Image resizing

public partial class ResizeKeepRatio : Form
{
    private string m_image_filename = null;
 
    public ResizeKeepRatio()
    {
        InitializeComponent();
    }
 
    private void button1_Click(object sender, EventArgs e)
    {
        openFileDialog1.ShowDialog();
        m_image_filename = openFileDialog1.FileName;
        pictureBox1.Invalidate();
    }
 
    private void eraseImage(Graphics graph)
    {
        Rectangle rect = new Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height);
        graph.DrawRectangle(new Pen(Brushes.Orange, (float) rect.Width), rect);
    }
 
    private void drawScaledImage(Graphics graph)
    {
        if(m_image_filename == null)
            return;
 
        Bitmap bmp = new Bitmap(m_image_filename);
        Rectangle sourceRect = new Rectangle(0, 0, bmp.Width, bmp.Height);
        Rectangle drawAreaRect = new Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height);
        Rectangle targetRect;
 
        // determine whether to resize horizontally or vertically
        // based on the ratio width/height of source image and target rectangle
        double sourceRatio = (double)sourceRect.Height / (double)sourceRect.Width;
        double targetRatio = (double)drawAreaRect.Height / (double)drawAreaRect.Width;
        double drawRatio;
        if (sourceRatio > targetRatio)
            drawRatio = (double) drawAreaRect.Height / (double) sourceRect.Height;
        else
            drawRatio = (double) drawAreaRect.Width / (double) sourceRect.Width;
 
        // calculate target rectangle and center
        targetRect = new Rectangle(
            (int) ((drawAreaRect.Width - drawRatio * sourceRect.Width) / 2), 
            (int) ((drawAreaRect.Height - drawRatio * sourceRect.Height) / 2), 
            (int) (drawRatio * sourceRect.Width), 
            (int) (drawRatio * sourceRect.Height));
 
        // draw the image
        graph.DrawImage(bmp, targetRect);
    }
 
    private void pictureBox1_Paint(object sender, PaintEventArgs e)
    {
        eraseImage(e.Graphics);
        drawScaledImage(e.Graphics);
    }
 
}

                                              

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Public Partial Class ResizeKeepRatio
    Inherits Form
    Private m_image_filename As String = Nothing
    
    Public Sub New()
        InitializeComponent()
    End Sub
    
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs)
        openFileDialog1.ShowDialog()
        m_image_filename = openFileDialog1.FileName
        pictureBox1.Invalidate()
    End Sub
    
    Private Sub eraseImage(ByVal graph As Graphics)
        Dim rect As New Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height)
        graph.DrawRectangle(New Pen(Brushes.Orange, CSng(rect.Width)), rect)
    End Sub
    
    Private Sub drawScaledImage(ByVal graph As Graphics)
        If m_image_filename Is Nothing Then
            Exit Sub
        End If
        
        Dim bmp As New Bitmap(m_image_filename)
        Dim sourceRect As New Rectangle(0, 0, bmp.Width, bmp.Height)
        Dim drawAreaRect As New Rectangle(0, 0, pictureBox1.Width, pictureBox1.Height)
        Dim targetRect As Rectangle
        
        ' determine whether to resize horizontally or vertically '
        ' based on the ratio width/height of source image and target 'rectangle
        Dim sourceRatio As Double = CDbl(sourceRect.Height) / CDbl(sourceRect.Width)
        Dim targetRatio As Double = CDbl(drawAreaRect.Height) / CDbl(drawAreaRect.Width)
        Dim drawRatio As Double
        If sourceRatio > targetRatio Then
            drawRatio = CDbl(drawAreaRect.Height) / CDbl(sourceRect.Height)
        Else
            drawRatio = CDbl(drawAreaRect.Width) / CDbl(sourceRect.Width)
        End If
        
        ' calculate target rectangle and center '
        targetRect = New Rectangle(CInt(((drawAreaRect.Width - drawRatio * sourceRect.Width) / 2)), CInt(((drawAreaRect.Height - drawRatio * sourceRect.Height) / 2)), CInt((drawRatio * sourceRect.Width)), CInt((drawRatio * sourceRect.Height)))
        
        ' draw the image '
        graph.DrawImage(bmp, targetRect)
    End Sub
    
    Private Sub pictureBox1_Paint(ByVal sender As Object, ByVal e As PaintEventArgs)
        eraseImage(e.Graphics)
        drawScaledImage(e.Graphics)
    End Sub
    
End Class
                                              

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Dim bp As New Bitmap(newSize.Width, newSize.Height)
                Dim g As Graphics = Graphics.FromImage(bp)
 
                ' Controls the quality of the image
                g.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
                g.InterpolationMode = Drawing2D.InterpolationMode.HighQualityBicubic
                g.PixelOffsetMode = Drawing2D.PixelOffsetMode.HighQuality
 
                Dim rect As New Rectangle(0, 0, newSize.Width, newSize.Height)
                g.DrawImage(currentImage, rect, 0, 0, currentImage.Width, currentImage.Height, GraphicsUnit.Pixel)
 
                ' Copy Meta from old image to new image
                For Each pItem As System.Drawing.Imaging.PropertyItem In currentImage.PropertyItems
                    bp.SetPropertyItem(pItem)
                Next
                newFileName = "Thumb_" & file.ToString
                ' Saves as jpeg
                bp.Save(NewDir & "\Thumbnails\" & newFileName, Imaging.ImageFormat.Jpeg)

                                              

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