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ICP Point Cloud Alignment

HardCV

Implement Iterative Closest Point (ICP) for 3D scan alignment, a 3D registration technique used to find the best alignment between two point clouds. ICP is crucial in 3D reconstruction as it enables the combination of multiple scans into a single, cohesive model.

The ICP process involves iteratively finding the closest points between the source and target point clouds, estimating the rigid transformation ( $R$ , $t$ ) that best aligns the two clouds, and applying this transformation to the source cloud. This process is repeated until convergence, at which point the source and target clouds are optimally aligned.

To achieve this, the following steps are taken:

Find closest points between source and target point clouds
Estimate rigid transformation ( $R$ , $t$ ) using the Procrustes method
Apply transformation to source point cloud
Repeat until convergence

R = \arg \min_{R \in SO(3)} \sum_{i=1}^{n} ||R \cdot \mathbf{x}_i + \mathbf{t} - \mathbf{y}_i||^2

This technique is widely used in computer vision and robotics for tasks such as 3D mapping and object recognition.

Example:

Input:

Two point clouds

Output:

Aligned source cloud

Reasoning:

Iterate: match → transform → repeat

Constraints:

Input point clouds: 3D numpy arrays of shape (n, 3) where n is the number of points in the cloud
Valid ranges: Point cloud coordinates are floating-point numbers in the range [-100, 100]
Output format: Return the aligned source point cloud as a 3D numpy array of shape (n, 3) with floating-point precision
Special conditions: The input point clouds are not empty and contain at least 3 points, and the target point cloud is not identical to the source point cloud
Convergence criteria: The iteration stops when the difference between the current and previous transformations is less than a threshold of 1e-6 or when a maximum of 100 iterations is reached

Editor

Python 3.13.1

Test Results

0/0

Run code to see test results.