Quick run through example

This example will show the basic commands required to run the 2d trajectory matching and 3D position triangulation.

Author: Thejasvi Beleyur, March 2022

import uuid
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
from track2trajectory.synthetic_data import generate_two_synthetic_cameras_version2
from track2trajectory.synthetic_data import make_brownian_particles
from track2trajectory.projection import project_to_2d_and_3d, calcFundamentalMatrix
from track2trajectory.match3d import match_2dpoints_to_3dtrajectories

Generating synthetic data

Let’s first generate 1) 2 cameras located at xyz [-1,0,0] and [1,0,0]. and 2) calculate the fundmental matrix mapping points between the two cameras.

cam1, cam2 = generate_two_synthetic_cameras_version2()
F = calcFundamentalMatrix(cam1, cam2)

two cameras - such that the particles stay within the common fields of view of both cameras most of the time.

num_particles  = 10
stepsize = 0.1 # in m
bounding_box = [[-4,4],
                [7,10],
                [-1,1]] # set the XYZ min-max limits for the bounding box
xyz_particles = make_brownian_particles(num_particles, bounding_box)

cam1_2dpoints, cam1_fails = project_to_2d_and_3d(xyz_particles, cam1)
cam2_2dpoints, cam2_fails = project_to_2d_and_3d(xyz_particles, cam2)
# Change the object IDs on cam2 - just to show that the object IDs can be
# any type alphanumeric code.

new_codes = [str(uuid.uuid4())[-4:] for each in range(num_particles)]
replacement = { each:new_codes[i]  for i,each in enumerate(cam2_2dpoints['oid'].unique())}
cam2_2dpoints['oid'] = cam2_2dpoints['oid'].replace(replacement)

cam2_2dpoints

Running trajectory matching

Let’s now run the match_2dpoints_to_3dtrajectories function, which checks for correspondences between points on each camera. If a correspondence is found, then a 3D point is calculated from it.

threed_matches = match_2dpoints_to_3dtrajectories(cam1, cam2,
                                                  cam1_2dpoints,
                                                  cam2_2dpoints, F)

threed_matches