User Interaction with an Environment for Image Processing and Graphics

Abstract

The Space Telescope Faint Object Camera is one of the most exciting projects in astronomical history, and will expand the volume of the observable universe by a factor of almost one thousand. In order to process the images from this instrument a FOC Image Processing System (FIPS) has been developed at the European Space Technology Centre (ESTEC) in Holland.Amongst other features, such as means to input, display, store, retrieve and output image and graphics data, FIPS places much emphasis on the user interface. The FIPS Command Language (FCL) is based on algorithmic languages such as PASCAL, C, ALGOL, etc, rather than conventional Job Control Languages, and thus includes control statements, compound statements, functions and procedures, assignment statements, etc. These allow the user to define complex functions out of the basic commands and to process for example, sets of images and graphics files without intervention.In addition, FCL allows command parameters to be specified either by default, canonically, by means of keywords, or via prompts to take account of the experience of the user. HELP information can be invoked both at the command and parameter levels, to assist the inexperienced user. As image processing can be time consuming, certain operations (e.g. rotate an image) can be performed asynchronously to avoid delaying interactive user input.Some examples of the practical usage of FIPS are also given, and the paper concludes with an assessment of how well FIPS has met its objectives and what improvements would be beneficial.FIPS is available on a commercial basis from Dynaflow Software Systems. For further information contact J Gras at the address indicated.