[Image] Add support for PPM images.

[aturetsk]

Summary:
Add support for PPM images as input for models.

Documentation:
N/A

Test Plan:
Added an ImageTest unit test.

[aturetsk]

@yinghai, @zrphercule, attempt #2.
I've moved cat.ppm from "imagenet" into a separate directory, so it should not interfere with CI scripts.

[facebook-github-bot]

@zrphercule has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[zrphercule]

LGTM, thanks!

[facebook-github-bot]

@zrphercule merged this pull request in fceb6a1.

[zrphercule]

@aturetsk Unfortunately this breaks Glow's CI once again: https://app.circleci.com/pipelines/github/pytorch/glow/13053/workflows/7b93ef9f-150a-410c-a7ac-3a12954934d0/jobs/95511
Same bug.

We will revert this pr again and wait for your fix...

[aturetsk]

Hi @zrphercule,
I don't think the problem is in my PR. Something wrong seems to happen after the changes were imported to Phabricator.
cat_285.ppm is empty in the commit which has been merged:
fceb6a1#diff-05eb6bbff5ad4fbd284f10b33eb61a074cb0f2dbb0ec076427f09c61764d1cd6
However it's not empty in my PR:
https://github.com/pytorch/glow/pull/5559/files#diff-05eb6bbff5ad4fbd284f10b33eb61a074cb0f2dbb0ec076427f09c61764d1cd6

[zrphercule]

Hi @zrphercule,
I don't think the problem is in my PR. Something wrong seems to happen after the changes were imported to Phabricator.
cat_285.ppm is empty in the commit which has been merged:
fceb6a1#diff-05eb6bbff5ad4fbd284f10b33eb61a074cb0f2dbb0ec076427f09c61764d1cd6
However it's not empty in my PR:
https://github.com/pytorch/glow/pull/5559/files#diff-05eb6bbff5ad4fbd284f10b33eb61a074cb0f2dbb0ec076427f09c61764d1cd6

Agree, this is very weird. I will land the revert, and could you please submit this diff once again? I would like to check why it is not imported to phabricator. Thanks!

[facebook-github-bot]

This pull request has been reverted by 7f83c03.