60 lines
1.7 KiB
Python
60 lines
1.7 KiB
Python
|
# -*- coding: utf-8 -*-
|
||
|
|
"""
|
||
|
|
Created on Mon Jun 10 17:30:40 2019
|
||
|
|
|
||
|
|
@author: Administrator
|
||
|
|
"""
|
||
|
|
|
||
|
|
from Jsteg import Jsteg
|
||
|
|
|
||
|
|
|
||
|
|
class F3(Jsteg):
|
||
|
|
def __init__(self):
|
||
|
|
Jsteg.__init__(self)
|
||
|
|
|
||
|
|
def set_sequence_after_dct(self,sequence_after_dct):
|
||
|
|
self.sequence_after_dct=sequence_after_dct
|
||
|
|
sum_len=len(self.sequence_after_dct)
|
||
|
|
zero_len=len([i for i in self.sequence_after_dct if i==0])
|
||
|
|
one_len=len([i for i in self.sequence_after_dct if i in (-1,1)])
|
||
|
|
self.available_info_len=sum_len-zero_len-one_len # 不是特别可靠
|
||
|
|
print ("Load>> 大约可嵌入",sum_len-zero_len-int(one_len/2),'bits')
|
||
|
|
print ("Load>> 最少可嵌入",self.available_info_len,'bits\n')
|
||
|
|
|
||
|
|
def _write(self,index,data):
|
||
|
|
origin=self.sequence_after_dct[index]
|
||
|
|
if origin == 0:
|
||
|
|
return False
|
||
|
|
elif origin in (-1,1) and data==0:
|
||
|
|
self.sequence_after_dct[index]=0
|
||
|
|
return False
|
||
|
|
|
||
|
|
lower_bit=origin%2
|
||
|
|
|
||
|
|
if lower_bit==data:
|
||
|
|
pass
|
||
|
|
elif origin>0:
|
||
|
|
self.sequence_after_dct[index]=origin-1
|
||
|
|
elif origin<0:
|
||
|
|
self.sequence_after_dct[index]=origin+1
|
||
|
|
return True
|
||
|
|
|
||
|
|
def _read(self,index):
|
||
|
|
if self.sequence_after_dct[index] != 0:
|
||
|
|
return self.sequence_after_dct[index]%2
|
||
|
|
else:
|
||
|
|
return None
|
||
|
|
|
||
|
|
|
||
|
|
if __name__=="__main__":
|
||
|
|
f3=F3()
|
||
|
|
# 写
|
||
|
|
sequence_after_dct=[-1,0,1]*100+[i for i in range(-7,500)]
|
||
|
|
f3.set_sequence_after_dct(sequence_after_dct)
|
||
|
|
info1=[0,1,0,1,1,0,1,0]
|
||
|
|
f3.write(info1)
|
||
|
|
# 读
|
||
|
|
sequence_after_dct2=f3.get_sequence_after_dct()
|
||
|
|
f3.set_sequence_after_dct(sequence_after_dct2)
|
||
|
|
info2=f3.read()
|
||
|
|
print (info2)
|