Crop an image w.r.t UIImageView without reducing quality of image

//Crop an image without reducing quality of image

imageView.image=[self imageByScalingAndCroppingForSize:CGSizeMake(100, 100)]; 

//crop Image function

- (UIImage *)imageByScalingAndCroppingForSize:(CGSize)targetSize

{

    UIImage *sourceImage = imageView.image;

    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) * 0.1;

        }

        else

            if (widthFactor < heightFactor)

            {

                thumbnailPoint.x = (targetWidth - scaledWidth) * 0.1;

            }

    }

    

    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)

         

    //pop the context to get back to the default

    UIGraphicsEndImageContext();

    return newImage;

}