Legacy ImageMagick Discussions Archive

Hi there,

once again I'm not sure if I'm just too stupid to use ImageMagick or if it's a real bug... So here's the story:

I have some 48 bit TIFF files. When just loading and saving them using convert like in
the resulting out.tif looks like mere pixel noise, with the outlines of the objects depicted on the input image faintly shining through -- as if some kind of edge detection had been applied to it...

When converting to some other output format, like jpg, colors are preserved perfectly, though. (Example see )

So I guess I must be missing some command-line option required to tell ImageMagick to not do, well, some kind of magic, or there must be a bug in the TIFF writing routine.

Any ideas?

-- Torsten

P.S. I'm on a 64 bit Debian Jessie system, using ImageMagick 6.8.9-9 Q16 x86_64

Can you post one of your 48-bit Tiff images, so others can test with it?

What is your version of libtiff?

You can see versions from
or

Fred,

I was reluctant to post any of those tiffs 'cause they're really huge (not less than 150 MB), but anyway... I uploaded one to http://www.tcrass.de/files/tmp/01.tif.

Regarding the libtiff version, I haven't checked yet; I'll do as soon as I get home.

Cheers --

-- Torsten

Hi,

it seems neither

fmw42 wrote: What is your version of libtiff?

You can see versions from

Code: Select all

convert -list format

nor

fmw42 wrote:

Code: Select all

tiffinfo

would tell me which version of libtiff is installed, but according to Debian package management info I have libtiff 4.0.3-12.3.

Cheers --

-- Torsten

When I do convert -list format, I get

TIFF* TIFF rw+ Tagged Image File Format (LIBTIFF, Version 4.0.6)

I am surprised that you do not get something like this.

What do you get from
Does it list Tiff or libtiff?


Might you have a smaller 48-bit image that you could provide?

Fred,

fmw42 wrote:When I do convert -list format, I get

TIFF* TIFF rw+ Tagged Image File Format (LIBTIFF, Version 4.0.6)

I am surprised that you do not get something like this.

sorry, my fault -- I grepped the output of for 'tif', but without the option, so I missed the all-capitals TIFF lines...

So here's what my ImageMagick installation says about TIFF:

fmw42 wrote:What do you get from

Code: Select all

convert -version

So yes, it does mention tiff.

fmw42 wrote:Might you have a smaller 48-bit image that you could provide?

Unfortunately not... And obviously I can't use ImageMagick to scale/crop one of those tiffs, can I? I just cropped one down using DigiKam, but -- funny enough -- when converting the image thus cropped like in , the resulting image looks fine! So it must be something in the original TIFFs which prevents IM from handling them correctly.

Cheers --

-- Torsten

I will download the current example later today and check it out.

Fred,

fmw42 wrote:I will download the current example later today and check it out.

great! Thank you so much!

Cheers --

-- Torsten

It converts fine for me on IM 6.9.3.5 Q16 Mac OSX using libtif 4.0.6. So I would suggest either upgrading IM or libtiff or both.

Hi,

usually I avoid bypassing the distribution's package management system when installing software, but I gave libtiff (4.0.6-1) from the current Debian Testing release a try -- and it worked! No more pixel noise! So in the case of ImageMagick the verdict is "not guilty"

I'll file a bug report with Debian, asking them to update the libtiff version distributed in the Stable branch.

Thanks again for having a look at this issue --

-- Torsten

Just realized that corresponding bug reports have already been filed: https://bugs.debian.org/cgi-bin/bugrepo ... bug=787966 and https://bugs.debian.org/cgi-bin/bugrepo ... bug=786910...

Also Debian bug 818360 which suggests the same workaround for Debian Jessie: installing the 4.0.6 version from Stretch: