An Easy Way to Resize an Image

Imports System.IO
Public Class frmResize
    Public strSource As String
    Public strDestination As String

 
    Public Function ImageResize(ByVal strImageSrcPath As String _
                              , ByVal strImageDesPath As String _
                              , Optional ByVal intWidth As Integer = 0 _
                              , Optional ByVal intHeight As Integer = 0) As String

        If System.IO.File.Exists(strImageSrcPath) = False Then Exit Function

        Dim objImage As System.Drawing.Image = System.Drawing.Image.FromFile(strImageSrcPath)

        If intWidth > objImage.Width Then intWidth = objImage.Width
        If intHeight > objImage.Height Then intHeight = objImage.Height
        If intWidth = 0 And intHeight = 0 Then
            intWidth = objImage.Width
            intHeight = objImage.Height
        ElseIf intHeight = 0 And intWidth <> 0 Then
            intHeight = Fix(objImage.Height * intWidth / objImage.Width)
        ElseIf intWidth = 0 And intHeight <> 0 Then
            intWidth = Fix(objImage.Width * intHeight / objImage.Height)
        End If

        Dim imgOutput As New Bitmap(objImage, intWidth, intHeight)
        Dim imgFormat = objImage.RawFormat

        objImage.Dispose()
        objImage = Nothing

        If strImageSrcPath = strImageDesPath Then System.IO.File.Delete(strImageSrcPath)
        ' send the resized image to the viewer
        imgOutput.Save(strImageDesPath, imgFormat)
        imgOutput.Dispose()

        Return strImageDesPath

    End Function


    Private Sub ButtonBrowseSource_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonBrowseSource.Click
        With OpenFileDialog1
            .ShowDialog()
            strSource = .FileName
            TextBox1.Text = strSource
        End With

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        With SaveFileDialog1
            .ShowDialog()
            strDestination = .FileName
            TextBox2.Text = strDestination
        End With
    End Sub

    Private Sub ButtonResize_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ButtonResize.Click
        If strSource <> vbNullString _
            And strDestination <> vbNullString _
                And TextBoxHeight.Text <> vbNullString _
                    And TextBoxWidth.Text <> vbNullString Then
            If (Me.ImageResize( _
                            strSource _
                           , strDestination _
                           , CInt(TextBoxWidth.Text) _
                           , CInt(TextBoxHeight.Text))) <> "" Then
                MsgBox("Resize completed.", MsgBoxStyle.Information)
            Else
                MsgBox("Error", MsgBoxStyle.Critical)
            End If

        End If
    End Sub

    Private Sub frmResize_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub
End Class