Question

I have these codes:

UIImage * img = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:IMAGEURL]]];
[self.imageView setImage:img];

But the IMAGEURL contains a high resolution picture so it takes much time to load. Can I resize the image data smaller to load faster?

Any help will be appreciated.

Thanks.

Answer 1

No, in order to resize the image you should at least read it in once, so unless the server has a low-quality version for you, there’s nothing you can do.

Unless you’re brave and the image is JPEG: libjpeg has a function to read in images downsampled by a factor of 2, 4 or 8. E.g. for scale 1/8 it reads DCT blocks and takes only the constant component. But this will be a little more complex. Read time will be drastically reduced.

See iphone-reading-an-area-of-an-image about this as well.