Seite - 35 - in Document Image Processing

J. Imaging 2018,4, 80 Figure5.Possible localizationofappropriatefragmentsonthepage. Therequirednumberoffragments isM=5. 3.Results Since there isnoprevioussimilarworktocomparewith,a trial ismadetoperformanabsolute evaluation invariousways. Thus, inorder toperformourexperimentsandevaluate theparameters, fourdatabaseswereused: 1. TheTrigraphSlant database (DB) [18], in order to perform tests on a renownedDB for slant. However, in thisDBeachwriterwasasked towrite twopagesofhisnatural slantandtwoof forceslants.Only thenatural slantdocumentswereusedhere (seeExperimentalResults). 2. The George Washington DB [19], in order to perform tests on a renowned DB of historicaldocuments. 3. TheBH2M:theBarcelonaHistoricalHandwrittenMarriagesdatabase [20], inorder toperform testsonasecondDBofhistoricaldocuments. 4. The PrintDB: printed documentswith artificial slant, in order to check the accuracy of the technique.Moreover, sinceall therestdonotguarantee theexistenceofall thepossibleslants, special carewas takento includeallpossibleslants, including0(noslant). Avalidationsetandatest setwerecreated. Thevalidationsetconsistsof20document images fromtheTrigraphSlantDB,4 fromtheWashingtonDB,4 fromtheBH2MDB,and80fromthePrintDB. Thetest set consistsof60document images fromtheTrigraphSlantDB,16 fromtheWashingtonDB,16 fromtheBH2MDB,and298fromthePrintDB. 35