topic Hi Lu, in Intel® Integrated Performance Primitives

How to create a 'db4' wavelet transform?

lu_h_1 — Thu, 14 Jan 2016 12:57:55 GMT

The wavelet transform example uses 'db2' filter which can be find in below link:

https://software.intel.com/en-us/forums/intel-integrated-performance-primitives/topic/308991?wapkw=ippsWTFwd

According to the wavelet transform examples, I get the 'db4' filter values from matlab using wfilters('db4') command.

The length of Lo_D,Hi_D,Lo_R,Hi_R is 8, so I define

static const int fwdFltLenL = 8;
static const int fwdFltLenH = 8;

....

And copy the values from matlab:

static const float fwdFltL[8] = {-0.0106......};

...................

Other code are the same with the example.

....

ippsWTFwd_32f (src, low, high, 6, state);

........

But the low and high values are not equal to the values get by matlab.

So how to create a 'db4' wavelet transform?

Hi,

Igor_A_Intel — Thu, 21 Jan 2016 14:57:09 GMT

Hi,

could you be more specific - please provide reproducibles - *.m file for Matlab and *.c(or *.cpp) for IPP - that can be built and executed. And please provide a difference - what is expected and what you see.

Regards, Igor

Hi Lu,

Shaojuan_Z_Intel — Tue, 26 Jan 2016 18:38:26 GMT

Hi Lu,

Attached please find the examples of creating db2 and db3 wavelet transforms. Creating db4 wavelet transforms should be similar. Thanks!