PRÉSENTATIONS DE PROJETS

Transcription

1 PRÉSENTATIONS DE PROJETS Rex Onlne (V. Atanasu) What s Rex? Rex s an onlne browser for collectons of wrtten documents [1]. Asde ths core functon t has however many other applcatons that make t nterestng for dgtal palaeography and graphonomcs. The purpose of ths paper s to present these applcatons. Techncal papers about the tool are avalable on Rex s webste, as well as the software used to process the documents. There s one dataset presently accessble [2], but others can be added and the nterested partes are encouraged to contact the author. How does Rex work? In Rex you can browse documents accordng to some crtera descrbng n an ntutve manner the vsual appearance of the scrpt, such as degree of character slant, roundness or densty (see the overleaf fgures). These descrptors are based on mathematcal propertes of a sngle scrpt feature, that of the orentaton of a tangent along the scrpt contour [3]. The techncal beauty of Rex s to have revealed correlatons between mathematcal and graphonomcal concepts, between logc and percepton. Form a user perspectve ts appeal s the use of common language through whch browsng takes place. What s Rex useful for? The man applcaton areas of Rex relate to aspects of dgtal lbraranshp, study and teachng of graphonomcs and the development of software for dgtal graphonomcs. Dgtal lbraranshp 1. Dataset browser As mentoned above Rex allows the browsng of datasets accordng to selected scrpt characterstcs. It s hoped that ths capablty wll get software developers more nterested n the documents they work on, whch has a benefcal mpact on the developed tools. Gazette du lvre médéval, n o

2 132 Gazette du lvre médéval, n o , fasc Document retrever If one searches for a specfc subpopulaton or even sngle document n a dataset, Rex can also be used as a document retrever (hence t s canne name). In ths t dffers from many document retreval systems needng an mage as nput, snce nteracton happens through words. Thus you can pnpont to a partcular aspect of the scrpt, what wth an mage you obvously can t. 3. Qualty control Rex was already used to dentfy msclassfcatons n the present dataset. An automated check backed by a vsual one found that a few documents wrtten by some wrters were erroneously classfed wth those of others. Study and teachng of graphonomcs Whle Rex wll appeal to researchers as an nvestgatve tool, t should also be useful to teach graphonomcs, n partcular due to ts vsualzaton capabltes. 4. Wrter characterstcs Through Rex users can access sngle documents as well as all documents of a sngle wrter, allowng the examnaton of wthn and n-between wrter varablty, an mportant nformaton for wrter dentfcaton and verfcaton. 5. Populaton characterstcs A vsualzaton of the scrpt profles of all documents n the dataset n a sngle mage s also provded by Rex. It helps the comparson of datasets and exploraton of the wrter demographcs. 6. Understandng scrpt features Analytcal scrpt descrptors, and to some degree the ntutve ones, used n wrtng analyss software have propertes that are not fully understood. For example t was surprsng how many dfferent aspects of a scrpt can be seen n the contour orentaton profle used by Rex. It was also found that scrpts lookng radcally dfferent can have the same profle [4]. Usng Rex and thnkng about what t does can help software developers and wrtng experts alke better understand analytcal and ntutve features, an essental keystone of ther ntellectual products. Software development 7. Human-computer nterfaces for graphonomcs software It was already mentoned how the use of navgaton by words rather than by mages can change what can be acheved wth a graphonomcs tool. Usng Rex as a testbed, there are many other ssues that can be nvestgated, such as colormaps, dsplay of pctures and nformaton on the lmted screen space, nformaton to provde, termnology, etc. 8. User needs Usng Rex and developng other graphonomcs tools whle learnng from Rex, acts as a translator between the user and developers. They have a model to comment on whle creatng new products. Conclusons There aren t many software avalable off-the-shelf to wrtng experts today. Therefore t s encouragng that even techncally smple solutons can have many useful applcatons for graphonomcs f they are conceved wth the users needs n mnd and developed

3 Présentatons de projets. 133 beyond the prototype stage. Other papers n ths volume, by G. Vogeler and P. Stokes, also underscore the pluralstc usage propensty of onlne palaeographc projects. May Internet save Palaeography! Vlad Atanasu atanasu@alum.mt.edu References [1] Atanasu, V. ; Lkforman-Sulem L. ; Vncent N., Rex, a descrpton-based retrever for wrtten documents, Aprl 2011 [Onlne]. Accessble: fr [Accessed: October 24, 2011]. [2] Mart, U. ; Bunke, H., The IAM-database: an Englsh sentence database for off-lne handwrtng recognton, Intl. J. on Document Analyss and Recognton, vol. 5, 2002, p Avalable: [3] Atanasu, V. ; Lkforman-Sulem, L. ; Vncent N., Wrter Retreval Exploraton of a Novel Bometrc Scenaro Usng Perceptual Features Derved from Scrpt Orentaton, 11th Intl. Conf. on Document Analyss and Recognton, Bejng, Chna, 2011, p Accessble: [Accessed: October 24, 2011]. [4] Atanasu V., Forensc vs. Computng wrtng features as seen by Rex, the ntutve document retrever, 1st Intl. Workshop on Automated Forensc Handwrtng Analyss, Bejng, Chna, 2011, p Accessble: atanasu2011features.pdf [Accessed: October 24, 2011].

4 134 Gazette du lvre médéval, n o Fg. 1. Documents n databases can be retreved by appearance by one of the followng methods: vsual (usng a reference document), semantc (descrbng scrpt features), haptc (by drawng) and exogenous (from metadata about the wrters). Semantc retreval s convenent because t s ntutve (t takes place va a graphcal and natural-language nterface), free of any preexstng model (not always avalable) and can descrbe parts of the scrpt (contrary to the holstc approach of vsual retreval). 1 2 extrema nflecton pont mode g g h Features of the orentatons dstrbuton basc ampltude nflecton pont full ampltude support f f Angle curlness densty horzontal style lgature mult-slant shear slant slant bas slant varablty squash x-heght basc ampltude basc aspect central ampltude entropy extrema full ampltude full aspect mass Perceptual correlatons modalty prncpal mode roughness support symmetry Probablty [1] An ansotropc Gaussan flter bank wth one degree radal resoluton s appled to the bnary contours of the scrpt mage to obtan the local orentaton at each contour pxel. [2] Statstcal propertes of the resultng dstrbuton are computed. [3] Expermentally t s found that these computatonal measurements relate to perceptually meanngful ndvdual scrpt features.

5 Présentatons de projets. 135 slant / mode : 3 backwards slant 45 curlness / entropy 0.8 lnear 0.99 shear / mass : 0.1 less shear 0.58 densty / support : 8 more dense 48 Fg. 2. Handwrtng samples from IAM OffLne Handwrtng Database forward slant curly more shear less dense