- 安装使用:
Tesseract下载地址
https://code.google.com/p/tesseract-ocr/
目前最新版本为3.02
windows版下载解压后,使用命令行,进入解压后目录运行
命令格式:
Usage:tesseract.exe imagename outputbase [-l lang] [-psm pagesegmode] e...] pagesegmode values are: 0 = Orientation and script detection (OSD) only. 1 = Automatic page segmentation with OSD. 2 = Automatic page segmentation, but no OSD, or OCR 3 = Fully automatic page segmentation, but no OSD. (Default) 4 = Assume a single column of text of variable sizes. 5 = Assume a single uniform block of vertically aligned text. 6 = Assume a single uniform block of text. 7 = Treat the image as a single text line. 8 = Treat the image as a single word. 9 = Treat the image as a single word in a circle. 10 = Treat the image as a single character. -l lang and/or -psm pagesegmode must occur before anyconfigfile. Single options: -v --version: version info --list-langs: list available languages for tesseract engine
命令举例:
F:\Tesseract-OCR>tesseract.exe 2013-09-05_154628.jpg eng -l eng -psm 6
相关命令列表:
功能 | 命令 |
ambiguous_words.exe | |
classifier_tester.exe | |
cntraining.exe | |
整合训练文件 | combine_tessdata.exe |
dawg2wordlist.exe | |
mftraining.exe | |
shapeclustering.exe | |
识别程序 | tesseract.exe |
unicharset_extractor.exe | |
wordlist2dawg.exe |
- 字库训练
需要的字库文件参考代码:
tesseract-ocr\ccutil\tessdatamanager.h
对字库相关的配置文件的格式要求:
ASCII or UTF-8 encoding without BOM
Unix end-of-line marker ('\n')
The last character must be an end of line marker ('\n'). Some text editors will show this as an empty line at the end of file. If you omit this you will got error message containing "last_char == '\n':Error:Assert failed..."
步骤:
1.生成训练图片
几个原则:
保证每个字符出现的频率一般10次,常用字20次,不常用字5次;
不能把特殊字符都放在一起,应该用更加接近实际使用的组合;
非常重要:在字符和行之间保持一定的间隔,否则可能导致失败。(可能在3.0之后的版本修复)
训练的数据需要以font分组,相同font的文字需要放在同一个tiff文件中,(支持多页page)
除非字体太小(高度小于15px),没有必要做不同尺寸的训练;
绝对不可以在同一个image文件中混杂多种字体
(可以参考下载页中的boxtiff文件样例)
Next print and scan (or use some electronic rendering method) to create an image of your training page. Upto 32 training files can be used (of multiple pages). It is best to create a mix of fonts and styles (but in separate files), including italic and bold.
生成tiff文件
2.制作box文件
生成box文件命令:
tesseract [lang].[fontname].exp[num].tif [lang].[fontname].exp[num] batch.nochop makebox
例:
tesseract eng.timesitalic.exp0.tif eng.timesitalic.exp0 batch.nochop makebox
3.得到一个新的字符集
- 其他
参考文档:
解压后doc目录中有API说明
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