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How to display scaled image without anti-aliasing?

Question
How can I scale an image in XAML quickly without anti-aliasing applied?
Background
I am trying to make a pixel editor as a Windows 8 XAML/C# app. I'm using c#/XAML because most of my experience is with c#/WPF.
Method 1: WriteableBitmap + Image control. Originally, I used a WriteableBitmap to store and edit an image. That image is displayed in a resized XAML Image control. The problem is that the image does not get scaled properly because of anti-aliasing. (XAML does not seem to provide the BitmapScalingOptions that are available in WPF)
Method 2: Redrawn WriteableBitmap + Image control. Next I tried writing my own scaling, where I take my original image and write to a larger WriteableBitmap so that the scaled image is pixelated. The scaled image is then presented inside a XAML Image control. This process is slow and inefficient.
Method 3: SharpDX + Direct2d ?? I am pretty sure a solution exists somewhere between SharpDx, SurfaceImageSource, and Direct2d. Event still, I can't quite figure out how to display a SharpDx.WIC.Bitmap inside a Windows.UI.Xaml Image control, and am generally getting lost in the documentation.
What exactly is a recommended setup for achieving my desired end? Are there c# samples available which might point me in the right direction?

I don't know if you mean by scaling it by resizing it with the mouse or just with a button click to auto scale to a predetermined size.
But the thing you can do is to use an Image panel and then, just set it to image.Stretch = Stretch.Fill; so if you override and create a method for the Resize event of the Image Panel, your image will take the size to fill the Image panel.

How do I get the dimensions of the ImageRectangle in PictureBox?

Background
I want to be able to get the drawn dimensions of a zoomed image inside the picturebox (I'll explain below).
The PictureBox.ImageRectangle property seems to be exactly what I'm looking for because it shows the height and width of the resized image, as well as it's relative top, left position inside the control.
The trouble is PictureBox.ImageRectangle is private and so I can't read the values without using reflection (which is obviously not ideal).
Actual Question
My question is, is there another way that I can easily get to these values without writing a method to calculate what the values "ought" to be? I can do that easily enough, but I feel I'd be reinventing the wheel.
Context:
I'm writing a simple image processing app in C# and one of the things it has to do is allow the user to draw a selection around a portion of the image (a lot like the Marquee tool in Photoshop).
I need to know the dimensions of the rendered image so I know where to set the bounds of my marquee tool and also to translate the values of the drawn rectangle to points on the scaled bitmap inside the control.

My answer look simple so maybe I'm missing something, but I think Control.DisplayRectangle suits your need.
EDIT
OK, missed the point; however see How to get the value of non- public members of picturebox?

if you want to access dimension of the image in picture box you can use
GraphicsUnit units = GraphicsUnit.Point;
RectangleF imgRectangleF = pictureBox1.Image.GetBounds(ref units);
Rectangle imgRectangle = Rectangle.Round(imgRectangleF);

Using a System.Drawing.Image as the centered part of a larger image?

I have a System.Drawing.Image that I would like to use as the centered portion for a new, larger image. I’m given the dimensions of the (always) larger image and the idea is to make that image all white and overlay its center with the first image. Is there a way to do this using GDI+? Some combination of TextureBrush and the Graphic class perhaps? I’m open to suggestions. Thanks!

Lots of similar questions, here's one that I think will show you the basics:
How could I position multiple transparent PNGs onto a JPG using c# and asp.net?

Display filter C#

It's a little hard to explain what I need but i'll try:
I need to write application (winform) which will be some kind of filter to image/other forms behind it. With one exception - all behind form should looks as is except of red (for example) color, which have to be replaced to any other specified color, white for example.
So let's imagine I have opened windows Word with few lines of text. With red and black letters.
So when i place my application above this text - it should "filter" red symbols and fill them to white.
So as i understand this task: i have to snap area behind the form, then process it (replace colors) and after draw this image on my form body.
Any links or keywords for solution?
UPD:
so - this is my final solution:
do form transparent (using TransparencyKey and BackColor properties)
place picturebox over the form
when we need to update image in picturebox - we replace current image with pictureBox1.Image = null;, then refreshing form with (this.Refresh()) and do new snapshot
thanks for all ;-)
UPD 2:
sample http://dl.dropbox.com/u/4486681/result.png
UPD 3:
here are sources

you can create a snapshot of the desktop using the following code:
public Bitmap CaptureScreen()
{
Bitmap b = new Bitmap(SystemInformation.VirtualScreen.Width, SystemInformation.VirtualScreen.Height);
Graphics g = Graphics.FromImage(b);
g.CopyFromScreen(0, 0, 0, 0, b.Size);
g.Dispose();
return b;
}
Replace the dimensions and position with the coordinates of your form. This way you get a bitmap of what's behind your form. Then you can do the color replacement on that bitmap.
Please note that due to settings like ClearType and other anti-aliasing mechanisms, you have to also take into account "intermediate pixels" when doing the color replacement. Otherwise things will look funny :-)

I don't know if this can be done at all (let's see what others answer :-).
You can get a handle to the screen device context, which gives you a bitmap of the screen.
HDC dc = GetDC(NULL);
(This is C++, you'll have to use P/Invoke, or create a mixed-mode library in C++)
Then you can redraw a region of the screen with your filtering process.
Now the problems start:
how do you know that the pixels in your interesting region has changed ?
if the region changes, are the changes visible or are they hidden by your own drawing.
You could have a button somewhere that hides your own app momentarily and shows it back when re-pressed, and filters the new content.
Good luck. Any possibility of sharing the user scenario ?

.Net & C#: Trying to have a transparent image on a button (assigned from IDE)

Using VS2005 and C#.
Having a button in a form and an image from a resource, the image does not have transparency.
How can I have transparency when assigning the image from the IDE ?
Thank you.

Open the image in an image editor (Paint.NET and GIMP are free) and add the transparencies wherever you need to.
It will all work once the image actually has transparent pixels.
You can also use a couple methods of the Bitmap class to do this:
Bitmap b = Properties.Resources.MyImage;
b.MakeTransparent(b.GetPixel(0, 0));

I don't really understand what you are asking. You can use an image with transparency on a button as long as the image type you are using supports transparency - such as .png.
Edit: I read your question again and it is still confusing, but maybe you meant to say that you want to add transparency to the image? If so, you would have to use an image editor to add the transparency and save it in a format that supports this. Paint.Net is a good free tool for this.