Fwd: install ImageMagick for MacOsx

hello:

I try to install the ImageMagick for MacOsx as this
http://www.imagemagick.org/script/binary-releases.php#macosx

After install i try to convert the jpeg image,it worked well
But when i use convet to transform a tiff image to jpeg,it can't
work.Theerror massage is:
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convert: Not a TIFF file, bad version number 10752 (0x2a00).
`/Volumes/DC_RAID_Set_1/IRMphoto/37.tif'.
convert: missing an image filename
`/Volumes/DC_RAID_Set_1/IRMphoto/sdfsf.jpg'.
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Then i installed libtiff ,but it also can't work with tiff image.
why?

thank you very much

Zhang