Can anyone help. I have a few shortcuts that allow me to resize images. If I use a JPEG it works fine, but if I use a RAW file nothing happed, ie it doesn't offer me the share sheet, grrrrrr. Any thoughts?
To understand why you can't do this, it's helpful to understand how RAW works.
A RAW doesn't actually contain colored pixels, it's a single channel ("gray scale") image representing alternating red blue and green pixels called a
Bayer pattern. To actually get the "actual" pixels, you have to extrapolate from each of the pixels neighbors using a complex algorithm called
de-bayering.
To “down-sample” a RAW image without first de-bayering, the only solution is to down-sample by a integer factor in each dimension by deleting red/green/blue triplets. This means the image size can shrink only by factors of 4,9, 16 etc. Some cameras can produce directly raw files in different sizes, e.g. from Canon, and additionally there are RAW formats which compress their data (e.g. Canon M- and S-RAW which dump half or a three quarters of the sensors pixels).
Apple does not offer such sensor data dumping/down sampling in their image workflows AFAIK. What for? You dump part of the RAW anyway, so why not choose a scaled, lossless, compressed format with high color depth as output for your shortcut?
EDIT: just realized that I might misunderstand your question - do you want to resize a RAW and save it again as RAW, or can’t you resize and convert the DNGs you take on your iPhone to e.g. JPEG? Which version of iOS/iPadOS?
