[benchmark] Histogram as archetype of pixel iteration and access

From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2019-06-21 21:57:09

Hi,

In our benchmarking prototype, I've added [1] new benchmark of various
pixel iteration and access methods for a contiguous images composed
of homogeneous pixels with single 8-bit integer channel (grayscale).

The implementation is available in histogram_gray8.cpp [2] and
currently it is only Celero-based and Google-based is coming soon.
There is also CSV file [3] (viewable on GitHub as a nice table)
with results based on MSVC 19.21 (VS2019).

Apart from the purpose of benchmarking, the histogram_gray8.cpp
provides a catalogue of available pixel iteration and access techniques
in a single place, easy to compare.
I think this particular aspect may be useful for our GSoC students.

[1] https://github.com/boost-gil/benchmark-prototype/commit/7eb74b84a58012452287b49f67e12cf4da9f82c0
[2] https://github.com/boost-gil/benchmark-prototype/blob/benchmark/benchmark/celero/histogram_gray8.cpp
[3] https://github.com/boost-gil/benchmark-prototype/blob/benchmark/benchmark/celero/histogram_gray8_msvc1421.csv

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net