unsigned char WatermarkGet(unsigned char a, unsigned char b, unsigned char c)
{
unsigned char code, position;
code=(GetLSB(a) * 4) + (GetLSB(b) * 2) + GetLSB(c);
switch (code)
{
case 0: position = 0; break;
case 7: position = 0; break;
case 1: position = 1; break;
case 6: position = 1; break;
case 2: position = 2; break;
case 5: position = 2; break;
case 3: position = 3; break;
case 4: position = 3; break;
}
return position;
}
void WatermarkSet(unsigned char &a, unsigned char &b, unsigned char &c, int position)
{
unsigned char bit1, bit2, bit3, code;
code=(GetLSB(a) * 4) + (GetLSB(b) * 2) + GetLSB(c);
switch (position)
{
/* On doit tatouer que le pixel effacé est x0 */
case 0:
switch (code)
{
case 1: c=ResetLSB(c); break;
case 2: b=ResetLSB(b); break;
case 3: a=SetLSB(a); break;
case 4: a=ResetLSB(a); break;
case 5: b=SetLSB(b); break;
case 6: c=SetLSB(c); break;
}
break;
/* On doit tatouer que le pixel effacé est x1 */
case 1:
switch (code)
{
case 0: c=SetLSB(c); break;
case 2: a=SetLSB(a); break;
case 3: b=ResetLSB(b); break;
case 4: b=SetLSB(b); break;
case 5: a=ResetLSB(a); break;
case 7: c=ResetLSB(c); break;
}
break;
/* On doit tatouer que le pixel effacé est x2 */
case 2:
switch (code)
{
case 0: b=SetLSB(b); break;
case 1: a=SetLSB(a); break;
case 3: c=ResetLSB(c); break;
case 4: c=SetLSB(c); break;
case 6: a=ResetLSB(a); break;
case 7: b=ResetLSB(b); break;
}
break;
/* On doit tatouer que le pixel effacé est x3 */
case 3:
switch (code)
{
case 0: a=SetLSB(a); break;
case 1: b=SetLSB(b); break;
case 2: c=SetLSB(c); break;
case 5: c=ResetLSB(c); break;
case 6: b=ResetLSB(b); break;
case 7: a=ResetLSB(a); break;
}
break;
}
return;
}
void add(int i, BitT v) { while (i <= n) { f[i] += v; i += GetLSB(i); } }
