Fussweg Datentools

Footpath image data processing tools.

Setting Up the Development Environment

The project now manages all third-party dependencies using git submodules. This includes exiv2, nlohmann_json, googletest, opencv, and the dependencies of opencv (zlib-ng and libpng). All of these reside in the contrib folder.

Cloning the Repository with Submodules

To fetch the repository alone, use the following command:

git clone https://github.com/ppmzhang2/fussweg-datentools.cpp

If you've already cloned the project and need to update or initialize the submodules, navigate to the project's root directory and run:

git submodule update --depth 1 --recursive --init

Compiling Dependencies

To compile the project, first compile the contribs. Run the following commands sequentially:

./scripts/csvparser_build.sh
./scripts/zlibng_build.sh
./scripts/libpng_build.sh
./scripts/exiv2_build.sh
./scripts/opencv_build.sh

Then, compile the project using the build.sh script with either the debug or release option:

./build.sh [debug|release]

Modules

The program includes three main modules:

1. fdt::exif: For handling EXIF data, such as extracting EXIF data from images.
2. fdt::annot: For annotation-related tasks, such as drawing bounding boxes on images based on annotations and calculating pavement distress statistics according to annotations.
3. fdt::cv: For computer vision tasks, including the perspective transformation example and calculating optical flow differences between image pairs.

Usage

Perspective Transformation

Find the perspective transformation matrix by providing the width and height, and eight points in the source image, which will determine two vanishing points. The program will further calculate the quadrilateral region of interest (ROI) by joining the vanishing points with the four apexes of the source image, and returning the intersections of the lines.

fdt pov-roi 5568 4872 \
1404 3764 2159 1519 5033 2712 3849 1159 3710 275 3279 295 1026 3774 5187 3710
# Output:
# TL -> 2537.67, 145.667
# TR -> 2975.28, 124.631
# BR -> 5551.82, 4842.37
# BL -> 0, 4872

Use the output to transform images to a bird's-eye view:

fdt pov-transform 200 1600 \
2537.67 145.667 2975.28 124.631 5551.82 4842.37 0.0 4872.0 \
path/to/image/folder \
path/to/output/folder

References

• Demo images from Exif Samples