Şimdiye kadar okuduğum en kolay yolu bir maske kullanmaktır görüntüleri bir Uİİmage üzerinde yuvarlak köşeler almaya çalışın. Bu Örneğin iPhone TheElements kodu kullandım ve bazı resim boyutlandırma kodu buldum. Benim sorunum resizedİmage her zaman mümkün değildir ve hata bulmuyorum

- (UIImage *)imageByScalingProportionallyToSize:(CGSize)targetSize
{
    CGSize imageSize = [self size];
    float width = imageSize.width;
    float height = imageSize.height;

    // scaleFactor will be the fraction that we'll
    // use to adjust the size. For example, if we shrink
    // an image by half, scaleFactor will be 0.5. the
    // scaledWidth and scaledHeight will be the original,
    // multiplied by the scaleFactor.
    //
    // IMPORTANT: the "targetHeight" is the size of the space
    // we're drawing into. The "scaledHeight" is the height that
    // the image actually is drawn at, once we take into
    // account the ideal of maintaining proportions

    float scaleFactor = 0.0; 
    float scaledWidth = targetSize.width;
    float scaledHeight = targetSize.height;

    CGPoint thumbnailPoint = CGPointMake(0,0);

    // since not all images are square, we want to scale
    // proportionately. To do this, we find the longest
    // edge and use that as a guide.

    if ( CGSizeEqualToSize(imageSize, targetSize) == NO )
    { 
    	// use the longeset edge as a guide. if the
    	// image is wider than tall, we'll figure out
    	// the scale factor by dividing it by the
    	// intended width. Otherwise, we'll use the
    	// height.

    	float widthFactor = targetSize.width / width;
    	float heightFactor = targetSize.height / height;

    	if ( widthFactor < heightFactor )
    		scaleFactor = widthFactor;
    	else
    		scaleFactor = heightFactor;

    	// ex: 500 * 0.5 = 250 (newWidth)

    	scaledWidth = width * scaleFactor;
    	scaledHeight = height * scaleFactor;

    	// center the thumbnail in the frame. if
    	// wider than tall, we need to adjust the
    	// vertical drawing point (y axis)

    	if ( widthFactor < heightFactor )
    		thumbnailPoint.y = (targetSize.height - scaledHeight) * 0.5;

    	else if ( widthFactor > heightFactor )
    		thumbnailPoint.x = (targetSize.width - scaledWidth) * 0.5;
    }


    CGContextRef mainViewContentContext;
    CGColorSpaceRef colorSpace;

    colorSpace = CGColorSpaceCreateDeviceRGB();

    // create a bitmap graphics context the size of the image
    mainViewContentContext = CGBitmapContextCreate (NULL, targetSize.width, targetSize.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast);

    // free the rgb colorspace
    CGColorSpaceRelease(colorSpace);    

    if (mainViewContentContext==NULL)
    	return NULL;

    //CGContextSetFillColorWithColor(mainViewContentContext, [[UIColor whiteColor] CGColor]);
    //CGContextFillRect(mainViewContentContext, CGRectMake(0, 0, targetSize.width, targetSize.height));

    CGContextDrawImage(mainViewContentContext, CGRectMake(thumbnailPoint.x, thumbnailPoint.y, scaledWidth, scaledHeight), self.CGImage);

    // Create CGImageRef of the main view bitmap content, and then
    // release that bitmap context
    CGImageRef mainViewContentBitmapContext = CGBitmapContextCreateImage(mainViewContentContext);
    CGContextRelease(mainViewContentContext);

    CGImageRef maskImage = [[UIImage imageNamed:@"Mask.png"] CGImage];

    CGImageRef resizedImage = CGImageCreateWithMask(mainViewContentBitmapContext, maskImage);
    CGImageRelease(mainViewContentBitmapContext);

    // convert the finished resized image to a UIImage 
    UIImage *theImage = [UIImage imageWithCGImage:resizedImage];

    // image is retained by the property setting above, so we can 
    // release the original
    CGImageRelease(resizedImage);

    // return the image
    return theImage;
}

Nasıl bu satırları

// Get your image somehow
UIImage *image = [UIImage imageNamed:@"image.jpg"];

// Begin a new image that will be the new image with the rounded corners 
// (here with the size of an UIImageView)
UIGraphicsBeginImageContextWithOptions(imageView.bounds.size, NO, 1.0);

// Add a clip before drawing anything, in the shape of an rounded rect
[[UIBezierPath bezierPathWithRoundedRect:imageView.bounds 
                            cornerRadius:10.0] addClip];
// Draw your image
[image drawInRect:imageView.bounds];

// Get the image, here setting the UIImageView image
imageView.image = UIGraphicsGetImageFromCurrentImageContext();

// Lets forget about that we were drawing
UIGraphicsEndImageContext();