CRISTAL: Four Key Preservation Issues Through the ability to merge text, graphics, and video images into an integrated digital environment, the CRISTAL system addresses four key issues in the preservation process. 1... documentation of cultural resources by gathering single frame images from real time video recordings, scanned graphics and text, and alphanumeric data generated by computer or entered by keyboard. Buildings that might not prove economically or logistically feasible to document with extensive hand measurements and drawings might be effectively recorded with the videographic system. 2... analysis of resources through the extraction of information relating to building dimensions, materials, code compliance, and stylistic character from graphic images. Specific information relating to building character or structure can be generated as required to fulfill management or design needs. Once a videographic database exists, the system user can exercise a high degree of discretion in determining the information to be extracted from the database. 3... simulation of the historic context and proposed designs or treatments through the addition of information to the recorded image. A more comprehensive understanding of the environmental and cultural context, and the impact of proposed changes, is possible through the computer manipulation of digital images. These processed images can be supplemented with drawings, photographs, and text. When a new building is designed for an historic district, or changes to an otherwise environmentally or culturally sensitive area are contemplated, the effects of these proposals can be studied by merging the video record of the existing context with a graphic simulation of the proposed project. These visual computer simulations can promote a dialogue between cultural resource professionals, architects, developers, public constituencies, and public administrators that results in more informed decisions about the effects of proposed design or management strategies. 4... the specification of prescriptive treatments and the assembly of construction documents, maintenance management guides, and monitoring systems. The development of a highly accessible, interactive, visual information base can contribute significantly to formulating maintenance, rehabilitation, and restoration strategies. In complex or large scale conservation projects, detailed recordings of building parts to be removed during construction can be made and placed in the system's database prior to removal. After repair or replication, these parts can be efficiently identified and correctly replaced according to the specifications or instructions contained in the original video document. CRISTAL: Introduction CRISTAL: Description CRISTAL: Resource Documentation CRISTAL: Information Management CRISTAL: Image Analysis CRISTAL: Graphic Output