Precompute histogram to speed up try_all_threshold

[sciunto]

Description

We recently merged a PR to use pre-computed histograms in threshold functions. This feature can be used internally in try_all_threshold. I noticed a 2x improvement on the hubble image.

Checklist

• Docstrings for all functions
• Gallery example in ./doc/examples (new features only)
• Benchmark in ./benchmarks, if your changes aren't covered by an
  existing benchmark
• Unit tests
• Clean style in the spirit of PEP8

For reviewers

• Check that the PR title is short, concise, and will make sense 1 year
  later.
• Check that new functions are imported in corresponding __init__.py.
• Check that new features, API changes, and deprecations are mentioned in
  doc/release/release_dev.rst.

[jni]

@sciunto you got us to go 2x faster to a test failure! 😂

____________________ TestSimpleImage.test_try_all_threshold ____________________

self = <skimage.filters.tests.test_thresholding.TestSimpleImage object at 0x7fd0a6a16cd0>

    def test_try_all_threshold(self):
        fig, ax = try_all_threshold(self.image)
        all_texts = [axis.texts for axis in ax if axis.texts != []]
        text_content = [text.get_text() for x in all_texts for text in x]
>       assert 'RuntimeError' in text_content
E       AssertionError: assert 'RuntimeError' in ['TypeError', 'TypeError', 'TypeError', 'TypeError', 'TypeError', 'TypeError', ...]

scikit-image/skimage/filters/tests/test_thresholding.py:48: AssertionError

Not all functions take a histogram, so probably this needs to check, either using the inspect module or in a try/except.

[sciunto]

Why this didn't happen during my test? 🤔

[grlee77]

LGTM. The build failure looks like an unrelated time-out on Azure.

[mkcor]

Nice! It looks like this contribution almost fell in the cracks...