Paper A Review and Texonomy of Distortion-Oriented 本文回顾和失真型分类

1、PaperA Review and Taxonomy of Distortion-Oriented Presentation TechniquesbyY.K.Leung (Swinburne Univ. of Tech., Australia)M.D.Apperley (Massey Univ., New Zealand) Presented by Haixia ZhaoA review paper!nDistortion-oriented presentation techniques are to solve the problem of displaying a large inform

2、ation space through a relatively small window.nThis paper is a review of such techniques before 1994.AgendanPart I. Content of the papernEssence of distortion-oriented techniquesnReview representative work.nA taxonomy of these techniques.nA unified theory.nDiscussion of implementation and performanc

3、e issuesnPart II. About the papernMy favorite sentencenContribution of the papernNotes on the referencesnCritique strengths and weaknessAgendanPart I. Content of the papernEssence of distortion-oriented techniquesn n nReview representative distortion-oriented presentation Review representative disto

4、rtion-oriented presentation Review representative distortion-oriented presentation techniques. techniques. techniques. n n nA taxonomy of these techniques.A taxonomy of these techniques.A taxonomy of these techniques.n n nA unified theory.A unified theory.A unified theory.n n nDiscussion of implemen

5、tation and performance issuesDiscussion of implementation and performance issuesDiscussion of implementation and performance issuesn n nPart II. About the paperPart II. About the paperPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContribution of the pa

6、perContribution of the paperContribution of the papern n nNotes on the referencesNotes on the referencesNotes on the referencesn n nCritique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessEssencenConcurrent presentation of local detail with global context as redu

7、ced magnification, in a format which allows dynamic interactive positioning of the local detail without severely compromising spatial relationships.Transformation function & Magnification functionAgendanPart I. Content of the papern n nEssence of distortion-oriented techniquesEssence of distorti

8、on-oriented techniquesEssence of distortion-oriented techniquesnReview representative distortion-oriented presentation techniques. n n nA taxonomy of these techniques.A taxonomy of these techniques.A taxonomy of these techniques.n n nA unified theory.A unified theory.A unified theory.n n nDiscussion

9、 of implementation and performance issuesDiscussion of implementation and performance issuesDiscussion of implementation and performance issuesn n nPart II. About the paperPart II. About the paperPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContributi

10、on of the paperContribution of the paperContribution of the papern n nNotes on the referencesNotes on the referencesNotes on the referencesn n nCritique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessPolyfocal display Kadmon & Shlomi 1978nProposed a polyfocal

11、 projection for the presentation of statistical data on cartographic maps, and proposed an implementation of a multifocal display.nLaid down a solid mathematical foundation for many later techniques.Polyfocal display (cont)Transformation & magnification functionsPolyfocal display on 1-D and 2-DP

12、olyfocal display (cont)Polyfocal display (cont)Multifocal polyfocal projection (multiple peaks)Bifocal display Spence & Apperley 1982Transformation & magnification functionsPolyfocal display on 1-D and 2-DBifocal display (cont)Fisheye view Furnas 1986A typical magnification functionnDOI(a|.=

13、b) = API(a) D(a,b)Beyond the papernFisheye view applications by FurnasnFisheye program code & Fisheye calendarnSome other works that use fisheye views.nKoike 1994 refined the tech. Using fractal algorithms to keep the total amount of displayed information nearly constant.Perspective Wall Mackinl

14、ay et al.c 1991Transformation & magnification functionsA conceptual descendant of the bifocal display.Perspective Wall (cont)It becomes bifocal view when theta=90.Perspective Wall (cont)Perspective wall applications in 1-D & 2-DBeyond this papernDocument lens Robertson and Machinlay 1993Grap

15、hical Fisheye Views Sarkar & Brown 1992Transformation & magnification functionsGraphical Fisheye Views (cont)Graphical Fisheye Views (cont)nFurthermore, Sarkar and Brown introduced a magnification in the third dimension based on the concept of API proposed by Furnas. nWith API, they provide

16、a flexible information suppression/enhancement mechanism. AgendanPart I. Content of the papern n nEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesn n nReview representative distortion-oriented presentation Review representati

17、ve distortion-oriented presentation Review representative distortion-oriented presentation techniques.techniques.techniques. nA taxonomy of these techniques.n n nA unified theory.A unified theory.A unified theory.n n nDiscussion of implementation and performance issuesDiscussion of implementation an

18、d performance issuesDiscussion of implementation and performance issuesn n nPart II. About the paperPart II. About the paperPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContribution of the paperContribution of the paperContribution of the papern n nNo

19、tes on the referencesNotes on the referencesNotes on the referencesn n nCritique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessA taxonomy of distortion-oriented presentation techniquenClassified by the magnification functions:nPiecewise continuous nConstant func

20、tion (bifocal display)nVarying function (perspective wall)nContinuousMulti-level constant piecewise continuous function approximates continuous effectContinuous magnification functionsnThe problem:ntend to distort the boundaries of the transformed image (e.g. Polyfocal display) nCan be overcomed by

21、nApplying transformation independently in the x and y directions, as the Cartesian fisheye view in Sarkar and Brown 1992nRemapping the distorted boundaries onto a rectangle size of the display area, as the Polar Fisheye view in Sarkar and Brown 1992Continuous magnification functions (cont)nThe magni

22、fication functions of Fisheye View and Polyfocal Projection show strong similarities, except that the Polyfocal Projection has dips. The dips make it possible to support a multiple-focus presentation.nFisheye View : a special case of Polyfocal Projection.AgendanPart I. Content of the papern n nEssen

23、ce of distortion-oriented techniquesEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesn n nReview representative distortion-oriented presentation Review representative distortion-oriented presentation Review representative distortion-oriented presentation techniques.t

24、echniques.techniques. n n nA taxonomy of these techniques.A taxonomy of these techniques.A taxonomy of these techniques.nA unified theory.n n nDiscussion of implementation and performance issuesDiscussion of implementation and performance issuesDiscussion of implementation and performance issuesn n

25、nPart II. About the paperPart II. About the paperPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContribution of the paperContribution of the paperContribution of the papern n nNotes on the referencesNotes on the referencesNotes on the referencesn n nCri

26、tique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessA unified theorynAn analogy: To treat the displayed information as if it was printed on a stretchable rubber sheet mounted on a rigid frame.nThe information is dense in the unstretched form, the viewer can see

27、only the global context of the information structure. To see the detailed information, the rubber sheet has to be stretched. The stretching of the rubber sheet is analogous to applying magnification to a section of the screen. As the rubber sheet is mounted on a rigid frame, any stretching in one pa

28、rt of the sheet results in an equivalent amount of “shrinkage” in other areas. The situation is similar in the case of a multiple-focus view. The only difference is that stretching or magnification will occur in a greater number of areas. The amount of stretching or magnification, and the manner in

29、which it is applied on the sheet, depend entirely on the magnification function used.AgendanPart I. Content of the papern n nEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesn n nReview representative distortion-oriented prese

30、ntation Review representative distortion-oriented presentation Review representative distortion-oriented presentation techniques.techniques.techniques. n n nA taxonomy of these techniques.A taxonomy of these techniques.A taxonomy of these techniques.n n nA unified theory.A unified theory.A unified t

31、heory.nDiscussion of implementation and performance issuesn n nPart II. About the paperPart II. About the paperPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContribution of the paperContribution of the paperContribution of the papern n nNotes on the re

32、ferencesNotes on the referencesNotes on the referencesn n nCritique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessPerformance issuesnWhen the user interactively change the focus region, the system may need to create and display a number of intermediate images, d

33、epending on what methods are used to change the focus. The response time depends on three factors: ncomplexity of the mathematical transformations involvednamount of information and detail to be presentedncomputational power and suitability of the system used for implementation.Performance issues (c

34、ont)nProper system response time:nExcessively long system response time will render an interface “unusable”. nUse dedicated computer hardware to speed up mathematical transformationnUse some tricks in the implementation, by taking advantage of the memory management system. (covered later)nToo fast s

35、ystem response could also be disconcerting to the user. The effect is similar to watching a home video taken by an amateur who panned the view jerkily at high speed.nSlowing down is easyImplementation issuesnThe complexities of different techniques depend on the transformation functions used.nFor st

36、epwise magnification functions, some tricks could be used, such as trading system memory for computational power,e.g.:nHave different view created and stored in memory in advance. Then in real time, just cut and past various sections of these bit maps to generate distorted views. Implementation issu

37、es (cont)nContinuous magnification function:nHave to cater to the continuum of magnification factors at every possible focus point, so it is impractical to use pre-generated view images. nInstead, use a piecewise continuous magnification function to approximate the continuous function. N * N bit map

38、s for N-level function in 2-D application.nDedicated hardware may be needed to provide computational power, if approximation of the transformation function is not desirable.Implementation issues (cont)nMultiple-focus viewsnUseful to examine and compare two entitiesnUnintended focus views are created

39、. (right figure)nThis typically happens in techniques with no dips in the magnification functions (like that of the Polyfocal Projection) (lack of flexibility in the function)nInstead, integrate other mechanisms such as a pop-up window to support multiple views. May create additional navigation prob

40、lems because of the discontinuity of the presentation in the detailed and the context.Use pop-up windowsConclusionnUseful but should be used with caution, considering the type of information to be conveyed and how it will be perceived by the user.Agendan n nPart I. Content of the paperPart I. Conten

41、t of the paperPart I. Content of the papern n nEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesEssence of distortion-oriented techniquesn n nReview representative distortion-oriented presentation Review representative distortion-oriented presentation Review represen

42、tative distortion-oriented presentation techniques.techniques.techniques. n n nA taxonomy of these techniques.A taxonomy of these techniques.A taxonomy of these techniques.n n nA unified theory.A unified theory.A unified theory.n n nDiscussion of implementation and performance issuesDiscussion of im

43、plementation and performance issuesDiscussion of implementation and performance issuesnPart II. About the papern n nMy favorite sentenceMy favorite sentenceMy favorite sentencen n nContribution of the paperContribution of the paperContribution of the papern n nNotes on the referencesNotes on the ref

44、erencesNotes on the referencesn n nCritique strengths and weaknessCritique strengths and weaknessCritique strengths and weaknessMy favorite sentencenThe basic law of distortion-oriented techniques is “where there is a magnification, there will be an equal amount of demagnification to compensate for the loss of display area in the confined space; otherwise the area of that confined space will change.” a corollary of Newtons third law of motion.Contribution of the papern(A good review)nUses transformation and magnification functions to describe different techniques, presents a taxonomy