arm-dwt-c-library

A C implementation of the one dimensional Discrete Wavelet Transform (DWT) based on CMSIS library.

How to use

Add arm_dwt_f32.h/c to your project. Link the CMSIS library

Then just call the init function arm_dwt_init_f32( ) with the right parameters, then call arm_dwt_f32( ). To see an example, please refer to the test I made.

Note: I did not provide a project or a Makefile because you can easily only add the files to your project. Moreover, the project would be target specific (for instance, to use the CMSIS library, you have to specify the cortex you are running your code on).

Implementation

The implementation is inspired by PyWavelets. The code has not been optimized for speed but for readability. Depending on your decomposition level, don't forget to update ARM_DWT_MAX_DEC_LEVEL.

Documentation

All the code is well-documented following Doxygen style.

Tests

The current fonction have been built with CMSIS 4 using Atollic TrueStudio. The test passes on a stm32h7 (cortex-m7) calling dwt_test_f32( 1E-4 ) which guarantee that the outputs between arm_dwt_f32( ) and the PyWavelet library are the same with a relative error of 1e-4.

Note: I only did the test on 1 sample

TODO

• Add the other padding possibilities (for now, only zero and symmetrical padding are supported)
• See if and how arm_conv_f32 could be used to optimize computation
• Do a short execution time test on a specific hardware