/*############################################################################# * 文件名：signature.c * 功能：  產生水印 * modified by  PRTsinghua@hotmail.com#############################################################################*/#include "signature.h"// 初始化水印位void init_signature_bits() {  bzero(signature, sizeof(signature));}// 初始化水印位void init_signature1_bits() {  bzero(signature1, sizeof(signature1));}// 初始化水印位void init_signature2_bits() {  bzero(signature2, sizeof(signature2));}// 獲得水印位int get_signature_bit(int n) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature_bit(): index out of range\n");#endif  return (signature[byte] & (1 << bit)) >> bit;}// 獲得水印位int get_signature1_bit(int n) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature1_bit(): index out of range\n");#endif  return (signature1[byte] & (1 << bit)) >> bit;}// 獲得水印位int get_signature2_bit(int n) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature2_bit(): index out of range\n");#endif  return (signature2[byte] & (1 << bit)) >> bit;}// 設置水印位void set_signature_bit(int n, int v) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature_bit(): index out of range\n");#endif  if (v)    signature[byte] |= (1 << bit);  else    signature[byte] &= ~(1 << bit);}// 設置水印位void set_signature1_bit(int n, int v) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature1_bit(): index out of range\n");#endif  if (v)    signature1[byte] |= (1 << bit);  else    signature1[byte] &= ~(1 << bit);}// 設置水印位void set_signature2_bit(int n, int v) {  int byte = n >> 3;  int bit = n & 7;#ifdef DEBUG  if (byte < 0 || byte >= NSIGNATURE)    fprintf(stderr, "get_signature2_bit(): index out of range\n");#endif  if (v)    signature2[byte] |= (1 << bit);  else    signature2[byte] &= ~(1 << bit);}