Compare images between them in Java?

[pboix]

I am trying to setup a project which can take a full screenshot of a webpage, and then compare it to see if there are any differences (basically, implementing a visual testing tool). I am trying to compare an image with another one by simply creating a dumpPage, and then trying to compare it. Is there a trivial way to solve that without having any specs file defined or whatsoever?

[Ivan Shubin]

Hi, 

I am actually right now working on something similar in here https://github.com/galenframework/galen-sample-tests/blob/master/tests/init.js#L195

It already works but I would like to refactor that function a bit so that it is more flexible. Also I will have to write docs for it. It should be ready this week.

It works like this:

1) You give it a spec file that you already have. 

2) It parses the spec file and throws away everything except page objects.

3) Then it looks into specified storage if there are any sample images

4) The first time there are of course no images, so it will throw an error

5) Then it makes a page dump and copies all the images into that storage in <iteration + 1> folder

6) Next time you run this test it will pick up the images from the storage and will compare it with sample images from previous run

I am not sure what you are looking for, but if you don't like this idea you can also just look at Rainbow4J from galen-rainbow4j library and use it for your own solution

Kind regards,

Ivan

[pau....@gmail.com]

I read your JS test and I finally re-implemented my own solution using Rainbow4J. This is exactly what I needed.

Thanks a lot for the tips. Great tool!

Cheers!

[Ivan Shubin]

Cool! by the way I have implemented the stuff that I was talking about in previous message. You can find it here https://github.com/galenframework/galen-bootstrap/blob/master/imageDiff-example.test.js

Though there is no documentation yet

[Purusothaman Ramanujam]

Hi Ivan,

I could not find that feature you have mentioned for image diff. Can you please let me know if it's in any new location?

I am trying to do layout testing without creating any spec file. Just image based comparison on different browsers.

[Ivan Shubin]

I don't understand what you want. In Galen you have to use a spec file as you have to somehow declare all the elements on the page. If you don't care about that and just want to compare complete screenshot only, then you could just generate a spec file dynamically and insert something like:

= Image validation =
    screen:
        image file imgs/sample-01.png

[Devendra Shrivastava]

Hi Ivan, I tried above but it gives NullPointerException.

[Devendra Shrivastava]

I downloaded the latest galen now it is working.