Tesseract安装使用

mac

brew install Tesseract

↳ Command-Line OCR with Tesseract on Mac OS X

tags:  ocr

This is a short writeup of the working process I came up with for command-line OCR of a non-OCR’d PDF with searchable PDF output on OS X, after running into a thousand little gotchas. ¹

Software Installation

1. Install homebrew (if you haven’t already).

2. Install ImageMagick with TIFF and Ghostscript support:

   brew install --with-libtiff --with-ghostscript imagemagick
   

3. Install Tesseract with all languages:

   brew install --all-languages tesseract
   

4. Install pdftk server from the package installer.

Processing Workflow

I’m going to assume you have a non-OCR’d PDF you want to convert into a searchable PDF.

1. Split and convert the PDF with ImageMagick convert:

   convert -density 300 input.pdf -type Grayscale -compress lzw -background white +matte -depth 32 page_%05d.tif
   

2. OCR the pages with Tesseract: ^2 3

   for i in page_*.tif; do echo $i; tesseract $i $(basename $i .tif) pdf; done
   

3. Join your individual PDF files into a single, searchable PDF with pdftk: ⁴

   pdftk page_*.pdf cat output merged.pdf

convert 9.png -resize 3000% -type Grayscale input9.tif （因为像素low所以要转）

tesseract input9.tif output9 -l eng

tesseract input9.png output9   (默认是eng英文)