Affordable Heritage Archive

Research and promotion of the monuments of historical heritage is related to the creation, storage and distribution of visual information about them. In the past, from the antiquity to the last century, the possibilities of creating visual information were limited to two-dimensional images created on different materials and (more recently) video and images films.
With the development of digital technologies, the three-dimensional scanning and visual regeneration of buildings of the cultural heritage combined with 3D virtual reconstruction is becoming increasingly popular tool for understanding and reconstructing the past.
As a part of South East Europe Bulgaria has an ancient history and culture. Being a crossroad of civilizations and religions throughout the centuries, the region has been acting as a natural link between the East and the West. This accounts for the wealth and diversity of its cultural heritage. The region boasts remarkable cultural treasures with unique identity, many of them listed as world heritage monuments. Its cultural integrity is unique, pointing back to common historical roots, intrinsic links and mutual influences. The cultural and historical heritage that has survived highlights distinct cultural corridors, dating back hundreds and thousands of years. Today, they are among the strongest bonds between nations as well as being the living memory of the local civilizations.The current status of the cultural heritage in Bulgaria and in the region is worrying because of its fragmentation within the closed national and local systems, rather than being seen in the existing trans-national cultural corridors. In most cases this unique cultural heritage linked together in clearly visible cultural corridors is ambiguously known in Europe, in the world and even in the region itself. There has been a deficit of effective regional cooperation for a coordinated protection and use of the existing cultural resource.Applying of affordable ICT tools can be a key driver for starting of a large scale cooperative activities in preservation of regional immovable cultural heritage including Bulgarian one.
The development of modern multimedia digital technologies and the global Internet network creates new opportunities for constructing visual images of objects. According to Kandulkova (2009), these technologies enable conditions for a new type of restoration activities – “Virtual Restoration” (“Information Technologies in the Study and Preservation of Architectural and Archaeological Monuments of Culture”, Heritage: ESPRIT, under the general editing of Prof. Dr. Todor Krustev, Varna: LiterNet, 2009). Unlike conventional restoration, the virtual one allows for the construction and depiction of several versions for a single artefact, creation of hypothetical images of the objects surveyed, without jeopardizing their authenticity. Through the construction of three-dimensional models, the spatial characteristics of the monument are examined in different moments of its existence.
One of the basic requirements for the restoration and reconstruction of buildings – architectural and historical monuments – is the restoration of the building with all its elements in their original shape. This requires a precise fixing of the dimensions and the spatial position of the building as well as all the facade elements – cornices, reliefs, friezes, pilasters, ornaments and others. Solving this problem by applying classical geodesic methods is too complicated and labour intensive. For this reason photogrammetric methods for creating spatial (3D) models for archiving historical and architectural monuments are finding a growing application.
3D scanning by photogrammetric methods is a modern, fast and accurate method for transforming the physical parameters of an object into an electronic format – a 3D digital model. The greater is the advantage of photogrammetric methods for 3D capture of architectural objects compared to laser scanning technology due to the huge difference in costs needed to implement the two alternative technologies. “… laser scanning takes too long and is still a very expensive technology compared to photogrammetric methods …” (“Applications of 3D Digitization”, Practical Guide, Sofia, 2014).
The archiving of the monuments of architecture is usually done by photogrammetric surveying and using a precisely defined geodesic network. The digital photogrammetric cameras used provide high quality and credibility to the images. The digital model allows not only the reliable storage of the data for an architectural object, but also the possibility to use it for the selection and assessment of new solutions related to its future development and preservation. (Pl. Maldjanski, “Development of Methods for Photographing and Processing of Data in Architectural Photogrammetry”, Sofia, 2012)
Regarding the theoretical development and the experimental application of the methods for capturing and processing data in architectural photogrammetry in Bulgaria, the leading contribution of Prof. Plamen Maldzhanski should be noted. His monograph “Development of methods for data capture and processing in architectural photogrammetry”(Maldjanski, 2003) is the most serious study in this field in Bulgaria.Important is his conclusionthat the high cost of laser scanners and digital stereo cameras is a prerequisite for searching for cheaper technological alternative as photogrammetry.
Experiments were made by capturing the facades of a monument of culture and architecture and applying the proposed technology. Another research paper by prof. Pl. Maldjanski was focused on use of photogrammetry approach in research and preservation of architectural heritage (Maldzhanski, 2012).
The project “Cultural Heritage: Education – Science – Preservation – Integrated in Tourism” has won a competition of the Ministry of Science and Culture (2006) and was implemented in 2007-2008 by the Bulgarian National Committee of ICOMOS with several Bulgarian partners: University of Architecture, Civil Engineering and Geodesy, National Academy of Art and Association for Cultural Tourism. It was targeted at creation of exchange, interaction and communication network between different sectors, associated to cultural heritage: science, education, preservation and cultural tourism, by use of the information technologies capacity. The project ambition was to create the missing communication between these sectors. Aiming this, in the frames of the project, an open scientific, educational and expert network was created.

Conclusion
ICT tools are relatively well used for systematization, exhibition and promotion of Bulgarian cultural heritage. However, in development of modern digital technologies for constructing and processing of digital spatial images of cultural heritage objects, Bulgaria is lacking the needed scale and advancement of research activities. The vast possibilities to apply at a large scale inexpensive digital photogrammetry tools for preserving cultural monuments in Bulgaria are still unexplored. Such opportunities are real and they need urgent implementation.