Resolution issue -- EXIF X and Y changed, XMP not rewritten

Started by L_Carver, February 05, 2017, 12:24:42 AM

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L_Carver

Using the command exiftool  foo.jpg -xresolution=128  -v2returnsJPEG APP1 (4654 bytes):
  Rewriting XMP
    [XMP rewritten with no changes]

while afterwards
exiftool -ALL:ALL foo.jpg"-v2 | grep -i ResolutionreturnsResolution Unit                 : None
X Resolution                    : 128
Y Resolution                    : 128
X Resolution                    : 128
Y Resolution                    : 128
Resolution Unit                 : Unknown (0)
Resolution Unit                 : Inch
X Resolution                    : 300
Y Resolution                    : 300

And using ImageMagick and exiv2, the same unchanged XMP Resolutions are returned. This is in a single console tab, i.e., one main BASH shell (ignoring subshells spawned and unterminated from running scripts).

And in version 0.84 x32 of XnViewMP, the resolution is now 128 in the general Properties tab and XMP tab (Browser mode) . The "physical" dimensions factor to what they would be if a printer could print at precisely 128dpi.

So why is Exiftool hesitating, or deeming it unnecessary, to change the XMP Resolutions from 300 to 128, if this is what's happening?

Carver
____________
Screen name comes from a story my ex-wife and I worked on for several years and never got past the first chapter. Llewellyn Carver was a Welsh drow elf living somewhere in New York state. Message me if you're curious to find out more.

StarGeek

What's the result of
exiftool -*resolution -G1 -a -s FILE

Off hand, I'm guessing that XResolution and YResolution are in someplace incorrect, like XMP-exif instead of XMP-tiff.
* Did you read FAQ #3 and use the command listed there?
* Please use the Code button for exiftool code/output.
 
* Please include your OS, Exiftool version, and type of file you're processing (MP4, JPG, etc).