FW: First Attempt at Crypto Library

Keith Wansbrough Keith.Wansbrough@cl.cam.ac.uk
Thu, 24 Apr 2003 10:25:25 +0100


Andrew J Bromage wrote:

> On Thu, Apr 24, 2003 at 08:21:59AM +0200, Ketil Z. Malde wrote:
> 
> > It handles binary data, surely?
> 
> Not in the same sense that Deflate does.  An arbitrary binary stream is
> not, in general, JPEG-compressible.  You at least need a width & height
> as metadata, plus a number of 3-byte triples equal to width*height.

Not to mention that it assumes those triples represent a
two-dimensional field of RGB colour values - the algorithm performs a
colour transformation first (into YUV), then a 2D spatial transform.
Arbitrary binary data will cause the algorithm to behave arbitrarily
badly when it tries this!  You'll just get noise out the other end.

--KW 8-)