Some free licenses automatically cover various versions of the licensed content, because under applicable copyright law, these versions would be considered the same work. For instance, you may wish to license thumbnail-quality files under a Creative Commons license while keeping raw, higher-resolution copies proprietary. However, when doing so, you should be warned that you might well be unintentionally licensing those other versions, because in regard to copyright, the two could be considered the same work. If you grant such a license for users to use a version of a work, the license may automatically give users the same rights to use any version that differs only in the level of some automatic conversion, regardless of the quality or resolution. While details of what would be considered the same work vary between jurisdictions, one key issue is whether or not enough creative expression is added in the conversion. As Creative Commons explains:
"You may license your copyright or distribute your work under more than one set of terms. For example, you may publish a photograph on your website, but only distribute high-resolution copies to people who have paid for access. This is a practice CC supports. However, if the low-resolution and high-resolution copies are the same work under applicable copyright law, permission under a CC license is not limited to a particular copy, and someone who receives a copy in high resolution may use it under the terms of the CC license applied to the low-resolution copy.
Note that, although CC strongly discourages the practice, CC cannot prevent licensors from attempting to impose restrictions through separate agreements on uses the license otherwise would allow. In that case, licensees may be contractually restricted from using the high-resolution copy, for example, even if the licensor has placed a CC license on the low-resolution copy."
"Generally, to be different works under copyright law, there must be expressive or original choices made that make one work a separate and distinct work from another. The determination depends on the standards for copyright in the relevant jurisdiction.
Under U.S. copyright law, for example, mechanical reproduction of a work into a different format is unlikely to create a separate, new work. Consequently, digitally enhancing or changing the format of a work absent some originality, such as expressive choices made in the enhancement or encoding, will not likely create a separate work for copyright purposes. The creative bar is low, but it is not non-existent. Accordingly, in some jurisdictions releasing a photograph under a CC license will give the public permission to reuse the photograph in a different resolution."
- Commons:Village pump/Copyright#File:Trabalhos.jpg
- Commons:Deletion requests/File:Trabalhos.jpg
- cc-community - Does license applicable for all resolutions? (November 2013) - downscaled image file and original image file
- cc-licenses - multiple licenses of same image (January 2007) - downscaled image file and original image file
- cc-licenses - different license for different bitrate (December 2006) - downsampled audio file and original audio file
- cc-licenses - Case study: Magnatune (November 2005) - downsampled audio file and original audio file
- misc.int-property - SW copyright: source/object identical, & linking question. (October 1998) - object code and source code