How to optimize UIImage scaling for fast scaling - objective-c

Question

People, i need your help.
Need optimizing scaling images on flow. I try two methods for scale image with save proportions, please inspect this code and say, how i can it optimize if you want/can:
// Draw image in rect (PNG 1000ms, JPG 834ms for 8 pictures)
+ (UIImage *)imageWithImage:(UIImage *)sourceImage
scaledToSizeWithSameAspectRatio:(CGSize)targetSize
withInterpolationQuality:(CGInterpolationQuality)quality
{
CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = (CGPoint){0.0, 0.0};
if (CGSizeEqualToSize(imageSize, targetSize) == NO) {
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor > heightFactor) {
scaledWidth = width * widthFactor;
scaledHeight = height * widthFactor;
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
}
else {
scaledWidth = width * heightFactor;
scaledHeight = height * heightFactor;
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
UIGraphicsBeginImageContextWithOptions(targetSize, YES, 1.0);
dispatch_sync(dispatch_queue_create("pro.idev.itux.projectNameHere", DISPATCH_QUEUE_SERIAL), ^{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextSetInterpolationQuality(ctx, quality);
[sourceImage drawInRect:(CGRect){thumbnailPoint, {scaledWidth, scaledHeight}}];
});
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}
// Draw CGImage in rect (PNG 1326ms, JPG 1026ms for 8 pictures)
+ (UIImage *)imageWithCGImage:(CGImageRef)sourceImage
scaledToSizeWithSameAspectRatio:(CGSize)targetSize
withInterpolationQuality:(CGInterpolationQuality)quality
{
CGFloat width = CGImageGetWidth(sourceImage);
CGFloat height = CGImageGetHeight(sourceImage);
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = (CGPoint){0.0, 0.0};
if (CGSizeEqualToSize((CGSize){width, height}, targetSize) == NO) {
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor > heightFactor) {
scaledWidth = width * widthFactor;
scaledHeight = height * widthFactor;
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
}
else {
scaledWidth = width * heightFactor;
scaledHeight = height * heightFactor;
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
UIGraphicsBeginImageContextWithOptions(targetSize, YES, 1.0);
dispatch_sync(dispatch_queue_create("pro.idev.itux.projectNameHere", DISPATCH_QUEUE_SERIAL), ^{
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, 0, targetHeight);
CGContextScaleCTM(ctx, 1.0, -1.0);
CGContextSetInterpolationQuality(ctx, quality);
CGContextDrawImage(ctx, (CGRect){thumbnailPoint, {scaledWidth, scaledHeight}}, sourceImage);
});
UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return newImage;
}