[Magick-bugs] Image header bug

[Dean S. Messing]

I seem to have tickled an interesting bug (or feature?) in IM.

I'm using:

Version: ImageMagick 6.2.5 09/21/06 Q16
Copyright: Copyright (C) 1999-2005 ImageMagick Studio LLC

I am generating greyscale images via a process that is not important
to this discussion except to say that it is a sufficiently random
process that the "improper header" (see below) came about entirely by
chance.

The image is called "out_image.gray". It is composed of 8-bit values
and is of size 1280x960.  The image generator is in a shell script
loop and the line following it is:

   convert -depth 8 -size 1280x960 out_image.gray out_image.png

I've run this script for days now w/o a problem.
Today the script  died with the following error:

   convert: Improper image header `out_image.gray'.

Evidently, by chance, the initial bytes of the image look enough like
a header that `convert' was fooled into thinking it _was_ a header,
though "improper".

I think the correct behaviour is for no header to be assumed if the
".gray" suffix is present, esp. if -size and -depth are explicitly
given.

I've saved the image and will send it to whereever you will if you
tell me a place to which to send it.

Dean


Dean S. Messing
Sr. Scientist
Display Algorithms & Visual Optimization Lab
Sharp Laboratories of America