Export tif image with 300 ppi

[Roberto Pinto]

When I export a 300 ppi image to tif, Gimp generates a file with 72ppi only and not 300 ppi as desired. But when I export the same source image do jpg, the target jpg image is 300 ppi.
Gimp 2.10
Ubuntu 24.10
Print size: 300ppi
How can I solve this problem and export a target tif file with 300ppi?

[Ofnuts]

72PPI is a default value, so probably your 72PPI is just  a missing print definition. However: if the file command doesn't show any print definition in an exported TIFF,

• re-importing the file in Gimp shows the correct print definition (I tried with a wacky value, to ensure it wasn't some default value being restored), so the print definition is somewhere in the file.
  
• The print definition is indicative, the important thing is the size in pixels. The print definiiton can be ignore/overriden at print time.
  

[Roberto Pinto]

(12-23-2024, 09:19 AM)Ofnuts Wrote: 72PPI is a default value, so probably your 72PPI is just  a missing print definition. However: if the file command doesn't show any print definition in an exported TIFF,

• re-importing the file in Gimp shows the correct print definition (I tried with a wacky value, to ensure it wasn't some default value being restored), so the print definition is somewhere in the file.
  
• The print definition is indicative, the important thing is the size in pixels. The print definiiton can be ignore/overriden at print time.
  

Unfortunately, the print size is correct, i.e., 300ppi but the exported tif image is still 72ppi.

[Tas_mania]

I looked at Preferences > Image Import and Export.

   

I would change some of the defaults here like adding floating point precision. It looks like something is rounded-down and losing definition.

[rich2005]

(12-23-2024, 11:08 PM)Roberto Pinto Wrote: .........snip......
Unfortunately, the print size is correct, i.e., 300ppi but the exported tif image is still 72ppi.

kubuntu 24.04 / Gimp 2.10.38 (PPA)
I just can not reproduce that. Open an image, jpeg or maybe RAW change resolution to 300 ppi and an exported tiff keeps the dpi. I do turn off layers.. most of the other tick boxes but keep exif data.
The question might be, what are you using for determining the exported tiff image ppi value ?
As an example: Using imagemagick and a 16 bit exported file from a raw image.
rich@rich-nova2:~/temp$ identify -verbose 1.tiff
Image:
Filename: 1.tiff
Permissions: rw-rw-r--
Format: TIFF (Tagged Image File Format)
Mime type: image/tiff
Class: DirectClass
Geometry: 3178x4770+0+0
Resolution: 300x300
Print size: 10.5933x15.9
Units: PixelsPerInch
Colorspace: sRGB
Type: TrueColor
Endianness: LSB
Depth: 16-bit
.........................