Re: Downscaling algorithms

From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2019-05-27 16:04:34

On Mon, 27 May 2019 at 15:07, stefan <stefan_at_[hidden]> wrote:
> On 2019-05-27 7:54 a.m., Olzhas Zhumabek wrote:
> >
> > For my GSoC project, I need a downscaling algorithm for ORB feature
> > detection, preferably of a good quality. Is there any in GIL already
> > (quick glance didn't reveal anything)? If not, I would like to
> > implement Lanczos resampling
> > <https://en.wikipedia.org/wiki/Lanczos_resampling>, which from what I
> > read is a good algorithm for scaling down. ORB also needs only
> > multiples of two downscaling, so I don't have any exquisite requirements.
> >
> > There is a public domain implementation, imageresampler
> > <https://github.com/rwohleb/imageresampler>. I was thinking about
> > incorporating it into GIL. I believe it shouldn't take too much time.
> >
> > What do you think?
>
> That's a good idea. And as this is a well-defined, self-contained task,

It is a good idea indeed.

> I would suggest to do that work on a feature branch of its own, and as
> soon as it's complete (including tests and perhaps even benchmarks),
> submit a PR to the `develop` branch of the master repo.

I agree.

Olzhas, please get familiar with and try to follow the guidelines from:
https://github.com/boostorg/gil/blob/develop/CONTRIBUTING.md

> Please also discuss with Miral & Mateusz as there are many more IP
> algorithms that will be added over the next couple of months,

Yes, we need to synchronise.

Miral, if you see any clash with the work you've planned, please let
Olzhas/us know.

> and it would be good to share a common directory structure as well as build &
> test logic.

w.r.t. to structure, so far, we've discussed with Miral some details
about documentation.
Miral will write prose about image processing algorithms in
doc/image_processing.rst
or
doc/image_processing/algo1.rst
doc/image_processing/algo2.rst

Regarding code structure, I think we will need similar, i.e.
separate directories for headers and tests:

include/boost/gil/image_processing/
test/image_processing/

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