concepts.gui.opencv.point_picker.CV2PointPicker#

class CV2PointPicker[source]#

Bases: object

A simple point picker using OpenCV.

Example

import cv2
import numpy as np
from concepts.gui.opencv.point_picker import CV2PointPicker

color_image = np.zeros((480, 640, 3), dtype=np.uint8)
depth_image = np.zeros((480, 640), dtype=np.uint16)

picker = CV2PointPicker()
points = picker.run(color_image, depth_image)

The order of the points corresponds to the order in which they were clicked. To remove a point, click on it again. The current checking radius is 10 pixels.

Methods

imshow(color_image, depth_image[, window_name])

Helper function to visualize the registered points on the color and depth images.

print_help()

register_point(event, x, y, flag, param)

Register a point based on the click by the user.

run(color_image[, depth_image, ...])

Run the point picker.
__init__(registered_points=None)[source]#

Initialize the point picker.

Parameters:

registered_points (List[Tuple[int, int]] | None) – list of points to be registered. Defaults to None.

__new__(**kwargs)#
imshow(color_image, depth_image, window_name=None)[source]#

Helper function to visualize the registered points on the color and depth images.

Parameters:

  • color_image (ndarray) – the color image.

  • depth_image (ndarray | None) – the depth image.

  • window_name (str | None) – the name of the window. Defaults to None, in which case the name of the class is used.

Return type:

None

print_help()[source]#
register_point(event, x, y, flag, param)[source]#

Register a point based on the click by the user. See OpenCV documentation for cv2.setMouseCallback() for more details.

Parameters:

  • event – the event type.

  • x – the x-coordinate of the click.

  • y – the y-coordinate of the click.

  • flag – the flag.

  • param – the parameter.

run(color_image, depth_image=None, file_dirname='visualization', file_prefix='', save=False, window_name=None)[source]#

Run the point picker.

  • To pick a point, click on the image.

  • To remove a point, click on it again.

  • Press ‘c’ to print the registered points, and save it to a file if save is True.

  • Press ‘esc’ or ‘q’ to exit. The function will return the registered points.

If save is True, the visualization and the points will be saved to the specified directory: {file_dirname}/{file_prefix}_visualization.png and {file_dirname}/{file_prefix}_points.pkl.

Parameters:

  • color_image (ndarray) – the color image.

  • depth_image (ndarray | None) – the depth image. Defaults to None. If specified, it will be shown side by side with the color image.

  • file_dirname (str) – the directory to save the visualization and the points. Defaults to ‘visualization’.

  • file_prefix (str) – the prefix for the file names. Defaults to ‘’.

  • save (bool) – whether to save the visualization and the points. Defaults to False.

  • window_name (str | None) – the name of the window. Defaults to None, in which case the name of the class is used.

Returns:

list of registered points.

Return type:

List[Tuple[int, int]]

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