Unable to change the dimension of image in VB.NET

[AdityaR]

I am unable to change the dimension of an image with the following code:

Dim pictbox As New PictureBox
Dim img_url As String = Server.MapPath("~/uploads/" & code_url & "/") + System.IO.Path.GetFileName(fup.PostedFile.FileName)
Dim MyStream As FileStream = New FileStream(img_url, FileMode.Open)
pictbox.Image = Drawing.Image.FromStream(MyStream)
pictbox.SizeMode = PictureBoxSizeMode.StretchImage
Dim height As Integer
Dim width As Integer
Dim W As Integer
Dim H As Integer
Dim coef As Double
height = pictbox.Image.Height
width = pictbox.Image.Width
pictbox.Height = H
pictbox.Width = W
pictbox.Update()
Try
    If type_file = ".png" Then
        pictbox.Image.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Png)
    ElseIf type_file = ".jpg" Or type_file = ".jpeg" Then
        pictbox.Image.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Jpeg)
    ElseIf type_file = ".gif" Then
        pictbox.Image.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Gif)
    End If
Catch ex As Exception
    Console.WriteLine(ex.Message)
End Try
MyStream.Close()
Return True

I can not assign a H and W have the image to resize!

[!const]

Normally to resizing an image is a bit more complicated

dim ImgRedimension as new bitmap(newWidth, newHeight)
dim g as graphics = graphics.fromimage(ImgRedimension)
g.Drawimage(image_of_base, divers_parameters)
ImgRedimension.save()

instead of [divers_parameters] you must use the overload with a source rectangle and destination rectangle (rectangles are 0.0 to img.width, img.height for source and dest with the new dimensions)

[AdityaR]

Hello, thank you for your answer, being that second year can you explain a little more simply please? Because I do not know what to do with graphics. Instead of pictbox.image.save I must put graphic.save? I do not see what you mean by source rectangle etc.

[!const]

I've put almost all the code to resize an image, you must create a new dimension for the new, create graphics associated with this new image drawing the basic image we have on the graphics with the new size then the image created can be saved

DrawImage has 30 overloads, one must use an application that SrcRect and DestRect (just read the intellisense)

and

dim srcrect as new rectangle (0,0,picturebox.image.width,picturebox.image.height)
dim destcrect as new rectangle (0,0,newWidth,newHeight)

[AdityaR]

Dim ImgRedimension As New Bitmap(W, H)
Dim g As Graphics = Graphics.FromImage(ImgRedimension)
g.DrawImage(pictbox.Image, pictbox.DisplayRectangle.Location)
Try
    If type_file = ".png" Then
            ImgRedimension.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Png)
    ElseIf type_file = ".jpg" Or type_file = ".jpeg" Then
            ImgRedimension.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Jpeg)
    ElseIf type_file = ".gif" Then
            ImgRedimension.Save(Server.MapPath("~/uploads/" & code_url & "/") + name_vig_file, Imaging.ImageFormat.Gif)
    End If
Catch ex As Exception
    Console.WriteLine(ex.Message)
End Try

Here I replaced divers_parameter by pictbox.displayrectangle, but ultimately my image is not resized!

[!const]

Dim imageFinal As System.Drawing.Image = Nothing
Dim g As System.Drawing.Graphics = Nothing
imageFinal = New System.Drawing.Bitmap(new_size.Width, new_size.Height)
g = System.Drawing.Graphics.FromImage(imageFinal)
Dim destRect As New System.Drawing.Rectangle(0, 0, new_size.Width, new_size.Height)
Dim srcRect As New System.Drawing.Rectangle(0, 0, IMG.Width, IMG.Height)
g.DrawImage(IMG, destRect, srcRect, System.Drawing.GraphicsUnit.Pixel)
imageFinal.save(...)

to adapt (IMG is the image of your PictureBox, new_size is the drawing.size of the new size desired)