This is a faithful photographic reproduction of an original two-dimensional work of art. The work of art itself is in the public domain for the following reason:

This image of simple geometry is ineligible for copyright and therefore in the public domain, because it consists entirely of information that is common property and contains no original authorship.

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I, the copyright holder of this work, release this work into the public domain. This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.

In many jurisdictions, faithful reproductions of two-dimensional public domain works of art are not copyrightable. The Wikimedia Foundation's position is that these works are not copyrightable in the United States (see Commons:Reuse of PD-Art photographs). In these jurisdictions, this work is actually in the public domain and the requirements of the digital reproduction's license are not compulsory.