What happens to copyright when you publish an article?
The majority of publishers ask for an assignment of copyright from authors.
Assignment is where a copyright owner may transfer ownership of his or her copyright to somebody else. Most peer-reviewed journals take an assignment of copyright and grant back to the author certain rights, for example the right to use an article for teaching purposes and the right to post the Accepted Manuscript on a non-commercial institutional repository after an embargo period. Following assignment the publisher becomes the sole owner of the copyright.
The full reasons for transferring copyright are outlined in the STM position paper Publishers Seek Copyright Transfers (Or Transfers Or Licences Of Exclusive Rights) To Ensure Proper Administration & Enforcement of Author Rights.
You can read more about rights granted back to authors under IOP's assignment form in the Copyright FAQs section.
As an author, if you wish to reuse your previously published content but you have assigned copyright to a publisher, you'll need to check the terms of the assignment to see what you're allowed to do and may need to request express permission from that publisher.
What can I do with other people's copyright works?
You will need the permission of the copyright owner to reproduce the whole or any substantial part of a work, whether you have made direct use or your use is indirect (such as “redrawing”).
If you wish to reproduce an image and the rights are owned by someone else, you need permission from the copyright owner (usually the publisher). A publisher may also require that you obtain the permission of the original author.
Creating a new image from scratch based on someone else's image or even modifying an existing image may result in the creation of a new copyright work. If permission is not sought there is the potential that the new or modified image could infringe the original's copyright.
Whether or not the new creation infringes will depend upon whether substantial elements of the original are incorporated into the new work. Such substantiality is to be judged in terms of its qualitative importance to the original, rather than in terms of quantity. For an example of an independently created work which was found to infringe a pre-existing one, see here.
Many publishers, IOP included, are signatories to the STM Permission Guidelines, which allow free reuse of small numbers of figures or portions of text in articles published by co-signatories.
Short, properly attributed quotes will not usually need permission; however, the emphasis is again on the importance of the reproduced element to the original work. There is no ‘safe' word-count or proportion of a work to copy.
Ideas & data
Copyright protects only the expression of an idea, not the idea itself. For example, you cannot infringe copyright by reporting facts or data in your own words. Reuse of graphs or tables created by another author expressing such data would, however, require permission. As a matter of best practice and professional courtesy, data sources should be acknowledged and properly referenced.
This joint statement by ALPSP and STM reflects IOP's stance on the relationship between journals and the data they publish.