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c#ocrtesseractregion

Steps to use tesseract to analyze rectangular area on screen

I would like to use tesseract OCR to get text on a rectangular area of the screen using c# on Visual Studio C#.

First, what are required to get tesseract working in Visual Studio C#? I am new to use Visual Studio and setting up wrappers. After hours of searching on Google, I found I would need: a wrapper(charlesw), a language pack from official site. Do I also need to install windows tesseract-ocr?

I have followed the steps on charlesw's GitHu to setup the wrapper in my project. Yet, I am still not sure how to use the functions.

I assume this is how to declare an OCR engine: TesseractEngine engine = new TesseractEngine(@"./tessdata", "eng", EngineMode.Default);

To analyze the rectangular region on the screen, I could capture the screen of certain region, and then save it in .bmp or .tif. Next, to use the engine to analyze the image. engine.[unkwonapi](imagepath); //what is the api name going to be? I tried to look it up [here][2]. Or, some people said it could be done by using tesseract's api, where we can input the coordination of the rectangular region.

Solution

  • The wrapper bundles Tesseract DLL (as libtesseract302.dll). You do not need to install windows tesseract-ocr; as a matter of fact, you should not, as it can interfere with the wrapper.

    You can use either of the following to specify a region of interest on the image:

    engine.Process(Bitmap image, Rect region, PageSegMode? pageSegMode = null)

    or

    engine.Process(Pix image, Rect region, PageSegMode? pageSegMode = null)