Paper

Results of the project have been documented in this paper: Entropy-Driven Adaptive Filtering for High-Accuracy and Resource-Efficient FPGA-Based Neural Network Systems https://www.mdpi.com/2079-9292/9/11/1765

RealTimeObjectRecognition

This program is for Real Time Object Recognition with Binary Neural Network on FPGA. Our main contribution is appending an Entropy driven Adaptive Filter for a more accurate and resources efficient system. This includes:

• Entropy-based Uncertainty Estimation {uncertainty.cpp}
• Window Filter with variable step size and length {win.cpp} which changes dynamically based on level of uncertainty in data. Enabling us to decimate frames as well
• Region-Of-Interest(ROI) Detection with Optical Flow and Contour Detection {roi_filter.cpp}
• Other possible power-saving features by altering configurations in {main.cpp, main-adaptivefil.cpp, main-uncertainty.cpp, main-windowfil.cpp}
  • Dynamic clock
  • ROI Filter - alternate between Optical Flow, Contour Detection and Reuse Past ROI based on level of uncertainty in data

Folder Architecture:

• code/bnn_lib_tests/Makefile is the Makefile
• code/bnn_lib_tests/src/* contains all the active sources files
• code/bnn_lib_tests/experiments/results is the directory for active test results
• code/bnn_lib_tests/experiments/images is the directory for active dataset
• testing/data/ contains all 12 datasets
• testing/TrailX contins results of previous tests

Dependencies:

• Avnet Zedboard with Linux GCC 5.2.1
• libkernelbnn.a file: the compiled BNN (includekernelbnn.hin headers to use it)
• sdslib.h file: part of SDSoC environment API, which provides functions to map memory spaces
• foldmv-offload files: for managing hardware offload•rawhls-offload files: for execution of HLS souce code
• OpenCV 2.4.9 Library: for image processing
• OpenMP 4.0 Library: for pipeline functions

---

Setting up the FPGA

After wiring up the FPGA to a linux PC, execute the program by following the steps below:

• To access the files, in the File system of the laptop, choose other location, and type:

sftp://198.168.137.99

• SSH to the remote sever at the terminal and initialise the FPGA via flashing the neural networkto it:

ssh −X [email protected]
password: xilinx
/home/xilinx/: su
/home/xilinx/: cp .Xauthority /root/
/home/xilinx/jose_bnn/: echo kernelbnn.linked.bit.bin > /sys/class/fpga_manager/fpga0/firmware

• Then in the bnnlibtests folder, run “make clean all" Upon compiling the program with the Makefile, 4 executables can be called: BNN, WindowFilExp,UncertaintyExp, AdaptiveFilExp.

---

Case 1: With Webcam Input

Uses webcam input for classification. Classify it as one of the ten classes ("airplane", "automobile", "bird", "cat", "deer", "dog", "frog", "horse", "ship", "truck")

Command avaliable: ./BNN [No. of frame] [Schemes] [Expected Class] [No. of frame]: number of frames to be Captured [Schemes]: either A/B/C/base, adaptive filtering schemes to be applied, with A being most accurate and C most resources efficient [Expected Class]: Enter the expected classification results, for analysing the system accuracy.

Example 1:

./BNN 500 A 4

The command means capture 500 frames, and apply scheme A for adaptive filter, expecting the input to be deer

Example 2:

./BNN 500 base 1

The command means capture 500 frames, and apply base model for adaptive filter, expecting the input to be automobile

Case 2: With Video Dataset as Input

Experiment for analysing the performance of different adaptive filter schemes under different scenarios. Scheme A is optimised for accuracy. Scheme B is optimised for accuracy and efficiency. Scheme C is optimised for accuracy and efficiency with more aggressive computational savings. Dataset is used instead of the webcam. Dataset Directory: ../experiments/DatasetX (X ranges from 1 - 5) Output Log Directory: ../experiments/result/result-overview.csv

For Scheme A :

./AdaptiveFilExp 1 1 10 15 12 15 1 10 10 13 

For Scheme B :

./AdaptiveFilExp 1 1 15 15 15 12 15 10 10 8

For Scheme C :

./AdaptiveFilExp 1 1 10 8 15 12 15 10 10 6

Users can also self-specified different scheme: ./BNN SS-1 WL-1 SS-2 WL-2 SS-3 WL-3 SS-4 WL-4 SS-5 WL-5 (Replace the numbers with your own StepSize and WindowLength Sets)

Case 3: Compare Uncertainty Estimation Schemes Experiments

Experiment for analysing the performance of different uncertainty estimation schemes under different scenarios. Dataset is used instead of the webcam. There are three estimation schemes:

• Entropy
• Autocorrelation
• Variance

Dataset Directory: ../experiments/uncertainty-datasetX (X ranges from 2 - 5) Output Log Directory: ../experiments/result/result-overview.csv

Run the experiment with the following command:

./UncertaintyExp

Case 4: Optimise Window Filter Configurations Experiments

Experiment for finding the optimium window filter settings (Window Step Size & Window Length) for different scenarios. Dataset is used instead of the webcam.

Dataset Directory: ../experiments/datasetX (X ranges from 1 - 5) Output Log Directory: ../experiments/result/result-overview.csv

Run the experiment with the following command:

./WindowFilExp

Other options

Region-of-Interst code is also embedded in the file. Users can change the roi_config in the main files from "full-roi" to "opt-roi", "cont-roi","eff-roi", which correspond to optical flow detection, contour detection and hybrid of the two