Notes on photo sphere/panoramic EXIF metadata
- Google's EXIF/XMP metadata tag specification for panoramic images
- Panorama images with sky are to have a negative value for the CroppedAreaTopPixels tag. (The panoramic viewer of Facebook ignores the value altogether, though, and assumes the horizon in the middle of the picture.)
- If a camera or software normally produces panoramic images with cylindrical projection, then doing a vertical capture actually produces a transverse cylindrical image. There is no standardized value for the EXIF ProjectionType field to cover this. (One option is to reproject them to equirectangular — which, again, is not very well supported.)
- Facebook's document on what tags to set
- The Facebook web interface insists that FullPanoHeightPixels be half the size of FullPanoWidthPixels. Else you get “no new photos were uploaded”.
/ Tags: Photo.
Developers' Build Systems Choice
New statistics as for what build systems are popular and which are for the gutter. openSUSE Factory as of June 22 2013 has some 6444 packages in the OBS repository, of which 6197 contained a .spec file and thus packagable software. (The remainder are _link packages, and auxiliary packages for things like ISO generation.) Since this is a multiple-choice test, sums can add past 100%.
| Amount | In % of 6197 | How tested? | Some tools needed to run a rule | |
|---|---|---|---|---|
| Packages inspected | 6197 | |||
| autoconf without automake | 323 | 5.2% | presence of configure.ac/.in, absence of Makefile.am | sh, sed, make |
| autoconf with automake | 2320 | 37.4% | presence of Makefile.am | sh, sed, make |
| perl-like | 866 | 14.0% | Makefile.PL (ExtUtils::MakeMaker) or Build.PL (Module::Build) | perl, make |
| python-like | 669 | 10.8% | setup.py | python |
| cmake | 514 | 8.3% | CMakeLists.txt | cmake, {make or ninja or VS or nmake or wmake or ...} |
| ant | 193 | 3.1% | build.xml | java, ant |
| qmake | 190 | 3.1% | *.pro yielding a match | qmake, ...? |
| php | 184 | 3.0% | package.xml | ? |
| xmkmf | 69 | 1.1% | Imakefile | xmkmf, cpp |
| maven | 41 | 0.7% | pom.xml | java, maven, ...? |
| android | 39 | 0.6% | [Aa]ndroid.mk | ? |
| scons | 36 | 0.6% | SConstruct | scons |
| haskell | 33 | 0.5% | ghc? | |
| waf | 30 | 0.5% | python | |
| plain | 560 | 9.0% | Makefile* excluding Makefile.am | make |
| none or unknown | 706 | 11.4% | - |
Since packages to rich scripting suites often use the “in-house” installation mechanism — Perl modules almost exclusively use ExtUtils::MakeMaker, for example — it might be worth interesting looking at the tally that excludes such modules. Or in fact, perhaps I should only look at C and C++ source code, since that is what most of the enlisted build systems target. (Another time, perhaps.) It would certainly mean that autoconf prevalence would reach 60%, or maybe more.
Personal remark: If I look at Samba's wscript, I can see why WAF is unpopular. It seems more like a plain Makefile written in Python rather than the “clever” use of prior modularized code.
Posted 2013-06-21 22:06 / Tags: Autotools, Development, Software. / link