它可以直接使用，或者（对于程序员）使用 API 从图像中提取输入，包括手写的或打印的文本。
与Microsoft Office Document Imaging（MODI）相比，我们可以不断的训练的库，使图像转换文本的能力不断增强；
如果团队深度需要，还可以以它为模板，开发出符合自身需求的OCR引擎。
源码地址为：https://github.com/tesseract-ocr/tesseract；
你可以训练它
大体流程为：安装jTessBoxEditor -> 获取样本文件 -> Merge样本文件 –> 生成BOX文件 -> 定义字符配置文件 -> 字符矫正 -> 执行批处理文件 -> 将生成的 traineddata 放 入tessdata 中。
具体细节参考：光学字符识别引擎 tesseract-ocr 样体训练
它是跨平台的，支持：
Linux
macOS
Windows
Tesseract-OCR4.0 版本在 Win7 上的安装过程
Tesseract-OCR4.0版本在VS2015上的编译与运行
它支持很多种的语言，包括：
| Lang Code | Language | 4.0 traineddata |
|---|---|---|
| afr | Afrikaans | afr.traineddata |
| amh | Amharic | amh.traineddata |
| ara | Arabic | ara.traineddata |
| asm | Assamese | asm.traineddata |
| aze | Azerbaijani | aze.traineddata |
| aze_cyrl | Azerbaijani - Cyrillic | aze_cyrl.traineddata |
| bel | Belarusian | bel.traineddata |
| ben | Bengali | ben.traineddata |
| bod | * | bod.traineddata |
| bos | Bosnian | bos.traineddata |
| bul | Bulgarian | bul.traineddata |
| cat | Catalan; Valencian | cat.traineddata |
| ceb | Cebuano | ceb.traineddata |
| ces | Czech | ces.traineddata |
| chi_sim | Chinese - Simplified | chi_sim.traineddata |
| chi_tra | Chinese - Traditional | chi_tra.traineddata |
| chr | Cherokee | chr.traineddata |
| cym | Welsh | cym.traineddata |
| dan | Danish | dan.traineddata |
| deu | German | deu.traineddata |
| dzo | Dzongkha | dzo.traineddata |
| ell | Greek, Modern (1453-) | ell.traineddata |
| eng | English | eng.traineddata |
| enm | English, Middle (1100-1500) | enm.traineddata |
| epo | Esperanto | epo.traineddata |
| est | Estonian | est.traineddata |
| eus | Basque | eus.traineddata |
| fas | Persian | fas.traineddata |
| fin | Finnish | fin.traineddata |
| fra | French | fra.traineddata |
| frk | Frankish | frk.traineddata |
| frm | French, Middle (ca. 1400-1600) | frm.traineddata |
| gle | Irish | gle.traineddata |
| glg | Galician | glg.traineddata |
| grc | Greek, Ancient (-1453) | grc.traineddata |
| guj | Gujarati | guj.traineddata |
| hat | Haitian; Haitian Creole | hat.traineddata |
| heb | Hebrew | heb.traineddata |
| hin | Hindi | hin.traineddata |
| hrv | Croatian | hrv.traineddata |
| hun | Hungarian | hun.traineddata |
| iku | Inuktitut | iku.traineddata |
| ind | Indonesian | ind.traineddata |
| isl | Icelandic | isl.traineddata |
| ita | Italian | ita.traineddata |
| ita_old | Italian - Old | ita_old.traineddata |
| jav | Javanese | jav.traineddata |
| jpn | Japanese | jpn.traineddata |
| kan | Kannada | kan.traineddata |
| kat | Georgian | kat.traineddata |
| kat_old | Georgian - Old | kat_old.traineddata |
| kaz | Kazakh | kaz.traineddata |
| khm | Central Khmer | khm.traineddata |
| kir | Kirghiz; Kyrgyz | kir.traineddata |
| kor | Korean | kor.traineddata |
| kur | Kurdish | kur.traineddata |
| lao | Lao | lao.traineddata |
| lat | Latin | lat.traineddata |
| lav | Latvian | lav.traineddata |
| lit | Lithuanian | lit.traineddata |
| mal | Malayalam | mal.traineddata |
| mar | Marathi | mar.traineddata |
| mkd | Macedonian | mkd.traineddata |
| mlt | Maltese | mlt.traineddata |
| msa | Malay | msa.traineddata |
| mya | Burmese | mya.traineddata |
| nep | Nepali | nep.traineddata |
| nld | Dutch; Flemish | nld.traineddata |
| nor | Norwegian | nor.traineddata |
| ori | Oriya | ori.traineddata |
| pan | Panjabi; Punjabi | pan.traineddata |
| pol | Polish | pol.traineddata |
| por | Portuguese | por.traineddata |
| pus | Pushto; Pashto | pus.traineddata |
| ron | Romanian; Moldavian; Moldovan | ron.traineddata |
| rus | Russian | rus.traineddata |
| san | Sanskrit | san.traineddata |
| sin | Sinhala; Sinhalese | sin.traineddata |
| slk | Slovak | slk.traineddata |
| slv | Slovenian | slv.traineddata |
| spa | Spanish; Castilian | spa.traineddata |
| spa_old | Spanish; Castilian - Old | spa_old.traineddata |
| sqi | Albanian | sqi.traineddata |
| srp | Serbian | srp.traineddata |
| srp_latn | Serbian - Latin | srp_latn.traineddata |
| swa | Swahili | swa.traineddata |
| swe | Swedish | swe.traineddata |
| syr | Syriac | syr.traineddata |
| tam | Tamil | tam.traineddata |
| tel | Telugu | tel.traineddata |
| tgk | Tajik | tgk.traineddata |
| tgl | Tagalog | tgl.traineddata |
| tha | Thai | tha.traineddata |
| tir | Tigrinya | tir.traineddata |
| tur | Turkish | tur.traineddata |
| uig | Uighur; * | uig.traineddata |
| ukr | Ukrainian | ukr.traineddata |
| urd | Urdu | urd.traineddata |
| uzb | Uzbek | uzb.traineddata |
| uzb_cyrl | Uzbek - Cyrillic | uzb_cyrl.traineddata |
| vie | Vietnamese | vie.traineddata |
| yid | Yiddish | yid.traineddata |