[racket] Thumbnailing

From: Paulo J. Matos (paulo at matos-sorge.com)
Date: Thu Oct 6 08:16:22 EDT 2011

On 05/10/11 15:26, Stephen Bloch wrote:
>> I am wondering if there's anything in place already to create an image
>> thumbnail. This is basically resizing an image.
> In the student graphics libraries (2htdp/image and picturing-programs, which is derived from 2htdp/image), you can use "scale" to scale an image up or down by a specified ratio.  For that matter, if you want to scale the x and y dimensions differently, you can use "scale/xy".  I believe this is a constant-time operation; the number-crunching comes later, when you render it to a bitmap for display on the screen or saving to a PNG file.

Thanks, I can't seem find a way to open image files (jpeg, png, bmp, 
etc). Is there anything like that in Racket currently? Or do we need ffi 
to libjpeg, libpng, etc.?


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