HOW TO PERFORM 3 LSB AND 4 LSB REPLACEMENT

SUPPOSE I HAVE AN ARRAY OF 512*512 PIXEL ELEMENTS. I ALSO HAVE ANOTHER ARRAY 'DATA' OF O AND 1 VALUES. I HAVE TO REPLACE THE LAST 3 OR 4 LSB BITS OF EACH PIXEL WITH THE VALUES OF DATA ARRAY VALUES BASED ON SOME CONDITION. LET THE CONDITION IS

IF X==0 
THEN I WILL APPLY 3 LSB REPLACEMENT
ELSE IF X==1 
4 LSB REPLACEMENT

KINDLY SUGGEST ME ...HOW CAN I PROCEED...THANK YOU

Answer 1

[Geoff Hayes]

aditya - to replace the least significant bits of your pixel, you can use bitset. For example, suppose that X is zero, and we want to replace the last three bits with 101. We would do

 X = uint8(0);
 X = bitset(X,1,1);
 X = bitset(X,2,0);
 X = bitset(X,3,1);

and X is now five which what we expect with 00000101.

[aditya sahu]

Thanks Geoff Hayes...actually , when x==0 we have to perform 3 LSB and for rest 4 LSB. when i apply your code then all pixels of original array becomes changing but i need some specific pixels which satisfy the conditions only

[Geoff Hayes]

aditya - please note the above is just an example of how to set specific bits and is meant only to indicate how you might do this. It is up to you to incorporate it into your main program...

Answer 2

[Image Analyst]

See my attached demos for how to set and view bitplanes.