− Noboru Koshizuka −
Data input is very important in every activity of digital museums because this directly creates digital contents. In digital museum, digital contents are indispensable in preserving materials as digital data, digital restoration of materials, retrieving information from digital archives, and exhibition using digital technologies.
There are various methods and technologies for inputting digital data according to input data format. First, to input text data, there are two major methods, manual typing and character recognition. In the former method, operators simply input text data by typing their keyboard manually. The latter method firstly scans text materials as image data, then translates it into text data by using character recognition processing.
The second data format is still images. There are two methods for inputting still images. The first method is to use digital image scanners directly. We have three types of scanners, drum scanners, flat-bed scanners (Fig.1), and overhead scanners (Fig.2). In digitizing, we use the most suitable type according to characteristic of materials and quality requirement. The second method is to use cameras. In using conventional cameras, we first take pictures then scan their films by using film scanners. Using digital cameras, we can directly take pictures, then transfer digital data from the digital camera into computers.
Fig.1 Flat-bed Scanner
Fig.2 Overhead Scanner
The third data format is moving images. In this case, there are also two methods: direct digitization and indirect digitization. The former uses digital video encoder and directly inputs digital moving images into computers. The latter firstly records images on movie films or video tapes/disks, then digitizes or captures the data.
The last format is 3D data, which includes 3D-shape data and pseudo 3D-image data. The former one records a 3D-object as mathematical expression of its shape. This data can be obtained by using 3D scanners (Fig.3). The latter one records it as a collection of still images from many angles. This data can be obtained taking pictures of the object from many angles.
In any methods, precision, efficiency, and damage on materials are important viewpoints. Basically, precise data input is desirable of course. However, in most cases, the precision is a tradeoff with input efficiency and damages on materials. For example, high-resolution image scanning takes a long time. Additionally, for precise input, we must sometimes process materials. For example, to scan a thick book, we must spread the book and expose it under strong light. This may damage the book.
Fig.3 3D Scanner
