#!/usr/bin/env python

import vtk
import vtk.test.Testing
from vtk.util.misc import vtkGetDataRoot
VTK_DATA_ROOT = vtkGetDataRoot()

# This script calculates the luminance of an image

renWin = vtk.vtkRenderWindow()
renWin.SetSize(512, 256)

# Image pipeline

image1 = vtk.vtkTIFFReader()
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)

image2 = vtk.vtkBMPReader()
image2.SetFileName(VTK_DATA_ROOT + "/Data/masonry.bmp")

# shrink the images to a reasonable size

color = vtk.vtkImageShrink3D()
color.SetInputConnection(image1.GetOutputPort())
color.SetShrinkFactors(2, 2, 1)

backgroundColor = vtk.vtkImageShrink3D()
backgroundColor.SetInputConnection(image2.GetOutputPort())
backgroundColor.SetShrinkFactors(2, 2, 1)

# create a greyscale version

luminance = vtk.vtkImageLuminance()
luminance.SetInputConnection(color.GetOutputPort())

backgroundLuminance = vtk.vtkImageLuminance()
backgroundLuminance.SetInputConnection(backgroundColor.GetOutputPort())

# create an alpha mask

table = vtk.vtkLookupTable()
table.SetTableRange(220, 255)
table.SetValueRange(1, 0)
table.SetSaturationRange(0, 0)
table.Build()

alpha = vtk.vtkImageMapToColors()
alpha.SetInputConnection(luminance.GetOutputPort())
alpha.SetLookupTable(table)
alpha.SetOutputFormatToLuminance()

# make luminanceAlpha and colorAlpha versions

luminanceAlpha = vtk.vtkImageAppendComponents()
luminanceAlpha.AddInputConnection(luminance.GetOutputPort())
luminanceAlpha.AddInputConnection(alpha.GetOutputPort())

colorAlpha = vtk.vtkImageAppendComponents()
colorAlpha.AddInputConnection(color.GetOutputPort())
colorAlpha.AddInputConnection(alpha.GetOutputPort())

foregrounds = ["luminance", "luminanceAlpha", "color", "colorAlpha"]
backgrounds = ["backgroundColor", "backgroundLuminance"]

deltaX = 1.0 / 4.0
deltaY = 1.0 / 2.0

blend = dict()
mapper = dict()
actor = dict()
imager = dict()

for row, bg in enumerate(backgrounds):
    for column, fg in enumerate(foregrounds):
        blend.update({bg:{fg:vtk.vtkImageBlend()}})
        blend[bg][fg].AddInputConnection(eval(bg + '.GetOutputPort()'))
        blend[bg][fg].SetBlendModeToCompound()
        if bg == "backgroundColor" or fg == "luminance" or fg == "luminanceAlpha":
            blend[bg][fg].AddInputConnection(eval(fg + '.GetOutputPort()'))
            blend[bg][fg].SetOpacity(1, 0.8)

        mapper.update({bg:{fg:vtk.vtkImageMapper()}})
        mapper[bg][fg].SetInputConnection(blend[bg][fg].GetOutputPort())
        mapper[bg][fg].SetColorWindow(255)
        mapper[bg][fg].SetColorLevel(127.5)

        actor.update({bg:{fg:vtk.vtkActor2D()}})
        actor[bg][fg].SetMapper(mapper[bg][fg])

        imager.update({bg:{fg:vtk.vtkRenderer()}})
        imager[bg][fg].AddActor2D(actor[bg][fg])
        imager[bg][fg].SetViewport(column * deltaX, row * deltaY, (column + 1) * deltaX, (row + 1) * deltaY)

        renWin.AddRenderer(imager[bg][fg])

        column += 1

# render and interact with data

iRen = vtk.vtkRenderWindowInteractor()
iRen.SetRenderWindow(renWin);
renWin.Render()
