I have a 2000x1500 image created with Photoshop CS6 Extended. When I save images in different formats for re-use in other programs, e.g. PNG, the image quality will suffer. I have nice basic gradiants and layout overlays but when I save it, the transparency will suffer a lot.
What to do? I would like to use PNG because I need to send that image to one company so they can print it (only PNG supported...).
It seems like you're noticing an RGB colour management issue.
PNGs saved from Photoshop can't have ICC Colour Profiles attached (the PNG format supports it, but PNGs with profiles are very rare).
If you'd like what's shown in the Windows photo viewer to match Photoshop, then you'll need to set up Photoshop in a way that it doesn't colour manage RGB images.
Here's how to do that:
Step 2: Open a document and go to Edit â†’ Assign Profile, then set it to Working RGB. This must be done for every single document you work on.
Please note that this step is ok as is, but there's a better way... you should set each document to "Don't Color Manage This Document".
After setting things up properly, your Photoshop document should now match Windows photo viewer.