index.js

var blobAnalysis = function(imgData, canvas){
    var cv = require('./cv');
    console.log(canvas);
    console.log('I am here')

    let src = cv.matFromImageData(imgData);
    let dst = new cv.Mat();
    let gray = new cv.Mat();
    let opening = new cv.Mat();
    let imageBg = new cv.Mat();
    let imageFg = new cv.Mat();
    let distTrans = new cv.Mat();
    let unknown = new cv.Mat();
    let markers = new cv.Mat();
   
    // gray and threshold image
    cv.cvtColor(src, gray, cv.COLOR_RGBA2GRAY, 0);
    cv.threshold(gray, gray, 0, 255, cv.THRESH_BINARY_INV + cv.THRESH_OTSU);
   
    // get background
    let M = cv.Mat.ones(3, 3, cv.CV_8U);
    cv.erode(gray, gray, M);
    cv.dilate(gray, opening, M);
    cv.dilate(opening, imageBg, M, new cv.Point(-1, -1), 3);
   
    // distance transform
    cv.distanceTransform(opening, distTrans, cv.DIST_L2, 5);
    cv.normalize(distTrans, distTrans, 1, 0, cv.NORM_INF);
   
    // get foreground
    cv.threshold(distTrans, imageFg, 0.7 * 1, 255, cv.THRESH_BINARY);
    imageFg.convertTo(imageFg, cv.CV_8U, 1, 0);
    cv.subtract(imageBg, imageFg, unknown);
   
    // get connected components markers
    cv.connectedComponents(imageFg, markers);
    for (let i = 0; i < markers.rows; i++) {
      for (let j = 0; j < markers.cols; j++) {
        markers.intPtr(i, j)[0] = markers.ucharPtr(i, j)[0] + 1;
        if (unknown.ucharPtr(i, j)[0] == 255) {
          markers.intPtr(i, j)[0] = 0;
        }
      }
    }
   
    cv.cvtColor(src, src, cv.COLOR_RGBA2RGB, 0);
    cv.watershed(src, markers);
   
    // draw barriers
    for (let i = 0; i < markers.rows; i++) {
      for (let j = 0; j < markers.cols; j++) {
        if (markers.intPtr(i, j)[0] == -1) {
          src.ucharPtr(i, j)[0] = 255; // R
          src.ucharPtr(i, j)[1] = 0; // G
          src.ucharPtr(i, j)[2] = 0; // B
        }
      }
    }
  
    cv.imshow(canvas, src);
  
    src.delete(); dst.delete(); gray.delete(); opening.delete(); imageBg.delete();
    imageFg.delete(); distTrans.delete(); unknown.delete(); markers.delete(); M.delete();

}
module.exports = blobAnalysis;