iOS-UIImageView-UIImage画像の向きを処理する方法
IImageViewをセットアップして画像の向きを処理することは可能ですか？ IImageViewを向きのある画像に設定するとRIGHT（カメラロールからの写真です）、画像が回転します右に、しかし、私はそれが取られたように、適切な方向にそれを見せたいです。
画像データを回転できることは知っていますが、もっとエレガントにすることは可能ですか？
ありがとうございました
私が理解していれば、あなたがしたいことはUIImageの向きを無視することですか？もしそうなら、あなたはこれを行うことができます：
UIImage *originalImage = [... whatever ...];
UIImage *imageToDisplay =
[UIImage imageWithCGImage:[originalImage CGImage]
scale:[originalImage scale]
orientation: UIImageOrientationUp];
したがって、元と同じピクセルデータ（そのCGImageプロパティを介して参照される）で新しいUIImageを作成していますが、データを回転させない方向を指定しています。
この回答のan0で示唆されているように、手動で変換とスケーリングを手動で行うことを完全に回避できます here ：
- (UIImage *)normalizedImage {
if (self.imageOrientation == UIImageOrientationUp) return self;
UIGraphicsBeginImageContextWithOptions(self.size, NO, self.scale);
[self drawInRect:(CGRect){0, 0, self.size}];
UIImage *normalizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return normalizedImage;
}
UIImageメソッド size および drawInRect のドキュメントでは、方向を考慮することを明示的に記載しています。
Anomie's answer here （suvish valsanによって上記のコピーペースト）のコードをSwiftに変換しました：
func fixOrientation() -> UIImage {
if self.imageOrientation == UIImageOrientation.Up {
return self
}
var transform = CGAffineTransformIdentity
switch self.imageOrientation {
case .Down, .DownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height)
transform = CGAffineTransformRotate(transform, CGFloat(M_PI));
case .Left, .LeftMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0);
transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2));
case .Right, .RightMirrored:
transform = CGAffineTransformTranslate(transform, 0, self.size.height);
transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2));
case .Up, .UpMirrored:
break
}
switch self.imageOrientation {
case .UpMirrored, .DownMirrored:
transform = CGAffineTransformTranslate(transform, self.size.width, 0)
transform = CGAffineTransformScale(transform, -1, 1)
case .LeftMirrored, .RightMirrored:
transform = CGAffineTransformTranslate(transform, self.size.height, 0)
transform = CGAffineTransformScale(transform, -1, 1);
default:
break;
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx = CGBitmapContextCreate(
nil,
Int(self.size.width),
Int(self.size.height),
CGImageGetBitsPerComponent(self.CGImage),
0,
CGImageGetColorSpace(self.CGImage),
UInt32(CGImageGetBitmapInfo(self.CGImage).rawValue)
)
CGContextConcatCTM(ctx, transform);
switch self.imageOrientation {
case .Left, .LeftMirrored, .Right, .RightMirrored:
// Grr...
CGContextDrawImage(ctx, CGRectMake(0, 0, self.size.height,self.size.width), self.CGImage);
default:
CGContextDrawImage(ctx, CGRectMake(0, 0, self.size.width,self.size.height), self.CGImage);
break;
}
// And now we just create a new UIImage from the drawing context
let cgimg = CGBitmapContextCreateImage(ctx)
let img = UIImage(CGImage: cgimg!)
return img;
}
（私のパラメーターはimageの拡張であるため、パラメーターselfのすべての出現をUIImageに置き換えました。）.
EDIT：Swift 3バージョン。
多くの中間呼び出しが失敗する可能性があり、!を使用したくないため、このメソッドはオプションを返します。
func fixOrientation() -> UIImage? {
guard let cgImage = self.cgImage else {
return nil
}
if self.imageOrientation == UIImageOrientation.up {
return self
}
let width = self.size.width
let height = self.size.height
var transform = CGAffineTransform.identity
switch self.imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: width, y: height)
transform = transform.rotated(by: CGFloat.pi)
case .left, .leftMirrored:
transform = transform.translatedBy(x: width, y: 0)
transform = transform.rotated(by: 0.5*CGFloat.pi)
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: height)
transform = transform.rotated(by: -0.5*CGFloat.pi)
case .up, .upMirrored:
break
}
switch self.imageOrientation {
case .upMirrored, .downMirrored:
transform = transform.translatedBy(x: width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform = transform.translatedBy(x: height, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
default:
break;
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
guard let colorSpace = cgImage.colorSpace else {
return nil
}
guard let context = CGContext(
data: nil,
width: Int(width),
height: Int(height),
bitsPerComponent: cgImage.bitsPerComponent,
bytesPerRow: 0,
space: colorSpace,
bitmapInfo: UInt32(cgImage.bitmapInfo.rawValue)
) else {
return nil
}
context.concatenate(transform);
switch self.imageOrientation {
case .left, .leftMirrored, .right, .rightMirrored:
// Grr...
context.draw(cgImage, in: CGRect(x: 0, y: 0, width: height, height: width))
default:
context.draw(cgImage, in: CGRect(x: 0, y: 0, width: width, height: height))
}
// And now we just create a new UIImage from the drawing context
guard let newCGImg = context.makeImage() else {
return nil
}
let img = UIImage(cgImage: newCGImg)
return img;
}
（注：Swift 3バージョンのodesはXcode 8.1でコンパイルされますが、実際に動作することをテストしていません。幅/高さが混在するなど、タイプミスがある可能性があります。 ）。
このメソッドは、最初にUIImageの現在の向きをチェックし、次に時計回りに向きを変更してUIImageを返します。この画像を次のように表示できます。
self.imageView.image = rotateImage（currentUIImage）
func rotateImage(image:UIImage)->UIImage
{
var rotatedImage = UIImage();
switch image.imageOrientation
{
case UIImageOrientation.Right:
rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Down);
case UIImageOrientation.Down:
rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Left);
case UIImageOrientation.Left:
rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Up);
default:
rotatedImage = UIImage(CGImage:image.CGImage!, scale: 1, orientation:UIImageOrientation.Right);
}
return rotatedImage;
}
Swift 4バージョン
func rotateImage(image:UIImage) -> UIImage
{
var rotatedImage = UIImage()
switch image.imageOrientation
{
case .right:
rotatedImage = UIImage(cgImage: image.cgImage!, scale: 1.0, orientation: .down)
case .down:
rotatedImage = UIImage(cgImage: image.cgImage!, scale: 1.0, orientation: .left)
case .left:
rotatedImage = UIImage(cgImage: image.cgImage!, scale: 1.0, orientation: .up)
default:
rotatedImage = UIImage(cgImage: image.cgImage!, scale: 1.0, orientation: .right)
}
return rotatedImage
}
Swift 3.1
func fixImageOrientation(_ image: UIImage)->UIImage {
UIGraphicsBeginImageContext(image.size)
image.draw(at: .zero)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage ?? image
}
これは、画像の向きを考慮した実行可能なサンプルタラです。
#define rad(angle) ((angle) / 180.0 * M_PI)
- (CGAffineTransform)orientationTransformedRectOfImage:(UIImage *)img
{
CGAffineTransform rectTransform;
switch (img.imageOrientation)
{
case UIImageOrientationLeft:
rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(90)), 0, -img.size.height);
break;
case UIImageOrientationRight:
rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(-90)), -img.size.width, 0);
break;
case UIImageOrientationDown:
rectTransform = CGAffineTransformTranslate(CGAffineTransformMakeRotation(rad(-180)), -img.size.width, -img.size.height);
break;
default:
rectTransform = CGAffineTransformIdentity;
};
return CGAffineTransformScale(rectTransform, img.scale, img.scale);
}
- (UIImage *)croppedImage:(UIImage*)orignialImage InRect:(CGRect)visibleRect{
//transform visible rect to image orientation
CGAffineTransform rectTransform = [self orientationTransformedRectOfImage:orignialImage];
visibleRect = CGRectApplyAffineTransform(visibleRect, rectTransform);
//crop image
CGImageRef imageRef = CGImageCreateWithImageInRect([orignialImage CGImage], visibleRect);
UIImage *result = [UIImage imageWithCGImage:imageRef scale:orignialImage.scale orientation:orignialImage.imageOrientation];
CGImageRelease(imageRef);
return result;
}
SwiftのUIImage拡張。ひっくり返す必要はまったくありません。 Objective-C 元はここにあります 、元の画像のアルファを尊重するビットを追加しました（粗いですが、不透明な画像と透明な画像を区別するために機能します）。
// from https://github.com/mbcharbonneau/UIImage-Categories/blob/master/UIImage%2BAlpha.m
// Returns true if the image has an alpha layer
private func hasAlpha() -> Bool {
guard let cg = self.cgImage else { return false }
let alpha = cg.alphaInfo
let retVal = (alpha == .first || alpha == .last || alpha == .premultipliedFirst || alpha == .premultipliedLast)
return retVal
}
func normalizedImage() -> UIImage? {
if self.imageOrientation == .up {
return self
}
UIGraphicsBeginImageContextWithOptions(self.size, !self.hasAlpha(), self.scale)
var rect = CGRect.zero
rect.size = self.size
self.draw(in: rect)
let retVal = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return retVal
}
誰かがそれを必要とする場合に備えて、コードを@Nicolas MiariからSwift 3に変換しました
func fixOrientation() -> UIImage
{
if self.imageOrientation == UIImageOrientation.up {
return self
}
var transform = CGAffineTransform.identity
switch self.imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: self.size.width, y: self.size.height)
transform = transform.rotated(by: CGFloat(M_PI));
case .left, .leftMirrored:
transform = transform.translatedBy(x: self.size.width, y: 0);
transform = transform.rotated(by: CGFloat(M_PI_2));
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: CGFloat(-M_PI_2));
case .up, .upMirrored:
break
}
switch self.imageOrientation {
case .upMirrored, .downMirrored:
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform = transform.translatedBy(x: self.size.height, y: 0)
transform = transform.scaledBy(x: -1, y: 1);
default:
break;
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx = CGContext(
data: nil,
width: Int(self.size.width),
height: Int(self.size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent,
bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: UInt32(self.cgImage!.bitmapInfo.rawValue)
)
ctx!.concatenate(transform);
switch self.imageOrientation {
case .left, .leftMirrored, .right, .rightMirrored:
// Grr...
ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.height ,height:self.size.width))
default:
ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.width ,height:self.size.height))
break;
}
// And now we just create a new UIImage from the drawing context
let cgimg = ctx!.makeImage()
let img = UIImage(cgImage: cgimg!)
return img;
}
Swift 3の翻訳をしてくれたWaseem05に感謝しますが、彼のメソッドはUIImageの拡張内にラップして、親クラスの外側/下に配置したときにしか機能しませんでした。
extension UIImage {
func fixOrientation() -> UIImage
{
if self.imageOrientation == UIImageOrientation.up {
return self
}
var transform = CGAffineTransform.identity
switch self.imageOrientation {
case .down, .downMirrored:
transform = transform.translatedBy(x: self.size.width, y: self.size.height)
transform = transform.rotated(by: CGFloat(M_PI));
case .left, .leftMirrored:
transform = transform.translatedBy(x: self.size.width, y: 0);
transform = transform.rotated(by: CGFloat(M_PI_2));
case .right, .rightMirrored:
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: CGFloat(-M_PI_2));
case .up, .upMirrored:
break
}
switch self.imageOrientation {
case .upMirrored, .downMirrored:
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
case .leftMirrored, .rightMirrored:
transform = transform.translatedBy(x: self.size.height, y: 0)
transform = transform.scaledBy(x: -1, y: 1);
default:
break;
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx = CGContext(
data: nil,
width: Int(self.size.width),
height: Int(self.size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent,
bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: UInt32(self.cgImage!.bitmapInfo.rawValue)
)
ctx!.concatenate(transform);
switch self.imageOrientation {
case .left, .leftMirrored, .right, .rightMirrored:
// Grr...
ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.height ,height:self.size.width))
default:
ctx?.draw(self.cgImage!, in: CGRect(x:0 ,y: 0 ,width: self.size.width ,height:self.size.height))
break;
}
// And now we just create a new UIImage from the drawing context
let cgimg = ctx!.makeImage()
let img = UIImage(cgImage: cgimg!)
return img;
}
}
それからそれを呼び出しました：
let correctedImage:UIImage = wonkyImage.fixOrientation()
そして、すべてがうまくいきました！ Appleは、フロント/バックカメラおよびデバイスの上下左右の向きのメタデータが必要ない場合に向きを簡単に破棄できるようにする必要があります。
回転して画像の向きを修正する必要がある場合は、拡張子の下にあると便利です。
extension UIImage {
public func imageRotatedByDegrees(degrees: CGFloat) -> UIImage {
//Calculate the size of the rotated view's containing box for our drawing space
let rotatedViewBox: UIView = UIView(frame: CGRect(x: 0, y: 0, width: self.size.width, height: self.size.height))
let t: CGAffineTransform = CGAffineTransform(rotationAngle: degrees * CGFloat.pi / 180)
rotatedViewBox.transform = t
let rotatedSize: CGSize = rotatedViewBox.frame.size
//Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize)
let bitmap: CGContext = UIGraphicsGetCurrentContext()!
//Move the Origin to the middle of the image so we will rotate and scale around the center.
bitmap.translateBy(x: rotatedSize.width / 2, y: rotatedSize.height / 2)
//Rotate the image context
bitmap.rotate(by: (degrees * CGFloat.pi / 180))
//Now, draw the rotated/scaled image into the context
bitmap.scaleBy(x: 1.0, y: -1.0)
bitmap.draw(self.cgImage!, in: CGRect(x: -self.size.width / 2, y: -self.size.height / 2, width: self.size.width, height: self.size.height))
let newImage: UIImage = UIGraphicsGetImageFromCurrentImageContext()!
UIGraphicsEndImageContext()
return newImage
}
public func fixedOrientation() -> UIImage {
if imageOrientation == UIImageOrientation.up {
return self
}
var transform: CGAffineTransform = CGAffineTransform.identity
switch imageOrientation {
case UIImageOrientation.down, UIImageOrientation.downMirrored:
transform = transform.translatedBy(x: size.width, y: size.height)
transform = transform.rotated(by: CGFloat.pi)
break
case UIImageOrientation.left, UIImageOrientation.leftMirrored:
transform = transform.translatedBy(x: size.width, y: 0)
transform = transform.rotated(by: CGFloat.pi/2)
break
case UIImageOrientation.right, UIImageOrientation.rightMirrored:
transform = transform.translatedBy(x: 0, y: size.height)
transform = transform.rotated(by: -CGFloat.pi/2)
break
case UIImageOrientation.up, UIImageOrientation.upMirrored:
break
}
switch imageOrientation {
case UIImageOrientation.upMirrored, UIImageOrientation.downMirrored:
transform.translatedBy(x: size.width, y: 0)
transform.scaledBy(x: -1, y: 1)
break
case UIImageOrientation.leftMirrored, UIImageOrientation.rightMirrored:
transform.translatedBy(x: size.height, y: 0)
transform.scaledBy(x: -1, y: 1)
case UIImageOrientation.up, UIImageOrientation.down, UIImageOrientation.left, UIImageOrientation.right:
break
}
let ctx: CGContext = CGContext(data: nil,
width: Int(size.width),
height: Int(size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent,
bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: CGImageAlphaInfo.premultipliedLast.rawValue)!
ctx.concatenate(transform)
switch imageOrientation {
case UIImageOrientation.left, UIImageOrientation.leftMirrored, UIImageOrientation.right, UIImageOrientation.rightMirrored:
ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.height, height: size.width))
default:
ctx.draw(self.cgImage!, in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
break
}
let cgImage: CGImage = ctx.makeImage()!
return UIImage(cgImage: cgImage)
}
}
extension UIImage {
func fixImageOrientation() -> UIImage {
UIGraphicsBeginImageContext(self.size)
self.draw(at: .zero)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage ?? self
}
}
- 上の例のような拡張機能を作成します。
それを呼び出します：
imageView.image?.fixImageOrientation()またはUIImage(named: "someImage").fixImageOrientation()頑張ってください！
トミーの答えのSwift 3.0バージョン
let imageToDisplay = UIImage.init(cgImage: originalImage.cgImage!, scale: originalImage.scale, orientation: UIImageOrientation.up)
@Aqua Answer .....からの着想.
Objective Cで
- (UIImage *)fixImageOrientation:(UIImage *)img {
UIGraphicsBeginImageContext(img.size);
[img drawAtPoint:CGPointZero];
UIImage *newImg = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if (newImg) {
return newImg;
}
return img;
}