Control device, control method, control program, and projection system

A control device that controls projection by a plurality of projection units having different projection ranges, the device comprising:

• a control unit that projects, by the plurality of projection units, a first image in which at least one content image is disposed on a first projection range having the projection ranges of the plurality of projection units;
• and
• an acquisition unit that acquires first attribute information associated with the content image, the first attribute information indicating whether an aspect ratio of the content image is made to be changeable in a case in which a size of the content image is changed or whether the aspect ratio of the content image is maintained in a case in which a size of the content image is changed,
• wherein, in a state in which projection is performed by a projection unit, among the plurality of projection units, except a part of the plurality of projection units, the control unit projects a second image in which at least a part of the content image is disposed on a second projection range having a projection range of the projection unit except the part of the plurality of projection units, and adjusts the size of the content image in generation of the second image based on the first attribute information.