package require vtk

# This script calculates the luminance of an image

vtkRenderWindow imgWin


# Image pipeline

vtkTIFFReader image1
  image1 SetFileName "$VTK_DATA_ROOT/Data/beach.tif"

# "beach.tif" image contains ORIENTATION tag which is 
# ORIENTATION_TOPLEFT (row 0 top, col 0 lhs) type. The TIFF 
# reader parses this tag and sets the internal TIFF image 
# orientation accordingly.  To overwrite this orientation with a vtk
# convention of ORIENTATION_BOTLEFT (row 0 bottom, col 0 lhs ), invoke
# SetOrientationType method with parameter value of 4.
  image1 SetOrientationType 4

vtkImageShrink3D shrink
shrink SetInputConnection [image1 GetOutputPort]
shrink SetShrinkFactors 2 2 1

set operators "ByPass And Nand Xor Or Nor"

foreach operator $operators {
    if { $operator != "ByPass" } {    
	vtkImageMaskBits operator${operator}
	operator${operator} SetInputConnection [shrink GetOutputPort]
        operator${operator} SetOperationTo${operator}
	operator${operator} SetMasks 255 255 0
    } 
    
    vtkImageMapper mapper${operator}
    if { $operator != "ByPass" } {    	
	mapper${operator} SetInputConnection [operator${operator} GetOutputPort]
    } else {
	mapper${operator} SetInputConnection [shrink GetOutputPort]
    }
    mapper${operator} SetColorWindow 255
    mapper${operator} SetColorLevel 127.5

    vtkActor2D actor${operator}
    actor${operator} SetMapper mapper${operator}

    vtkRenderer imager${operator}
    imager${operator} AddActor2D actor${operator}

    imgWin AddRenderer imager${operator}
}

set column 1
set row 1
set deltaX [expr 1.0/3.0]
set deltaY [expr 1.0/2.0]

foreach operator $operators {
    imager${operator} SetViewport [expr ($column - 1) * $deltaX] [expr ($row - 1) * $deltaY] [expr $column * $deltaX] [expr $row * $deltaY]
    incr column
    if { $column > 3 } {set column 1; incr row}
}

imgWin SetSize 384 256
imgWin Render

wm withdraw .