UIImageを水平方向に反転させる方法は？
UIImageを水平に反転する方法、UIImageOrientationUpMirroredクラス参照でUIImage列挙値を見つけた、このプロパティを使用してUIImageを反転する方法。
UIImage* sourceImage = [UIImage imageNamed:@"whatever.png"];
UIImage* flippedImage = [UIImage imageWithCGImage:sourceImage.CGImage
scale:sourceImage.scale
orientation:UIImageOrientationUpMirrored];
これを実現する非常に簡単な方法は、UIImageの代わりにUIImageViewを作成し、UIImageViewで変換を行うことです。
yourImageView.image =[UIImage imageNamed:@"whatever.png"];
yourImageView.transform = CGAffineTransform(scaleX: -1, y: 1); //Flipped
お役に立てれば。
glTexImage2d(...)を使用してOpenGLテクスチャを初期化するには、多くの場合、垂直反転が必要です。上記のトリックは、実際には画像データを変更しないため、この場合は機能しません。 https://stackoverflow.com/a/17909372 に触発された実際のデータフリップを実行するコードを次に示します。
- (UIImage *)flipImage:(UIImage *)image
{
UIGraphicsBeginImageContext(image.size);
CGContextDrawImage(UIGraphicsGetCurrentContext(),CGRectMake(0.,0., image.size.width, image.size.height),image.CGImage);
UIImage *i = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return i;
}
私はimageFlippedForRightToLeftLayoutDirectionを試し、異なる向きで新しいUIImageを作成しましたが、少なくともこれは私の画像を反転させるための唯一の解決策です
let ciimage: CIImage = CIImage(CGImage: imagenInicial.CGImage!)
let rotada3 = ciimage.imageByApplyingTransform(CGAffineTransformMakeScale(-1, 1))
あなたが私の遊び場で見ることができるように、それは働いた！ :) 
そして、もちろん、finalImage = UIImage（CIImage：rotada3）
画像の向きの定義：
typedef NS_ENUM(NSInteger, UIImageOrientation) {
UIImageOrientationUp, // default orientation
UIImageOrientationDown, // 180 deg rotation
UIImageOrientationLeft, // 90 deg CCW
UIImageOrientationRight, // 90 deg CW
UIImageOrientationUpMirrored, // as above but image mirrored along other axis. horizontal flip
UIImageOrientationDownMirrored, // horizontal flip
UIImageOrientationLeftMirrored, // vertical flip
UIImageOrientationRightMirrored, // vertical flip
};
AVCaptureSessionからUIImageを処理するなど、より多くの状況でいくつかの改善を行いました。
UIImage* sourceImage = [UIImage imageNamed:@"whatever.png"];
UIImageOrientation flipingOrientation;
if(sourceImage.imageOrientation>=4){
flippedOrientation = sourceImage.imageOrientation - 4;
}else{
flippedOrientation = sourceImage.imageOrientation + 4;
}
UIImage* flippedImage = [UIImage imageWithCGImage:sourceImage.CGImage
scale: sourceImage.scale orientation: flipingOrientation];
Swift version：（コメントでこの質問を見ました）
let srcImage = UIImage(named: "imageName")
let flippedImage = UIImage(CGImage: srcImage.CGImage, scale: srcImage.scale, orientation: UIImageOrientation.UpMirrored)
これは、UIImageを水平にミラー/フリップするための堅実な実装であり、画像に前後に適用できます。基になる画像データが変更されるため、描画（スクリーンショットなど）も変更されます。動作テスト済み、品質低下なし。
func flipImage() -> UIImage? {
UIGraphicsBeginImageContextWithOptions(self.size, false, self.scale)
let bitmap = UIGraphicsGetCurrentContext()!
bitmap.translateBy(x: size.width / 2, y: size.height / 2)
bitmap.scaleBy(x: -1.0, y: -1.0)
bitmap.translateBy(x: -size.width / 2, y: -size.height / 2)
bitmap.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image?
}
これはいくつかのために役立つかもしれません：
UIImageOrientation imageOrientation;
switch (sourceImage.imageOrientation) {
case UIImageOrientationDown:
imageOrientation = UIImageOrientationDownMirrored;
break;
case UIImageOrientationDownMirrored:
imageOrientation = UIImageOrientationDown;
break;
case UIImageOrientationLeft:
imageOrientation = UIImageOrientationLeftMirrored;
break;
case UIImageOrientationLeftMirrored:
imageOrientation = UIImageOrientationLeft;
break;
case UIImageOrientationRight:
imageOrientation = UIImageOrientationRightMirrored;
break;
case UIImageOrientationRightMirrored:
imageOrientation = UIImageOrientationRight;
break;
case UIImageOrientationUp:
imageOrientation = UIImageOrientationUpMirrored;
break;
case UIImageOrientationUpMirrored:
imageOrientation = UIImageOrientationUp;
break;
default:
break;
}
resultImage = [UIImage imageWithCGImage:sourceImage.CGImage scale:sourceImage.scale orientation:imageOrientation];
Swift 3/4：の場合
imageView.transform = CGAffineTransform(scaleX: -1, y: 1)
iOS 10以降
[myImage imageWithHorizontallyFlippedOrientation];
スウィフト4：
let flippedImage = myImage.withHorizontallyFlippedOrientation()
シンプルな拡張。
extension UIImage {
var flipped: UIImage {
guard let cgImage = cgImage else {
return self
}
return UIImage(cgImage: cgImage, scale: scale, orientation: .upMirrored)
}
}
使用法：
let image = #imageLiteral(resourceName: "imageName")
let imageView = UIImageView(image: image.flipped)
Swift 3以上）でテスト済み
拡張機能を使用してこの問題を解決する簡単なソリューションを次に示します。私はそれをテストし、機能しました。任意の方向にミラーリングできます。
extension UIImage {
func imageUpMirror() -> UIImage {
guard let cgImage = cgImage else { return self }
return UIImage(cgImage: cgImage, scale: scale, orientation: .upMirrored)
}
func imageDownMirror() -> UIImage {
guard let cgImage = cgImage else { return self }
return UIImage(cgImage: cgImage, scale: scale, orientation: .downMirrored)
}
func imageLeftMirror() -> UIImage {
guard let cgImage = cgImage else { return self }
return UIImage(cgImage: cgImage, scale: scale, orientation: .leftMirrored)
}
func imageRightMirror() -> UIImage {
guard let cgImage = cgImage else { return self }
return UIImage(cgImage: cgImage, scale: scale, orientation: .rightMirrored)
}
}
このコードの使用法
let image = #imageLiteral(resourceName: "imageName")
flipHorizontally = image.imageUpMirror()
など、他の機能を使用できます。
これは、動作するiOS8/9互換バージョンです。
UIImage *image = [UIImage imageNamed:name];
if ([[UIApplication sharedApplication] userInterfaceLayoutDirection] == UIUserInterfaceLayoutDirectionRightToLeft) {
if ([image respondsToSelector:@selector(imageFlippedForRightToLeftLayoutDirection)]) {
//iOS9
image = image.imageFlippedForRightToLeftLayoutDirection;
}
else {
//iOS8
CIImage *coreImage = [CIImage imageWithCGImage:image.CGImage];
coreImage = [coreImage imageByApplyingTransform:CGAffineTransformMakeScale(-1, 1)];
image = [UIImage imageWithCIImage:coreImage scale:image.scale orientation:UIImageOrientationUp];
}
}
return image;
Swift 3：でのarothの答え
let sourceImage = UIImage(named: "whatever.png")!
let flippedImage = UIImage(cgImage: sourceImage.cgImage!, scale: sourceImage.scale, orientation: .upMirrored)
これを使用して、必要に応じて画像を回転できます
Swift 4
extension UIImage {
public func imageRotatedByDegrees(degrees: CGFloat, flip: Bool) -> UIImage {
let radiansToDegrees: (CGFloat) -> CGFloat = {
return $0 * (180.0 / CGFloat(M_PI))
}
let degreesToRadians: (CGFloat) -> CGFloat = {
return $0 / 180.0 * CGFloat(M_PI)
}
// calculate the size of the rotated view's containing box for our drawing space
let rotatedViewBox = UIView(frame: CGRect(Origin: CGPoint.zero, size: size))
let t = CGAffineTransform(rotationAngle: degreesToRadians(degrees));
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize)
let bitmap = UIGraphicsGetCurrentContext()!
bitmap.translateBy(x: rotatedSize.width / 2.0, y: rotatedSize.height / 2.0)
// Move the Origin to the middle of the image so we will rotate and scale around the center.
//CGContextTranslateCTM(bitmap, rotatedSize.width / 2.0, rotatedSize.height / 2.0);
// // Rotate the image context
bitmap.rotate(by: degreesToRadians(degrees))
// CGContextRotateCTM(bitmap, degreesToRadians(degrees));
// Now, draw the rotated/scaled image into the context
var yFlip: CGFloat
if(flip){
yFlip = CGFloat(-1.0)
} else {
yFlip = CGFloat(1.0)
}
bitmap.scaleBy(x: yFlip, y: -1.0)
//CGContextScaleCTM(bitmap, yFlip, -1.0)
bitmap.draw(self.cgImage!, in: CGRect.init(x: -size.width / 2, y: -size.height / 2, width: size.width, height: size.height))
// CGContextDrawImage(bitmap, CGRectMake(-size.width / 2, -size.height / 2, size.width, size.height), CGImage)
let newImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}
}
上記の修正された回答の1つとSwiftは、画像を前後に反転させ続ける必要があるボタンがあるときに特に便利だとわかりました。
func flipImage(sourceImage: UIImage,orientation: UIImageOrientation) -> UIImage {
var imageOrientation = orientation
switch sourceImage.imageOrientation {
case UIImageOrientation.down:
imageOrientation = UIImageOrientation.downMirrored;
break;
case UIImageOrientation.downMirrored:
imageOrientation = UIImageOrientation.down;
break;
case UIImageOrientation.left:
imageOrientation = UIImageOrientation.leftMirrored;
break;
case UIImageOrientation.leftMirrored:
imageOrientation = UIImageOrientation.left;
break;
case UIImageOrientation.right:
imageOrientation = UIImageOrientation.rightMirrored;
break;
case UIImageOrientation.rightMirrored:
imageOrientation = UIImageOrientation.right;
break;
case UIImageOrientation.up:
imageOrientation = UIImageOrientation.upMirrored;
break;
case UIImageOrientation.upMirrored:
imageOrientation = UIImageOrientation.up;
break;
}
return UIImage(cgImage: sourceImage.cgImage!, scale: sourceImage.scale, orientation: imageOrientation)
}
つかいます：
imageToFlip: UIImage = flipImage(sourceImage: imageToFlip, orientation: imageToFlip.imageOrientation)
スイフト4
yourImage.transform = CGAffineTransform(scaleX: -1, y: 1)
ラップ解除のため、次の手順を実行します。
let srcImage = UIImage(named: "myimage")!
let flippedImage = UIImage(cgImage: srcImage.cgImage!,
scale: srcImage.scale, orientation: UIImage.Orientation.upMirrored)