An MPEG-7 Extension for Describing Visual Impairments

Analysing the condition of audiovisual essence is an important step in audiovisual production and preservation. Standardised impairment description of audiovisual media is a pre-requisite for system interoperability between content digitisation, documentation, management, restoration, production and delivery systems.We analyse existing capabilities for describing impairment in audiovisual metadata standards. Because of its unique detailed spatiotemporally structured description capabilities we have selected MPEG-7 as the basis for visual impairment description. Following the approach for audio quality description, we define a general description scheme for visual impairments, which allows representing defect events and statistical quality measures. For certain defects, more specialised descriptors are proposed. In addition, we define a comprehensive classification scheme for visual impairments.