Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
You found a bug in the PNG coder. The conversion seems to work fine for other formats such as MIFF, GIF, PBM, etc. We will apply a patch to ImageMagick 6.2.7 Beta. The only workaround we can think of is to compensate for the inversion with the -negate option.
The TIFF conversion worked fine for us with ImageMagick 6.2.6-8 the current release. The PNG coder is fixed in ImageMagick 6.2.7 Beta. Thanks for bringing this problem to our attention.
Understood. Our conclusion is that ImageMagick 6.2.2 and below and ImageMagick 6.2.6-7 can read/write your monochrome TIFF image just fine. 6.2.6-7 has a problem writing it to PNG. ImageMagick 6.2.7 Beta can read/write monochrome TIFF and PNG without any problems.