new trouble with "convert ... histogram: ..."

firewood · Post by **firewood** » 2006-12-19T17:03:29-07:00

I have frequently and successfully used the command:
convert image_file.gif histogram:text_file.txt

Recently, however, using ImageMagick 6.3.0, I've been getting a useless list of almost all black and white pixels. The image I am using has a lot of color. It is definitely not the correct histogram.

Has anyone reported problems with the histogram option on that version?

This is all being done on my webhost's servers. I recently changed servers (same webhost), and the version of IM was not the same on the new server, so I am a bit in the dark about whether this is an IM problem or if my webhost has IM configured wrong.

Any suggestions will be greatly appreciated.

Post by **anthony** » 2006-12-19T18:22:59-07:00

There was I believe a bug, which was fixed. get the next version of IM

firewood · Post by **firewood** » 2006-12-19T19:21:21-07:00

Anthony,
Thanks for the info. That is what I suspected.
By the way, thanks for your terrific tutorials on IM. I have found them to be extremely informative and helpful.
Tim

Post by **anthony** » 2006-12-19T19:33:36-07:00

Why else would you be using histogram output.

Few peopel used it until I added it to IM Examples.

This is what IM examples is all about, if you come across something interesting please let me know about it so others can benifit.

firewood · Post by **firewood** » 2006-12-20T13:28:52-07:00

Well, I took your advice, Anthony, and requested my webhost to upgrade IM to the next version. They refused!!

They use a software set from Red Hat that has to be tested for security and potential conflicts with other software. When they "upgraded" to the most recent version of Red Hat, it included the histogram bug, and now they won't correct it, until RH sends them a new upgrade. That could take months.

So I have to install IM myself on my local account. I did so (configure, make, make install) and tried to run the same command as before with the following results:

./IM/bin/convert img_file.gif histogram:histogram.txt
convert: NoDecodeDelegateForThisImageFormat `img_file.gif'.
convert: MissingAnImageFilename `histogram:histogram.txt'.

Why would a standard install not be able to read a gif format? I gather I have a dependency problem here, but gif is so common, that I can't believe that the standard set of IM files wouldn't include the appropriate delegate.

I looked at the config.log, and it was Greek to me. Any advice?

Post by **anthony** » 2006-12-20T16:41:57-07:00

RH never does updates, unless it is a security problem!

However there has been a disscussion on the forums about installing your own version of ImageMagick

just watch the LD_LIBRARY_PATH, to make sure it gets the right ones.

No guranttees.