I spoke to my friend and I introduced him my vision of art. The friend agreed, and then he sent me the photograph in a high resolution. After processing and finishing work, we have published a joint work.
There are three requirements for joint authorship to exist. First, every collaborator must have contributed to the work and make a significant and original contribution to the creation of the work. Second, the authors must have collaborated whilst producing the work. Third, the individual contributions must merge into one whole work.
Absent an agreement to the contrary, authors own the work jointly and equally. Each joint author, therefore, has the right to exercise any or all of the exclusive rights inherent in the joint work. This means that each author can grant third parties permission to use the work on a non-exclusive basis without the consent of other joint authors. Additionally, each joint author has a duty to account to the other joint authors for any profits received from licensing the joint work.