Re: Fast Image access for binarization

Siddharth,

you may at least want to reduce the width*height in the for loop. On
each iteration you're doing a multiplication that is not really needed
(assuming the compiler doesn't optimize this out).

Perhaps you can also try

int image[512*512];
int *pixel = image;
int *end = &image[512*512];

while (pixel!=end)
{
*pixel++ = *pixel>threshold;
}

and see if this makes a difference. Note that some compilers may not
compile the *pixel++ correctly. Also if you can make the 'threshold' a
constant that may help a little too.

You may also find that adding a

if (*pixel)
*pixel++ = *pixel>threshold;
else
pixel++;

may also make a difference depending on how your CPU caches read versus
write memory statements. Note that uneeded writes can sometimes be more
expensive than a read and comparison from a cache ... but this is very
CPU dependant.

Hope this helps!

STeven.
http://www.roborealm.com/
Where robots live ...

.

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