Created
May 17, 2011 18:19
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UIImage Resize and Crop
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@implementation UIImage (Extras) | |
#pragma mark - | |
#pragma mark Scale and crop image | |
- (UIImage*)imageByScalingAndCroppingForSize:(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; // scale to fit height | |
else | |
scaleFactor = heightFactor; // scale to fit width | |
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; | |
} | |
} | |
UIGraphicsBeginImageContext(targetSize); // this will crop | |
CGRect thumbnailRect = CGRectZero; | |
thumbnailRect.origin = thumbnailPoint; | |
thumbnailRect.size.width = scaledWidth; | |
thumbnailRect.size.height = scaledHeight; | |
[sourceImage drawInRect:thumbnailRect]; | |
newImage = UIGraphicsGetImageFromCurrentImageContext(); | |
if(newImage == nil) | |
NSLog(@"could not scale image"); | |
//pop the context to get back to the default | |
UIGraphicsEndImageContext(); | |
return newImage; | |
} |
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