C#调用IronOcr识别文字不理想

识别文字不理想，不知道什么原因，文字太小就几乎无法识别。。。。

 void Test()
        {

            DateTime d1 = DateTime.Now;
            var ocr = new IronTesseract();
            ocr.Language = OcrLanguage.ChineseSimplifiedBest;
            //ocr.UseCustomTesseractLanguageFile("custom_tesseract_files/custom.traineddata");
            using (var ocrInput = new OcrInput())
            {
                ocrInput.AddImage("D:\\1.png");
                //  ocrInput.AddPdf("document.pdf");

                // Optionally Apply Filters if needed:
                //ocrInput.Deskew();  // use only if image not straight
                //ocrInput.DeNoise(); // use only if image contains digital noise
                ocrInput.Invert();
                //ocrInput.ToGrayScale();
                ocrInput.EnhanceResolution();
                var ocrResult = ocr.Read(ocrInput);
                var useSeconds = (DateTime.Now - d1).TotalMilliseconds;

                Console.WriteLine("" + useSeconds + ":" + ocrResult.Text);

            }
        }