image-js/src/image/utility/getPixelsGrid.js

Image processing and manipulation in JavaScript

/**
 * @memberof Image
 * @instance
 * @param {object} [options]
 * @param {number[]} [options.sampling=[10, 10]]
 * @param {boolean} [options.painted=false]
 * @param {Image} [options.mask]
 * @return {object}
 */
export default function getPixelsGrid(options = {}) {
  let { sampling = [10, 10], painted = false, mask } = options;

  this.checkProcessable('getPixelsGrid', {
    bitDepth: [8, 16],
    channels: 1,
  });

  if (!Array.isArray(sampling)) {
    sampling = [sampling, sampling];
  }

  const xSampling = sampling[0];
  const ySampling = sampling[1];

  const xyS = [];
  const zS = [];

  const xStep = this.width / xSampling;
  const yStep = this.height / ySampling;
  let currentX = Math.floor(xStep / 2);

  for (let i = 0; i < xSampling; i++) {
    let currentY = Math.floor(yStep / 2);
    for (let j = 0; j < ySampling; j++) {
      let x = Math.round(currentX);
      let y = Math.round(currentY);
      if (!mask || mask.getBitXY(x, y)) {
        xyS.push([x, y]);
        zS.push(this.getPixelXY(x, y));
      }
      currentY += yStep;
    }
    currentX += xStep;
  }

  const toReturn = { xyS, zS };

  if (painted) {
    toReturn.painted = this.rgba8().paintPoints(xyS);
  }

  return toReturn;
}