xbm是什么件格式？如何在程序中解析？

有个网站好像用这个东西在做验证码。取得文件内容如下：
#define counter_width 32
#define counter_height 10
static unsigned char counter_bits[] = {
0xfe,0x60,0x18,0x3c,0xfe,0x30,0x1c,0x66,0x06,0x18,0x18,0xc0,0x06,0x0c,0x18,0x60,0x3e,0x3e,0x18,0x1c,0x60,0x63,0x18,0x60,0xc0,0xc3,0x18,0xc0,0xc3,0xc3,0x18,0xc0,0x66,0x66,0x18,0x66,0x3c,0x3c,,0x38};显示的验证码是5613。如何通过上述数据来知道这个5613呢？