An interface that compares two image data on two canvas tags with RGBa-value.
https://github.com/YujiSODE/deltaImgJS
Wiki: https://github.com/YujiSODE/deltaImgJS/wiki

Copyright (c) 2017 Yuji SODE <[email protected]>
This software is released under the MIT License.
See LICENSE or http://opensource.org/licenses/mit-license.php

• deltaImgJS.js: function deltaImgJS(canvasId1,canvasId2)
  This function returns function that compares two image data on two canvas tags with average RGBa-value.
  Calculated p-value shows probability of hypothesis that two images are identical.

• canvasId1 and canvasId2: id of two canvas tags.

• function(N,max,Vcrit): function that compares two image data on two canvas tags,
  and returns size of sampling area to scan (dx and dy).

• N: positive integers; size of sampling area (dx and dy) is defined by
  dx=(canvas.width)/N and dy=(canvas.height)/N.
• max: positive integers; number of sampling areas to scan.
• Vcrit: critical value that ranges from 0 to 1.

• result: Result object.

This object can be accessed with a property result in returned function, and has 4 values.

• p: p-value; probability of hypothesis that two images are identical.
• critical: critical value.
• sampling: number of scanned areas.
• dataset: datasets of differences.