _, v := range infos {
if v == nil {
break
}
formats = append(formats, C.GoString(v.name))
}
freeMagickMemory(p)
return formats, nil
}
func (im *Image) Apply(f func(*Image) (*Image, error)) (*Image, error) {
if im.IsOrphan() || im.parent != nil {
return f(im)
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
cur, free := im.coalescedCImage(&ex)
if cur == nil {
return nil, exError(&ex, "coalescing")
}
buf := &Image{
parent: im,
image: cur,
}
first, err := f(buf)
if err != nil {
return nil, err
}
prev := first.image
var res *Image
for cur := (*C.Image)(im.image.next); cur != nil; cur = (*C.Image)(cur.next) {
buf.image = cur
res, err = f(buf)
if err != nil {
break
}
dontFree(res)
img := res.image
if img != cur {
prev.next = (*C.struct__Image)(img)
img.previous = (*C.struct__Image)(prev)
}
prev = img
}
if free && (first.image != cur || err != nil) {
C.DestroyImageList(cur)
}
if err != nil {
return nil, err
}
return first, nil
}
// SetPixels changes the pixels in the given rect, in row major order.
// Note that the number of elements in p must match r.Width * r.Height,
// otherwise an error is returned.
func (im *Image) SetPixels(r Rect, p []*Pixel) error {
if int(r.Width*r.Height) != len(p) {
return fmt.Errorf("rect contains %d pixels, but %d were provided", int(r.Width*r.Height), len(p))
}
if len(p) == 0 {
return nil
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
packets := make([]C.PixelPacket, len(p))
for ii, v := range p {
copyPixel(v, &packets[ii])
}
if !im.setPixels(&r, (*C.PixelPacket)(unsafe.Pointer(&packets[0])), &ex) {
return exError(&ex, "setting pixels")
}
return nil
}
func (im *Image) AddFrame(f Frame, c *Pixel) (*Image, error) {
return im.Apply(func(i *Image) (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var m *Pixel
if c != nil {
m = i.MatteColor()
i.SetMatteColor(c)
}
framed := C.FrameImage(i.image, f.frameInfo(), &ex)
if m != nil {
i.SetMatteColor(m)
}
if framed == nil {
return nil, exError(&ex, "adding border")
}
return newImage(framed, nil), nil
})
}
func (im *Image) AddBorder(r Rect, c *Pixel) (*Image, error) {
return im.Apply(func(i *Image) (*Image, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var b *Pixel
if c != nil {
b = i.BorderColor()
im.SetBorderColor(c)
}
bordered := C.BorderImage(i.image, r.rectangleInfo(), &ex)
if b != nil {
i.SetBorderColor(b)
}
if bordered == nil {
return nil, exError(&ex, "adding border")
}
return newImage(bordered, nil), nil
})
}
// Pixels returns the image pixels contained in the given rect,
// in row major order. Note that modifications to the returned pixels
// won't alter the image. Use SetPixels to change pixels in the
// image.
func (im *Image) Pixels(r Rect) ([]*Pixel, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
ptr := im.pixels(&r, &ex)
if ptr == nil {
return nil, exError(&ex, "getting pixels")
}
count := int(r.Width * r.Height)
var pkts []C.PixelPacket
header := (*reflect.SliceHeader)((unsafe.Pointer(&pkts)))
header.Cap = count
header.Len = count
header.Data = uintptr(unsafe.Pointer(ptr))
px := make([]*Pixel, count)
for ii, v := range pkts {
px[ii] = newPixel(&v)
}
return px, nil
}
// Encode writes the image to the given io.Writer, encoding
// it according to the info parameter. Please, see the
// Info type for the available encoding options.
func (im *Image) Encode(w io.Writer, info *Info) error {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
if info == nil {
info = NewInfo()
}
/* ImageToBlob copies the format from the image into
the image info. Overwrite if required and then restore
*/
im.mu.Lock()
var format *C.char
copied := false
if info.info.magick[0] != 0 {
copied = true
if im.image.magick[0] != 0 {
format = C.strdup(&im.image.magick[0])
}
C.strncpy(&im.image.magick[0], &info.info.magick[0], C.MaxTextExtent)
}
var s C.size_t
mem := imageToBlob(info, im, &s, &ex)
if copied {
/* Restore image format */
if format != nil {
C.strncpy(&im.image.magick[0], format, C.MaxTextExtent)
C.free(unsafe.Pointer(format))
} else {
C.memset(unsafe.Pointer(&im.image.magick[0]), 0, C.MaxTextExtent)
}
}
im.mu.Unlock()
if mem == nil {
return exError(&ex, "encoding")
}
b := goBytes(mem, int(s))
w.Write(b)
C.free(mem)
return nil
}
// FloatMatrix returns an Image in the GRAY colorspace as FloatMatrix,
// where each pixel represents an element of the matrix. Each element
// is normalized to the [0,1] range.
func (im *Image) FloatMatrix() (FloatMatrix, error) {
if im.Colorspace() != GRAY {
return nil, fmt.Errorf("FloatMatrix() is available only for GRAY images, this one is in %s", im.Colorspace())
}
width := im.Width()
height := im.Height()
m := make([][]float64, width)
ptrs := make([]unsafe.Pointer, width)
for ii := range m {
col := make([]float64, height)
m[ii] = col
ptrs[ii] = unsafe.Pointer(&col[0])
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
C.image_matrix(im.image, (**C.double)(unsafe.Pointer(&ptrs[0])), &ex)
if ex.severity != C.UndefinedException {
return nil, exError(&ex, "generating float matrix")
}
return FloatMatrix(m), nil
}
func (im *Image) histogram() (*Histogram, error) {
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
var colors C.ulong
hist := C.GetColorHistogram(im.image, &colors, &ex)
if hist == nil {
return nil, exError(&ex, "getting histogram")
}
defer C.free(unsafe.Pointer(hist))
count := int(colors)
items := make([]*HistogramItem, count)
var hitems []C.HistogramColorPacket
sliceHeader := (*reflect.SliceHeader)((unsafe.Pointer(&hitems)))
sliceHeader.Cap = count
sliceHeader.Len = count
sliceHeader.Data = uintptr(unsafe.Pointer(hist))
for ii, v := range hitems {
px := newPixel(&v.pixel)
items[ii] = &HistogramItem{px, int(v.count)}
}
return &Histogram{items}, nil
}
func (im *Image) operateChannel(op Operator, ch Channel, value float64) error {
var cop C.QuantumOperator
switch op {
case OpAdd:
cop = C.AddQuantumOp
case OpAnd:
cop = C.AndQuantumOp
case OpAssign:
cop = C.AssignQuantumOp
case OpDepth:
cop = C.DepthQuantumOp
case OpDivide:
cop = C.DivideQuantumOp
case OpGamma:
cop = C.GammaQuantumOp
case OpLog:
cop = C.LogQuantumOp
case OpLShift:
cop = C.LShiftQuantumOp
case OpMax:
cop = C.MaxQuantumOp
case OpMin:
cop = C.MinQuantumOp
case OpMultiply:
cop = C.MultiplyQuantumOp
case OpGaussianNoise:
cop = C.GammaQuantumOp
case OpImpulseNoise:
cop = C.NoiseImpulseQuantumOp
case OpLaplacianNoise:
cop = C.NoiseLaplacianQuantumOp
case OpMultiplicativeNoise:
cop = C.NoiseMultiplicativeQuantumOp
case OpPoissonNoise:
cop = C.NoisePoissonQuantumOp
case OpRandomNoise:
cop = C.NoiseRandomQuantumOp
case OpUniformNoise:
cop = C.NoisePoissonQuantumOp
case OpOr:
cop = C.OrQuantumOp
case OpPow:
cop = C.PowQuantumOp
case OpRShift:
cop = C.RShiftQuantumOp
case OpSubstract:
cop = C.SubtractQuantumOp
case OpThresholdBlack:
cop = C.ThresholdBlackQuantumOp
case OpThreshold:
cop = C.ThresholdQuantumOp
case OpThresholdWhite:
cop = C.ThresholdWhiteQuantumOp
case OpXor:
cop = C.XorQuantumOp
default:
return notImplementedError(fmt.Sprintf("operator %s", op))
}
var ex C.ExceptionInfo
C.GetExceptionInfo(&ex)
defer C.DestroyExceptionInfo(&ex)
if C.QuantumOperatorImage(im.image, C.ChannelType(ch), cop, C.double(value), &ex) != C.MagickTrue {
return exError(&ex, "operating")
}
return nil
}