Explanation of terms, PowerPoint, Exif

Explanation of terms

Following are definitions for some of the terms used throughout these Operating Instructions.

PowerPoint

Application software for creating presen- tations which is included as part of Microsoft Office. 95, 97 and 2000 ver- sions are available, but the JPEG Convertor software which is bundled with the projector is only compatible with the 97 and 2000 versions.

JPEG

Abbreviation for Joint Photographic Experts Group. JPEG is the name of an international organisation which was jointly established by the ISO and the ITU-TS (formerly the CCIT), but the term is normally used to refer to the specifica- tions for the still picture compression algorithm which was formulated by the JPEG. This algorithm allows still images such as photographs, single frames of moving images and scanned images to be compressed to up to 1/100th of their original sizes. However, images which are compressed in this way cannot be fully restored to their original quality (some deterioration in quality occurs), so that compression rates of 1/5 to 1/30 are normally used. Because of differences in colour separation, two format sub-types are used: RGB (red, green and blue) and CMYK (cyan, magenta, yellow, black). The projector and the JPEG Convertor software do not support the CMYK sub- type of JPEG file.

BMP

Abbreviation for BitMaP. This is the standard image format for the bitmapped files (image files consisting of a collection of dots) which are handled by Windows. Colour levels of monochrome, 16 colours, 256 colours and 16.7 million colours are supported.

RLE

Abbreviation for Run Length Encoding. It can be used to achieve high rates of compression for image files which contain large areas of a single colour. RLE can be used with monochrome, 16-colour and 256-colour BMP image files. (JPEG

Convertor does not support files com- pressed using RLE.)

TIFF

Abbreviation for Tagged-Image File Format. This type of file is used to exchange documents between comput- ers. Colour levels of monochrome, 256 colours and 16.7 million colours are supported. TIFF files in 16.7 million colour format can include transparent colour.

LZW

Abbreviation for Lempel-Ziv-Welch. LZW is a compression method used for TIFF files, and is named thus because it was developed by three people named Lempel, Ziv and Welch. It compresses the files by converting patterns within the images into short codes. There is no deterioration in image quality resulting from compression, but high rates of compression which are comparable to JPEG files cannot be expected to be obtained. (JPEG Convertor does not support files compressed using LZW.)

DCF

Abbreviation for Design rule for Camera File system. DCF is a standard which was established by the Japan Electronic Industry Development Association (JEIDA) with the aim of realising a common image file format, directory name format and file name format for the images used with digital still cameras. It is based on recommendations such as Exif Version 2.1.

Exif 2.1

Abbreviation for Exchangeable Image File Format. This is an image file format which was established by the Japan Electronic Industry Development Association (JEIDA). It defines the common informa- tion format and range of application for images used with digital still cameras, centring around TIFF and JPEG-format images. Version 2.1 is the latest version of the Exif standard.