Table of Contents - DSpace

Use CaseGoal in ContextPreconditionSuccess End ConditionFailed End ConditionPrimary ActorTriggerCompare colours.The comparison result between target colour and matchcolours under different combination of illuminants andobservers are shown in different colourspace valuestogether with on-screen colour tiles.There are more than one colours chosen by the user forthe comparison purpose.The comparison result between target colour and matchcolours under different combination of illuminants andobservers are shown in different colourspace values.The comparison result between target colour and matchcolours under different combination of illuminants andobservers failed to be shown in different colourspacevalues.User of Web-based Colour Communication System.The actor executes “compare colours” function.Basic Flow of EventsActor Action1. User selects “compare colours”function.3. User selects the colours that he wishesto compare from the colour list.5. User selects the target colour as thereference point for the comparison.7. User selects the colours to be comparedwith the reference point colour.Alternative flows andexceptionsSystem Response2. System displays “compare colours”module.4. System retrieves the detailed informationregarding the selected colour objects.6. System displays the selected colour asthe reference point.8. System displays the selected colours onthe User Interface screen, colour spacevalues of all selected colours and the colourdifference between each selected colourwith the colour acts as reference point.a) At step 3, user doesn't find the digital colour object(s)which he wishes to choose.Use case end.Figure 4.5: Textual description for use case scenario “Compare colours”67