The samples below use the Graphics.SetClip function to draw shaped borders in your pictures.
The trick here is to use the CombineMode.XOR enumeration, that forces the drawing to the external part of the shape, like in the samples below.
Playing with the source image below:
Prerequisites
Visual FoxPro 9 and the GdiPlusX library from VFPX 
Please make sure that you have the latest version, because this sample may be using some functions that were added or fixed recently.
http://www.codeplex.com/VFPX/Wiki/View.aspx?title=GDIPlusX&referringTitle=Home
Sample 1: Ellipse shape
DO LOCFILE("System.app")
WITH _Screen.System.Drawing
* Get an image file
LOCAL loBmp as xfcBitmap
loBmp = .Bitmap.FromFile(GETPICT())
* Create a Gfx object that will allow us to make the transformation
LOCAL loGfx as xfcGraphics
loGfx = .Graphics.FromImage(loBmp)
LOCAL lnWidth, lnHeight
lnWidth = loBmp.Width
lnHeight = loBmp.Height
* Create GraphicsPath object.
LOCAL loClipPath as xfcGraphicsPath
loClipPath = .Drawing2D.GraphicsPath.New()
* An Ellipse shape
loClipPath.AddEllipse(0, 0, lnWidth, lnHeight)
* Set clipping region to path.
* CombineMode enumeration
* http://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.combinemode.aspx
* CombineMode.Xor - Two clipping regions are combined by taking only the areas
* enclosed by one or the other region, but not both.
loGfx.SetClip(loClipPath, ;
_Screen.System.Drawing.Drawing2D.CombineMode.Xor)
* Fill rectangle to demonstrate clipping region.
loGfx.FillRectangle( .Brushes.White, 0, 0, loBmp.Width, loBmp.Height)
* Save the image to the disk and show
loBmp.Save("Clipped.Jpg", "image/jpeg")
RUN /n Explorer.Exe Clipped.Jpg
ENDWITH
Sample 2: Doughnut shape
DO LOCFILE("System.app")
WITH _Screen.System.Drawing
* Get an image file
LOCAL loBmp as xfcBitmap
loBmp = .Bitmap.FromFile(GETPICT())
* Create a Gfx object that will allow us to make the transformation
LOCAL loGfx as xfcGraphics
loGfx = .Graphics.FromImage(loBmp)
LOCAL lnWidth, lnHeight
lnWidth = loBmp.Width
lnHeight = loBmp.Height
* Create GraphicsPath object.
LOCAL loClipPath as xfcGraphicsPath
loClipPath = .Drawing2D.GraphicsPath.New()
* A Doughnut slice shape
loClipPath.AddEllipse(0, 0, lnWidth, lnHeight * 2)
loClipPath.AddEllipse(lnWidth / 4, lnHeight / 2, lnWidth/2, lnHeight * 4)
* Set clipping region to path.
* CombineMode enumeration
* http://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.combinemode.aspx
* CombineMode.Xor - Two clipping regions are combined by taking only the areas
* enclosed by one or the other region, but not both.
loGfx.SetClip(loClipPath, ;
_Screen.System.Drawing.Drawing2D.CombineMode.Xor)
* Fill rectangle to demonstrate clipping region.
loGfx.FillRectangle( .Brushes.White, 0, 0, loBmp.Width, loBmp.Height)
* Save the image to the disk and show
loBmp.Save("Clipped.Jpg", "image/jpeg")
RUN /n Explorer.Exe Clipped.Jpg
ENDWITH
Sample 3: Star shape
DO LOCFILE("System.app")
WITH _Screen.System.Drawing
* Get an image file
LOCAL loBmp as xfcBitmap
loBmp = .Bitmap.FromFile(GETPICT())
* Create a Gfx object that will allow us to make the transformation
LOCAL loGfx as xfcGraphics
loGfx = .Graphics.FromImage(loBmp)
LOCAL lnWidth, lnHeight
lnWidth = loBmp.Width
lnHeight = loBmp.Height
* Create GraphicsPath object.
LOCAL loClipPath as xfcGraphicsPath
loClipPath = .Drawing2D.GraphicsPath.New()
* Source for the star drawing
* http://www.java2s.com/Code/VB/2D/GraphicsPathDrawwithFillModeWinding.htm
LOCAL lnRadius, lnPi, lnRadian72, n, lnEdges
lnRadius = lnHeight / 2
lnPi = 3.141592
lnEdges = 5
lnRadian72 = (lnPi * 4.0 ) / lnEdges
LOCAL laPoints(lnEdges)
FOR n = 1 TO lnEdges
laPoints(n) = .Point.New(;
+ lnRadius * SIN( n * lnRadian72 ) + lnRadius , ;
- lnRadius * COS( n * lnRadian72 ) + lnRadius )
ENDFOR
loClipPath.AddPolygon(@laPoints)
* Set the Clip Mode to Winding
* ClipMode enumeration
*http://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.fillmode.aspx
loClipPath.FillMode = _Screen.System.Drawing.Drawing2D.FillMode.Winding
* Set clipping region to path.
* CombineMode enumeration
* http://msdn.microsoft.com/en-us/library/system.drawing.drawing2d.combinemode.aspx
* CombineMode.Xor - Two clipping regions are combined by taking only the areas
* enclosed by one or the other region, but not both.
loGfx.SetClip(loClipPath, ;
_Screen.System.Drawing.Drawing2D.CombineMode.Xor)
* Fill rectangle to demonstrate clipping region.
loGfx.FillRectangle( .Brushes.White, 0, 0, loBmp.Width, loBmp.Height)
* Save the image to the disk and show
loBmp.Save("Clipped.Jpg", "image/jpeg")
RUN /n Explorer.Exe Clipped.Jpg
ENDWITH
Notice that the only difference between the code samples is the shape definition !