README.md

ceres-backprojection

An experiment backprojecting the 2D points to 3d space base ceres-solver

Data Preparation

the file structure:

.
└── data
    └── video
        ├── flows
        │   ├── 00000.flo
        │   ├── ...
        └── images
            ├── 00000.png
            ├── ...

we only need the frames in folder images and the flows in flows , then run the jupyter notebook process.ipynb to generate the folder points under the video's path, in points folder, every file 000xxx.txt is corresponding to a frame, the points is organized with the format u1 v1 u2 v2 for every line, which means the 2d-2d correspondence from source to scene frame

Then we need to computer the 2d-3d correspondence from scene frame to the 3D pointcloud. However there is no additional conditions to obtain the 3D point, so we can only use some prior constraints, such as the pixel's neigborhood, so we use the ceres-solver to solve this problem.

Build & Run

first we need to compile the code

mkdir build && cd build && cmake ..

then, if the data is not prepared, run the process.ipynb and following command line, this may spend several minutes

./ceresBackProjection /path/to/video/

finally, run the visualization

./visualize /path/to/video