change image size

I have an image that I want to resize, but the property is read-only. I tried creating a bitmap and setting it equal to the image, but that didn't work:

Code:

---

            Dim bmp As Bitmap = New Bitmap(x, y)
            bmp = pbBefore.Image
            pbBefore.Image = bmp

---

How can I achieve my goal without looping through and drawing each pixel up to a certain length?

VB Code:

Dim b As New Bitmap(w, h)
Dim g As Graphics = Graphics.FromImage(b)
 
g.DrawImage(pbx.Image)
g.Dispose()
 
pbx.Image = b

I typed this in i.e, so there may be a few errors.

Thanks. This is what I have now:

Code:

---

                    Dim b As New Bitmap(x, y)
                    Dim g As Graphics = Graphics.FromImage(b)

                    g.DrawImage(pbAfter.Image, New Point(0, 0))
                    g.Dispose()

                    pbAfter.Image = b

---

It almost does what I want, but not quit. It increases the drawing surface, which is half of what I want. The actual image doesn't resize. It stays the same and the new area is filled with grey. Any ideas on how to fix that?

specify the new image size with a rectangle then draw your image in that rectangle

VB Code:

Dim ImageRect as new Rectangle([I]your rectangle coords[/I])
g.Graphics.DrawImage(pbAfter.Image, ImageRect)

I think that should do it
kevin

Excellent! That worked perfectly!

Thanks kevin.

welcome....

ahh, kebo, I've got another problem with that now. It's warping the images really bad when I resize them.... Is there some way of getting around this?

Quote:

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Originally Posted by System_Error

ahh, kebo, I've got another problem with that now. It's warping the images really bad when I resize them.... Is there some way of getting around this?

---

Well, have a look at this:

VB Code:

Private Sub CreateThumbGenie()
        Dim NewImage As Image = Image.FromFile("filename")
 
        ' Make a bitmap for the result.
        Dim DestSize As New Bitmap( _
        CInt(PictureBox1.Width), _
        CInt(PictureBox1.Height))
 
        ' Make a Graphics object for the result Bitmap.
        Dim GenDest As Graphics = Graphics.FromImage(DestSize)
 
        ' Copy the source image into the destination bitmap.
        GenDest.DrawImage(NewImage, 0, 0, _
        DestSize.Width + 1, _
        DestSize.Height + 1)
 
        ' Display the result.
        PictureBox1.Image = DestSize
 
    End Sub
 
'later in a command button, you can call it as:
[b]  CreateThumbGenie()[/b]

This will create a smaller representation of the picture, without distorting

Hope it helps..

Thanks. I figured out the problem. I was thinking your code was again, causing a distortion, but it's not. I am using a numeric ticker that updates automatically. When it updates automatically I get the distortion. If I enter the value in myself, and then click enter, everything is fine. Is it like, painting over top of each of the images? How can I fix that?


THanks for the help.

not really sure....maybe you can post some code?

Sure...

This is the handle_resize method which does all the resizing:

Code:

---

  If x > 0 And y > 0 Then
                    Dim NewImage As Image = pbAfter.Image

                    ' Make a bitmap for the result.
                    Dim DestSize As New Bitmap(x, y)

                    ' Make a Graphics object for the result Bitmap.
                    Dim GenDest As Graphics = Graphics.FromImage(DestSize)

                    ' Copy the source image into the destination bitmap.
                    GenDest.DrawImage(NewImage, 0, 0, _
                    x, _
                    y)

                    ' Display the result.
                    pbAfter.Image = DestSize
                End If

---

Now, it is called EACH time the value of my numeric ticker is changed. The ticker simply calls handle_resize() and does nothing else.


There's got to be a reason why it's doing this. It's like it's painting overtop of the other image. If I type in the values, then it works fine, but I can't consistently press the ticker.