Re: Convertire pdf in bianco e nero
On Tue, Jun 22, 2021 at 06:56:21PM +0200, Davide Meloni wrote:
> Buonasera.
> Generalmente scansiono i documenti di testo nella modalità "bianco e nero"
> (non scala di grigi) al fine di ottenere un file quanto più leggero
> possibile.
Sarebbe utile sapere il perché. Se è per uso archiviazione documentale
sappi che lo standard è usare :
1) 400dpi
2) compressione fax CCITT gruppo 4 o altro (vedi sotto)
3) profondità immagini 1 bit
4) incapsulamento tiff (ma lo stesso si può fare con il formato contenitore pdf)
recentemente è uscito un formato (sono scaduti i diritti) di compressione
che non ricordo che è ancora migliore del CCITT. Credo che lo supporti
nativamente djpdf.
Strumenti consigliati quindi:
- GIMP
- Imagemagick
- Scan Taylor (o S. T. Advanced)
ma soprattutto:
- djpdf che trovi su flatpak con il supporto di un mucchio di lingue
(compreso l'Esperanto!) per la procedura di OCR necessaria per ottenere
dei pdf il cui testo possa essere copiato.
https://flathub.org/apps/details/com.github.unrud.djpdf
https://github.com/Unrud/djpdf
Facendo: flatpak search djpdf
Ecco il risultato:
Name Description Application ID Version Branch Remotes
OCR Yoruba OCR extension for Yoruba language (yor) com.github.unrud.djpdf.OCR.Yor stable flathub
OCR Yiddish OCR extension for Yiddish language (yid) com.github.unrud.djpdf.OCR.Yid stable flathub
OCR Vietnamese OCR extension for Vietnamese language (vie) com.github.unrud.djpdf.OCR.Vie stable flathub
OCR Uzbek - Cyrilic OCR extension for Uzbek - Cyrilic language (uzb_cyrl) com.github.unrud.djpdf.OCR.UzbCyrl stable flathub
OCR Uzbek OCR extension for Uzbek language (uzb) com.github.unrud.djpdf.OCR.Uzb stable flathub
OCR Urdu OCR extension for Urdu language (urd) com.github.unrud.djpdf.OCR.Urd stable flathub
OCR Ukrainian OCR extension for Ukrainian language (ukr) com.github.unrud.djpdf.OCR.Ukr stable flathub
OCR Uighur; Uyghur OCR extension for Uighur; Uyghur language (uig) com.github.unrud.djpdf.OCR.Uig stable flathub
OCR Turkish OCR extension for Turkish language (tur) com.github.unrud.djpdf.OCR.Tur stable flathub
OCR Tonga OCR extension for Tonga language (ton) com.github.unrud.djpdf.OCR.Ton stable flathub
OCR Tigrinya OCR extension for Tigrinya language (tir) com.github.unrud.djpdf.OCR.Tir stable flathub
OCR Thai OCR extension for Thai language (tha) com.github.unrud.djpdf.OCR.Tha stable flathub
OCR Tagalog (new - Filipino) OCR extension for Tagalog (new - Filipino) language (tgl) com.github.unrud.djpdf.OCR.Tgl stable flathub
OCR Tajik OCR extension for Tajik language (tgk) com.github.unrud.djpdf.OCR.Tgk stable flathub
OCR Telugu OCR extension for Telugu language (tel) com.github.unrud.djpdf.OCR.Tel stable flathub
OCR Tatar OCR extension for Tatar language (tat) com.github.unrud.djpdf.OCR.Tat stable flathub
OCR Tamil OCR extension for Tamil language (tam) com.github.unrud.djpdf.OCR.Tam stable flathub
OCR Syriac OCR extension for Syriac language (syr) com.github.unrud.djpdf.OCR.Syr stable flathub
OCR Swedish OCR extension for Swedish language (swe) com.github.unrud.djpdf.OCR.Swe stable flathub
OCR Swahili OCR extension for Swahili language (swa) com.github.unrud.djpdf.OCR.Swa stable flathub
OCR Sundanese OCR extension for Sundanese language (sun) com.github.unrud.djpdf.OCR.Sun stable flathub
OCR Serbian - Latin OCR extension for Serbian - Latin language (srp_latn) com.github.unrud.djpdf.OCR.SrpLatn stable flathub
OCR Serbian OCR extension for Serbian language (srp) com.github.unrud.djpdf.OCR.Srp stable flathub
OCR Albanian OCR extension for Albanian language (sqi) com.github.unrud.djpdf.OCR.Sqi stable flathub
OCR Spanish; Castilian - Old OCR extension for Spanish; Castilian - Old language (spa_old) com.github.unrud.djpdf.OCR.SpaOld stable flathub
OCR Spanish; Castilian OCR extension for Spanish; Castilian language (spa) com.github.unrud.djpdf.OCR.Spa stable flathub
OCR Sindhi OCR extension for Sindhi language (snd) com.github.unrud.djpdf.OCR.Snd stable flathub
OCR Slovenian OCR extension for Slovenian language (slv) com.github.unrud.djpdf.OCR.Slv stable flathub
OCR Slovak - Fraktur OCR extension for Slovak - Fraktur language (slk_frak) com.github.unrud.djpdf.OCR.SlkFrak stable flathub
OCR Slovak OCR extension for Slovak language (slk) com.github.unrud.djpdf.OCR.Slk stable flathub
OCR Sinhala; Sinhalese OCR extension for Sinhala; Sinhalese language (sin) com.github.unrud.djpdf.OCR.Sin stable flathub
OCR Script Vietnamese OCR extension for Vietnamese script (script/Vietnamese) com.github.unrud.djpdf.OCR.ScriptVietnamese stable flathub
OCR Script Tibetan OCR extension for Tibetan script (script/Tibetan) com.github.unrud.djpdf.OCR.ScriptTibetan stable flathub
OCR Script Thai OCR extension for Thai script (script/Thai) com.github.unrud.djpdf.OCR.ScriptThai stable flathub
OCR Script Thaana OCR extension for Thaana script (script/Thaana) com.github.unrud.djpdf.OCR.ScriptThaana stable flathub
OCR Script Telugu OCR extension for Telugu script (script/Telugu) com.github.unrud.djpdf.OCR.ScriptTelugu stable flathub
OCR Script Tamil OCR extension for Tamil script (script/Tamil) com.github.unrud.djpdf.OCR.ScriptTamil stable flathub
OCR Script Syriac OCR extension for Syriac script (script/Syriac) com.github.unrud.djpdf.OCR.ScriptSyriac stable flathub
OCR Script Sinhala OCR extension for Sinhala script (script/Sinhala) com.github.unrud.djpdf.OCR.ScriptSinhala stable flathub
OCR Script Oriya (Odia) OCR extension for Oriya (Odia) script (script/Oriya) com.github.unrud.djpdf.OCR.ScriptOriya stable flathub
OCR Script Myanmar OCR extension for Myanmar script (script/Myanmar) com.github.unrud.djpdf.OCR.ScriptMyanmar stable flathub
OCR Script Malayalam OCR extension for Malayalam script (script/Malayalam) com.github.unrud.djpdf.OCR.ScriptMalayalam stable flathub
OCR Script Latin OCR extension for Latin script (script/Latin) com.github.unrud.djpdf.OCR.ScriptLatin stable flathub
OCR Script Lao OCR extension for Lao script (script/Lao) com.github.unrud.djpdf.OCR.ScriptLao stable flathub
OCR Script Khmer OCR extension for Khmer script (script/Khmer) com.github.unrud.djpdf.OCR.ScriptKhmer stable flathub
OCR Script Kannada OCR extension for Kannada script (script/Kannada) com.github.unrud.djpdf.OCR.ScriptKannada stable flathub
OCR Script Japanese vertical OCR extension for Japanese vertical script (script/Japanese_vert) com.github.unrud.djpdf.OCR.ScriptJapaneseVert stable flathub
OCR Script Japanese OCR extension for Japanese script (script/Japanese) com.github.unrud.djpdf.OCR.ScriptJapanese stable flathub
OCR Script Hebrew OCR extension for Hebrew script (script/Hebrew) com.github.unrud.djpdf.OCR.ScriptHebrew stable flathub
OCR Script Hangul vertical OCR extension for Hangul vertical script (script/Hangul_vert) com.github.unrud.djpdf.OCR.ScriptHangulVert stable flathub
OCR Script Hangul OCR extension for Hangul script (script/Hangul) com.github.unrud.djpdf.OCR.ScriptHangul stable flathub
OCR Script Han traditional vert… OCR extension for Han traditional vertical script (script/HanT_vert) com.github.unrud.djpdf.OCR.ScriptHanTVert stable flathub
OCR Script Han traditional OCR extension for Han traditional script (script/HanT) com.github.unrud.djpdf.OCR.ScriptHanT stable flathub
OCR Script Han simplified verti… OCR extension for Han simplified vertical script (script/HanS_vert) com.github.unrud.djpdf.OCR.ScriptHanSVert stable flathub
OCR Script Han simplified OCR extension for Han simplified script (script/HanS) com.github.unrud.djpdf.OCR.ScriptHanS stable flathub
OCR Script Gurmukhi OCR extension for Gurmukhi script (script/Gurmukhi) com.github.unrud.djpdf.OCR.ScriptGurmukhi stable flathub
OCR Script Gujarati OCR extension for Gujarati script (script/Gujarati) com.github.unrud.djpdf.OCR.ScriptGujarati stable flathub
OCR Script Greek OCR extension for Greek script (script/Greek) com.github.unrud.djpdf.OCR.ScriptGreek stable flathub
OCR Script Georgian OCR extension for Georgian script (script/Georgian) com.github.unrud.djpdf.OCR.ScriptGeorgian stable flathub
OCR Script Fraktur OCR extension for Fraktur script (script/Fraktur) com.github.unrud.djpdf.OCR.ScriptFraktur stable flathub
OCR Script Ethiopic OCR extension for Ethiopic script (script/Ethiopic) com.github.unrud.djpdf.OCR.ScriptEthiopic stable flathub
OCR Script Devanagari OCR extension for Devanagari script (script/Devanagari) com.github.unrud.djpdf.OCR.ScriptDevanagari stable flathub
OCR Script Cyrillic OCR extension for Cyrillic script (script/Cyrillic) com.github.unrud.djpdf.OCR.ScriptCyrillic stable flathub
OCR Script Cherokee OCR extension for Cherokee script (script/Cherokee) com.github.unrud.djpdf.OCR.ScriptCherokee stable flathub
OCR Script Canadian Aboriginal OCR extension for Canadian Aboriginal script (script/Canadian_Abori… …github.unrud.djpdf.OCR.ScriptCanadianAboriginal stable flathub
OCR Script Bengali OCR extension for Bengali script (script/Bengali) com.github.unrud.djpdf.OCR.ScriptBengali stable flathub
OCR Script Armenian OCR extension for Armenian script (script/Armenian) com.github.unrud.djpdf.OCR.ScriptArmenian stable flathub
OCR Script Arabic OCR extension for Arabic script (script/Arabic) com.github.unrud.djpdf.OCR.ScriptArabic stable flathub
OCR Sanskrit OCR extension for Sanskrit language (san) com.github.unrud.djpdf.OCR.San stable flathub
OCR Russian OCR extension for Russian language (rus) com.github.unrud.djpdf.OCR.Rus stable flathub
OCR Romanian; Moldavian; Moldov… OCR extension for Romanian; Moldavian; Moldovan language (ron) com.github.unrud.djpdf.OCR.Ron stable flathub
OCR Quechua OCR extension for Quechua language (que) com.github.unrud.djpdf.OCR.Que stable flathub
OCR Pushto; Pashto OCR extension for Pushto; Pashto language (pus) com.github.unrud.djpdf.OCR.Pus stable flathub
OCR Portuguese OCR extension for Portuguese language (por) com.github.unrud.djpdf.OCR.Por stable flathub
OCR Polish OCR extension for Polish language (pol) com.github.unrud.djpdf.OCR.Pol stable flathub
OCR Panjabi; Punjabi OCR extension for Panjabi; Punjabi language (pan) com.github.unrud.djpdf.OCR.Pan stable flathub
OCR Oriya OCR extension for Oriya language (ori) com.github.unrud.djpdf.OCR.Ori stable flathub
OCR Occitan (post 1500) OCR extension for Occitan (post 1500) language (oci) com.github.unrud.djpdf.OCR.Oci stable flathub
OCR Norwegian OCR extension for Norwegian language (nor) com.github.unrud.djpdf.OCR.Nor stable flathub
OCR Dutch; Flemish OCR extension for Dutch; Flemish language (nld) com.github.unrud.djpdf.OCR.Nld stable flathub
OCR Nepali OCR extension for Nepali language (nep) com.github.unrud.djpdf.OCR.Nep stable flathub
OCR Burmese OCR extension for Burmese language (mya) com.github.unrud.djpdf.OCR.Mya stable flathub
OCR Malay OCR extension for Malay language (msa) com.github.unrud.djpdf.OCR.Msa stable flathub
OCR Maori OCR extension for Maori language (mri) com.github.unrud.djpdf.OCR.Mri stable flathub
OCR Mongolian OCR extension for Mongolian language (mon) com.github.unrud.djpdf.OCR.Mon stable flathub
OCR Maltese OCR extension for Maltese language (mlt) com.github.unrud.djpdf.OCR.Mlt stable flathub
OCR Macedonian OCR extension for Macedonian language (mkd) com.github.unrud.djpdf.OCR.Mkd stable flathub
OCR Marathi OCR extension for Marathi language (mar) com.github.unrud.djpdf.OCR.Mar stable flathub
OCR Malayalam OCR extension for Malayalam language (mal) com.github.unrud.djpdf.OCR.Mal stable flathub
OCR Luxembourgish OCR extension for Luxembourgish language (ltz) com.github.unrud.djpdf.OCR.Ltz stable flathub
OCR Lithuanian OCR extension for Lithuanian language (lit) com.github.unrud.djpdf.OCR.Lit stable flathub
OCR Latvian OCR extension for Latvian language (lav) com.github.unrud.djpdf.OCR.Lav stable flathub
OCR Latin OCR extension for Latin language (lat) com.github.unrud.djpdf.OCR.Lat stable flathub
OCR Lao OCR extension for Lao language (lao) com.github.unrud.djpdf.OCR.Lao stable flathub
OCR Kurdish (Arabic Script) OCR extension for Kurdish (Arabic Script) language (kur_ara) com.github.unrud.djpdf.OCR.KurAra stable flathub
OCR Kurdish OCR extension for Kurdish language (kur) com.github.unrud.djpdf.OCR.Kur stable flathub
OCR Korean (vertical) OCR extension for Korean (vertical) language (kor_vert) com.github.unrud.djpdf.OCR.KorVert stable flathub
OCR Korean OCR extension for Korean language (kor) com.github.unrud.djpdf.OCR.Kor stable flathub
OCR Kirghiz; Kyrgyz OCR extension for Kirghiz; Kyrgyz language (kir) com.github.unrud.djpdf.OCR.Kir stable flathub
OCR Central Khmer OCR extension for Central Khmer language (khm) com.github.unrud.djpdf.OCR.Khm stable flathub
OCR Kazakh OCR extension for Kazakh language (kaz) com.github.unrud.djpdf.OCR.Kaz stable flathub
OCR Georgian - Old OCR extension for Georgian - Old language (kat_old) com.github.unrud.djpdf.OCR.KatOld stable flathub
OCR Georgian OCR extension for Georgian language (kat) com.github.unrud.djpdf.OCR.Kat stable flathub
OCR Kannada OCR extension for Kannada language (kan) com.github.unrud.djpdf.OCR.Kan stable flathub
OCR Japanese (vertical) OCR extension for Japanese (vertical) language (jpn_vert) com.github.unrud.djpdf.OCR.JpnVert stable flathub
OCR Japanese OCR extension for Japanese language (jpn) com.github.unrud.djpdf.OCR.Jpn stable flathub
OCR Javanese OCR extension for Javanese language (jav) com.github.unrud.djpdf.OCR.Jav stable flathub
OCR Italian - Old OCR extension for Italian - Old language (ita_old) com.github.unrud.djpdf.OCR.ItaOld stable flathub
OCR Italian OCR extension for Italian language (ita) com.github.unrud.djpdf.OCR.Ita stable flathub
OCR Icelandic OCR extension for Icelandic language (isl) com.github.unrud.djpdf.OCR.Isl stable flathub
OCR Indonesian OCR extension for Indonesian language (ind) com.github.unrud.djpdf.OCR.Ind stable flathub
OCR Inuktitut OCR extension for Inuktitut language (iku) com.github.unrud.djpdf.OCR.Iku stable flathub
OCR Armenian OCR extension for Armenian language (hye) com.github.unrud.djpdf.OCR.Hye stable flathub
OCR Hungarian OCR extension for Hungarian language (hun) com.github.unrud.djpdf.OCR.Hun stable flathub
OCR Croatian OCR extension for Croatian language (hrv) com.github.unrud.djpdf.OCR.Hrv stable flathub
OCR Hindi OCR extension for Hindi language (hin) com.github.unrud.djpdf.OCR.Hin stable flathub
OCR Hebrew OCR extension for Hebrew language (heb) com.github.unrud.djpdf.OCR.Heb stable flathub
OCR Haitian; Haitian Creole OCR extension for Haitian; Haitian Creole language (hat) com.github.unrud.djpdf.OCR.Hat stable flathub
OCR Gujarati OCR extension for Gujarati language (guj) com.github.unrud.djpdf.OCR.Guj stable flathub
OCR Greek, Ancient (to 1453) OCR extension for Greek, Ancient (to 1453) language (grc) com.github.unrud.djpdf.OCR.Grc stable flathub
OCR Galician OCR extension for Galician language (glg) com.github.unrud.djpdf.OCR.Glg stable flathub
OCR Irish OCR extension for Irish language (gle) com.github.unrud.djpdf.OCR.Gle stable flathub
OCR Scottish Gaelic OCR extension for Scottish Gaelic language (gla) com.github.unrud.djpdf.OCR.Gla stable flathub
OCR Western Frisian OCR extension for Western Frisian language (fry) com.github.unrud.djpdf.OCR.Fry stable flathub
OCR French, Middle (ca.1400-160… OCR extension for French, Middle (ca.1400-1600) language (frm) com.github.unrud.djpdf.OCR.Frm stable flathub
OCR German - Fraktur OCR extension for German - Fraktur language (frk) com.github.unrud.djpdf.OCR.Frk stable flathub
OCR French OCR extension for French language (fra) com.github.unrud.djpdf.OCR.Fra stable flathub
OCR Finnish OCR extension for Finnish language (fin) com.github.unrud.djpdf.OCR.Fin stable flathub
OCR Filipino (old - Tagalog) OCR extension for Filipino (old - Tagalog) language (fil) com.github.unrud.djpdf.OCR.Fil stable flathub
OCR Persian OCR extension for Persian language (fas) com.github.unrud.djpdf.OCR.Fas stable flathub
OCR Faroese OCR extension for Faroese language (fao) com.github.unrud.djpdf.OCR.Fao stable flathub
OCR Basque OCR extension for Basque language (eus) com.github.unrud.djpdf.OCR.Eus stable flathub
OCR Estonian OCR extension for Estonian language (est) com.github.unrud.djpdf.OCR.Est stable flathub
OCR Math / equation detection m… OCR extension for Math / equation detection module (equ) com.github.unrud.djpdf.OCR.Equ stable flathub
OCR Esperanto OCR extension for Esperanto language (epo) com.github.unrud.djpdf.OCR.Epo stable flathub
OCR English, Middle (1100-1500) OCR extension for English, Middle (1100-1500) language (enm) com.github.unrud.djpdf.OCR.Enm stable flathub
OCR Greek, Modern (1453-) OCR extension for Greek, Modern (1453-) language (ell) com.github.unrud.djpdf.OCR.Ell stable flathub
OCR Dzongkha OCR extension for Dzongkha language (dzo) com.github.unrud.djpdf.OCR.Dzo stable flathub
OCR Divehi OCR extension for Divehi language (div) com.github.unrud.djpdf.OCR.Div stable flathub
OCR German - Fraktur OCR extension for German - Fraktur language (deu_frak) com.github.unrud.djpdf.OCR.DeuFrak stable flathub
OCR German OCR extension for German language (deu) com.github.unrud.djpdf.OCR.Deu stable flathub
OCR Danish - Fraktur OCR extension for Danish - Fraktur language (dan_frak) com.github.unrud.djpdf.OCR.DanFrak stable flathub
OCR Danish OCR extension for Danish language (dan) com.github.unrud.djpdf.OCR.Dan stable flathub
OCR Welsh OCR extension for Welsh language (cym) com.github.unrud.djpdf.OCR.Cym stable flathub
OCR Corsican OCR extension for Corsican language (cos) com.github.unrud.djpdf.OCR.Cos stable flathub
OCR Cherokee OCR extension for Cherokee language (chr) com.github.unrud.djpdf.OCR.Chr stable flathub
OCR Chinese - Traditional (vert… OCR extension for Chinese - Traditional (vertical) language (chi_tr… com.github.unrud.djpdf.OCR.ChiTraVert stable flathub
OCR Chinese - Traditional OCR extension for Chinese - Traditional language (chi_tra) com.github.unrud.djpdf.OCR.ChiTra stable flathub
OCR Chinese - Simplified (verti… OCR extension for Chinese - Simplified (vertical) language (chi_sim… com.github.unrud.djpdf.OCR.ChiSimVert stable flathub
OCR Chinese - Simplified OCR extension for Chinese - Simplified language (chi_sim) com.github.unrud.djpdf.OCR.ChiSim stable flathub
OCR Czech OCR extension for Czech language (ces) com.github.unrud.djpdf.OCR.Ces stable flathub
OCR Cebuano OCR extension for Cebuano language (ceb) com.github.unrud.djpdf.OCR.Ceb stable flathub
OCR Catalan; Valencian OCR extension for Catalan; Valencian language (cat) com.github.unrud.djpdf.OCR.Cat stable flathub
OCR Bulgarian OCR extension for Bulgarian language (bul) com.github.unrud.djpdf.OCR.Bul stable flathub
OCR Breton OCR extension for Breton language (bre) com.github.unrud.djpdf.OCR.Bre stable flathub
OCR Bosnian OCR extension for Bosnian language (bos) com.github.unrud.djpdf.OCR.Bos stable flathub
OCR Tibetan OCR extension for Tibetan language (bod) com.github.unrud.djpdf.OCR.Bod stable flathub
OCR Bengali OCR extension for Bengali language (ben) com.github.unrud.djpdf.OCR.Ben stable flathub
OCR Belarusian OCR extension for Belarusian language (bel) com.github.unrud.djpdf.OCR.Bel stable flathub
OCR Azerbaijani - Cyrilic OCR extension for Azerbaijani - Cyrilic language (aze_cyrl) com.github.unrud.djpdf.OCR.AzeCyrl stable flathub
OCR Azerbaijani OCR extension for Azerbaijani language (aze) com.github.unrud.djpdf.OCR.Aze stable flathub
OCR Assamese OCR extension for Assamese language (asm) com.github.unrud.djpdf.OCR.Asm stable flathub
OCR Arabic OCR extension for Arabic language (ara) com.github.unrud.djpdf.OCR.Ara stable flathub
OCR Amharic OCR extension for Amharic language (amh) com.github.unrud.djpdf.OCR.Amh stable flathub
OCR Afrikaans OCR extension for Afrikaans language (afr) com.github.unrud.djpdf.OCR.Afr stable flathub
Scans to PDF Create small, searchable PDFs from scanned documents com.github.unrud.djpdf 0.1.3 stable flathub
[marco@marco-N24-25JU ~]$ flatpak install flathub flathub com.github.unrud.djpdf.OCR.Epo
Looking for matches…
Found ref ‘app/org.flathub.flatpak-external-data-checker/x86_64/stable’ in remote ‘flathub’ (system).
Use this ref? [Y/n]: y
Required runtime for org.flathub.flatpak-external-data-checker/x86_64/stable (runtime/org.freedesktop.Sdk/x86_64/20.08) found in remote flathub
Do you want to install it? [Y/n]: y
Impressing ha?
--
Saluton,
Marco Ciampa
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