How to extract text from the predefined rectangle from a PDF document?

PdfLoadedDocument loadedDocument = new PdfLoadedDocument("../../Data/Barcode.pdf");
            using (OCRProcessor processor = new OCRProcessor("../../Tesseract binaries"))
            {
                //Language to process the OCR
                processor.Settings.Language = Languages.English;
                Bitmap image = loadedDocument.ExportAsImage(0);
                //Define the bounds from which the text to be extracted
                Rectangle textBounds = new Rectangle(274, 53, 68, 15);
                //Point to Pixel conversion
                RectangleF rect = new RectangleF(textBounds.X * 1.3333f, textBounds.Y * 1.3333f, textBounds.Width * 1.3333f, textBounds.Height * 1.3333f);
                using (Bitmap clonedImage = image.Clone(rect, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
                {
                    string ocrText = processor.PerformOCR(clonedImage, @"../../Tessdata/");                 
                }
                image.Dispose();
            }