Image or Canvas expected when using in nodejs

[gpstmp]

Hi!
I'm trying to get imagediff work in nodejs but with no luck.
My code is pretty simple and looks like https://github.com/HumbleSoftware/js-imagediff/blob/master/bin/imagediff

var fs = require('fs'),
  imagediff = require('imagediff'),
  Canvas = require('canvas');

function loadImage (url, callback) {
  var image = new Canvas.Image();
  fs.readFile(url, function (error, data) {
    if (error) throw error;
    image.onload = function () {
      callback(image);
    };
    image.src = data;
  });
  return image;
}

var aName = 'test.png';

loadImage(aName, function (a) {
  var aData = imagediff.toImageData(a);
  console.log(" >>>>> equal: ", imagediff.equal(aData, aData));
});

But i got an error:

/vagrant/node_modules/imagediff/imagediff.js:126
    context.drawImage(image, 0, 0);
           ^
TypeError: Image or Canvas expected...

I have found related issue #38 but it gave me no new info about the problem.

I'm using:

• "canvas": "1.2.7"
• "imagediff": "1.0.8"
• "node": "0.10.37"

I have tried to run imagediff command line tool and it is working as expected. I also noticed that imagediff uses old version of "canvas" (1.1.6) and have tried to use it in my project but with no success (have the same error).

Thanks for any help.

[cburgmer]

I just run the following (your example + file from examples/1_normal_a.jpg):

var fs = require('fs'),
    imagediff = require('./imagediff'),
    Canvas = require('canvas');

function loadImage (url, callback) {
  var image = new Canvas.Image();
  fs.readFile(url, function (error, data) {
    if (error) throw error;
    image.onload = function () {
      callback(image);
    };
    image.src = data;
  });
  return image;
}

var aName = 'examples/1_normal_a.jpg';

loadImage(aName, function (a) {
  var aData = imagediff.toImageData(a);
  console.log(" >>>>> equal: ", imagediff.equal(aData, aData));
});

This prints

 >>>>> equal:  true

on Mac OSX with node v0.12.7, canvas 1.2.7 and the trunk version of imagediff.

Can you try rerunning with trunk + the above image to cross check?

[gpstmp]

Thanks for quick response. Yes, trunk version works as expected both with your image and mine. So, what is the problem? I see that trunk uses "canvas": "~1.2.7".

[cburgmer]

I actually just pushed the version bump. You can see all the changes since 1.0.8 here:v1.0.8...master

[trajan-p]

I have the same issue. When reverting to imagediff v.1.0.6 it works fine though.

[chocochik92]

Still getting this issue as well, fixed it with "imagediff": "1.0.6" and "canvas": "1.2.7"

[cesutherland]

@cburgmer think it's safe to bump to 1.0.9 with canvas 1.2.7 to resolve this?

[Mange]

I'm also wondering this.