IMAGE J - Loss of quality when "save as"

I almost hope this is a nooby issue, i searched by myself… and i’m so deseperate.
I’m working on images 4592x3064 (with resolution of 180 px/inch).

After “save as” (what ever jpg, tif, bmp…), the resolution become 72px/inch for 4592x3064 px…(looking on photoshop)
For details values of px changing after “save as”, by a sort of “flattening” of contrast

Does somebody have a great idea ?


I think this answer (second answer) from the ImageJ mailing list from @schmid should give you an answer:

Please save the file lossless as *.tif and not in a lossy format.