Package org.opencv.ximgproc

Class ScanSegment

  • public class ScanSegment
extends Algorithm
    Class implementing the F-DBSCAN (Accelerated superpixel image segmentation with a parallelized DBSCAN algorithm) superpixels algorithm by Loke SC, et al. CITE: 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.

    • Constructor Detail

      • ScanSegment

        protected ScanSegment​(long addr)

    • Method Detail

      • __fromPtr__

        public static ScanSegment __fromPtr__​(long addr)

      • getNumberOfSuperpixels

        public int getNumberOfSuperpixels()
        Returns the actual superpixel segmentation from the last image processed using iterate. Returns zero if no image has been processed.
        Returns:
        automatically generated

      • iterate

        public void iterate​(Mat img)
        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.
        Parameters:
        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

        public void getLabels​(Mat labels_out)
        Returns the segmentation labeling of the image. Each label represents a superpixel, and each pixel is assigned to one superpixel label.
        Parameters:
        labels_out - Return: A CV_32UC1 integer array containing the labels of the superpixel segmentation. The labels are in the range [0, getNumberOfSuperpixels()].

      • getLabelContourMask

        public void getLabelContourMask​(Mat image,
                                boolean thick_line)
        Returns the mask of the superpixel segmentation stored in the ScanSegment object. The function return the boundaries of the superpixel segmentation.
        Parameters:
        image - 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.

      • getLabelContourMask

        public void getLabelContourMask​(Mat image)
        Returns the mask of the superpixel segmentation stored in the ScanSegment object. The function return the boundaries of the superpixel segmentation.
        Parameters:
        image - Return: CV_8UC1 image mask where -1 indicates that the pixel is a superpixel border, and 0 otherwise.

      • finalize

        protected void finalize()
                 throws java.lang.Throwable
        Overrides:
        finalize in class Algorithm
        Throws:
        java.lang.Throwable