UIImage Größenanpassung funktioniert nicht richtig

Question

Also habe ich versucht, herauszufinden, was ich jetzt falsch mache, und ich kann es nicht herausfinden. Was ich versuche, dies zu erreichen:

1. Nehmen Sie ein Foto mit UIImagePickerController
2. das resultierende Foto aufnehmen und die oberen und unteren Ernte ab, so dass es ein Quadrat (ähnlich wie Instagram)
3. Anzeige wird, dass Bild innerhalb eines UIButton

Aus irgendeinem Grund nehmen jedes Mal, wenn ich das Foto in der UIButton verzerrt endet und es scheint, als ob das Beschneiden richtig funktionierte nicht. Hier ist was ich mache. Im didFinishPickingMediaWithInfo Methode habe ich den folgenden Code:

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info 
{ 
    //Copy the image to the userImage variable 
    [picker dismissModalViewControllerAnimated:YES]; 
    userImage = nil; 

    //Rotate & resize image 
    userImage = [self resizeAndRotatePhoto:(UIImage *)[info objectForKey:UIImagePickerControllerOriginalImage]]; 
    NSLog(@"Userimage size, width: %f , height: %f", userImage.size.width , userImage.size.height); 

    //Update the image form field with the image and set the image in the controller 
    NSLog(@"Button size is height: %f , width: %f" , userImageAvatarButton.frame.size.height , userImageAvatarButton.frame.size.width); 
    [userImageAvatarButton.layer setMasksToBounds:YES]; 
    [userImageAvatarButton.layer setCornerRadius:3.0]; 
    [userImageAvatarButton setImage:userImage forState:UIControlStateNormal]; 
} 

ich die resizeAndRotatePhoto Methode vorübergehend schließen würde, aber das Ergebnis ist unten. Außerdem ist @property (strong) (UIImage *)userImage; im obigen Code in der Headerdatei des ViewControllers definiert. Die Protokollausgabe ergibt sich auch:

2012-05-07 17:38:07.995 NewApp[10666:707] Userimage size, width: 1936.000000 , height: 1936.000000 
2012-05-07 17:38:08.000 NewApp[10666:707] Button size is height: 60.000000 , width: 60.000000 

Wie Sie im Bild unten sehen, es verzerrt landet.

Was die resizeAndRotate Methode, hier ist es:

- (UIImage *)resizeAndRotatePhoto:(UIImage *)source 
{ 
if(source.imageOrientation == UIImageOrientationRight) 
{ 
    source = [self rotateImage:source byDegrees:90]; 
} 
if(userImage.imageOrientation == UIImageOrientationLeft) 
{ 
    source = [self rotateImage:source byDegrees:-90]; 
} 

CGFloat x,y; 
CGFloat size; 
if(source.size.width > source.size.height){ 
    size = source.size.height; 
    x = (source.size.width - source.size.height)/2; 
    y = 0; 
} 
else { 
    size = source.size.width; 
    x = 0; 
    y = (source.size.height - source.size.width)/2; 
} 


CGImageRef imageRef = CGImageCreateWithImageInRect([source CGImage], CGRectMake(x,y,size,size)); 
return [UIImage imageWithCGImage:imageRef]; 
} 

An dieser Stelle habe ich keine Ahnung, wie dieses Bild bekommen unverfälscht zu zeigen. Es scheint, dass es falsch abgeschnitten und falsch angezeigt wird, obwohl das System sagt, dass das Bild tatsächlich ein Quadrat ist.

Answer 1

ich aufgegeben, dass vocaro.com Lösung aus anderen Gründen (die Lösung zum Absturz bringen, wenn sie mit atypischen Bildformaten, zum Beispiel CMYK verwendet würde).

Wie auch immer, ich benutze jetzt die imageByScalingAspectFillSize Methode der folgenden UIImage Kategorie, um meine quadratischen Thumbnails zu machen.

Übrigens, dies gilt automatisch die Skala des Hauptbildschirms des Geräts (zB UIButton Schaltfläche, die 60x60 Punkte auf einem Retina-Gerät ist, wird diese Skala von 2x (oder 3x) gelten, dh eine 120x120 oder 180x180 Bild).

UIImage + SimpleResize.h:

/* UIImage+SimpleResize.h 
* 
* Modified by Robert Ryan on 5/19/11. 
*/ 

@import UIKit; 

/** Image resizing category. 
* 
* Modified by Robert Ryan on 5/19/11. 
* 
* Inspired by http://ofcodeandmen.poltras.com/2008/10/30/undocumented-uiimage-resizing/ 
* but adjusted to support AspectFill and AspectFit modes. 
*/ 

@interface UIImage (SimpleResize) 

/** Resize the image to be the required size, stretching it as needed. 
* 
* @param size   The new size of the image. 
* @param contentMode The `UIViewContentMode` to be applied when resizing image. 
*      Either `UIViewContentModeScaleToFill`, `UIViewContentModeScaleAspectFill`, or 
*      `UIViewContentModeScaleAspectFit`. 
* 
* @return    Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingToSize:(CGSize)size contentMode:(UIViewContentMode)contentMode; 

/** Resize the image to be the required size, stretching it as needed. 
* 
* @param size   The new size of the image. 
* @param contentMode The `UIViewContentMode` to be applied when resizing image. 
*      Either `UIViewContentModeScaleToFill`, `UIViewContentModeScaleAspectFill`, or 
*      `UIViewContentModeScaleAspectFit`. 
* @param scale  The scale factor to apply to the bitmap. If you specify a value of 0.0, the scale factor is set to the scale factor of the device’s main screen. 
* 
* @return    Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingToSize:(CGSize)size contentMode:(UIViewContentMode)contentMode scale:(CGFloat)scale; 

/** Crop the image to be the required size. 
* 
* @param bounds  The bounds to which the new image should be cropped. 
* 
* @return    Cropped `UIImage`. 
*/ 

- (UIImage * _Nullable)imageByCroppingToBounds:(CGRect)bounds; 

/** Crop the image to be the required size. 
* 
* @param bounds  The bounds to which the new image should be cropped. 
* @param scale  The scale factor to apply to the bitmap. If you specify a value of 0.0, the scale factor is set to the scale factor of the device’s main screen. 
* 
* @return    Cropped `UIImage`. 
*/ 

- (UIImage * _Nullable)imageByCroppingToBounds:(CGRect)bounds scale:(CGFloat)scale; 

/** Resize the image to fill the rectange of the specified size, preserving the aspect ratio, trimming if needed. 
* 
* @param size The new size of the image. 
* 
* @return  Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingAspectFillSize:(CGSize)size; 

/** Resize the image to fill the rectange of the specified size, preserving the aspect ratio, trimming if needed. 
* 
* @param size The new size of the image. 
* @param scale The scale factor to apply to the bitmap. If you specify a value of 0.0, the scale factor is set to the scale factor of the device’s main screen. 
* 
* @return  Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingAspectFillSize:(CGSize)size scale:(CGFloat)scale; 

/** Resize the image to be the required size, stretching it as needed. 
* 
* @param size The new size of the image. 
* 
* @return  Resized `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingToFillSize:(CGSize)size; 

/** Resize the image to be the required size, stretching it as needed. 
* 
* @param size The new size of the image. 
* @param scale The scale factor to apply to the bitmap. If you specify a value of 0.0, the scale factor is set to the scale factor of the device’s main screen. 
* 
* @return  Resized `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingToFillSize:(CGSize)size scale:(CGFloat)scale; 

/** Resize the image to fit within the required size, preserving the aspect ratio, with no trimming taking place. 
* 
* @param size The new size of the image. 
* 
* @return  Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingAspectFitSize:(CGSize)size; 

/** Resize the image to fit within the required size, preserving the aspect ratio, with no trimming taking place. 
* 
* @param size The new size of the image. 
* @param scale The scale factor to apply to the bitmap. If you specify a value of 0.0, the scale factor is set to the scale factor of the device’s main screen. 
* 
* @return  Return `UIImage` of resized image. 
*/ 

- (UIImage * _Nullable)imageByScalingAspectFitSize:(CGSize)size scale:(CGFloat)scale; 

@end 

UIImage + SimpleResize.m:

// UIImage+SimpleResize.m 
// 
// Created by Robert Ryan on 5/19/11. 

#import "UIImage+SimpleResize.h" 

@implementation UIImage (SimpleResize) 

- (UIImage *)imageByScalingToSize:(CGSize)size contentMode:(UIViewContentMode)contentMode { 
    return [self imageByScalingToSize:size contentMode:contentMode scale:0]; 
} 

- (UIImage *)imageByScalingToSize:(CGSize)size contentMode:(UIViewContentMode)contentMode scale:(CGFloat)scale { 
    if (contentMode == UIViewContentModeScaleToFill) { 
     return [self imageByScalingToFillSize:size]; 
    } 
    else if ((contentMode == UIViewContentModeScaleAspectFill) || 
      (contentMode == UIViewContentModeScaleAspectFit)) { 
     CGFloat horizontalRatio = self.size.width/size.width; 
     CGFloat verticalRatio  = self.size.height/size.height; 
     CGFloat ratio; 

     if (contentMode == UIViewContentModeScaleAspectFill) 
      ratio = MIN(horizontalRatio, verticalRatio); 
     else 
      ratio = MAX(horizontalRatio, verticalRatio); 

     CGSize sizeForAspectScale = CGSizeMake(self.size.width/ratio, self.size.height/ratio); 

     UIImage *image = [self imageByScalingToFillSize:sizeForAspectScale scale:scale]; 

     // if we're doing aspect fill, then the image still needs to be cropped 

     if (contentMode == UIViewContentModeScaleAspectFill) { 
      CGRect subRect = CGRectMake(floor((sizeForAspectScale.width - size.width)/2.0), 
             floor((sizeForAspectScale.height - size.height)/2.0), 
             size.width, 
             size.height); 
      image = [image imageByCroppingToBounds:subRect]; 
     } 

     return image; 
    } 

    return nil; 
} 

- (UIImage *)imageByCroppingToBounds:(CGRect)bounds { 
    return [self imageByCroppingToBounds:bounds scale:0]; 
} 

- (UIImage *)imageByCroppingToBounds:(CGRect)bounds scale:(CGFloat)scale { 
    if (scale == 0) { 
     scale = [[UIScreen mainScreen] scale]; 
    } 
    CGRect rect = CGRectMake(bounds.origin.x * scale, bounds.origin.y * scale, bounds.size.width * scale, bounds.size.height * scale); 
    CGImageRef imageRef = CGImageCreateWithImageInRect([self CGImage], rect); 
    UIImage *croppedImage = [UIImage imageWithCGImage:imageRef scale:scale orientation:self.imageOrientation]; 
    CGImageRelease(imageRef); 
    return croppedImage; 
} 

- (UIImage *)imageByScalingToFillSize:(CGSize)size { 
    return [self imageByScalingToFillSize:size scale:0]; 
} 

- (UIImage *)imageByScalingToFillSize:(CGSize)size scale:(CGFloat)scale { 
    UIGraphicsBeginImageContextWithOptions(size, false, scale); 
    [self drawInRect:CGRectMake(0, 0, size.width, size.height)]; 
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); 
    UIGraphicsEndImageContext(); 

    return image; 
} 

- (UIImage *)imageByScalingAspectFillSize:(CGSize)size { 
    return [self imageByScalingAspectFillSize:size scale:0]; 
} 

- (UIImage *)imageByScalingAspectFillSize:(CGSize)size scale:(CGFloat)scale { 
    return [self imageByScalingToSize:size contentMode:UIViewContentModeScaleAspectFill scale:scale]; 
} 

- (UIImage *)imageByScalingAspectFitSize:(CGSize)size { 
    return [self imageByScalingAspectFitSize:size scale:0]; 
} 

- (UIImage *)imageByScalingAspectFitSize:(CGSize)size scale:(CGFloat)scale { 
    return [self imageByScalingToSize:size contentMode:UIViewContentModeScaleAspectFit scale:scale]; 
} 

@end