Bilateral Filter

Bilateral Filter example resides in L2/examples/bilateralfilter directory.

This benchmark tests the performance of bilateralfilter function. To preserve the edges while smoothing, a bilateral filter can be used. In an analogous way as the Gaussian filter, the bilateral filter also considers the neighboring pixels with weights assigned to each of them.

The tutorial provides a step-by-step guide that covers commands for building and running kernel.

Executable Usage

  • Work Directory(Step 1)

The steps for library download and environment setup can be found in README of L2 folder. For getting the design,

cd L2/examples/bilateralfilter

  • Build kernel(Step 2)

Run the following make command to build your XCLBIN and host binary targeting a specific device. Please be noticed that this process will take a long time, maybe couple of hours.

export OPENCV_INCLUDE=< path-to-opencv-include-folder >
export OPENCV_LIB=< path-to-opencv-lib-folder >
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:< path-to-opencv-lib-folder >
export DEVICE=< path-to-platform-directory >/< platform >.xpfm
make host xclbin TARGET=hw

  • Run kernel(Step 3)

To get the benchmark results, please run the following command.

make run TARGET=hw

  • Example output(Step 4)

-----------bilateral filter Design---------------
INFO: Running OpenCL section.
Found Platform
Platform Name: Xilinx
INFO: Device found - xilinx_u200_xdma_201830_2
XCLBIN File Name: krnl_bilateralfilter
INFO: Importing Vitis_Libraries/vision/L2/examples/bilateralfilter/Xilinx_Bilateralfilter_L2_Test_vitis_hw_u200/build_dir.hw.xilinx_u200_xdma_201830_2/krnl_bilateralfilter.xclbin
Loading: 'Vitis_Libraries/vision/L2/examples/bilateralfilter/Xilinx_Bilateralfilter_L2_Test_vitis_hw_u200/build_dir.hw.xilinx_u200_xdma_201830_2/krnl_bilateralfilter.xclbin'
     Minimum error in intensity = 0
     Maximum error in intensity = 0
     Percentage of pixels above error threshold = 0
------------------------------------------------------------

Profiling

The Bilateral Filter design is validated on Alveo u200 board at 300 MHz frequency. The hardware resource utilizations are listed in the following table.

Table 1 Hardware resources for Bilateral Filter

Name

Dataset

LUT

BRAM

FF

DSP

bilateralfilter

Full HD(1920x1080)

12513

18

13451

44

4k (3840x2160)

22523

35

22862

65

The performance is shown below

Table 2 Performance numbers for Bilateral Filter

Dataset

FPS(CPU)

FPS(FPGA)

Full HD(1920x1080)

200

1100

4k (3840x2160)

72

289