func vipsSave(image *C.VipsImage, o vipsSaveOptions) ([]byte, error) {
defer C.g_object_unref(C.gpointer(image))
tmpImage, err := vipsPreSave(image, &o)
if err != nil {
return nil, err
}
// When an image has an unsupported color space, vipsPreSave
// returns the pointer of the image passed to it unmodified.
// When this occurs, we must take care to not dereference the
// original image a second time; we may otherwise erroneously
// free the object twice.
if tmpImage != image {
defer C.g_object_unref(C.gpointer(tmpImage))
}
length := C.size_t(0)
saveErr := C.int(0)
interlace := C.int(boolToInt(o.Interlace))
quality := C.int(o.Quality)
var ptr unsafe.Pointer
switch o.Type {
case WEBP:
saveErr = C.vips_webpsave_bridge(tmpImage, &ptr, &length, 1, quality)
break
case PNG:
saveErr = C.vips_pngsave_bridge(tmpImage, &ptr, &length, 1, C.int(o.Compression), quality, interlace)
break
case GIF:
return nil, errors.New("VIPS cannot save to GIF")
case PDF:
return nil, errors.New("VIPS cannot save to PDF")
case SVG:
return nil, errors.New("VIPS cannot save to SVG")
default:
saveErr = C.vips_jpegsave_bridge(tmpImage, &ptr, &length, 1, quality, interlace)
break
}
if int(saveErr) != 0 {
return nil, catchVipsError()
}
buf := C.GoBytes(ptr, C.int(length))
// Clean up
C.g_free(C.gpointer(ptr))
C.vips_error_clear()
return buf, nil
}
func getImageBuffer(image *C.VipsImage) ([]byte, error) {
var ptr unsafe.Pointer
length := C.size_t(0)
interlace := C.int(0)
quality := C.int(100)
err := C.int(0)
err = C.vips_jpegsave_bridge(image, &ptr, &length, 1, quality, interlace)
if int(err) != 0 {
return nil, catchVipsError()
}
defer C.g_free(C.gpointer(ptr))
defer C.vips_error_clear()
return C.GoBytes(ptr, C.int(length)), nil
}
// vipsError converts from vips to Go errors.
func vipsError(e C.int) error {
if e == 0 {
return nil
}
// The VIPS error buffer is global, and checking and clearing it are
// not atomic. If errors are infrequent, this will probably return
// our error. It may also return nothing or unrelated errors.
// TODO: Consider vips_error_freeze() and skipping this.
s := C.GoString(C.vips_error_buffer())
C.vips_error_clear()
if s != "" {
return errors.New(s)
}
// At least return something generic.
return ErrImageOp
}
func vipsSave(image *C.struct__VipsImage, o vipsSaveOptions) ([]byte, error) {
length := C.size_t(0)
err := C.int(0)
interlace := C.int(boolToInt(o.Interlace))
// Remove ICC profile metadata
if o.NoProfile {
C.remove_profile(image)
}
// Force RGB color space
var outImage *C.struct__VipsImage
C.vips_colourspace_bridge(image, &outImage)
defer C.g_object_unref(C.gpointer(image))
defer C.g_object_unref(C.gpointer(outImage))
var ptr unsafe.Pointer
switch o.Type {
case PNG:
err = C.vips_pngsave_bridge(outImage, &ptr, &length, 1, C.int(o.Compression), C.int(o.Quality), interlace)
break
case WEBP:
err = C.vips_webpsave_bridge(outImage, &ptr, &length, 1, C.int(o.Quality))
break
default:
err = C.vips_jpegsave_bridge(outImage, &ptr, &length, 1, C.int(o.Quality), interlace)
break
}
if int(err) != 0 {
return nil, catchVipsError()
}
buf := C.GoBytes(ptr, C.int(length))
// Clean up
C.g_free(C.gpointer(ptr))
C.vips_error_clear()
return buf, nil
}
func vipsSave(image *C.VipsImage, o vipsSaveOptions) ([]byte, error) {
defer C.g_object_unref(C.gpointer(image))
tmpImage, err := vipsPreSave(image, &o)
if err != nil {
return nil, err
}
defer C.g_object_unref(C.gpointer(tmpImage))
length := C.size_t(0)
saveErr := C.int(0)
interlace := C.int(boolToInt(o.Interlace))
quality := C.int(o.Quality)
var ptr unsafe.Pointer
switch o.Type {
case WEBP:
saveErr = C.vips_webpsave_bridge(tmpImage, &ptr, &length, 1, quality)
break
case PNG:
saveErr = C.vips_pngsave_bridge(tmpImage, &ptr, &length, 1, C.int(o.Compression), quality, interlace)
break
default:
saveErr = C.vips_jpegsave_bridge(tmpImage, &ptr, &length, 1, quality, interlace)
break
}
if int(saveErr) != 0 {
return nil, catchVipsError()
}
buf := C.GoBytes(ptr, C.int(length))
// Clean up
C.g_free(C.gpointer(ptr))
C.vips_error_clear()
return buf, nil
}
func resizeError() error {
s := C.GoString(C.vips_error_buffer())
C.vips_error_clear()
return errors.New(s)
}
func Resize(buf []byte, o Options) ([]byte, error) {
debug("%#+v", o)
// detect (if possible) the file type
typ := UNKNOWN
switch {
case bytes.Equal(buf[:2], MARKER_JPEG):
typ = JPEG
case bytes.Equal(buf[:2], MARKER_PNG):
typ = PNG
default:
return nil, errors.New("unknown image format")
}
// create an image instance
var image, tmpImage *C.struct__VipsImage
// feed it
switch typ {
case JPEG:
C.vips_jpegload_buffer_seq(unsafe.Pointer(&buf[0]), C.size_t(len(buf)), &image)
case PNG:
C.vips_pngload_buffer_seq(unsafe.Pointer(&buf[0]), C.size_t(len(buf)), &image)
}
// cleanup
defer func() {
C.vips_thread_shutdown()
C.vips_error_clear()
}()
// defaults
if o.Quality == 0 {
o.Quality = 100
}
// get WxH
inWidth := int(image.Xsize)
inHeight := int(image.Ysize)
// prepare for factor
factor := 0.0
// image calculations
switch {
// Fixed width and height
case o.Width > 0 && o.Height > 0:
xf := float64(inWidth) / float64(o.Width)
yf := float64(inHeight) / float64(o.Height)
if o.Crop {
factor = math.Min(xf, yf)
} else {
factor = math.Max(xf, yf)
}
// Fixed width, auto height
case o.Width > 0:
factor = float64(inWidth) / float64(o.Width)
o.Height = int(math.Floor(float64(inHeight) / factor))
// Fixed height, auto width
case o.Height > 0:
factor = float64(inHeight) / float64(o.Height)
o.Width = int(math.Floor(float64(inWidth) / factor))
// Identity transform
default:
factor = 1
o.Width = inWidth
o.Height = inHeight
}
debug("transform from %dx%d to %dx%d", inWidth, inHeight, o.Width, o.Height)
// shrink
shrink := int(math.Floor(factor))
if shrink < 1 {
shrink = 1
}
// residual
residual := float64(shrink) / factor
// Do not enlarge the output if the input width *or* height are already less than the required dimensions
if !o.Enlarge {
if inWidth < o.Width && inHeight < o.Height {
factor = 1
shrink = 1
residual = 0
o.Width = inWidth
o.Height = inHeight
}
}
debug("factor: %v, shrink: %v, residual: %v", factor, shrink, residual)
// Try to use libjpeg shrink-on-load
shrinkOnLoad := 1
if typ == JPEG && shrink >= 2 {
switch {
case shrink >= 8:
factor = factor / 8
shrinkOnLoad = 8
case shrink >= 4:
factor = factor / 4
shrinkOnLoad = 4
case shrink >= 2:
factor = factor / 2
shrinkOnLoad = 2
}
}
if shrinkOnLoad > 1 {
debug("shrink on load %d", shrinkOnLoad)
// Recalculate integral shrink and double residual
factor = math.Max(factor, 1.0)
shrink = int(math.Floor(factor))
residual = float64(shrink) / factor
// Reload input using shrink-on-load
err := C.vips_jpegload_buffer_shrink(unsafe.Pointer(&buf[0]), C.size_t(len(buf)), &tmpImage, C.int(shrinkOnLoad))
C.g_object_unref(C.gpointer(image))
image = tmpImage
if err != 0 {
return nil, resizeError()
}
}
if shrink > 1 {
debug("shrink %d", shrink)
// Use vips_shrink with the integral reduction
err := C.vips_shrink_0(image, &tmpImage, C.double(float64(shrink)), C.double(float64(shrink)))
C.g_object_unref(C.gpointer(image))
image = tmpImage
if err != 0 {
return nil, resizeError()
}
// Recalculate residual float based on dimensions of required vs shrunk images
shrunkWidth := int(image.Xsize)
shrunkHeight := int(image.Ysize)
residualx := float64(o.Width) / float64(shrunkWidth)
residualy := float64(o.Height) / float64(shrunkHeight)
if o.Crop {
residual = math.Max(residualx, residualy)
} else {
residual = math.Min(residualx, residualy)
}
}
// Use vips_affine with the remaining float part
debug("residual: %v", residual)
if residual != 0 {
debug("residual %.2f", residual)
// Create interpolator - "bilinear" (default), "bicubic" or "nohalo"
is := C.CString(o.Interpolator.String())
interpolator := C.vips_interpolate_new(is)
// Perform affine transformation
err := C.vips_affine_interpolator(image, &tmpImage, C.double(residual), 0, 0, C.double(residual), interpolator)
C.g_object_unref(C.gpointer(image))
image = tmpImage
C.free(unsafe.Pointer(is))
C.g_object_unref(C.gpointer(interpolator))
if err != 0 {
return nil, resizeError()
}
}
// Crop/embed
affinedWidth := int(image.Xsize)
affinedHeight := int(image.Ysize)
if affinedWidth != o.Width || affinedHeight != o.Height {
if o.Crop {
// Crop
debug("cropping")
left, top := sharpCalcCrop(affinedWidth, affinedHeight, o.Width, o.Height, o.Gravity)
o.Width = int(math.Min(float64(affinedWidth), float64(o.Width)))
o.Height = int(math.Min(float64(affinedHeight), float64(o.Height)))
err := C.vips_extract_area_0(image, &tmpImage, C.int(left), C.int(top), C.int(o.Width), C.int(o.Height))
C.g_object_unref(C.gpointer(image))
image = tmpImage
if err != 0 {
return nil, resizeError()
}
} else if o.Embed {
debug("embedding with extend %d", o.Extend)
left := (o.Width - affinedWidth) / 2
top := (o.Height - affinedHeight) / 2
err := C.vips_embed_extend(image, &tmpImage, C.int(left), C.int(top), C.int(o.Width), C.int(o.Height), C.int(o.Extend))
C.g_object_unref(C.gpointer(image))
image = tmpImage
if err != 0 {
return nil, resizeError()
}
}
} else {
debug("canvased same as affined")
}
// Always convert to sRGB colour space
C.vips_colourspace_0(image, &tmpImage, C.VIPS_INTERPRETATION_sRGB)
C.g_object_unref(C.gpointer(image))
image = tmpImage
// Finally save
length := C.size_t(0)
var ptr unsafe.Pointer
C.vips_jpegsave_custom(image, &ptr, &length, 1, C.int(o.Quality), 0)
C.g_object_unref(C.gpointer(image))
// get back the buffer
buf = C.GoBytes(ptr, C.int(length))
C.g_free(C.gpointer(ptr))
return buf, nil
}
func catchVipsError() error {
s := C.GoString(C.vips_error_buffer())
C.vips_error_clear()
C.vips_thread_shutdown()
return errors.New(s)
}
func AutoRotate(file string, o Options) ([]byte, error) {
debug("%#+v", o)
// detect (if possible) the file type
/*typ := UNKNOWN
switch {
case bytes.Equal(buf[:2], MARKER_JPEG):
typ = JPEG
case bytes.Equal(buf[:2], MARKER_PNG):
typ = PNG
default:
return nil, errors.New("unknown image format")
}
// create an image instance
var image, tmpImage *C.struct__VipsImage
// feed it
switch typ {
case JPEG:
C.vips_jpegload_buffer_seq(unsafe.Pointer(&buf[0]), C.size_t(len(buf)), &image)
case PNG:
C.vips_pngload_buffer_seq(unsafe.Pointer(&buf[0]), C.size_t(len(buf)), &image)
}*/
// create an image instance
var image, tmpImage *C.struct__VipsImage
image = C.vips_load_from_file(C.CString(file))
// cleanup
defer func() {
C.vips_thread_shutdown()
C.vips_error_clear()
}()
if image == nil {
return nil, catchVipsError()
}
rotate, flip := calculateRotationAndFlip(image, 0)
if rotate == 0 && !flip {
return nil, nil //Remain unchanged
}
ret := C.vips_autorotate(image, &tmpImage)
if ret != 0 {
return nil, catchVipsError()
}
if o.Quality == 0 {
o.Quality = 100
}
length := C.size_t(0)
var ptr unsafe.Pointer
switch o.Savetype {
case WEBP:
C.vips_webpsave_custom(tmpImage, &ptr, &length, C.int(o.Quality))
case PNG:
C.vips_pngsave_custom(tmpImage, &ptr, &length, 1, C.int(o.Quality), 0)
default:
C.vips_jpegsave_custom(tmpImage, &ptr, &length, 1, C.int(o.Quality), 0)
}
C.g_object_unref(C.gpointer(tmpImage))
// get back the buffer
var buf []byte
buf = C.GoBytes(ptr, C.int(length))
C.g_free(C.gpointer(ptr))
return buf, nil
}