density change not showing in photoshop (8bim profile)

[pascal]

Hi

We use imagemagick to change the density of TIFF images. when opening those images with photoshop, the old value is still displayed.
This is behaviour as described in the documentation, i know. (identify also shows the wrong values btw.)

What can i do about it? I need photoshop to show proper values afterwards.
With a bit of try and error (i'm not really an expert on this topic) i found that it's the "8bim" profile which is read by photoshop to store the density information?

When i remove the 8bim profile, open in PS and save, then the 8bim profile gets re-created but this time the density values are ok.

Is removing the 8bim profile enough? What information do i loose by deleting the "8bim" profile (i keep the icc/iptc profiles)? What does Photoshop store in this profile?

thanks for hints, clarification and comments!

Pascal

[anthony]

Photoshop stores and uses density (resolution) settings in it own profile! It only uses the correctly defined density location when its own profile has been deleted (-strip).

It is a real pain in this regard!

[pascal]

hi anthony

thanks for your reply!


i think -strip is not an option since it also removes other profiles and exif and comments, right?

isn't there a more selective way to get photoshop to read the right numbers after density change?
and one thing i noticed: identify reads the same wrong numbers as photoshop. only after removing xmp and 8bim profiles both, identify and PS showed good values.

if i can not get it done in IM: is there another command line tool i could use to change density (resolution)?


thanks again!

pascal

[anthony]

Sorry no one has posted a general solution for setting photoshop resolution.

At least not yet!

[pascal]

my version (until someone comes up with a better solution....) is to remove all the profiles (8bim, itcp, xmp, ...) and keep the icc profile (i need this one later on) and then setting the density.

this works and keeps at least some of the meta info....(though i loose meta i need to keep)


so if someone has a good idea here.... let me know! thanks.

[stroker]

You can try exiftool, http://www.sno.phy.queensu.ca/~phil/exiftool/

Exiftool can read and write photoshop meta info http://www.sno.phy.queensu.ca/~phil/exi ... oshop.html

I haven't tried it, but I think this should work

Code: Select all

exiftool -g -Photoshop:XResolution=300 -Photoshop:YResolution=300 file.tif 

[anthony]

stoker thanks, I have added your suggestion to IM Examples, Basics, Density or Resolution
Photoshop and Density
If you like to add something further, or have other suggestions, please let me know, either here, PM, or Email.

Anthony Thyssen <anthony AT griffith.edu.au>