The Functions of Imaging in Document Examination and Other Special Techniques
David Ellen, Stephen Day, Christopher Davies · 2018
This chapter discusses three main functions of imaging in document examination. The first function is to make a permanent record of the document before it is damaged in the course of certain examinations. The second function is to detect certain features that are not visible and for which other methods are unavailable or less convenient. The third function is to prepare material from which demonstration charts for use in courts are prepared. A properly prepared image of a document can display most of the information visible on the original and can therefore be used as a substitute for it in a court or in preliminary investigation. Magnification is an important feature of document examination. Enlargement can be produced using imaging techniques, and high-resolution imaging can now be almost as good as seeing the original document. The preparation of a high-quality image made for a record now usually involves scanning or digital imaging rather than conventional photography.