Re: Image scaling

FROM : Adam Knight
DATE : Mon Jan 07 18:41:54 2008

On Jan 4, 2008, at 5:51 PM, John Stiles wrote:
> I'd suggest that if you are trying to demonstrate an image's 
> sharpness, a lossy format like JPG is not the format to use :)
>
> FWIW it's entirely possible that Flickr is explicitly running a 
> sharpening filter on the image before scaling it down. I am not 100% 
> sure but I am fairly positive that Google's photo service (Picasa) 
> does this when you scale down images from within its iPhoto plugin.


That's actually exactly what's happening.  I did some searching and 
they boost saturation and run a sharpness filter on the thumbnails. 
So, using Core Image, I did the same things after running the Lanczos 
filter and managed to get a decent result.  Thanks for the lead. :)

Adam Knight
Co-Founder; CTO
adam.<email_removed>