unsigned images

[Nicolas Devillard]

On Fri, 21 Feb 1997, Michael Olberg wrote:
[...]
> I think, the following code is ANSI compliant:
> 
> int i;
> short data[DATALEN];
> for (i = 0; i < DATALEN; i++) {
>     data[i] ^= (1<<15);
> }
[...]

ANSI, but not portable. If on your machine (and compiler) 'int i' means
'short int i', you may well run into trouble when addressing more than 32
kpixels. Furthermore, when declaring 'short data[DATALEN]', nothing
ensures that 'data' contains 16 bit integers, nor should any assumption be
made on the its sign. Portability...

Have a look in C FAQ's about portability and machine endian-ness. You may
well find answers to your problem there, together with simple source codes
for data conversion.

Hope it helps,
--Nicolas
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