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()
        #self._setTableValue()

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

        # NOTE: Build have to be executed prior to using SetTableValue.
        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.__vtk_lookup_table = vtk.vtkLookupTable()
        self.__setHueRange(0,0)
        self.__setSaturationRange(0,0)
        self.__setValueRange(1,0)
        self.__setNumberOfTableValues(256)
        self.__setRampToSQRT()
        #self.__vtk_lookup_table.Build()

    def __setValueRange(self, lower_range, upper_range):
        """
        Set value range (brighness) 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 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 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 values in the lookup table.
        """

        self.__vtk_lookup_table.SetNumberOfTableValues(table_values)

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