Legacy ImageMagick Discussions Archive

I tried it. It doesn't seem to work.

I was thinking:

So it looks to me that if I want to force #XXYY to convert to #XX (regardless of YY), I should first modify it to #XXXX.
Do you agree?

Thanks a ton for your assistance!

16-bit=>8-bit(#9ABC) = #99, not #9A

I give up. How do you get #99 from the top bits of #9ABC?

Is there documentation of the rules for converting from 16 to 8 bit?

The version output was from "convert -version", but Magick::Quantum is 1 (byte) and MaxRGB is 255, so I think you are right that my command line utilities are 16-bit and my library is 8.

Can I use convert to write only the upper (or lower) 8 bits of a 16-bit grayscale TIF? That is, will the following work? convert original.tif -evaluate and 255 -depth 8 lower.png convert original.tif -evaluate RightShift 8 -evaluate and 255 -depth 8 upper.png I don't want any normalization to occur ...

I believe my problem is that the version of the Magick++ library I am using is 8-bit, and therefore the 16-bit image being read is converted to 8-bit when I call read(). Does this sound like a reasonable conclusion?

6.6.9-7 is dated Aug 17, 2012. That may be "old", but "very old" is a stretch.

No. When I run the command it generates a proper 16-bit JP2 file!

Obviously I am relatively new to Magick++. I read in a 16-bit TIF file, but its depth prints as 8, and the resultant JPEG2000 file is also only 8 bpp. Can you tell me what I'm doing wrong? Thank you. Version: ImageMagick 6.6.9-7 2012-08-17 Q16 $ identify fullres.tif fullres.tif TIFF 2560x3328 ...

I have a 16-bit image file and want to create two images/files from it:

• - the low 8 bits only
  - the high 8 bits only

How can I do this?