This program demonstrates the use of the Epiphany on the Parallella computer for image processing. The package includes a noise-imposed image, "lenna.jpg". By default, the program loads this image, and filters the high-frequency noise, generating a clean file "lenna.lpf.jpg". For reference, the resulting image is "lenna.lpf.ref.jpg".
The program uses the DevIL library for reading and writing the image file from/to the storage. After reading the file, the pixel data is extracted and loaded to the Epiphany, where the filter program is running.
To install DevIL on Linux, type:
$ sudo apt-get install libdevil-dev
$ sudo apt-get install libdevil1c2Timing measurements of the various parts are displayed after the calculation concludes.
For performance reference, an implementation of 2D-FFT transform of the same size is provided. The reference utilizes the FFTW library, which is considered a best-in-class library for DFT calculations. We used an ARM port for the FFTW. This version can be found here:
http://www.vesperix.com/arm/fftw-arm/source/index.html
For reference on the FFTW library, read:
$ sudo apt-get install fftw3 fftw3-devGPL v3
Contributed by Yaniv Sapir. Copyright 2012, 2014 Adapteva, Inc.