Mac Ports and Octave - failure to read images

Some time ago, while looking for something totally unrelated I found a paper by Scott Acton from the IEEE on multigrid anisotropic diffusion, for processing images.

Whenever I try to use the imread() function, I have the following error message:

octave:1> T=imread('/Users/jean-francoisgobin/Desktop/Columbia 02-gray.jpg')
Assertion failed: (semaphore_info != (SemaphoreInfo *) NULL), function LockSemaphoreInfo, file magick/semaphore.c, line 531. panic: Abort trap -- stopping myself... warning: unable to open `octave-core' for writing...

I tried to install the octave-image port, but it depends on ImageMagick and libpng 1.4, where octave depends on GraphicsMagick and libpng 1.5. Deactivating libpng 1.5 and activating libpng 1.4 resulted in octave completely failing. Uninstalling and recompiling octave failed as libpng 1.5 is a dependency.

At this time, I am a bit stuck: nothing I can think of works. If you had more luck, feel free to comment or contact me.