영삼이의 전문 정보 발행처

#import <Foundation/Foundation.h>

@interface UIImage (UIImageSizeExtention)

- (UIImage *)fixImageSize;

- (UIImage *)fitToSize:(CGSize)newSize;

- (UIImage *)scaleToSize:(CGSize)newSize;

- (UIImage *)scaleProportionlyToWidth:(CGFloat)width;

- (UIImage *)scaleProportionlyToHeight:(CGFloat)height;

- (UIImage *)cropToRect:(CGRect)newRect;

@end   

#import "UIImage+SizeExtention.h"

@implementation UIImage (UIImageSizeExtention)
 

#pragma mark -

#pragma mark Basic

- (UIImage*)fixImageSize 

{

    // Fix some strange bug

    UIGraphicsBeginImageContext(self.size);

    [self drawInRect:CGRectMake(0, 0, self.size.width, self.size.height)];

    UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newImage;

}

#pragma mark -

#pragma mark Fit (Combination)

- (UIImage *)fitToSize:(CGSize)newSize {

    float originalProportion = self.size.width/self.size.height;

    float targetProportion = newSize.width/newSize.height;

    float scaleProportion = newSize.width/self.size.width;

    UIImage *targetImage;

    if (targetProportion == originalProportion) {

        // Same Proportion

        // Do not have to crop, Direct scale

        targetImage = [self scaleToSize:newSize];

    } else if (targetProportion) {

        // Relative Landscape

        // Crop Rect

        CGFloat originX = self.size.width*scaleProportion/2 - newSize.width/2;

        CGRect cropRect = CGRectMake(originX, 0, newSize.width, newSize.height);

        // Scale to Height, Crop

        targetImage = [[self scaleProportionlyToHeight:newSize.height] cropToRect:cropRect];

    } else {

        // Relative Portrait

        // Scale to Width

        CGFloat originY = self.size.height*scaleProportion/2 - newSize.height/2;

        CGRect cropRect = CGRectMake(0, originY, newSize.width, newSize.height);

        targetImage = [[self scaleProportionlyToWidth:newSize.width] cropToRect:cropRect];

    }

   return targetImage;

}

#pragma mark -

#pragma mark Scale

- (UIImage *)scaleToSize:(CGSize)newSize {

    UIImage *targetImage = [self fixImageSize];

    // Prepare new size context

    UIGraphicsBeginImageContext(newSize);

    // Get current image

    CGContextRef context = UIGraphicsGetCurrentContext();

    // Change the coordinate from CoreGraphics (Quartz2D) to UIView

    CGContextTranslateCTM(context, 0.0, newSize.height);

    CGContextScaleCTM(context, 1.0, -1.0);

    // Draw (Scale)

    // The size of this drawRect is for scale

    CGRect drawRect = CGRectMake(0, 0, newSize.width, newSize.height);

    CGContextDrawImage(context, drawRect, targetImage.CGImage);

    // Get result and clean

    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return scaledImage;

}

- (UIImage *)scaleProportionlyToWidth:(CGFloat)width {

    float originalProportion = self.size.width/self.size.height;

    CGFloat height = width/originalProportion;

    return [self scaleToSize:CGSizeMake(width, height)];

}

- (UIImage *)scaleProportionlyToHeight:(CGFloat)height {

    float originalProportion = self.size.width/self.size.height;

    CGFloat width = height*originalProportion;

    return [self scaleToSize:CGSizeMake(width, height)];

}

#pragma mark -

#pragma mark Crop

- (UIImage *)cropToRect:(CGRect)newRect {

    UIImage *targetImage = [self fixImageSize];

    // Prepare new rect context

    UIGraphicsBeginImageContext(newRect.size);

    // Get current image

    CGContextRef context = UIGraphicsGetCurrentContext();

    // Change the coordinate from CoreGraphics (Quartz2D) to UIView

    CGContextTranslateCTM(context, 0.0, newRect.size.height);

    CGContextScaleCTM(context, 1.0, -1.0);

    // Draw (Crop)

    // This drawRect is for crop

    CGRect clippedRect = CGRectMake(0, 0, newRect.size.width, newRect.size.height);

    CGContextClipToRect(context, clippedRect);

    CGRect drawRect = CGRectMake(newRect.origin.x*(-1), newRect.origin.y*(-1), targetImage.size.width, targetImage.size.height);

    CGContextDrawImage(context, drawRect, targetImage.CGImage);

    UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return croppedImage;

}    

@end

UIImage *image = [UIImage imageNamed:/*Image name*/];


if (image.size.width > image.size.height) 

{

// If the width of a image is longer than the height
// rescale to width

image = [image scaleProportionlyToWidth:/*Image width*/];

}

else

{        

// If the height of a image is longer than the width
// recale to height

image = [image scaleProportionlyToHeight: /*Image height*/];

}

CGRect drawRect = CGRectMake(0, 0, image.size.width, image.size.height);

[image drawInRect:drawRect];