How can I get a HD image of a website in objective c

i need to be able to get a HD logo from a website. I now use this but it totally isn't HD.

NSString *myUrl = @"http://www.autodesk.com";
            NSString *myURLString1 = @"http://ift.tt/ArJoPd";
            NSString *myURLString = [myURLString1 stringByAppendingString:myUrl];
            NSURL *myURL=[NSURL URLWithString: myURLString];
            NSData *myData=[NSData dataWithContentsOfURL:myURL];
            NSImage *myImage = [[NSImage alloc] initWithData:myData];

Because it's just a favoicon, it really isn't big enough. Does anybody have an alternative or solution?

Thanks