I create images from blender, and they lack Exif metadata, which I add using the bash command exiv2. (Because the software these images are passed to will use the metadata.)
For example, I can set the Image Width to 960 using exiv2 -M"set Exif.Image.ImageWidth 960" image.jpg and then read it out using exiv2 -g Exif.Image.ImageWidth -Pv image.jpg.
For a quick summary, I can do exiv2 image.jpg to get a list of set Exif metadata. This includes
$ exiv2 image.jpg
File name : image.jpg
File size : 32975 Bytes
MIME type : image/jpeg
Image size : 960 x 540
How can I use this Image size to set Exif.Image.ImageWidth and Exif.Image.ImageLength in bash?
The standard Exif tags don't list ImageSize.
As ghoti suggested, parsing the output works:
exiv2 image.jpg | grep "Image size" | sed -n "s/^.*Image size\s*:\s\([0-9]*\)\sx\s\([0-9]*\).*$/\1/p"
gives the width, and
exiv2 lowerCircle_0100.jpg | grep "Image size" | sed -n "s/^.*Image size\s*:\s\([0-9]*\)\sx\s\([0-9]*\).*$/\2/p"
the height.
I'm still hoping for a cleaner answer though.
Explanation of the sed command:
sed -n "s/^.*Image size\s*:\s\([0-9].*\)\sx\s\([0-9]*\).*$/\1/p"
-n suppress printing
"s/ substitute match
^.* everything from the start
Image size until "Image size" is encountered
\s*:\s whitespace, colon, a single space
([0-9]*\) any number of digits. store that in \1
\sx\s space x space
([0-9]*\) another group of digits. store that in \2
.*$ everything until the end of line
/\1 substitute all that with the first group
/p" and print the substituted result