pyvisi/py_src/lookuptable.py

"""
@author: John NGUI
"""

import vtk

class LookupTable:
    """
    Class that defines a lookup table for mapping scalar values into colors.
    """

    def __init__(self):
        """
        Initialise the lookup table.
        """

        self.__vtk_lookup_table = vtk.vtkLookupTable()
        self.__vtk_inverse_lookup_table = vtk.vtkLookupTable()
        self.__build()

    def __build(self):
        """
        Generates the lookup table.
        """

        # NOTE: Build have to be executed prior to using SetTableValue (if any).
        self.__vtk_lookup_table.Build()
        self.__vtk_inverse_lookup_table.Build()

    def _setTableValue(self):
        """
        Setup the lookup table with colors.
        """

        # NOTE: The color values are inversed because VTK's default lookup
        # table is inversed by itself. SetTableValue have to be executed after
        # the Build.
        for i in range(256):
            self.__vtk_lookup_table.SetTableValue(
                    i, self.__vtk_inverse_lookup_table.GetTableValue(255 - i))

    def _setLookupTableToGreyScale(self):
        """
        Setup the lookup table with grey scale. 
        """

        self.__setHueRange(0,0)
        self.__setSaturationRange(0,0)
        self.__setValueRange(1,0)
        self.__setNumberOfTableValues(256)
        self.__setRampToSQRT()

    def __setValueRange(self, lower_range, upper_range):
        """
        Set the value range (brightness) for the lookup table (between 0 and 1).

        @type lower_range: Number
        @param lower_range:Lower value range 
        @type upper_range: Number
        @param upper_range: Upper value range
        """

        self.__vtk_lookup_table.SetValueRange(lower_range, upper_range)

    def __setHueRange(self, lower_range, upper_range):
        """
        Set the hue (color) range for the lookup table (between 0 and 1).

        @type lower_range: Number
        @param lower_range:Lower hue range 
        @type upper_range: Number
        @param upper_range: Upper hue range
        """

        self.__vtk_lookup_table.SetHueRange(lower_range, upper_range)

    def __setSaturationRange(self, lower_range, upper_range):
        """
        Set the saturation (vibrancy) range for the lookup table \
        (between 0 and 1).

        @type lower_range: Number
        @param lower_range:Lower saturantion range 
        @type upper_range: Number
        @param upper_range: Upper saturation range
        """

        self.__vtk_lookup_table.SetSaturationRange(lower_range, upper_range)
    
    def __setRampToSQRT(self):
        """
        Set the table ramp to SQRT. The default ramp is S-curve.    
        """

        self.__vtk_lookup_table.SetRampToSQRT()

    def __setNumberOfTableValues(self, table_values):
        """
        Set the number of values (i.e. colors) in the lookup table. 

        @type table_values: Number
        @param table_values: Number of colors in the lookup table.
        """

        self.__vtk_lookup_table.SetNumberOfTableValues(table_values)

    def _getLookupTable(self):
        """
        Return the lookup table.

        @rtype: vtkLookupTable
        @return: Lookup table
        """

        return self.__vtk_lookup_table


1	"""
2	@author: John NGUI
3	"""
4
5	import vtk
6
7	class LookupTable:
8	"""
9	Class that defines a lookup table for mapping scalar values into colors.
10	"""
11
12	def __init__(self):
13	"""
14	Initialise the lookup table.
15	"""
16
17	self.__vtk_lookup_table = vtk.vtkLookupTable()
18	self.__vtk_inverse_lookup_table = vtk.vtkLookupTable()
19	self.__build()
20
21	def __build(self):
22	"""
23	Generates the lookup table.
24	"""
25
26	# NOTE: Build have to be executed prior to using SetTableValue (if any).
27	self.__vtk_lookup_table.Build()
28	self.__vtk_inverse_lookup_table.Build()
29
30	def _setTableValue(self):
31	"""
32	Setup the lookup table with colors.
33	"""
34
35	# NOTE: The color values are inversed because VTK's default lookup
36	# table is inversed by itself. SetTableValue have to be executed after
37	# the Build.
38	for i in range(256):
39	self.__vtk_lookup_table.SetTableValue(
40	i, self.__vtk_inverse_lookup_table.GetTableValue(255 - i))
41
42	def _setLookupTableToGreyScale(self):
43	"""
44	Setup the lookup table with grey scale.
45	"""
46
47	self.__setHueRange(0,0)
48	self.__setSaturationRange(0,0)
49	self.__setValueRange(1,0)
50	self.__setNumberOfTableValues(256)
51	self.__setRampToSQRT()
52
53	def __setValueRange(self, lower_range, upper_range):
54	"""
55	Set the value range (brightness) for the lookup table (between 0 and 1).
56
57	@type lower_range: Number
58	@param lower_range:Lower value range
59	@type upper_range: Number
60	@param upper_range: Upper value range
61	"""
62
63	self.__vtk_lookup_table.SetValueRange(lower_range, upper_range)
64
65	def __setHueRange(self, lower_range, upper_range):
66	"""
67	Set the hue (color) range for the lookup table (between 0 and 1).
68
69	@type lower_range: Number
70	@param lower_range:Lower hue range
71	@type upper_range: Number
72	@param upper_range: Upper hue range
73	"""
74
75	self.__vtk_lookup_table.SetHueRange(lower_range, upper_range)
76
77	def __setSaturationRange(self, lower_range, upper_range):
78	"""
79	Set the saturation (vibrancy) range for the lookup table \
80	(between 0 and 1).
81
82	@type lower_range: Number
83	@param lower_range:Lower saturantion range
84	@type upper_range: Number
85	@param upper_range: Upper saturation range
86	"""
87
88	self.__vtk_lookup_table.SetSaturationRange(lower_range, upper_range)
89
90	def __setRampToSQRT(self):
91	"""
92	Set the table ramp to SQRT. The default ramp is S-curve.
93	"""
94
95	self.__vtk_lookup_table.SetRampToSQRT()
96
97	def __setNumberOfTableValues(self, table_values):
98	"""
99	Set the number of values (i.e. colors) in the lookup table.
100
101	@type table_values: Number
102	@param table_values: Number of colors in the lookup table.
103	"""
104
105	self.__vtk_lookup_table.SetNumberOfTableValues(table_values)
106
107	def _getLookupTable(self):
108	"""
109	Return the lookup table.
110
111	@rtype: vtkLookupTable
112	@return: Lookup table
113	"""
114
115	return self.__vtk_lookup_table
116
117