#define Sigma_width 16
#define Sigma_height 16
static char Sigma_bits[] = {
   0xfc, 0x3f, 0x0c, 0x20, 0x08, 0x00, 0x18, 0x00, 0x30, 0x00, 0x60, 0x00,
   0x40, 0x00, 0xc0, 0x00, 0xc0, 0x00, 0x40, 0x00, 0x60, 0x00, 0x30, 0x00,
   0x10, 0x00, 0x08, 0x00, 0x0c, 0x20, 0xfc, 0x3f};