ImageMagick: add HDRI support

[fmw42 (Fred Weinhaus)]

Please advise how to install Imagemagick with HDRI enabled. I do not see HDRI as a variant.

[ryandesign (Ryan Carsten Schmidt)]

It is currently not possible to install ImageMagick with hdri support in MacPorts.

It was necessary to remove the hdri, q8, q16 and q32 variants in r106049 because using them changes the API of the library—including changing the library's install_name—and thus makes such a library incompatible with other ports built with ImageMagick built without those variants. For example, if you installed ImageMagick with the old hdri variant, then installed a port that links with ImageMagick (such as digikam), you might receive a binary of digikam from our build server. Our build server uses default variants, so it would not have used the hdri variant. And digikam would fail to work because the non-hdri version of ImageMagick it was linked with would not be available on your system.

The only way we could re-add hdri support would be to break the libraries of the ImageMagick port out into nonconflicting subports: one for the standard Q16 libraries, one for the hdri libraries, and one each for the Q8 and Q32 libraries. The main ImageMagick port would then be for the programs like convert and mogrify and might have variants to let you choose which libraries it should use, while still allowing other ports (like digikam) to use the Q16 libraries as usual.

[fmw42 (Fred Weinhaus)]

OK. Thanks. I understand.

But, there are other ports that have numerous port variations. I hope you reconsider and do what you are suggesting for Imagemagick. For me, it would be adequate simply to have Q16 (non-hdri) and Q16 HDRI ports. When running Imagemagick to use its real/imaginary format FFT processing (FFTW-3 delegate) via commands +fft and +ift, one needs at least Q16 HDRI. With HDRI, I do not see the need for Q32 HDRI and Q8 HDRI is not adequate. Others, however, might want a Q8 (non-hdri) port.

Rational: I have a number of Imagemagick scripts that do FFT processing and many of them require real/imaginary FFT rather than magnitude/phase FFT. For example see my web site and FFT tutorial at

​http://www.fmwconcepts.com/imagemagick/index.html ​http://www.fmwconcepts.com/imagemagick/fourier_transforms/fourier.html

I personally can get around your limitation by installing all my delegates from MacPorts and install IM manually from source. But others are not so knowledgeable.

Thanks for all the work you do keeping an Imagemagick port.