Add prompt and settings in PNG's metadata (XMP)

[Oros42]

When we create new image, it's useful to store settings data.
That why an yaml is created.
But it's a bit boring to have so many files. And not practical to store / share / show in gallery...

That why come to me the idea of storing this in PNG's metadata!
https://en.wikipedia.org/wiki/Extensible_Metadata_Platform

Have write a lite POC who use pyexiv2.
Setup : pip install pyexiv2

import pyexiv2
img = pyexiv2.Image('00000-50_k_lms_305139102_0.00.png')
print(img.read_xmp())
img.modify_xmp({'Xmp.xmp.CreatorTool': 'Stable Diffusion'})

infos = {
	'batch_size': '1',
	'cfg_scale': '7.5',
	'ddim_eta': '0',
	'ddim_steps': '50',
	'height': '512',
	'n_iter': '1',
	'prompt': 'A fantasy landscape, trending on artstation',
	'sampler_name': 'k_lms',
	'seed': '305139102',
	'target': 'txt2img',
	'toggles': '1;2;3;4;5',
	'width': '512'
}
img.modify_xmp({'Xmp.dc.description': infos['prompt']})

pyexiv2.registerNs('Stable Diffusion info', 'SDi') # SDi is a suggestion but can be change
for k in infos:
	img.modify_xmp({f'Xmp.SDi.{k}': infos[k]})

img.close()

What do you think ?
If you like it I will implement it in stable-diffusion ;-)