matlab - how to develop LeGall 5/3 filter for reversible watermarking?

Question

I want to implement a reversible image watermarking that use IWT transform and filter 5/3. at first I thing this filter is cdf 5.3 that it is in matlab. but after running the code I found out that this is not true and filter 5/3 is different. after search that I had, I found this filter is legall 5/3 that used in JPEG2000. now I should implement filter legall 5/3 at first and then choose subband HL1 to embedding my data for watermarking. I am a little confused how to implement this filter and use of HL.

Answer 1

LeGall 5/3 小波 (CDF 5/3) 在 MATLAB 中被命名为 bior2.2。带参数的dwt2命令'bior2.2'执行二维 CDF 5/3 小波分解：

[LL,HL,LH,HH] = dwt2(x,'bior2.2');

这将返回请求的 HL 子带。但是，您可能不想使用它。

正如您所提到的，在 JPEG 2000 标准中也使用 CDF 5/3 小波的整数到整数近似来进行无损压缩。这要归功于提升方案。在 MATLAB 中，整数 CDF 5/3 提升方案被命名为 cdf2.2。因此，您可能正在寻找以下命令：

ls = liftwave('cdf2.2');
[LL,HL,LH,HH] = lwt2(x,ls);

有关lwt2更多详细信息，请参阅。