>> how many blades of grass must be drawn manually you are looking at it the wrong way. The manual labor is not what defines derivative work. Your changes or

>> how many blades of grass must be drawn manually you are looking at it the wrong way. The manual labor is not what defines derivative work. Your changes or additions to the public domain image must be original and result from a modicum of creative effort on your part. Simple, minor changes might not meet the threshold of originality required for copyright protection. The modifications or additions to the image should not be trivial. You should aim to add new expression, meaning, or message to the original work. This might include significant artistic modifications, adding new elements, or creating a new composition that incorporates the public domain image. Your derivative work should reflect your creative choices and contributions. It’s not about the quantity of changes but the qualitative effect of those changes on the original work. And yes you are right if you see a brand using midjourney or other AI images you can also use them.