I have an image with pixel dimensions of 677 x 847 and a DPI of 600, which Image Size reports as 28.66mm x 35.86mm which seems correct.
But I want to print at 8x10 inches - so what I'd normally do then is change the image size to the desired physical size with resampling turned OFF, and leave the printer to deal with resampling, as it does that anyway.
When I do this in Pixelmator 3.7, it works as expected - the image looks identical on-screen, the pixel dimensions remain the same at 677 x 847, but the size changes to 8x10 inches and DPI changes to 84.6, and the image prints at the desired size.
When I do this in Pixelmator Pro 1.0.8, weird stuff happens - the image looks slightly pixelated, but the app reports that the pixel dimensions have actually increased to 4800 x 6005, and DPI has stayed the same at 600. This is with resampling turned OFF.
This looks like a bug to me, as the image is clearly being resampled when it shouldn't, and the resolution appears to decrease while the pixel dimensions increase?
Is something not working like it should? Let us know.