Bugfix: EPS thumbnail failed

[eliempje]

EPS thumbnail failed to resize correctly due to incorrect resolution argument (should be a function of the image size and bounding box). This is fixed in this commit.

[eliempje]

Why did the Travis CI build fail? I just changed a few lines of code.

[hugovk]

This test failed:

Tests/test_file_eps.py:91: assert_image_similar(image1_scale2, image1_scale2_compare, 5) failed:
- average pixel value difference 10.8121 > epsilon 5.0000
Tests/test_file_eps.py:98: assert_image_similar(image2_scale2, image2_scale2_compare, 10) failed:
- average pixel value difference 18.9240 > epsilon 10.0000

Also, do you have a test that shows the bug fails before the fix, and passes with the fix?

[eliempje]

Do you know who to correct this?

[aclark4life]

@eliempje We need you to know how to fix it 😄

[eliempje]

I will try. I get back to you.

[karstenw]

If you have a test that checks for image sizes and change the output imagesize, it has to fail.

I have a fork where eps files work for me. Not patch quality:
https://github.com/karstenw/Pillow/blob/master/PIL/EpsImagePlugin.py

[eliempje]

Test passed this time. This commit even adds another bugfix for #302
Could you merge now?

[hugovk]

I've submitted resize and thumbnail tests to @eliempje's fork here: eliempje#2

How can #302 be tested?

[eliempje]

make an eps with binary preview in the header (you could use ghostscript for that). I have one but its copyrighted.

[eliempje]

Thanks for adding tests.

[eliempje]

Did mean ghostscript but photoshop (under windows). This will add a preview in the first few bytes.

[hugovk]

You're welcome for the tests. Unfortunately the build failed: https://travis-ci.org/python-imaging/Pillow/builds/24725294

running test_file_eps ...
Tests/test_file_eps.py:132: assert_equal(image1.size, new_size) failed:
- got (100, 76), expected (100, 100)
Tests/test_file_eps.py:133: assert_equal(image2.size, new_size) failed:
- got (360, 252), expected (100, 100)

Actually, I just spotted a bug in the test. image1 is thumbnailed a second time, instead of image2. I've sent a PR to fix it (eliempje#3), but it only accounts for the second failure, not the first.

If you want to run just that test locally, call python Tests/test_file_eps.py, or python Tests/run.py for the whole set.

I don't have Photoshop, maybe someone else can create a test image.

[hugovk]

Apologies, the reason it's failing is due to me not reading the docs properly. With the latest build, it fails like this:

Tests/test_file_eps.py:132: assert_equal(image1.size, new_size) failed:
- got (100, 76), expected (100, 100)
Tests/test_file_eps.py:133: assert_equal(image2.size, new_size) failed:
- got (100, 70), expected (100, 100)

https://travis-ci.org/hugovk/Pillow/jobs/24741008

But Image.thumbnail's docs say:

This method modifies the image to contain a thumbnail version of itself, no larger than the given size. This method calculates an appropriate thumbnail size to preserve the aspect of the image...

I'll fix the test properly and update the PR.

[hugovk]

OK, eliempje#3 passes now (https://travis-ci.org/hugovk/Pillow/builds/24742214). Sorry for the confusion!

[wiredfool]

@hugovk Thanks for picking up the slack and looking at this (and the other issues). I'm kind of snowed under right now, but I am paying enough attention to know that I'm way behind on review and merging.

[hugovk]

@wiredfool No problem! Don't worry, there's months until the next release :)

[aclark4life]

True 😄 Just under 2 months

[eliempje]

Test added. Now ready for merge

[wiredfool]

Thanks everyone.