jpeg verification sometimes fails

[etam]

Description

Golem Version: 6f4df24

OS: Linux

Branch: develop

Description of the issue:

Jpeg verification sometimes fails. Probably due to lossy compression introducing too much noise in image.

Steps To Reproduce

Run test_jpeg integration test.

Expected behavior

It should always pass.

Logs and any additional context

https://buildbot.golem.network/buildbot/#/builders/15/builds/973

Proposed Solution?

Option hard: make verification better.
Option easy: disable lossy output formats.

[shadeofblue]

@etam I'd look at option 3: see if we can increase the quality of the images to limit the impact of the lossy compression

[etam]

https://en.wikipedia.org/wiki/Lossless_JPEG ;)