X Resolution, Y Resolution how to set so photoshop will recognize it

[ubacher]

I usually have my images at 300 ppi resolution.
Using the filter facility of IM I found that I had many images with different resolution.
Now the problem: How (what meta data tag) to change it so photoshop will recognize it.

Exiftool output shows (screenshot) an IFD0 X Resolution and Y Resolution but I do not know which metadata tag these are
copied into.  And I wonder if IM will be able to write these tags then back.
Obviously I could use exiftool to make the change - but I look for an easier way.

(I have tried the resolutions under Exif/Main, XMP/Photoshop, XMP/tiff but changing these seems is not recognized by photoshop.)



[attachment deleted by admin]

[sinus]

Easy.

Create a file in Photoshop.
Save maybe with a special dpi, like 277 for better spotting.

Scan it in IM5.
Use the browser of the metadata. There you will see a point "Photoshop Resolution" and there are the fields
X Resolution
Y ...
The variables are {File.MD.Photoshop::Resolution\2\DisplayedUnitsX\0} ....

Try to change this resolution, write back, open in PS, check the Bildgrösse - dpi, voila.

[ubacher]

I have played with this and learned the following:

[IFD0] X Resolution in exiftool output maps to exif:X Resolution.

[JFIF] Resolution does not seem to be used.
[IFD1] Resolution is still a mystery.

IM keeps EXIF and Tiff resolutions synchronized. Where Tiff seems to be the master.


Photoshop uses the photoshop setting if it exists.
Else it uses the Tiff settings
Else it uses the Exif setting.

When I set the resolution inside PS and then write out the file IM shows the value under Photoshop, EXIF, and tiff.

If I change the value of the photoshop resolution within IM it only changes it. It does not synchronize the other 2. Should it?

[sinus]

So you have changed your mind? First you wanted only know this here:

How (what meta data tag) to change it so photoshop will recognize it.

and for this I gave you an answer, what at least works here.

What you ask now, I personally do not know.
But FOR ME it seems logically, that for example the exif-resolution should not be changed, when you change the dpi inside PS.
Because exif means the original dpi of the image (what is anyway not that important).

So maybe can somebody else help.