http://www.libpng.org/pub/png/libpng.html

Fix distortion figure in calib3d. Positive radial distortion corresponds to pincushion distortion and negative to barrel distortion. Add another figure that illustrates the influence of k1 in the distortion effect.

"as opposed to" is a phrase of opposed meaning distinguished from or in contrast with. e.g., "an approach that is theoretical as opposed to practical"
synonyms: in contrast with, as against, as contrasted with, rather than, instead of, as an alternative to
example: "we use only steam, as opposed to chemical products, to clean our house"

Update depth map for python-opencv

- https://python.readthedocs.io/en/stable/whatsnew/3.4.html
- The `sysconfig` key `SO` is deprecated, it has been replaced by `EXT_SUFFIX`

* Updated ICV packages and IPP integration

* core(test): minMaxIdx IPP regression test

* core(ipp): workaround minMaxIdx problem

* core(ipp): workaround meanStdDev() CV_32FC3 buffer overrun

* Returned semicolon after CV_INSTRUMENT_REGION_IPP()