pysdic.View.image_project#

View.image_project(world_points, dx=False, dintrinsic=False, ddistortion=False, dextrinsic=False)[source]#

Project 3D world points to gray level or image values using the camera’s intrinsic, extrinsic, distortion parameters and image interpolation function.

See also

Parameters:

  • world_points (numpy.ndarray) – The 3D world points to be projected. The shape should be (…, 3) representing \(N_p\) points and each point is represented by its \((x, y, z)\) coordinates.

  • dx (bool, optional) – If True, the function will also return the jacobian of the gray levels with respect to the world points. Default is False.

  • dintrinsic (bool, optional) – If True, compute the Jacobian of the gray levels with respect to the intrinsic parameters. Default is False.

  • ddistortion (bool, optional) – If True, compute the Jacobian of the gray levels with respect to the distortion parameters. Default is False.

  • dextrinsic (bool, optional) – If True, compute the Jacobian of the gray levels with respect to the extrinsic parameters. Default is False.

Returns:

An instance of ImageProjectionResult containing:

  • gray_levels: An array of shape (…, channels) representing the image values at the projected pixel points.

  • jacobian_dx: (optional) An array of shape (…, channels, 3) representing the jacobian of the normalized points with respect to the world points if dx is True.

  • jacobian_dintrinsic: (optional) An array of shape (…, channels, \(N_{\text{intrinsic}}\)) representing the jacobian of the pixel points with respect to the intrinsic parameters if dintrinsic is True.

  • jacobian_ddistortion: (optional) An array of shape (…, channels, \(N_{\text{distortion}}\)) representing the jacobian of the pixel points with respect to the distortion parameters if ddistortion is True.

  • jacobian_dextrinsic: (optional) An array of shape (…, channels, \(N_{\text{extrinsic}}\)) representing the jacobian of the pixel points with respect to the extrinsic parameters if dextrinsic is True.

Return type:

ImageProjectionResult

Examples

Lets create a simple view and project some 3D points:

import numpy
from pysdic import Camera, Image, View
from pycvcam import Cv2Extrinsic, Cv2Intrinsic

rotation_vector = numpy.array([0.1, 0.2, 0.3])
translation_vector = numpy.array([12.0, 34.0, 56.0])

extrinsic = Cv2Extrinsic.from_rt(rotation_vector, translation_vector)

intrinsic = Cv2Intrinsic.from_matrix(
    numpy.array([[1000, 0, 320],
                [0, 1000, 240],
                [0, 0, 1]])
)

camera = Camera(
    sensor_height=480,
    sensor_width=640,
    intrinsic=intrinsic,
    extrinsic=extrinsic,
)

# Create a simple view with a blank image
image = Image.from_array(numpy.zeros((480, 640), dtype=numpy.uint8))
view = View(camera=camera, image=image)

# Define some 3D world points
world_points = numpy.array([
    [0, 0, 1000],
    [100, 0, 1000],
    [0, 100, 1000],
    [100, 100, 1000]
])

# Project the 3D points to 2D image points
image_projection_result = view.image_project(world_points, dx=True, dintrinsic=True, dextrinsic=True)

Extracting the projected image points and jacobians:

gray_levels = image_projection_result.image_points # The projected 2D image points of shape (4, 1)
jacobian_dx = image_projection_result.jacobian_dx # The jacobian with respect to the world points of shape (4, 1, 3)
jacobian_dintrinsic = image_projection_result.jacobian_dintrinsic # The jacobian with respect to the intrinsic parameters of shape (4, 1, 4)
jacobian_dextrinsic = image_projection_result.jacobian_dextrinsic # The jacobian with respect to the extrinsic parameters of shape (4, 1, 6)
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