How do you improve the accuracy of the Tesseract OCR?

How do you improve the accuracy of the Tesseract OCR?

13 Answers

1. fix DPI (if needed) 300 DPI is minimum.
2. fix text size (e.g. 12 pt should be ok)
3. try to fix text lines (deskew and dewarp text)
4. try to fix illumination of image (e.g. no dark part of image)
5. binarize and de-noise image.

How well does Tesseract work?

The only Tesseract usage was accurate on ~70% with perfect image, with bad lighting/quality the image accuration was ~30%. As the result was insufficient I decided to use Vision library by Apple. I used it for block finding and its recognition.

How do I know if my OCR is accurate?

Measuring OCR accuracy is done by taking the output of an OCR run for an image and comparing it to the original version of the same text. You can then either count how many characters were detected correctly (character level accuracy), or count how many words were recognized correctly (word level accuracy).

How do I get the best OCR results?

9 Steps To Improve OCR Accuracy

1. Checking the Source Image Quality. ...
2. Choosing the Best OCR Engine. ...
3. Scaling the Image to the Right Size. ...
4. Enhancing the Contrast of Images. ...
5. Removing Noise From the Images. ...
6. Preparing and Handling the Document Properly. ...
7. Deskewing and Analyzing Page Layout. ...
8. Analyzing Character Edge.

How long does it take Tesseract to do an OCR?

Although Tesseract’s accuracy for interpreting images to text is sufficient and compares well to commercial options, its execution speed is slow. From sample runs, it takes roughly 8-10 seconds to perform OCR on a small pdf document (3-4 pages). The immediate culprit here isn’t Tesseract though, it’s Ghostscript.

How is tesseract used for Optical Character Recognition?

The method of extracting text from images is also called Optical Character Recognition (OCR) or sometimes simply text recognition. Tesseract was developed as a proprietary software by Hewlett Packard Labs. In 2005, it was open sourced by HP in collaboration with the University of Nevada, Las Vegas.

Is there an open source version of tesseract?

In 2005 HP released Tesseract as an open-source software. Since 2006 it is developed by Google. OCRopus — OCRopus is an open-source OCR system allowing easy evaluation and reuse of the OCR components by both researchers and companies. A collection of document analysis programs, not a turn-key OCR system.

What kind of OCR engine does tesseract 4 have?

Tesseract 4 has two OCR engines — Legacy Tesseract engine and LSTM engine. There are four modes of operation chosen using the — oem option. 0 Legacy engine only. 1 Neural nets LSTM engine only. 2 Legacy + LSTM engines. 3 Default, based on what is available. Pytesseract is a wrapper for Tesseract-OCR Engine.