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