Image Editing Tool in VB.Net: Part 2

This is the next article of the 'How to make Image editing tool' project. In first article we have learnt how to show or open image file in our vb.net application with very professionally look.

Image Editing Tool in VB.Net: Part 1

Now in this article we will learn about resizing of the image

Design Right panel with the help of tabcontrol, and DomainUpDown control, so that user can input percentage of original size of image

Put the values 1 to 1000 in domainupdown control

Private Sub BindDomainIUpDown()

For i As Integer = 1 To 999

DomainUpDown1.Items.Add(i)

DomainUpDown1.Text = 100

End Sub

We declare two another variables modifiedSize and originalSize, OriginalSize refers to original width and height of image and modifiedSize refers to width and height of image after DomainUpDown control's value selection.

Private OriginalImageSize As Size

Private ModifiedImageSize As Size

We can calulate original size of the image like this

Dim imgWidth As Integer = Img.Width

Dim imghieght As Integer = Img.Height

OriginalImageSize = New Size(imgWidth, imghieght)

And modifiedSize:

Private Sub DomainUpDown1_SelectedItemChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DomainUpDown1.SelectedItemChanged

Dim percentage As Integer = 0

Try

percentage = Convert.ToInt32(DomainUpDown1.Text)

ModifiedImageSize = New Size((OriginalImageSize.Width * percentage) \ 100, (OriginalImageSize.Height * percentage) \ 100)

SetResizeInfo()

Catch ex As Exception

MessageBox.Show("Invalid Percentage")

Exit Sub

End Try

End Sub

Resizing image:

Now We have to resize image according to modifiedSize

Private Sub btnOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOk.Click

Dim bm_source As New Bitmap(PictureBox1.Image) ' Make a bitmap for the result.

Dim bm_dest As New Bitmap(CInt(ModifiedImageSize.Width), CInt(ModifiedImageSize.Height))

' Make a Graphics object for the result Bitmap.

Dim gr_dest As Graphics = Graphics.FromImage(bm_dest) ' Copy the source image into the destination bitmap.

gr_dest.DrawImage(bm_source, 0, 0, bm_dest.Width + 1, bm_dest.Height + 1) ' Display the result.

PictureBox1.Image = bm_des

End Sub

Picturebox will show image after resizing

So this is very easy to do this you can download sourcecode for better understanding.