[2] Algorithms used for boundary tracing:[4] Marching squares extracts contours by checking all corners of all cells in a two-dimensional field.
While the algorithm's nomenclature may evoke a sense of complexity, its underlying principle aligns closely with the familiar Moore-Neighbor Tracing technique.
However, the Radial Sweep algorithm, while functionally equivalent to Moore-Neighbor Tracing, introduces a novel perspective on identifying the next black pixel within the Moore neighborhood of a given boundary point.
Subsequently, the algorithm systematically rotates this segment about point P in a clockwise direction until it intersects with a black pixel within P's Moore neighborhood.
[10] Effectively, this rotational movement mirrors the process of inspecting each pixel surrounding point P in the Moore neighborhood.
By employing this method, the Radial Sweep algorithm offers a distinctive strategy for traversing boundary pixels within digital images.
The tracing process continues until the algorithm returns to the first border pixel, completing the contour of the item.
The approach is reasonably simple to implement, making it a popular choice for a variety of applications such as object detection, shape analysis, and pattern recognition in computer vision and image processing tasks.