// Auto-orientates canvas based on its original image's EXIF metadata
func (self *Canvas) AutoOrientate() error {
data := self.Metadata()
orientation, err := strconv.Atoi(data["exif:Orientation"])
if err != nil {
return err
}
switch uint(orientation) {
case TOP_LEFT_ORIENTATION:
// normal
case TOP_RIGHT_ORIENTATION:
self.Flop()
case BOTTOM_RIGHT_ORIENTATION:
self.RotateCanvas(math.Pi)
case BOTTOM_LEFT_ORIENTATION:
self.Flip()
case LEFT_TOP_ORIENTATION:
self.Flip()
self.RotateCanvas(-math.Pi / 2)
case RIGHT_TOP_ORIENTATION:
self.RotateCanvas(math.Pi / 2)
case RIGHT_BOTTOM_ORIENTATION:
self.Flop()
self.RotateCanvas(-math.Pi / 2)
case LEFT_BOTTOM_ORIENTATION:
self.RotateCanvas(-math.Pi / 2)
default:
return errors.New("No orientation data found in file.")
}
success := C.MagickSetImageOrientation(self.wand, (C.OrientationType)(TOP_LEFT_ORIENTATION))
if success == C.MagickFalse {
return fmt.Errorf("Could not orientate photo: %s", self.Error())
}
self.SetMetadata("exif:Orientation", (string)(TOP_LEFT_ORIENTATION))
return nil
}
// Auto-orientates canvas based on its original image's EXIF metadata
func (cv Canvas) AutoOrientate() bool {
data := cv.Metadata()
orientation, err := strconv.Atoi(data["exif:Orientation"])
if err != nil {
return false
}
switch uint(orientation) {
case TOP_LEFT_ORIENTATION:
// normal
case TOP_RIGHT_ORIENTATION:
cv.Flop()
case BOTTOM_RIGHT_ORIENTATION:
cv.RotateCanvas(math.Pi)
case BOTTOM_LEFT_ORIENTATION:
cv.Flip()
case LEFT_TOP_ORIENTATION:
cv.Flip()
cv.RotateCanvas(-math.Pi / 2)
case RIGHT_TOP_ORIENTATION:
cv.RotateCanvas(-math.Pi / 2)
case RIGHT_BOTTOM_ORIENTATION:
cv.Flop()
cv.RotateCanvas(-math.Pi / 2)
case LEFT_BOTTOM_ORIENTATION:
cv.RotateCanvas(math.Pi / 2)
default:
return false
}
C.MagickSetImageOrientation(cv.wand, (C.OrientationType)(TOP_LEFT_ORIENTATION))
cv.SetMetadata("exif:Orientation", (string)(TOP_LEFT_ORIENTATION))
return true
}