Disable DEP for specific applications. How to Disable DEP for Specific Applications Click the Start button on your Windows computer and choose Computer > System Properties > Advanced System Settings. From the System Properties dialog, select Settings. Select the Data Execution Prevention tab. Select Turn on DEP for all programs and services except those I … Read more
Create a config file (e.g “letters”) in tessdata/configs directory – usually /usr/share/tesseract/tessdata/configs or /usr/share/tesseract-ocr/tessdata/configs And add this line to the config file: tessedit_char_whitelist abcdefghijklmnopqrstuvwxyz …or maybe [a-z] works. I don’t know. Then call tesseract similar to this: tesseract input.tif output nobatch letters That will limit tesseract to recognize only the wanted characters.
Tesseract is an OCR engine. It’s used, worked on and funded by Google specifically to read text from images, perform basic document segmentation and operate on specific image inputs (a single word, line, paragraph, page, limited dictionaries, etc.). OpenCV, on the other hand, is a computer vision library that includes features that let you perform … Read more
You can grab eng.traineddata Github: wget https://github.com/tesseract-ocr/tessdata/raw/main/eng.traineddata Check https://github.com/tesseract-ocr/tessdata for a full list of trained language data. When you grab the file(s), move them to the /usr/local/share/tessdata folder. Warning: some Linux distributions (such as openSUSE and Ubuntu) may be expecting it in /usr/share/tessdata instead. # If you got the data from Google, unzip it first! … Read more
OCR can be pretty CPU intensive, you might want to reconsider doing it on a smart phone. That aside, to my knowledge the popular OCR libraries are Aspire and Tesseract. Neither are straight up Java, so you’re not going to get a drop-in Android OCR library. However, Tesseract is open source (GitHub hosted infact); so … Read more
I recommend trying the Java OCR project on sourceforge.net. I originally developed it, and I have a blog posting on it. Since I put it up on sourceforge, its functionality been expanded and improved quite a bit through the great work of a volunteer researcher/developer. Give it a try, and if you don’t like it, … Read more
I notice that almost all the answers here relate to the ineffectiveness of the concept of CAPTCHA, in principle – and while I very much agree with them, in fact gave a talk at OWASP a few months ago explaining just that – the question is very specific, so I will provide for a demonstration. … Read more
fix DPI (if needed) 300 DPI is minimum fix text size (e.g. 12 pt should be ok) try to fix text lines (deskew and dewarp text) try to fix illumination of image (e.g. no dark part of image) binarize and de-noise image There is no universal command line that would fit to all cases (sometimes … Read more
Well, I decided to workout myself on my question to solve the above problem. What I wanted is to implement a simple OCR using KNearest or SVM features in OpenCV. And below is what I did and how. (it is just for learning how to use KNearest for simple OCR purposes). 1) My first question … Read more