Reduce file size of output PDF in IronOcr

IronOCR will automatically upscale inputs that are detected as low quality (below 150DPI) to ensure accurate read results.

If DPI below 150 is detected, TargetDPI (default 225DPI) defines the DPI that a PDF is rendered at - this is the same as manually setting TargetDPI = 225.

To reduce output file size you can set a lower TargetDPI, which will create smaller PDFs, but going too low may affect OCR performance. Everything in balance.

Suggested values are 96, 72, 48

// how to reduce and usage by by reducing DPI
//Example 1
using IronOcr;
var Ocr = new IronTesseract();
using (var Input = new OcrInput())
{
    Input.TargetDPI = 96;    // DPI of output, default is 225
    Input.AddPdf("example.pdf", "password");
    var Result = Ocr.Read(Input);
    Console.WriteLine(Result.Text);
}

//Example 2
var ocr = new IronTesseract();
using (var ocrInput = new OcrInput())
{
ocrInput.AddPdf("img/Input.pdf", 72); //TargetDPI
var ocrResult = ocr.Read(ocrInput);
ocrResult.SaveAsSearchablePdf(@"Output.pdf");
}
	

To disable automatic upscaling, please use TargetDPI = 0. This will ignore the TargetDPI value and the input file will be read as-in.

See the API for more information: https://ironsoftware.com/csharp/ocr/object-reference/api/IronOcr.OcrInput.html?q=targetdpi#IronOcr_OcrInput_TargetDPI