Affinity Photo - How to Keep An Image the Same Size after Editing

[ktorres08]

I've noticed that Affinity Photo has a tendency to change an image's format and size after I've imported it. Let's say that I'm working on a PNG file sprite for a game. When I bring it into Affinity, it changes the format to .afphoto and the only way to save it back to PNG is to export it in PNG format, therefore changing the file size. How do I keep existing images the EXACT SAME format and size?

Thank you!

[walt.farrell]

You would normally use File > Export to save it as a PNG file, though File > Save will work (and overwrite the original) if you start with a PNG file and haven't added any layers.

But you can never guarantee, with any program, that the file size won't change when you save a PNG. That is entirely up to the method of file optimization chosen by the program, and the file content (including colors used). From what I've read, Affinity Photo's optimization for file size is not as strong as some other programs, so you might need to use an additional png optimization program to get the file size smaller, if you really need to.

[GarryP]

When you Open a PNG in Photo the document type is still PNG.
As mentioned by Walt above, if you Save that document it will be saved (and overwritten) as a PNG.
However, if you Save As then it will, by default, set the document type as AFPHOTO.
I don’t think there’s a way of overriding either of the above functionalities.
However, every document has a default Slice in the Export Persona which you can set to whichever file type you want (defaulted to PNG for a PNG file) and whatever settings you want.
This way you can edit your image as a Photo document (AFPHOTO), keeping all of your layers etc, and very quickly export via the Export Persona in a way that is consistent.