Adding Antialiasing To An Image

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Jeppe Nielsen
This antialias function created by Leadwerks, might do the trick :-)
taken from here:
http://www.blitzbasic.co.nz/Community/posts.php?topic=39429

Just change the path to your image:
Graphics3D 800,600,32,2

image=LoadImage("YourImageHere.bmp")


DrawBlock image,0,0

Color 0,0,0

Text 400,50,"Image Not Antialiased, press space to antialias it",True,True


Flip
Repeat

	If KeyDown(1)
		End
	EndIf

Until KeyHit(57)
FlushKeys

DrawBlock image,0,0

Text 400,50,"Antialiasing.... please wait",True,True

Flip

AntiAliasBuffer(ImageBuffer(image),ImageWidth(image)-1,ImageHeight(image)-1,1,40)


DrawBlock image,0,0

Text 400,50,"Image Antialiased!",True,True

Flip
Repeat

	If KeyDown(1)
		End
	EndIf

Until KeyHit(57)
FlushKeys



;function by Leadwerks: www.leadwerks.com
;taken from here: 
;http://www.blitzbasic.co.nz/Community/posts.php?topic=39429
Function AntiAliasBuffer(buffer,w,h,passes=1,threshhold=20)
gfxbuffer=GraphicsBuffer()
SetBuffer buffer
LockBuffer buffer
For p=1 To passes
	For x=0 To w-1
		For y=0 To h-1
			hue=ReadPixelFast(x,y)
			r=Red(hue)
			g=Green(hue)
			b=Blue(hue)
			count=BottomLeftPixelsAntialiased(buffer,w,h,x,y,threshhold)
			For n=1 To count
				perc#=Float(n)/Float(count)
				hue=ReadPixelFast(x-n,y)
				lr=Red(hue)*perc+r*(1.0-perc)
				lg=Green(hue)*perc+g*(1.0-perc)
				lb=Blue(hue)*perc+b*(1.0-perc)
				WritePixelFast x-n,y,RGB(lr,lg,lb)
				Next
			count=BottomRightPixelsAntialiased(buffer,w,h,x,y,threshhold)
			For n=1 To count
				perc#=Float(n)/Float(count)
				hue=ReadPixelFast(x+n,y)
				lr=Red(hue)*perc+r*(1.0-perc)
				lg=Green(hue)*perc+g*(1.0-perc)
				lb=Blue(hue)*perc+b*(1.0-perc)
				WritePixelFast x+n,y,RGB(lr,lg,lb)
				Next
			count=VerticalBottomLeftPixelsAntialiased(buffer,w,h,x,y,threshhold)
			For n=1 To count
				perc#=Float(n)/Float(count)
				hue=ReadPixelFast(x,y-n)
				lr=Red(hue)*perc+r*(1.0-perc)
				lg=Green(hue)*perc+g*(1.0-perc)
				lb=Blue(hue)*perc+b*(1.0-perc)
				WritePixelFast x,y-n,RGB(lr,lg,lb)
				Next
			count=VerticalBottomRightPixelsAntialiased(buffer,w,h,x,y,threshhold)
			For n=1 To count
				perc#=Float(n)/Float(count)
				hue=ReadPixelFast(x,y+n)
				lr=Red(hue)*perc+r*(1.0-perc)
				lg=Green(hue)*perc+g*(1.0-perc)
				lb=Blue(hue)*perc+b*(1.0-perc)
				WritePixelFast x,y+n,RGB(lr,lg,lb)
				Next
			Next
		Next
	Next
UnlockBuffer buffer
SetBuffer gfxbuffer
End Function

Function BottomLeftPixelsAntialiased(buffer,w,h,x,y,threshhold)
If x=0 Return
hue=ReadPixelFast(x,y)
r=Red(hue)
g=Green(hue)
b=Blue(hue)
Repeat
	found=False
	hue=ReadPixelFast(x-1,y)
	lr=Red(hue)
	lg=Green(hue)
	lb=Blue(hue)
	If Abs(lr-r)>threshhold Or Abs(lg-g)>threshhold Or Abs(lb-b)>threshhold
		If y<h
			hue=ReadPixelFast(x-1,y+1)
			blr=Red(hue)
			blg=Green(hue)
			blb=Blue(hue)
			If Abs(blr-r)<threshhold And Abs(blg-g)<threshhold And Abs(blb-b)<threshhold
				found=True
				EndIf				
			EndIf
		EndIf
	If found
		count=count+1
		Else
		Exit
		EndIf
	If x=0 Exit
	x=x-1
	Forever
Return count
End Function

Function BottomRightPixelsAntialiased(buffer,w,h,x,y,threshhold)
hue=ReadPixelFast(x,y)
r=Red(hue)
g=Green(hue)
b=Blue(hue)
If x=w Return
Repeat
	found=False
	hue=ReadPixelFast(x+1,y)
	lr=Red(hue)
	lg=Green(hue)
	lb=Blue(hue)	
	If Abs(lr-r)>threshhold Or Abs(lg-g)>threshhold Or Abs(lb-b)>threshhold
		If y<h
			hue=ReadPixelFast(x+1,y+1)
			blr=Red(hue)
			blg=Green(hue)
			blb=Blue(hue)
			If Abs(blr-r)<threshhold And Abs(blg-g)<threshhold And Abs(blb-b)<threshhold
				found=True
				EndIf				
			EndIf
		EndIf
	If found
		count=count+1
		Else
		Exit
		EndIf
	If x=w-1 Exit
	x=x+1
	Forever
Return count
End Function

Function VerticalBottomLeftPixelsAntialiased(buffer,w,h,x,y,threshhold)
If y=0 Return
hue=ReadPixelFast(x,y)
r=Red(hue)
g=Green(hue)
b=Blue(hue)
Repeat
	found=False
	hue=ReadPixelFast(x,y-1)
	lr=Red(hue)
	lg=Green(hue)
	lb=Blue(hue)
	If Abs(lr-r)>threshhold Or Abs(lg-g)>threshhold Or Abs(lb-b)>threshhold
		If x>0
			hue=ReadPixelFast(x-1,y-1)
			blr=Red(hue)
			blg=Green(hue)
			blb=Blue(hue)
			If Abs(blr-r)<threshhold And Abs(blg-g)<threshhold And Abs(blb-b)<threshhold
				found=True
				EndIf				
			EndIf
		EndIf
	If found
		count=count+1
		Else
		Exit
		EndIf
	If y=0 Exit
	y=y-1
	Forever
Return count
End Function

Function VerticalBottomRightPixelsAntialiased(buffer,w,h,x,y,threshhold)
If y=h Return
hue=ReadPixelFast(x,y)
r=Red(hue)
g=Green(hue)
b=Blue(hue)
Repeat
	found=False
	hue=ReadPixelFast(x,y+1)
	lr=Red(hue)
	lg=Green(hue)
	lb=Blue(hue)
	If Abs(lr-r)>threshhold Or Abs(lg-g)>threshhold Or Abs(lb-b)>threshhold
		If x>0
			hue=ReadPixelFast(x-1,y+1)
			blr=Red(hue)
			blg=Green(hue)
			blb=Blue(hue)
			If Abs(blr-r)<threshhold And Abs(blg-g)<threshhold And Abs(blb-b)<threshhold
				found=True
				EndIf				
			EndIf
		EndIf
	If found
		count=count+1
		Else
		Exit
		EndIf
	If y=h Exit
	y=y+1
	Forever
Return count
End Function


Function rgb(r,g,b)
	Return b + g Shl 8 + r Shl 16
End Function


Function Red(rgb)
	Return rgb Shr 16
End Function

Function Green(rgb)
	Return rgb Shr 8 - ((rgb Shr 16) Shl 8)
End Function

Function Blue(rgb)
	Return rgb-red(rgb) Shl 16-green(rgb) Shl 8
End Function