Fix snapshot diff bug with resolution

[leonidmelnyk]

Problem statement

The captured test image has size with scale 2 when the reference image that is loaded from a file has size * 2 with scale 1.

Solution

Adjust the image sizes that are drawn into the resulting image based on their scales.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

---

Leonid Melnyk seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}