private int checkcmap()
{
int r = 0;
int g = 0;
int b = 0;
int n = 1 << bitspersample;
while (n-- > 0)
{
if (redcmap[r] >= 256 || greencmap[g] >= 256 || bluecmap[b] >= 256)
return 16;
r++;
g++;
b++;
}
return 8;
}