'======== Example ========
SuperStrict
Local pix:TPixmap = gaussianblur(LoadPixmap("yourimagehere.png"), 5)
Local gfx:TGraphics = Graphics(pix.width, pix.height)
DrawPixmap(pix, 0, 0)
Flip
WaitMouse()
'====== Example Ends ======
Function gaussianblur:TPixmap(tex:TPixmap, radius:Int)
If radius <=0 Return tex
Local texclone:TPixmap = tex.copy() 'clone incoming texture
Local filter:TGaussianFilter = New TGaussianFilter 'instantiate a new gaussian filter
filter.radius = radius 'configure it
Return filter.apply(tex, texclone)
End Function
Type TGaussianFilter
Field radius:Double
Field kernel:TKernel
Method apply:TPixmap(src:TPixmap, dst:TPixmap)
Self.kernel = makekernel(Self.radius)
Self.convolveAndTranspose(Self.kernel, src, dst, PixmapWidth(src), PixmapHeight(src), True)
Self.convolveAndTranspose(Self.kernel, dst, src, PixmapHeight(dst), PixmapWidth(dst), True)
dst = Null
GCCollect()
Return src
End Method
'Make a Gaussian blur kernel.
Method makekernel:TKernel(radius:Double)
Local r:Int = Int(Ceil(radius))
Local rows:Int = r*2+1
Local matrix:Double[] = New Double[rows]
Local sigma:Double = radius/3.0
Local sigma22:Double = 2*sigma*sigma
Local sigmaPi2:Double = 2*Pi*sigma
Local sqrtSigmaPi2:Double = Double(Sqr(sigmaPi2))
Local radius2:Double = radius*radius
Local total:Double = 0
Local index:Int = 0
For Local row:Int = -r To r
Local distance:Double = Double(row*row)
If (distance > radius2)
matrix[index] = 0
Else
matrix[index] = Double(Exp(-(distance/sigma22)) / sqrtSigmaPi2)
total:+matrix[index]
index:+1
End If
Next
For Local i:Int = 0 Until rows
matrix[i] = matrix[i]/total 'normalizes the gaussian kernel
Next
Return mkernel(rows, 1, matrix)
End Method
Function mkernel:TKernel(w:Int, h:Int, d:Double[])
Local k:TKernel = New TKernel
k.width = w
k.height = h
k.data = d
Return k
End Function
Method convolveAndTranspose(kernel:TKernel, in:TPixmap, out:TPixmap, width:Int, height:Int, alpha:Int)
Local inba:Byte Ptr = in.pixels
Local outba:Byte Ptr = out.pixels
Local matrix:Double[] = kernel.getKernelData()
Local cols:Int = kernel.getWidth()
Local cols2:Int = cols/2
For Local y:Int = 0 Until height
Local index:Int = y
Local ioffset:Int = y*width
For Local x:Int = 0 Until width
Local r:Double = 0, g:Double = 0, b:Double = 0, a:Double = 0
Local moffset:Int = cols2
For Local col:Int = -cols2 To cols2
Local f:Double = matrix[moffset+col]
If (f <> 0)
Local ix:Int = x+col
If ( ix < 0 )
ix = 0
Else If ( ix >= width)
ix = width-1
End If
Local rgb:Int = (Int Ptr inba)[ioffset+ix]
a:+f *((rgb Shr 24) & $FF)
b:+f *((rgb Shr 16) & $FF)
g:+f *((rgb Shr 8) & $FF)
r:+f *(rgb & $FF)
End If
Next
Local ia:Int
If alpha = True Then ia = clamp(Int(a+0.5)) Else ia = $FF
Local ir:Int =clamp( Int(r+0.5))
Local ig:Int = clamp(Int(g+0.5))
Local ib:Int = clamp(Int(b+0.5))
(Int Ptr outba)[index] =((ia Shl 24) | (ib Shl 16) | (ig Shl 8) | (ir Shl 0))
index:+height
Next
Next
End Method
End Type
Type TKernel
Field width:Int
Field height:Int
Field data:Double[]
Method getkerneldata:Double[]()
Return Self.data
End Method
Method getwidth:Int()
Return Self.width
End Method
Method getheight:Int()
Return Self.height
End Method
End Type
Function clamp:Int(val:Int)
If val < 0
Return 0
ElseIf val > 255
Return 255
Else
Return val
EndIf
End Function |
