board.js

const cv = require('opencv4nodejs');
const fs = require('fs');

const BoardSVM = require("./svm");
const BoardSolver = require("./board_solver");

const vc = new cv.VideoCapture(0);

const svm = new BoardSVM();
const solver = new BoardSolver();

const tiles = [];

while (true) {
  const img = vc.read().rotate(cv.ROTATE_180);
  //const img = cv.imread("data/raw/23.jpg");
  const gray = img.cvtColor(cv.COLOR_RGB2GRAY);
  const binary = gray.threshold(140, 255, cv.THRESH_BINARY);
  const edges = binary.canny(170, 220, 3);

  const mode = cv.RETR_TREE;
  const method = cv.CHAIN_APPROX_NONE;

  const contours = edges.findContours(mode, method)
    .filter(c => !c.isConvex)
    .filter(c => {
      const perimeter = c.arcLength(true);
      const approx = c.approxPolyDP(0.02 * perimeter, true);
      const isRect = approx.length === 4;

      if (!isRect) return false;

      const bbox = c.minAreaRect();
      const ratio = bbox.size.width / bbox.size.height;

      if (c.hierarchy.x === -1) {
        return false;
      }

      if (ratio < 0.85 || ratio > 1.15) {
        return false;
      }

      if (c.area < 40) {
        return false;
      }

      return true;
    })


  const contourPoints = contours.map(c => c.getPoints())
  img.drawContours(contourPoints, -1, new cv.Vec(0, 0, 255), { thickness: 2 })

  contours.forEach((c, i) => {
    let tileRect = c.boundingRect().pad(0.9);
    const roi = gray.getRegion(tileRect);

    const resized = roi.resize(30, 30);
    const prediction = svm.predict(resized);

    const seen = tiles.filter(tile => {
      const xDiff = (tile.x - tileRect.x);
      const yDiff = (tile.y - tileRect.y);

      const diff = Math.sqrt(xDiff * xDiff + yDiff * yDiff);

      return diff < 2 && tile.label === prediction
    }).length > 0;

    if(seen) {
      return;
    }

    tiles.push({ x: tileRect.x, y: tileRect.y, label: prediction })
  })

  //cv.imshow("a", edges);
  //cv.waitKey();

  tiles.forEach(tile => {
    cv.drawTextBox(img, { x: tile.x, y: tile.y }, [{ text: tile.label }], 0.8)
  })

  // cv.waitKey(1);

  if(tiles.length === 16) {
    solver.solve(tiles);
    return;
  }
}