best file type for resizing 8/16-bit graphics

[second.exodous]

I'm trying to take a picture from a SNES game to upscale and use elements of it like take the chat window borders and use them on my desktop/videos.

So I put SNES9x to 1x size, take a picture of the screen, crop out the window boarders and the screen itself looks really good, I can zoom in all the way and the pixels are sharp. I scale it up to where the height is 720(for a 720p display) and it still looks good, 1 pixel turns into multiple pixels but still staying sharp, what I want. I tired exporting it as a .png, .bmp, .jpeg, and when I import it to any other program and stretch it it gets all fuzzy.

Is there a way to save it that when stretched with keeping it's aspect ratio the pixels will stay sharp?

Thanx,
Stan

[Blighty]

(09-09-2018, 09:11 PM)second.exodous Wrote: when I import it to any other program and stretch it it gets all fuzzy.

I am trying to figure out what the initial image size in pixels is; and what the final image size in pixels is. But your description doesn't provide this info.

For example, initial image size is 640x480 pixels.
Final image size is 1920x1080 pixels.

[Ofnuts]

Maybe a few example images (see this howto if necessary).