Get image height and width without creating bitmap

By HAFIZ Kashkoush

Usually to resize an image we upload the image ,create bitmap ,resize it
and save the new resized image.
I can use this technique in case that I need a new resized image file otherwise
this technique become very complicated .

In this article I going to
1:-Upload an image to Image control (image1)
2:-Get image info (width and height)
3:-When user click resize button the image will be resized for 50%
of it original size.

First i add to my form 2 controls
A:-Image control -Image ID="Image1"
B:-Button control to resize image - Button ID="BResize"

2:- In my code I declare 3 global variables
Dim ImageWidth As Integer 'Image width
Dim ImageHeight As Integer 'Image height
Dim imageurl As String 'Image URL

3:- In my page load event I load the image to image1 control and get image info.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
'************************************************************************
'******* This string contain image URL
'******* My image name is "1_o.jpg" and it located in my application
'******* directory in this case the image URL="1_o.jpg"
'************************************************************************
imageurl = Server.MapPath("1_o.jpg")
'******** Load the image into image1 control
Image1.ImageUrl = imageurl
'******** Get Image Info
Dim fullSizeImg As System.Drawing.Image = System.Drawing.Image.FromFile(imageurl)
'******** Image Width
ImageWidth = fullSizeImg.Width
'******** Image Height
ImageHeight = fullSizeImg.Height
End Sub

4:-In the button resize click event I resize the image to 50% of it original size
by changing image1 width an height values.
Protected Sub BResize_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Image1.Height = Int(ImageHeight / 2)
Image1.Width = Int(ImageWidth / 2)
End Sub