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24bit jpg to tiff file conversion ends up as 8bit b&w

Posted: 2015-03-13T12:03:48-07:00
by graemeNPS
Hi,
we use ImageMagick to convert a wide variety of formats to various output formats.
It does a great job of that.
But, every once in awhile....
A customer is complaining that some 24bit RGB jpgs are not consistently converting to 24bit RGB tifs. Some resulting TIF files are 8bit b&w.
I am hoping for some guidance, either for the customer to fix the jpgs, or what we can do to render the tifs consistently as 24bit RGB

I have placed the customer source jpgs and our results in our ftp site:
site:ftp.northplains.com
user:publicforum
pass:543publicforum123
dir:/imagemagick/ts-10381-samplefiles/
or the zip ts-10381-samplefiles.zip at /imagemagick

Any help is much appreciated,
graeme

Re: 24bit jpg to tiff file conversion ends up as 8bit b&w

Posted: 2015-03-13T12:16:09-07:00
by snibgo
A customer is complaining that some 24bit RGB jpgs are not consistently converting to 24bit RGB tifs. Some resulting TIF files are 8bit b&w.
I suppose the input file is monochrome with less than 256 colours, so IM only needs 8 bits. Try comparing the input and output. Are they identical? If so, then what is the problem?


There are a lot of files in that zip. Can you give an input and output file, and what command made the output?

Re: 24bit jpg to tiff file conversion ends up as 8bit b&w

Posted: 2015-04-23T08:04:57-07:00
by graemeNPS
The problem is that the customer expects the conversion from RGB 24 bit to yield RGB 24 bit.
The results are not identical, in that the color space has changed, and the results are inconistent.
Imagemagick is inconsistent in doing that with this set of jpegs converted to tiff. See the converted(x) directories.

Mogrify and convert gave the same inconsistent results. The source files are the jpegs, the output files are the tiffs in the converted(x) directories. readme.txt tells how the outputs were made.

Re: 24bit jpg to tiff file conversion ends up as 8bit b&w

Posted: 2015-04-23T10:28:51-07:00
by magick
Add -type truecolor to your command line. Does that solve the problem?