[vtk-developers] The ImageStencil Issue

[dean.inglis at camris.ca]

David,

have a look at php bug tracker item  #1452.
If I run the tcl script as is, the ROI
is not updated correctly.  If I modify the
script to delay updating the vtkImageAccumulate
and vtkTextActor pipeline until after the
first render, things work out (see modified
tcl script below).  Prior to executives,
the submitted bug script would work.  I believe
there is still a pipeline issue here.  Sorry I
can't be of much help: I still haven't found time
to dive into and figure out executives...

>>
>> The vtkImageStencilSource class requires the Spacing and Origin of 
>> whichever image eventually uses the stencil to be propagated the wrong 
>> way along the pipeline.  Ouch!
>>


Dean

#///////////////////////////////////////
package require vtk
package require vtkinteraction

proc UpdateROI {} {

  accum Update
  set aN [accum GetVoxelCount]
  set amin [accum GetMin]
  set amax [accum GetMax]
  set amean [accum GetMean]
  set astd  [accum GetStandardDeviation]

  set atext {}
  append atext "N: "
  append atext [string toupper $aN]
  append atext ", \["
  append atext [string toupper [lindex $amin 0] ]
  append atext " -> "
  append atext [string toupper [lindex $amax 0] ]
  append atext "\] "
  append atext [string toupper [lindex $amean 0] ]
  append atext " +- "
  append atext [string toupper [lindex $astd 0] ]
  append atext " HU"

  textActor SetInput $atext

# not sure if this is just on my Borland build
# but the text actor will not show the modified input text
# correctly (looks garbled and squished) unless
# we wait till later to add the text actor
#
  ren AddViewProp textActor
 
}

  vtkVolume16Reader v16
  v16 SetDataDimensions 64 64
  v16 SetDataByteOrderToLittleEndian
  v16 SetImageRange 1 93
  v16 SetDataSpacing 3.2 3.2 1.5
  v16 SetFilePrefix "$VTK_DATA_ROOT/Data/headsq/quarter"
  v16 ReleaseDataFlagOn
  v16 SetDataMask 0x7fff

  vtkExtractVOI extract
  extract SetVOI 31 31 0 63 0 92
  extract SetSampleRate 1 1 1
  extract SetInput [v16 GetOutput]
  extract ReleaseDataFlagOff
  extract Update

  set range [[extract GetOutput] GetScalarRange]
  set min [lindex $range 0]
  set max [lindex $range 1]
  set diff [expr $max - $min]
  set avg [expr 0.5*($max + $min)]
  set bounds [[extract GetOutput] GetBounds]

  vtkPoints points
  points SetNumberOfPoints 5

  set x [lindex $bounds 0]
  set y0 [expr 0.25*[lindex $bounds 3]]
  set y1 [expr 0.75*[lindex $bounds 3]]
  set z0 [expr 0.25*[lindex $bounds 5]]
  set z1 [expr 0.75*[lindex $bounds 5]]

  points SetPoint 0 $x $y0 $z0
  points SetPoint 1 $x $y1 $z0
  points SetPoint 2 $x $y1 $z1
  points SetPoint 3 $x $y0 $z1
  points SetPoint 4 $x $y0 $z0

  vtkCellArray cells
  cells InsertNextCell 5

  for {set i 0} {$i < 5} {incr i} {
    cells InsertCellPoint $i
    }

  vtkPolyData region
  region SetPoints points
  region SetLines cells

  vtkPolyDataMapper regionMapper
  regionMapper SetInput region

  vtkActor regionActor
  regionActor SetMapper regionMapper
  [regionActor GetProperty ] SetColor 1 0 0

  vtkLinearExtrusionFilter extrude
  extrude SetScaleFactor 1
  extrude SetExtrusionTypeToNormalExtrusion
  extrude SetVector 1 0 0
  extrude SetInput region

  vtkPolyDataToImageStencil dataToStencil
  dataToStencil SetInput [extrude GetOutput]

  vtkImageStencil stencil
  stencil SetInput [extract GetOutput]
  stencil SetStencil [dataToStencil GetOutput]
  stencil ReverseStencilOff
  stencil SetBackgroundValue $min

  vtkImageMapToWindowLevelColors imageMapper
  imageMapper SetOutputFormatToLuminance
  imageMapper SetInput [stencil GetOutput]
  imageMapper SetLevel $avg
  imageMapper SetWindow $diff

  vtkImageActor imageActor
  imageActor SetInput [imageMapper GetOutput]
  imageActor SetDisplayExtent 31 31 0 63 0 92
  imageActor InterpolateOff

  vtkImageAccumulate accum
  accum SetInput [extract GetOutput]
  accum ReverseStencilOff
  accum SetStencil [stencil GetStencil]
  accum SetComponentSpacing 1 0 0
  accum SetComponentExtent 0 $diff 0 0 0 0
  accum SetComponentOrigin $min 0 0
  accum ReleaseDataFlagOff

#  comment out old bug submission 
#
#  accum Update

#  set aN [accum GetVoxelCount]
#  set amin [accum GetMin]
#  set amax [accum GetMax]
#  set amean [accum GetMean]
#  set astd  [accum GetStandardDeviation]

#  set atext {}
#  append atext "N: "
#  append atext [string toupper $aN]
#  append atext ", \["
#  append atext [string toupper [lindex $amin 0] ]
#  append atext " -> "
#  append atext [string toupper [lindex $amax 0] ]
#  append atext "\] "
#  append atext [string toupper [lindex $amean 0] ]
#  append atext " +- "
#  append atext [string toupper [lindex $astd 0] ]
#  append atext " HU"

  vtkTextActor textActor
  textActor ScaledTextOff
#  textActor SetInput $atext
  textActor SetInput "ROI:"
  [textActor GetPositionCoordinate] SetCoordinateSystemToNormalizedDisplay
  [textActor GetPositionCoordinate] SetValue 0.05 0.05

  set tprop [textActor GetTextProperty]
  $tprop SetFontSize 16
  $tprop SetFontFamilyToArial
  $tprop BoldOff
  $tprop ItalicOff
  $tprop ShadowOff
  $tprop SetLineSpacing 0.9
  $tprop SetJustificationToLeft
  $tprop SetVerticalJustificationToBottom
  $tprop SetColor 1 1 0

  vtkRenderer ren
  ren SetBackground 0.4 0.4 0.5

  vtkRenderWindow renWin
  renWin AddRenderer ren
  renWin SetSize 400 400

  vtkInteractorStyleImage interactor

  vtkRenderWindowInteractor iren
  iren SetInteractorStyle interactor
  iren SetRenderWindow renWin

  ren AddViewProp imageActor
  ren AddViewProp regionActor

#  see comment above in UpdateROI proc
#
#  ren AddViewProp textActor

  iren AddObserver UserEvent {wm deiconify .vtkInteract}
  renWin Render

  set cam [ren GetActiveCamera]
  $cam SetViewUp 0 1 0
  $cam Azimuth 270
  $cam Roll 270
  $cam Dolly 1.7
  ren ResetCameraClippingRange

  renWin Render

# Prevent the tk window from showing up then start the event loop.
  wm withdraw .

# pipeline works in current VTK CVS if we
# now update the accumulate here with a tcl proc
#
  UpdateROI