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ximgproc_ScanSegment

Extended image processingclassOpenCV 5.0.0
import { ximgproc_ScanSegment } from '@banou/opencv-wasm'

Use after await initOpenCV(). See the initialization and named imports guide.

ARGUMENTSConstructor or factory
CLASSximgproc_ScanSegment
RETURN TYPEOwned native handle
Call structure. A void return can still write to destination arguments. The parameter descriptions define inputs, outputs and ownership.

Native object: release it with using or delete(). Factories can return null; check before calling methods. Inherits Algorithm.

Class implementing the F-DBSCAN (Accelerated superpixel image segmentation with a parallelized DBSCAN algorithm) superpixels algorithm by Loke SC, et al. [loke2021accelerated] for original paper.

The algorithm uses a parallelised DBSCAN cluster search that is resistant to noise, competitive in segmentation quality, and faster than existing superpixel segmentation methods. When tested on the Berkeley Segmentation Dataset, the average processing speed is 175 frames/s with a Boundary Recall of 0.797 and an Achievable Segmentation Accuracy of 0.944. The computational complexity is quadratic O(n2) and more suited to smaller images, but can still process a 2MP colour image faster than the SEEDS algorithm in OpenCV. The output is deterministic when the number of processing threads is fixed, and requires the source image to be in Lab colour format.

Constructors and members

clone

Create another handle to the same native object. This retains the object without copying its pixels or algorithm state; dispose both handles separately.

clone(): this;
Returns

The this result.

getNumberOfSuperpixels

Returns the actual superpixel segmentation from the last image processed using iterate.

Returns zero if no image has been processed.
getNumberOfSuperpixels(): number;
Returns

The number result.

iterate

Calculates the superpixel segmentation on a given image with the initialized parameters in the ScanSegment object.

This function can be called again for other images without the need of initializing the algorithm with createScanSegment().
This save the computational cost of allocating memory for all the structures of the algorithm.
iterate(img: Mat): void;
img

Input image. Supported format: CV_8UC3. Image size must match with the initialized image size with the function createScanSegment(). It MUST be in Lab color space.

getLabels

Returns the segmentation labeling of the image.

Each label represents a superpixel, and each pixel is assigned to one superpixel label.
getLabels(labels_out: Mat): void;
labels_out

Output destination, filled by the native operation. Return: A CV_32UC1 integer array containing the labels of the superpixel segmentation. The labels are in the range [0, getNumberOfSuperpixels()].

getLabelContourMask

Returns the mask of the superpixel segmentation stored in the ScanSegment object.

The function return the boundaries of the superpixel segmentation.
getLabelContourMask(image: Mat, thick_line: boolean): void;
2 available overloads
getLabelContourMask(image: Mat): void;
getLabelContourMask(image: Mat, thick_line: boolean): void;
image

Output destination, filled by the native operation. Return: CV_8UC1 image mask where -1 indicates that the pixel is a superpixel border, and 0 otherwise.

thick_line

If false, the border is only one pixel wide, otherwise all pixels at the border are masked.

These signatures describe this package. Upstream documentation can mention optional backends that are absent from this build. Check runtime compatibility before choosing a backend or file format.