While the list column choices include width x height, there is no choice to display dpi for images in list view. I know the dpi is displayed as part of the Size in the Inspector, but that’s only for a single image record. I’ve worked around it somewhat using a script to copy the dpi to a custom metadata “resolution”, but it’s an extra step.
My use case: I have huge numbers of images of town record book pages, probate files, newspaper pages, etc., downloaded from various providers at 72 dpi. I often need to merge multiple images into a pdf, which results in very large (e..g., 30"x45"), and varying size, pages in the pdf if merged at 72 dpi. Converting the images to 300 dpi before merging them usually brings them down to something close to 8.5"x11". I want to be able to see the dpi in the list view so I know immediately which images have been converted to 300 dpi and which still need to be worked on.
Perhaps it would be easier to unconditionally “convert” every incoming image to 300dpi. There’s no conversion involved, actually, it’s just a metadata field that is set to another value. And afaict, DT is not able to do that anyway, so you have to use another program.
macOS comes with sips that allows to change image parameters on the command line, and it can handle and arbitrary number of files:
I’d have that set the DPI to whatever value I want before importing into DT.
Just to clarify, you’re not doing anything more than switching the listed dpi. You aren’t resampling the image.
Your image has a specific number of pixels, say 1000 x 1000.
- At 72dpi, the relative size is (1000/72) x (1000/72) or 13.89 inches.
- At 300dpi, the relative size (1000/300) x (1000/300) or 3.33 inches.
Yes, the larger dimensions will govern the page size of a converted PDF document but it’s something you should be aware of.
And both images are the exact same file size.
1 Like
