1. A method of image retrieval, the method comprising: obtaining, at a processor, information selecting a plurality of objects represented in a digital image, the digital image associated with a location space and the plurality of selected objects distributed about the location space; selecting, by the processor, a particular candidate geometrical arrangement of the plurality of selected objects among multiple candidate geometrical arrangements of the plurality of selected objects; determining, at the processor, a reference position based on the particular candidate geometrical arrangement of the plurality of selected objects; generating, by the processor, metadata descriptive of the particular candidate geometrical arrangement and the reference position; and searching, by the processor, a metadata index corresponding to a plurality of digital images to identify at least one digital image from the plurality of digital images, the at least one digital image identified based on comparison of the metadata with an entry of the metadata index such that the at least one digital image depicts the plurality of selected objects, relative to the reference position, arranged according to the particular candidate geometrical arrangement.