[ft] Problem in pixel height

[samaram s]

Hi,

Can anybody please explain me,
When i set, 
FT_Set_Char_Size( face,0*64,12*64,72,72 );
i thought the height of the glyph in pixels is 12. But when i tried printing glyphs i am not getting of that height.

Glyph Data:0c 00 0c 00 16 00 12 00 32 00 3f 00 21 00 41
bbox = [-1 0 9 8]      Unicode Val = 00
Pixel Mode in main 1
Bitmap Left -1
Bitmap Top 8
Bitmap width is 10
Bitmap rows is 8

....**.....
....**.....
...*.**....
...*..*....
..**..*....
..******...
..*....*...
.*.....*...

Why is it less than 12 pixel height?? Am i missing anything ?

Could any one Please help me?

Thanks&Regards,
Sam