OSX builds not using IM's built in tiff + jpeg libs?

[Greg]

I noticed that under OSX, a default build of IM won't include TIFF or JPEG support because 'configure' doesn't find tiff or jpeg libraries. (Apparently OSX doesn't come with them).

I understand installing MacPorts and using that to install the external tiff and jpeg libs will solve the problem, and am going that route, but I guess I'm curious:

Doesn't IM have its own TIFF and JPEG readers (coders/tiff.c and coders/jpeg.c),
and if so, why doesn't 'configure' fail over to using them?

I'm thinking maybe these built-in files are old and shouldn't be used, but since they're part of the distro, it has me wondering..

[magick]

ImageMagick depends on external delegate libraries for certain image format support (e.g. JPEG). Not only must the library be present on your system but also the development headers (e.g. jpeg.h). Once the delegate library is installed, run the ImageMagick configure command line script and it will tell you if it can validate the delegate library. If so, install ImageMagick and it will then be able to read / write the image format (.e.g. convert image.gif image.jpg).

[Greg]

OK.. I see.

It seemed like "coders/tiff.c" and "coders/jpeg.c" were maybe self-contained replacements for the external libs; for instance there were a couple of large hashes in jpeg.c that made it look like it might be full-on support for the image format.

But on closer inspection, apparently these files are wrappers around the external libs, and not actual implementations of the image format themselves.

Thanks for the quick reply!