UIImageを90度回転する方法は？
UIImage（portrait）であるUIImageOrientationUpがあります。これを反時計回りに90度（横向きに）回転させます。 CGAffineTransformを使用したくありません。 UIImageのピクセルが実際に位置をシフトするようにします。これを行うためにUIImageのサイズを変更することを最初に意図したコードブロック（以下に示す）を使用しています。ターゲット変数をUIImageの現在のサイズとして設定しましたが、エラーが発生します：
（エラー）：CGBitmapContextCreate：無効なデータバイト/行：8整数ビット/コンポーネント、3コンポーネント、kCGImageAlphaPremultipliedLastに対して少なくとも1708である必要があります。
（ターゲットサイズBTWとしてSMALLERサイズを指定しても、エラーは発生しません）。現在のサイズを維持しながら、コアグラフィックス関数のみを使用してUIImage 90度CCWを回転させるにはどうすればよいですか？
-(UIImage*)reverseImageByScalingToSize:(CGSize)targetSize:(UIImage*)anImage
{
UIImage* sourceImage = anImage;
CGFloat targetWidth = targetSize.height;
CGFloat targetHeight = targetSize.width;
CGImageRef imageRef = [sourceImage CGImage];
CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);
if (bitmapInfo == kCGImageAlphaNone) {
bitmapInfo = kCGImageAlphaNoneSkipLast;
}
CGContextRef bitmap;
if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) {
bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
} else {
bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);
}
if (sourceImage.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -targetHeight);
} else if (sourceImage.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -targetWidth, 0);
} else if (sourceImage.imageOrientation == UIImageOrientationDown) {
// NOTHING
} else if (sourceImage.imageOrientation == UIImageOrientationUp) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -targetHeight);
}
CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* newImage = [UIImage imageWithCGImage:ref];
CGContextRelease(bitmap);
CGImageRelease(ref);
return newImage;
}
次のようなものはどうですか：
static inline double radians (double degrees) {return degrees * M_PI/180;}
UIImage* rotate(UIImage* src, UIImageOrientation orientation)
{
UIGraphicsBeginImageContext(src.size);
CGContextRef context = UIGraphicsGetCurrentContext();
if (orientation == UIImageOrientationRight) {
CGContextRotateCTM (context, radians(90));
} else if (orientation == UIImageOrientationLeft) {
CGContextRotateCTM (context, radians(-90));
} else if (orientation == UIImageOrientationDown) {
// NOTHING
} else if (orientation == UIImageOrientationUp) {
CGContextRotateCTM (context, radians(90));
}
[src drawAtPoint:CGPointMake(0, 0)];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
私は最も簡単な方法（そしてスレッドセーフでもある）はそうすることだと信じています：
//assume that the image is loaded in landscape mode from disk
UIImage * landscapeImage = [UIImage imageNamed:imgname];
UIImage * portraitImage = [[UIImage alloc] initWithCGImage: landscapeImage.CGImage
scale: 1.0
orientation: UIImageOrientationRight];
注：As Brainwareは、これは画像の方向データを変更するだけで、ピクセルデータは変更されないことを示しています。一部のアプリケーションでは、これでは不十分な場合があります。
またはスウィフトで：
let portraitImage : UIImage = UIImage(CGImage: landscapeImage.CGImage ,
scale: 1.0 ,
orientation: UIImageOrientation.Right)
cutting-scaling-and-rotating-uiimages でHardy Maciaのシンプルで素晴らしいコードをチェックしてください。
電話するだけ
UIImage *rotatedImage = [originalImage imageRotatedByDegrees:90.0];
ありがとう、ハーディ・マシア！
ヘッダ：
- （UIImage *）imageAtRect：（CGRect）rect;
- （UIImage *）imageByScalingProportionallyToMinimumSize：（CGSize）targetSize;
- （UIImage *）imageByScalingProportionallyToSize：（CGSize）targetSize;
- （UIImage *）imageByScalingToSize：（CGSize）targetSize;
- （UIImage *）imageRotatedByRadians：（CGFloat）radians;
- （UIImage *）imageRotatedByDegrees：（CGFloat）degrees;
リンクが死ぬかもしれないので、ここに完全なコードがあります
//
// UIImage-Extensions.h
//
// Created by Hardy Macia on 7/1/09.
// Copyright 2009 Catamount Software. All rights reserved.
//
#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>
@interface UIImage (CS_Extensions)
- (UIImage *)imageAtRect:(CGRect)rect;
- (UIImage *)imageByScalingProportionallyToMinimumSize:(CGSize)targetSize;
- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize;
- (UIImage *)imageByScalingToSize:(CGSize)targetSize;
- (UIImage *)imageRotatedByRadians:(CGFloat)radians;
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;
@end;
//
// UIImage-Extensions.m
//
// Created by Hardy Macia on 7/1/09.
// Copyright 2009 Catamount Software. All rights reserved.
//
#import "UIImage-Extensions.h"
CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};
@implementation UIImage (CS_Extensions)
-(UIImage *)imageAtRect:(CGRect)rect
{
CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect);
UIImage* subImage = [UIImage imageWithCGImage: imageRef];
CGImageRelease(imageRef);
return subImage;
}
- (UIImage *)imageByScalingProportionallyToMinimumSize:(CGSize)targetSize {
UIImage *sourceImage = self;
UIImage *newImage = nil;
CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
if (CGSizeEqualToSize(imageSize, targetSize) == NO) {
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor > heightFactor)
scaleFactor = widthFactor;
else
scaleFactor = heightFactor;
scaledWidth = width * scaleFactor;
scaledHeight = height * scaleFactor;
// center the image
if (widthFactor > heightFactor) {
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
} else if (widthFactor < heightFactor) {
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
// this is actually the interesting part:
UIGraphicsBeginImageContext(targetSize);
CGRect thumbnailRect = CGRectZero;
thumbnailRect.Origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if(newImage == nil) NSLog(@"could not scale image");
return newImage ;
}
- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize {
UIImage *sourceImage = self;
UIImage *newImage = nil;
CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
if (CGSizeEqualToSize(imageSize, targetSize) == NO) {
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor < heightFactor)
scaleFactor = widthFactor;
else
scaleFactor = heightFactor;
scaledWidth = width * scaleFactor;
scaledHeight = height * scaleFactor;
// center the image
if (widthFactor < heightFactor) {
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
} else if (widthFactor > heightFactor) {
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
// this is actually the interesting part:
UIGraphicsBeginImageContext(targetSize);
CGRect thumbnailRect = CGRectZero;
thumbnailRect.Origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if(newImage == nil) NSLog(@"could not scale image");
return newImage ;
}
- (UIImage *)imageByScalingToSize:(CGSize)targetSize {
UIImage *sourceImage = self;
UIImage *newImage = nil;
// CGSize imageSize = sourceImage.size;
// CGFloat width = imageSize.width;
// CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
// CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
// this is actually the interesting part:
UIGraphicsBeginImageContext(targetSize);
CGRect thumbnailRect = CGRectZero;
thumbnailRect.Origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
if(newImage == nil) NSLog(@"could not scale image");
return newImage ;
}
- (UIImage *)imageRotatedByRadians:(CGFloat)radians
{
return [self imageRotatedByDegrees:RadiansToDegrees(radians)];
}
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees
{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
[rotatedViewBox release];
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the Origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, DegreesToRadians(degrees));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
@end;
これは奇妙に思えますが、次のコードで問題は解決しました。
+ (UIImage*)unrotateImage:(UIImage*)image {
CGSize size = image.size;
UIGraphicsBeginImageContext(size);
[image drawInRect:CGRectMake(0,0,size.width ,size.height)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
スレッドセーフな回転関数は次のとおりです（より適切に機能します）。
-(UIImage*)imageByRotatingImage:(UIImage*)initImage fromImageOrientation:(UIImageOrientation)orientation
{
CGImageRef imgRef = initImage.CGImage;
CGFloat width = CGImageGetWidth(imgRef);
CGFloat height = CGImageGetHeight(imgRef);
CGAffineTransform transform = CGAffineTransformIdentity;
CGRect bounds = CGRectMake(0, 0, width, height);
CGSize imageSize = CGSizeMake(CGImageGetWidth(imgRef), CGImageGetHeight(imgRef));
CGFloat boundHeight;
UIImageOrientation orient = orientation;
switch(orient) {
case UIImageOrientationUp: //EXIF = 1
return initImage;
break;
case UIImageOrientationUpMirrored: //EXIF = 2
transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
break;
case UIImageOrientationDown: //EXIF = 3
transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationDownMirrored: //EXIF = 4
transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
break;
case UIImageOrientationLeftMirrored: //EXIF = 5
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeft: //EXIF = 6
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRightMirrored: //EXIF = 7
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
case UIImageOrientationRight: //EXIF = 8
boundHeight = bounds.size.height;
bounds.size.height = bounds.size.width;
bounds.size.width = boundHeight;
transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
default:
[NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];
}
// Create the bitmap context
CGContextRef context = NULL;
void * bitmapData;
int bitmapByteCount;
int bitmapBytesPerRow;
// Declare the number of bytes per row. Each pixel in the bitmap in this
// example is represented by 4 bytes; 8 bits each of red, green, blue, and
// alpha.
bitmapBytesPerRow = (bounds.size.width * 4);
bitmapByteCount = (bitmapBytesPerRow * bounds.size.height);
bitmapData = malloc( bitmapByteCount );
if (bitmapData == NULL)
{
return nil;
}
// Create the bitmap context. We want pre-multiplied ARGB, 8-bits
// per component. Regardless of what the source image format is
// (CMYK, Grayscale, and so on) it will be converted over to the format
// specified here by CGBitmapContextCreate.
CGColorSpaceRef colorspace = CGImageGetColorSpace(imgRef);
context = CGBitmapContextCreate (bitmapData,bounds.size.width,bounds.size.height,8,bitmapBytesPerRow,
colorspace, kCGBitmapAlphaInfoMask & kCGImageAlphaPremultipliedLast);
if (context == NULL)
// error creating context
return nil;
CGContextScaleCTM(context, -1.0, -1.0);
CGContextTranslateCTM(context, -bounds.size.width, -bounds.size.height);
CGContextConcatCTM(context, transform);
// Draw the image to the bitmap context. Once we draw, the memory
// allocated for the context for rendering will then contain the
// raw image data in the specified color space.
CGContextDrawImage(context, CGRectMake(0,0,width, height), imgRef);
CGImageRef imgRef2 = CGBitmapContextCreateImage(context);
CGContextRelease(context);
free(bitmapData);
UIImage * image = [UIImage imageWithCGImage:imgRef2 scale:initImage.scale orientation:UIImageOrientationUp];
CGImageRelease(imgRef2);
return image;
}
承認済みの回答を含め、上記のすべてに問題がありました。ハーディのカテゴリをメソッドに変換し直したのは、イメージを回転させるだけだったからです。コードと使用方法は次のとおりです。
- (UIImage *)imageRotatedByDegrees:(UIImage*)oldImage deg:(CGFloat)degrees{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,oldImage.size.width, oldImage.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(degrees * M_PI / 180);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the Origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, (degrees * M_PI / 180));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-oldImage.size.width / 2, -oldImage.size.height / 2, oldImage.size.width, oldImage.size.height), [oldImage CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
そして使用法：
UIImage *image2 = [self imageRotatedByDegrees:image deg:90];
ありがとう、ハーディ！
画像を90度回転（時計回り/反時計回り）
関数呼び出し-
UIImage *rotatedImage = [self rotateImage:originalImage clockwise:YES];
実装：
- (UIImage*)rotateImage:(UIImage*)sourceImage clockwise:(BOOL)clockwise
{
CGSize size = sourceImage.size;
UIGraphicsBeginImageContext(CGSizeMake(size.height, size.width));
[[UIImage imageWithCGImage:[sourceImage CGImage]
scale:1.0
orientation:clockwise ? UIImageOrientationRight : UIImageOrientationLeft]
drawInRect:CGRectMake(0,0,size.height ,size.width)];
UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
シンプル。画像の向きのフラグを変更するだけです。
UIImage *oldImage = [UIImage imageNamed:@"whatever.jpg"];
UIImageOrientation newOrientation;
switch (oldImage.imageOrientation) {
case UIImageOrientationUp:
newOrientation = UIImageOrientationLandscapeLeft;
break;
case UIImageOrientationLandscapeLeft:
newOrientation = UIImageOrientationDown;
break;
case UIImageOrientationDown:
newOrientation = UIImageOrientationLandscapeRight;
break;
case UIImageOrientationLandscapeRight:
newOrientation = UIImageOrientationUp;
break;
// you can also handle mirrored orientations similarly ...
}
UIImage *rotatedImage = [UIImage imageWithCGImage:oldImage.CGImage scale:1.0f orientation:newOrientation];
Swift 3 UIImage拡張機能：
func fixOrientation() -> UIImage {
// No-op if the orientation is already correct
if ( self.imageOrientation == .up ) {
return self;
}
// We need to calculate the proper transformation to make the image upright.
// We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
var transform: CGAffineTransform = .identity
if ( self.imageOrientation == .down || self.imageOrientation == .downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: self.size.height)
transform = transform.rotated(by: .pi)
}
if ( self.imageOrientation == .left || self.imageOrientation == .leftMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.rotated(by: .pi/2)
}
if ( self.imageOrientation == .right || self.imageOrientation == .rightMirrored ) {
transform = transform.translatedBy(x: 0, y: self.size.height);
transform = transform.rotated(by: -.pi/2);
}
if ( self.imageOrientation == .upMirrored || self.imageOrientation == .downMirrored ) {
transform = transform.translatedBy(x: self.size.width, y: 0)
transform = transform.scaledBy(x: -1, y: 1)
}
if ( self.imageOrientation == .leftMirrored || self.imageOrientation == .rightMirrored ) {
transform = transform.translatedBy(x: self.size.height, y: 0);
transform = transform.scaledBy(x: -1, y: 1);
}
// Now we draw the underlying CGImage into a new context, applying the transform
// calculated above.
let ctx: CGContext = CGContext(data: nil, width: Int(self.size.width), height: Int(self.size.height),
bitsPerComponent: self.cgImage!.bitsPerComponent, bytesPerRow: 0,
space: self.cgImage!.colorSpace!,
bitmapInfo: self.cgImage!.bitmapInfo.rawValue)!;
ctx.concatenate(transform)
if ( self.imageOrientation == .left ||
self.imageOrientation == .leftMirrored ||
self.imageOrientation == .right ||
self.imageOrientation == .rightMirrored ) {
ctx.draw(self.cgImage!, in: CGRect(x: 0.0,y: 0.0,width: self.size.height,height: self.size.width))
} else {
ctx.draw(self.cgImage!, in: CGRect(x: 0.0,y: 0.0,width: self.size.width,height: self.size.height))
}
// And now we just create a new UIImage from the drawing context and return it
return UIImage(cgImage: ctx.makeImage()!)
}
写真を90度単位で回転させ続ける写真回転ボタンを追加する場合は、ここに進みます。 （finalImageは、別の場所で既に作成されているUIImageです。）
- (void)rotatePhoto {
UIImage *rotatedImage;
if (finalImage.imageOrientation == UIImageOrientationRight)
rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
scale: 1.0
orientation: UIImageOrientationDown];
else if (finalImage.imageOrientation == UIImageOrientationDown)
rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
scale: 1.0
orientation: UIImageOrientationLeft];
else if (finalImage.imageOrientation == UIImageOrientationLeft)
rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
scale: 1.0
orientation: UIImageOrientationUp];
else
rotatedImage = [[UIImage alloc] initWithCGImage: finalImage.CGImage
scale: 1.0
orientation: UIImageOrientationRight];
finalImage = rotatedImage;
}
これは、任意の角度で画像を回転させるUIImageのSwift拡張です。次のように使用します：let rotatedImage = image.rotated(byDegrees: degree)。他の回答の1つでObjective-Cコードを使用し、間違っている（回転したボックスのもの）数行を削除し、UIImageの拡張機能に変更しました。
extension UIImage {
func rotate(byDegrees degree: Double) -> UIImage {
let radians = CGFloat(degree*M_PI)/180.0 as CGFloat
let rotatedSize = self.size
let scale = UIScreen.mainScreen().scale
UIGraphicsBeginImageContextWithOptions(rotatedSize, false, scale)
let bitmap = UIGraphicsGetCurrentContext()
CGContextTranslateCTM(bitmap, rotatedSize.width / 2, rotatedSize.height / 2);
CGContextRotateCTM(bitmap, radians);
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2 , self.size.width, self.size.height), self.CGImage );
let newImage = UIGraphicsGetImageFromCurrentImageContext()
return newImage
}
}
私はこのコードを試して、それが機能し、 http://www.catamount.com/blog/1015/uiimage-extensions-for-cutting-scaling-and-rotating-uiimages/
+ (UIImage *)rotateImage:(UIImage*)src byRadian:(CGFloat)radian
{
// calculate the size of the rotated view's containing box for our drawing space
UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0, src.size.width, src.size.height)];
CGAffineTransform t = CGAffineTransformMakeRotation(radian);
rotatedViewBox.transform = t;
CGSize rotatedSize = rotatedViewBox.frame.size;
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the Origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, radian);
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-src.size.width / 2, -src.size.height / 2, src.size.width, src.size.height), [src CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
Hardy Maciaのコードに基づく他の回答への小さな変更。回転した画像の境界矩形を計算するためだけにUIViewオブジェクト全体を作成する必要はありません。 CGRectApplyAffineTransformを使用して、イメージの四角形に回転変換を適用するだけです。
static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;}
static CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/M_PI;}
- (CGSize)rotatedImageSize:(CGFloat)degrees
{
CGAffineTransform t = CGAffineTransformMakeRotation(DegreesToRadians(degrees));
CGRect originalImageRect = CGRectMake(0, 0, self.size.width, self.size.height);
CGRect rotatedImageRect = CGRectApplyAffineTransform(originalImageRect, t);
CGSize rotatedSize = rotatedImageRect.size;
return rotatedSize;
}
- (UIImage*)imageRotatedByDegrees:(CGFloat)degrees
{
// calculate the size of the rotated view's containing box for our drawing space
CGSize rotatedSize = [self rotatedImageSize:degrees];
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize);
CGContextRef bitmap = UIGraphicsGetCurrentContext();
// Move the Origin to the middle of the image so we will rotate and scale around the center.
CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
// // Rotate the image context
CGContextRotateCTM(bitmap, DegreesToRadians(degrees));
// Now, draw the rotated/scaled image into the context
CGContextScaleCTM(bitmap, 1.0, -1.0);
CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
RawMeanの答え ：のSwift 4.2バージョン
extension UIImage {
func rotated(byDegrees degree: Double) -> UIImage {
let radians = CGFloat(degree * .pi) / 180.0 as CGFloat
let rotatedSize = self.size
let scale = UIScreen.main.scale
UIGraphicsBeginImageContextWithOptions(rotatedSize, false, scale)
let bitmap = UIGraphicsGetCurrentContext()
bitmap?.translateBy(x: rotatedSize.width / 2, y: rotatedSize.height / 2)
bitmap?.rotate(by: radians)
bitmap?.scaleBy(x: 1.0, y: -1.0)
bitmap?.draw(
self.cgImage!,
in: CGRect.init(x: -self.size.width / 2, y: -self.size.height / 2 , width: self.size.width, height: self.size.height))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext() // this is needed
return newImage!
}
}
私はPeter Sarnowskiの答えのシンプルなエレガンスが好きですが、EXIFメタデータなどに依存できない場合に問題を引き起こす可能性があります。 実際の画像データを回転する必要がある状況ではこのようなことをお勧めします：
- (UIImage *)rotateImage:(UIImage *) img
{
CGSize imgSize = [img size];
UIGraphicsBeginImageContext(imgSize);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextRotateCTM(context, M_PI_2);
CGContextTranslateCTM(context, 0, -640);
[img drawInRect:CGRectMake(0, 0, imgSize.height, imgSize.width)];
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
上記のコードは、向きがLandscape（Landscape LeftかLandscape Rightか覚えていない）の画像を取り、それをPortraitに回転します。これは、ニーズに合わせて変更できる例です。
使用する必要のある重要な引数はCGContextRotateCTM(context, M_PI_2)で、ここでどの程度回転させるかを決定しますが、CGContextTranslateCTM(context, 0, -640)を使用して画像が画面に描画されることを確認する必要があります。この最後の部分は、空白の画面ではなく画像を確認するために非常に重要です。
詳細については、 source をご覧ください。
「tint uiimage grayscale」は、これに適したGoogle-Fuのようです
すぐに私は得る：
https://discussions.Apple.com/message/8104516?messageID=8104516�
https://discussions.Apple.com/thread/2751445?start=0&tstart=
Swiftの場合：UIImageの簡単な拡張は次のとおりです。
//ImageRotation.Swift
import UIKit
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: CGPointZero, size: size))
let t = CGAffineTransformMakeRotation(degreesToRadians(degrees));
rotatedViewBox.transform = t
let rotatedSize = rotatedViewBox.frame.size
// Create the bitmap context
UIGraphicsBeginImageContext(rotatedSize)
let bitmap = UIGraphicsGetCurrentContext()
// 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
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)
}
CGContextScaleCTM(bitmap, yFlip, -1.0)
CGContextDrawImage(bitmap, CGRectMake(-size.width / 2, -size.height / 2, size.width, size.height), CGImage)
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}
（ ソース ）
以下で使用します：
rotatedPhoto = rotatedPhoto?.imageRotatedByDegrees(90, flip: false)
前者は、画像が回転し、反転がtrueに設定されている場合に反転します。
resize-a-uiimage-the-right-way これを行うための多くのコードサンプルが抱える問題のいくつかを説明し、UIImagesを扱うのに役立つコードスニペットを持っています-UIImage + resizeのプライベートヘルパーメソッド.mは回転を許可する変換を受け入れるため、パブリックインターフェイスとして公開する必要があります。
// Returns a copy of the image that has been transformed using the given affine transform and scaled to the new size
// The new image's orientation will be UIImageOrientationUp, regardless of the current image's orientation
// If the new size is not integral, it will be rounded up
- (UIImage *)resizedImage:(CGSize)newSize
transform:(CGAffineTransform)transform
drawTransposed:(BOOL)transpose
interpolationQuality:(CGInterpolationQuality)quality {
CGRect newRect = CGRectIntegral(CGRectMake(0, 0, newSize.width, newSize.height));
CGRect transposedRect = CGRectMake(0, 0, newRect.size.height, newRect.size.width);
CGImageRef imageRef = self.CGImage;
// Build a context that's the same dimensions as the new size
CGContextRef bitmap = CGBitmapContextCreate(NULL,
newRect.size.width,
newRect.size.height,
CGImageGetBitsPerComponent(imageRef),
0,
CGImageGetColorSpace(imageRef),
CGImageGetBitmapInfo(imageRef));
// Rotate and/or flip the image if required by its orientation
CGContextConcatCTM(bitmap, transform);
// Set the quality level to use when rescaling
CGContextSetInterpolationQuality(bitmap, quality);
// Draw into the context; this scales the image
CGContextDrawImage(bitmap, transpose ? transposedRect : newRect, imageRef);
// Get the resized image from the context and a UIImage
CGImageRef newImageRef = CGBitmapContextCreateImage(bitmap);
UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
// Clean up
CGContextRelease(bitmap);
CGImageRelease(newImageRef);
return newImage;
}
これはそのファイルからのライセンスです：
// Created by Trevor Harmon on 8/5/09.
// Free for personal or commercial use, with or without modification.
// No warranty is expressed or implied.
NYXImagesKitという非常に効率的なUIImageカテゴリがあります。 vDSP、CoreImage、vImageを使用して、可能な限り高速化します。私の一日を救ったUIImage + Rotatingカテゴリがあります:)