Which library provides Image::PNG

[mfasold]

I would like to use Image::Format imageFormat = Image::PNG; which is used, for example, in this project.

But the symbol cannot be found.

[franFodor]

Sorry for the late reply. That project was using wrong Image class. The color Inkplates are supposed to use ImageColor class instead. The fix is to replace the:
Image::Format imageFormat = Image::PNG;
line with:
ImageColor::Format imageFormat = ImageColor::PNG;
It has been applied to the dev branch which you could use or you could apply the fix yourself in the example.