算术编码算法MATLAB实现
时间: 2023-11-30 12:42:16 浏览: 54
以下是算术编码算法的MATLAB实现:
1. 编码算法
```matlab
function [code] = BasicArithmeticCode(probability, data)
% probability: 每个符号的概率
% data: 待编码的数据
% code: 编码后的数据
% 初始化
low = 0;
high = 1;
range = 1;
code = [];
% 编码
for i = 1:length(data)
symbol = data(i);
symbol_low = low + range * sum(probability(1:symbol-1)); symbol_high = low + range * sum(probability(1:symbol)); low = symbol_low;
high = symbol_high;
range = high - low;
end
% 输出编码结果
code = (low + high) / 2;
end
```
2. 解码算法
```matlab
function [data] = BasicArithmeticDecode(probability, code, length_data)
% probability: 每个符号的概率
% code: 编码后的数据
% length_data: 数据长度
% data: 解码后的数据
% 初始化
low = 0;
high = 1;
range = 1;
data = [];
% 解码
for i = 1:length_data
for j = 1:length(probability)
symbol_low = low + range * sum(probability(1:j-1));
symbol_high = low + range * sum(probability(1:j));
if code >= symbol_low && code < symbol_high
symbol = j;
break;
end
end
data = [data symbol];
symbol_low = low + range * sum(probability(1:symbol-1));
symbol_high = low + range * sum(probability(1:symbol));
low = symbol_low;
high = symbol_high;
range = high - low;
end
end
```
3. 编码器
```matlab
function [code] = Encoder(probability, data)
% probability: 每个符号的概率
% data: 待编码的数据
% code: 编码后的数据
% 调用编码算法
code = BasicArithmeticCode(probability, data);
end
```
4. 解码器
```matlab
function [data] = Decoder(probability, code, length_data)
% probability: 每个符号的概率
% code: 编码后的数据
% length_data: 数据长度
% data: 解码后的数据
% 调用解码算法
data = BasicArithmeticDecode(probability, code, length_data);
end
```
5. 计算压缩后总的比特数
```matlab
function [bits] = CaculateBits(probability, data)
% probability: 每个符号的概率
% data: 待编码的数据
% bits: 压缩后总的比特数
% 调用编码算法
code = BasicArithmeticCode(probability, data);
% 计算比特数
bits = ceil(-log2(1 - code));
end
```