image-js/lib/image/utility/getThreshold.js

Image processing and manipulation in JavaScript

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = getThreshold;
var _thresholdAlgorithms = require("../transform/mask/thresholdAlgorithms");
/**
 * Returns a threshold for the creation of a binary mask with the `mask()` method.
 * @memberof Image
 * @instance
 * @param {object} [options]
 * @param {ThresholdAlgorithm} [options.algorithm='otsu']
 * @return {number}
 */
function getThreshold(options = {}) {
  let {
    algorithm = _thresholdAlgorithms.names.otsu
  } = options;
  this.checkProcessable('getThreshold', {
    components: 1,
    bitDepth: [8, 16]
  });
  let method = _thresholdAlgorithms.methods[algorithm.toLowerCase()];
  if (method) {
    let histogram = this.getHistogram();
    return method(histogram, this.size);
  } else {
    throw new Error(`unknown thresholding algorithm: ${algorithm}`);
  }
}