LZW编码算法，尝试使用matlab计算
%encoder LZW for matlab
%yu 20170503
clc;
clear;
close all;
%初始字典
dic = cell(512,1);
for i = 1:256
dic{i} = {num2str(i)};
end
%输入字符串a，按空格拆分成A，注意加1对应围1~256 a = input('input:','s');
a = deblank(a);
A = regexp(a,'\s+','split');
L = length(A);
for j=1:L
A{j} = num2str(str2num(A{j})+1);
end
A_t = A{1};%可识别序列
B_t = 'test';%待验证词条
d = 256;%字典指针
b = 1;%输出指针
B = cell(L,1);%输出初始
output = ' ';%输出初始
j=1;
for j = 2:L
m=1;
B_t =deblank([A_t,' ',A{j}]);%合成待验证词条
while(m <= d)
if strcmp(dic{m},B_t)
A_t = B_t;
break
else
m=m+1;
end
end
while(m == d+1)
d = d+1;
dic{d} = B_t;
q=1;
for q=1:d
if strcmp(dic{q},A_t)
B{b} = num2str(q);
b = b+1;
end
end
A_t = A{j};
end
end
for q=1:d%处理最后一个序列输出
if strcmp(dic{q},A_t)
B{b} = num2str(q);
b = b+1;
end
end
for n = 1:(b-1)
B{n} =num2str(str2num(B{n})-1);
output=deblank([output,' ',B{n}]);
end
output
运算结果
计算结果为39 39 126 126 256 258 260 259 257 126
LZW解码算法，使用matlab计算
%decoder LZW for matlab
%yu 20170503
clc;
clear;
close all;
%初始字典
dic = cell(512,1);
for i = 1:256
dic{i} = {num2str(i)};
end
%输入字符串a，按空格拆分成A，注意加1对应围1~256
a = input('input:','s');
a = deblank(a);
A = regexp(a,'\s+','split');
L = length(A);
for j=1:L
A{j} = num2str(str2num(A{j})+1);
end
B_t = A{1};%待验证词条
d = 256;%字典指针
b = 1;%输出指针
B = cell(L,1);%输出初始
output = ' ';%输出初始
j=1;
B{b} = char(dic{str2num(A{j})});
b = b+1;
for j = 2:L
BB = char(dic{str2num(A{j})});
B_d = regexp(BB,'\s+','split');%按空格拆分
L_B = length(B_d);
p=1;
for p=1:L_B
B{(b+p-1)} = B_d{p};
m=1;
B_t =deblank([char(B_t),' ',char(B_d{p})]);%合成待验证词条
while(m <= d)
if strcmp(dic{m},B_t)
B_t = B_t;
break
else
m=m+1;
end
end
while(m == d+1)
d = d+1;
dic{d} = B_t;
B_t = B_d{p};
end
end
b = b+L_B;
end
for n = 1:(b-L_B)
B{n} = num2str(str2num(B{n})-1);
output=deblank([output,' ',B{n}]);
end
output
运算结果
运算结果为39 39 126 126 39 39 126 126 39 39 126 126 39 39 126 126。