The question is how did you do training. If in the process you 'copied' the image (e.g. from network to memory) you did require copyright. Reading with a human

The question is how did you do training. If in the process you 'copied' the image (e.g. from network to memory) you did require copyright. Reading with a human is not copying, but reading by machine is - there are several cases where that has been enforced. This is covered by reproduction rights.