Low quality picture produced by snapshot. WPF

The program below creates a snapshot with the content of the main window of the application itself. However the quality of the produced picture is not equivalent to the print screen program of windows 10, which produces the desired result.

Here is a snapshot of the program running, taken with the print screen program of windows 10, zoomed in:



And here is the snapshot that the program below is producing, zoomed in:



Is there something we can try to improve the quality of the snapshot that this program produse?

I tried Bitmap Encoder but is the same result , just without transparency, (Don't need to have transparency) also tried some other Pixel Formats but I get errors, only Pbgra32 seems to work as the program is.

Thanks in advance.

using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApp2
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }
        private void Button_Click(object sender, RoutedEventArgs e)
        {
            if (linevertical.Visibility == Visibility.Hidden)
            { linevertical.Visibility = Visibility.Visible; }
            else { linevertical.Visibility = Visibility.Hidden; }
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            if (lineo.Visibility == Visibility.Hidden)
            { lineo.Visibility = Visibility.Visible; }
            else { lineo.Visibility = Visibility.Hidden; }
        }

        private void Mainwindow_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.A)
            {
                lineo.Visibility = Visibility.Hidden;
                linevertical.Visibility = Visibility.Hidden;
            }
            if (e.Key == Key.S)
            {
                lineo.Visibility = Visibility.Visible;
                linevertical.Visibility = Visibility.Visible;

            }

            if (e.Key == Key.P)
            {
                //Set scrollviewer's Content property as UI element to capture full content
                UIElement element = mainwindow.Content as UIElement;
                Uri path = new Uri(@"C:\\Desktop\screenshot.png");
                CaptureScreen(element, path);
            }

        }
            public void CaptureScreen(UIElement source, Uri destination)
            {
                try
                {
                    Double Height, renderHeight, Width, renderWidth;

                    Height = renderHeight = source.RenderSize.Height;
                    Width = renderWidth = source.RenderSize.Width;

                    //Specification for target bitmap like width/height pixel etc.
                    RenderTargetBitmap renderTarget = new RenderTargetBitmap((int)renderWidth, (int)renderHeight, 96, 96, PixelFormats.Pbgra32);
                    //creates Visual Brush of UIElement
                    VisualBrush visualBrush = new VisualBrush(source);

                    DrawingVisual drawingVisual = new DrawingVisual();
                    using (DrawingContext drawingContext = drawingVisual.RenderOpen())
                    {
                        //draws image of element
                        drawingContext.DrawRectangle(visualBrush, null, new Rect(new Point(0, 0), new Point(Width, Height)));
                    }
                    //renders image
                    renderTarget.Render(drawingVisual);

                    //PNG encoder for creating PNG file
                    PngBitmapEncoder encoder = new PngBitmapEncoder();
                    encoder.Frames.Add(BitmapFrame.Create(renderTarget));
                    using (FileStream stream = new FileStream(destination.LocalPath, FileMode.Create, FileAccess.Write))
                    {
                        encoder.Save(stream);
                    }
                }
                catch (Exception e)
                {
                    MessageBox.Show(e.ToString());
                }
            }

        

    }
}