Postup jak vygenerovat kvalitní OCR

```
pdfimages Co_jest_obect_KHB.pdf cojeimg
pdfinfo Co_jest_obect_KHB.pdf 
for img in cojeimg-*.ppm ; do textcleaner -g $img ${img%*.ppm}-clean.ppm ; done
for img in cojeimg-*-clean.ppm ; do tesseract $img ${img%*-clean.ppm} -l ces -c tessedit_create_hocr=1 ; done
cat cojeimg-0*.txt >cojestobec-img.txt
```