PNG Resolution

[Chris S]

Any chance PNG resolution could be reported with -XResolution and -YResolution like most other common image formats, or do we just use -MacOS:MDItemResolutionHeightDPI and -MacOS:MDItemResolutionWidthDPI instead for PNGs?

[Phil Harvey]

PNG uses PixelsPerUnitX and PixelsPerUnitY, with the units usually being metres, but this information is optional and often doesn't exist in a file.  If it is missing, the default is 2834 pixels/metre, which is about 72 dpi.

- Phil

[Chris S]

Thanks! I'll just use the tags from MacOS then as those appear to give me what I'm looking for.