/gpu_flow

GPU based optical flow extraction in OpenCV

Primary LanguageC++

GPU based optical flow extraction in OpenCV

Features:

  • OpenCV wrapper for Real-Time optical flow extraction on GPU
  • Automatic directory handling using Qt
  • Allows saving of optical flow to disk, ** either with clipping large displacements ** or by adaptively scaling the displacements to the radiometric resolution of the output image

Dependencies

Installation

  1. mkdir -p build
  2. cd build
  3. cmake ..
  4. make

Configuration:

You should adjust the input and output directories by editing the variables vid_path, out_path and out_path_jpeg in compute_flow.cpp. Note that these folders have to exist before executing.

Usage:

./brox_flow [OPTION]...

Available options:

  • start_video: start with video number in vid_path directory structure [1]
  • gpuID: use this GPU ID [0]
  • type: use this flow method Brox = 0, TVL1 = 1 [1]
  • skip: the number of frames that are skipped between flow calcuation [1]

Additional features in compute_flow.cpp:

  • float MIN_SZ = 256: defines the smallest side of the frame for optical flow computation
  • float OUT_SZ = 256: defines the smallest side of the frame for saving as .jpeg
  • bool clipFlow = true;: defines whether to clip the optical flow larger than [-20 20] pixels and maps the interval [-20 20] to [0 255] in grayscale image space. If no clipping is performed the mapping to the image space is achieved by finding the frame-wise minimum and maximum displacement and mapping to [0 255] via an adaptive scaling, where the scale factors are saved as a binary file to out_path.

Example:

./brox_flow gpuID=0 type=1