string Result = ""; var ocr = new IronTesseract(); // Crop the bitmap to the specified rect var croppedBitmap = bitmap.Clone(rect, bitmap.PixelFormat); using (MemoryStream ms = new MemoryStream()) { croppedBitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png); AnyBitmap test = new AnyBitmap(ms); Result = ocr.Read(test).Text; }