DPI Changed

[rigsy88]

Hi there,

I have been using the exif tool for a while, and it is working well for me.

I did have an issue where one of my customers informed me that the DPI on their images had changed after I had ran it through the exif tool. Their images went from 300dpi to 96dpi.

Please excuse my ignorance, but is this normal behaviour? Is it possible to keep the DPI but remove all other data?

I am currently using the below command:

Code Select Expand

exiftool -overwrite_original -all= FILE

Thank you

[Joanna Carter]

Try putting

exiftool -overwrite_original -all= --jfif:Xresolution --jfif:Yresolution FILE

[StarGeek]

If you remove all metadata with -All=, then of course the resolution tags are going to be removed.

There are multiple places the resolution can be held, so try this command to see where the data is
exiftool -G1 -s -a -*Resolution file.jpg

You might try this command to make sure that the resolution tags are preserved.
exiftool -All= -TagsFromFile @ -Photoshop:all -JFIF:*Resolution* -EXIF:*Resolution* file.jpg

[Phil Harvey]

Try putting

exiftool -overwrite_original -all= --jfif:Xresolution --jfif:Yresolution FILE

You can't exclude individual tags from a mass delete.  Instead, assuming the resolutions are stored in JFIF, you would do this:

exiftool -overwrite_original -all= --jfjf:all FILE

since JFIF doesn't store much else other than the resolutions.

But StarGeek's idea will handle the more general case.

- Phil

[StarGeek]

Phil, am I correct in assuming that the Photoshop resolution tags can't be created if the Photoshop block doesn't already exist?

[Phil Harvey]

Correct.

[StarGeek]

Cool.  I faintly remembered something along those lines and that's why I included the -Photoshop:all in my command in case the Photoshop resolution tags were the important ones.

[rigsy88]

Thank you all for the replies. I will give it a go today.

[Joanna Carter]

Try putting

exiftool -overwrite_original -all= --jfif:Xresolution --jfif:Yresolution FILE

You can't exclude individual tags from a mass delete.  Instead, assuming the resolutions are stored in JFIF, you would do this:

exiftool -overwrite_original -all= --jfjf:all FILE

since JFIF doesn't store much else other than the resolutions.

Thanks Phil. It was a case of a little knowledge being a dangerous thing 

[StarGeek]

It's a mistake I've made before and had to be corrected about it on a StackExchange answer I posted.