Create graph and loading on PDF in Visual Studio C#

Question

In the C# project that I'm working on, when I click on a button the code create a PDF where I load a graph previously created with datas from source code. I used ScottPlot Library, but this library create a png file, saved and then load it on the PDF (this one created with iText7 library), but the quality is kinda blurry.

Is there a way to direclty create a graph on a PDF with better graphic quality? Even with a different library (for the graph and pdf).

This is my code where I create and load the graph on the PDF:

/******** GRAPH ********/
var plt = new ScottPlot.Plot(600, 400);

// create sample data
double[] values = { 26, 20, 23, 7, 16 };

// add a bar graph to the plot
plt.AddBar(values);

// adjust axis limits so there is no padding below the bar graph
plt.SetAxisLimits(yMin: 0);

//ADD GRAPH TO PDF
Add_Graph(plt, "bar_quickstart.png", doc);

Funzione Add_Graph:

private void Add_Graph(ScottPlot.Plot plt, string png, Document doc)
{
  plt.SaveFig(png);
  // Aggiungi il grafico alla posizione desiderata
  var image = new iText.Layout.Element.Image(ImageDataFactory.Create(png));
  image.SetFixedPosition(doc.GetLeftMargin() + 152, doc.GetBottomMargin(), 615);
  doc.Add(image);
}

doc in this last function is how I create the PDF:

string pdfPath = "dataGraphic.pdf";
var pdfDocument = new PdfDocument(new PdfWriter(pdfPath));
var document = new Document(pdfDocument, PageSize.A4.Rotate(), false);