# NamedColorPatches

VTKExamples/Python/Visualization/NamedColorPatches

### Description

This example shows how to produce a HTML page called VTKNamedColorPatches showing the available colors in vtkNamedColors.

It also shows how to select the text color based on luminance. In this case Digital CCIR601 is used which gives less weight to the red and blue components of a color.

In the class HTMLTableMaker there are four methods that generate the HTML tables:

- MakeWebColorPage() -- Makes a page of just the colors and names known to Web Browsers.
- MakeVTKColorPage() -- Makes a page of colors and names corresponding to those in vtkColors.txt.
- MakeSynonymColorPage() -- Makes a page of color names and their synonyms.
- MakeCombinedColorPage() -- Makes an indexed page with all the colors and names in the class vtkNamedColors.

### Code

NamedColorPatches.py

    #!/usr/bin/env python
    # -*- coding: utf-8 -*-

    """
    =========================================================================

      Program:   Visualization Toolkit
      Module:    NamedColorPatches.py

      Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
      All rights reserved.
      See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

         This software is distributed WITHOUT ANY WARRANTY; without even
         the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
         PURPOSE.  See the above copyright notice for more information.

    =========================================================================

    Produce a HTML page called VTKNamedColorPatches.html showing the available
     colors in vtkNamedColors.

    It also shows how to select the text color based on luminance.
    In this case Digital CCIR601 is used which gives less weight to the
     red and blue components of a color.

    """

    from __future__ import print_function

    import vtk

    def RGBToHTMLColor(rgb):
        """
        Convert an [R, G, B] list to #RRGGBB.
        :param: rgb - The elements of the array rgb are unsigned chars (0..255).
        :return: The html color.
        """
        hexcolor = "#" + ''.join(['{:02x}'.format(x) for x in rgb])
        return hexcolor

    def HTMLColorToRGB(colorString):
        """
        Convert #RRGGBB to a [R, G, B] list.
        :param: colorString a string in the form: #RRGGBB where RR, GG, BB are hexadecimal.
        The elements of the array rgb are unsigned chars (0..255).
        :return: The red, green and blue components as a list.
        """
        colorString = colorString.strip()
        if colorString[0] == '#': colorString = colorString[1:]
        if len(colorString) != 6:
            raise ValueError("Input #%s is not in #RRGGBB format" % colorString)
        r, g, b = colorString[:2], colorString[2:4], colorString[4:]
        r, g, b = [int(n, 16) for n in (r, g, b)]
        return [r, g, b]

    def RGBToLumaCCIR601(rgb):
        """
        RGB -> Luma conversion
        Digital CCIR601 (gives less weight to the R and B components)
        :param: rgb - The elements of the array rgb are unsigned chars (0..255).
        :return: The luminance.
        """
        Y = 0.299 * rgb[0] + 0.587 * rgb[1] + 0.114 * rgb[2]
        return Y

    def FormatRGBForHTML(rgb):
        """
        Format the rgb colors for display on a html table.
        :param: rgb - The elements of the array rgb are unsigned chars (0..255).
        :return: A formatted string for the html table.
        """
        s = ','.join(['{:3d}'.format(x) for x in rgb])
        s = s.replace(' ', '&#160;')
        s = s.replace(',', '&#160;&#160;')
        return s

    class HTMLTableMaker(object):
        """
          This class creates HTML Tables displaying all the colors in
          the class vtkNamedColors grouped by various categories.
        """

        def __init__(self):
            self.cn = {
                'Red': ['IndianRed', 'LightCoral', 'Salmon', 'DarkSalmon',
                        'LightSalmon', 'Red', 'Crimson', 'FireBrick', 'DarkRed'],
                'Pink': ['Pink', 'LightPink', 'HotPink', 'DeepPink',
                         'MediumVioletRed', 'PaleVioletRed'],
                'Orange': ['LightSalmon', 'Coral', 'Tomato', 'OrangeRed',
                           'DarkOrange', 'Orange'],
                'Yellow': ['Gold', 'Yellow', 'LightYellow', 'LemonChiffon',
                           'LightGoldenrodYellow', 'PapayaWhip', 'Moccasin',
                           'PeachPuff', 'PaleGoldenrod', 'Khaki', 'DarkKhaki'],
                'Purple': ['Lavender', 'Thistle', 'Plum', 'Violet', 'Orchid',
                           'Fuchsia', 'Magenta', 'MediumOrchid', 'MediumPurple',
                           'BlueViolet', 'DarkViolet', 'DarkOrchid', 'DarkMagenta',
                           'Purple', 'Indigo', 'DarkSlateBlue', 'SlateBlue',
                           'MediumSlateBlue'],
                'Green': ['GreenYellow', 'Chartreuse', 'LawnGreen', 'Lime',
                          'LimeGreen', 'PaleGreen', 'LightGreen',
                          'MediumSpringGreen', 'SpringGreen', 'MediumSeaGreen',
                          'SeaGreen', 'ForestGreen', 'Green', 'DarkGreen',
                          'YellowGreen', 'OliveDrab', 'Olive', 'DarkOliveGreen',
                          'MediumAquamarine', 'DarkSeaGreen', 'LightSeaGreen',
                          'DarkCyan', 'Teal'],
                'Blue/Cyan': ['Aqua', 'Cyan', 'LightCyan', 'PaleTurquoise',
                              'Aquamarine', 'Turquoise', 'MediumTurquoise',
                              'DarkTurquoise', 'CadetBlue', 'SteelBlue',
                              'LightSteelBlue', 'PowderBlue', 'LightBlue',
                              'SkyBlue', 'LightSkyBlue', 'DeepSkyBlue',
                              'DodgerBlue', 'CornflowerBlue', 'RoyalBlue', 'Blue',
                              'MediumBlue', 'DarkBlue', 'Navy', 'MidnightBlue'],
                'Brown': ['Cornsilk', 'BlanchedAlmond', 'Bisque', 'NavajoWhite',
                          'Wheat', 'BurlyWood', 'Tan', 'RosyBrown', 'SandyBrown',
                          'Goldenrod', 'DarkGoldenrod', 'Peru', 'Chocolate',
                          'SaddleBrown', 'Sienna', 'Brown', 'Maroon'],
                'White': ['White', 'Snow', 'Honeydew', 'MintCream', 'Azure',
                          'AliceBlue', 'GhostWhite', 'WhiteSmoke', 'Seashell',
                          'Beige', 'OldLace', 'FloralWhite', 'Ivory',
                          'AntiqueWhite', 'Linen',
                          'LavenderBlush', 'MistyRose'],
                'Gray': ['Gainsboro', 'LightGrey', 'Silver', 'DarkGray', 'Gray',
                         'DimGray', 'LightSlateGray', 'SlateGray', 'DarkSlateGray',
                         'Black']
            }
            # Ordering of the tables and when to start and end a column of tables
            # in the layout.
            self.cnOrder = ['Red', 'Pink', 'Orange', 'Yellow', 'Purple', 'Green',
                            'Blue/Cyan', 'Brown', 'White', 'Gray']
            self.cnStartTable = ['Red', 'Green', 'Brown']
            self.cnEndTable = ['Purple', 'Blue/Cyan', 'Gray']

            self.vtkcn = {
                'Whites': ['antique_white', 'azure', 'bisque', 'blanched_almond',
                           'cornsilk', 'eggshell', 'floral_white', 'gainsboro',
                           'ghost_white', 'honeydew', 'ivory', 'lavender',
                           'lavender_blush', 'lemon_chiffon', 'linen', 'mint_cream',
                           'misty_rose', 'moccasin', 'navajo_white', 'old_lace',
                           'papaya_whip', 'peach_puff', 'seashell', 'snow',
                           'thistle', 'titanium_white', 'wheat', 'white',
                           'white_smoke', 'zinc_white'],
                'Greys': ['cold_grey', 'dim_grey', 'grey', 'light_grey',
                          'slate_grey', 'slate_grey_dark', 'slate_grey_light',
                          'warm_grey'],
                'Blacks': ['black', 'ivory_black', 'lamp_black'],
                'Reds': ['alizarin_crimson', 'brick', 'cadmium_red_deep', 'coral',
                         'coral_light', 'deep_pink', 'english_red', 'firebrick',
                         'geranium_lake', 'hot_pink', 'indian_red', 'light_salmon',
                         'madder_lake_deep', 'maroon', 'pink', 'pink_light',
                         'raspberry', 'red', 'rose_madder', 'salmon', 'tomato',
                         'venetian_red'],
                'Browns': ['beige', 'brown', 'brown_madder', 'brown_ochre',
                           'burlywood', 'burnt_sienna', 'burnt_umber', 'chocolate',
                           'deep_ochre', 'flesh', 'flesh_ochre', 'gold_ochre',
                           'greenish_umber', 'khaki', 'khaki_dark', 'light_beige',
                           'peru', 'rosy_brown', 'raw_sienna', 'raw_umber', 'sepia',
                           'sienna', 'saddle_brown', 'sandy_brown', 'tan',
                           'van_dyke_brown'],
                'Oranges': ['cadmium_orange', 'cadmium_red_light', 'carrot',
                            'dark_orange', 'mars_orange', 'mars_yellow', 'orange',
                            'orange_red', 'yellow_ochre'],
                'Yellows': ['aureoline_yellow', 'banana', 'cadmium_lemon',
                            'cadmium_yellow', 'cadmium_yellow_light', 'gold',
                            'goldenrod', 'goldenrod_dark', 'goldenrod_light',
                            'goldenrod_pale', 'light_goldenrod', 'melon',
                            'naples_yellow_deep', 'yellow', 'yellow_light'],
                'Greens': ['chartreuse', 'chrome_oxide_green', 'cinnabar_green',
                           'cobalt_green', 'emerald_green', 'forest_green', 'green',
                           'green_dark', 'green_pale', 'green_yellow', 'lawn_green',
                           'lime_green', 'mint', 'olive', 'olive_drab',
                           'olive_green_dark', 'permanent_green', 'sap_green',
                           'sea_green', 'sea_green_dark', 'sea_green_medium',
                           'sea_green_light', 'spring_green', 'spring_green_medium',
                           'terre_verte', 'viridian_light', 'yellow_green'],
                'Cyans': ['aquamarine', 'aquamarine_medium', 'cyan', 'cyan_white',
                          'turquoise', 'turquoise_dark', 'turquoise_medium',
                          'turquoise_pale'],
                'Blues': ['alice_blue', 'blue', 'blue_light', 'blue_medium',
                          'cadet', 'cobalt', 'cornflower', 'cerulean', 'dodger_blue',
                          'indigo', 'manganese_blue', 'midnight_blue', 'navy',
                          'peacock', 'powder_blue', 'royal_blue', 'slate_blue',
                          'slate_blue_dark', 'slate_blue_light',
                          'slate_blue_medium', 'sky_blue', 'sky_blue_deep',
                          'sky_blue_light', 'steel_blue', 'steel_blue_light',
                          'turquoise_blue', 'ultramarine'],
                'Magentas': ['blue_violet', 'cobalt_violet_deep', 'magenta',
                             'orchid', 'orchid_dark', 'orchid_medium',
                             'permanent_red_violet', 'plum', 'purple',
                             'purple_medium', 'ultramarine_violet', 'violet',
                             'violet_dark', 'violet_red', 'violet_red_medium',
                             'violet_red_pale']
            }
            # Ordering of the tables and when to start and end a column of tables
            # in the layout.
            self.vtkcnOrder = ['Whites', 'Greys', 'Blacks', 'Reds', 'Oranges', 'Browns', 'Yellows', 'Greens', 'Cyans',
                               'Blues',
                               'Magentas']
            self.vtkcnStartTable = ['Whites', 'Browns', 'Cyans']
            self.vtkcnEndTable = ['Oranges', 'Greens', 'Magentas']
            # The vtkNamedColors class.
            self.nc = vtk.vtkNamedColors()

        def MakeHTMLHeader(self):
            s = '<!DOCTYPE html>\n'
            s += '<html lang="en" dir="ltr" class="client-nojs">\n'
            s += '<head>\n'
            s += '<title>vtkNamedColors</title>\n'
            s += '<meta charset="UTF-8" />\n'
            s += '</head>\n'
            return s

        def MakeHTMLIndex(self):
            s = '<h2>Index</h2>\n'
            s += '<ul>\n'
            s += '\t<li><a href="#WebColorNames">Web color Names</li>\n'
            s += '\t<li><a href="#VTKColorNames">VTK color Names</li>\n'
            s += '\t<li><a href="#Synonyms">Synonyms</li>\n'
            s += '</ul>\n'
            return s

        def MakeTableHeader(self):
            s = '<tr>\n'
            s += '<th style="background:lightgrey">HTML name</th>\n'
            s += '<th style="background:lightgrey">Decimal code<br />\n'
            s += '&#160;&#160;R&#160;&#160;&#160;&#160;&#160;&#160;'
            s += 'G&#160;&#160;&#160;&#160;&#160;&#160;B</th>\n'
            s += '</tr>\n'
            return s

        def MakeSynonymTableHeader(self):
            s = '<tr>\n'
            s += '<th style="background:lightgrey">Synonyms</th>\n'
            s += '<th style="background:lightgrey">Decimal code<br />\n'
            s += '&#160;&#160;R&#160;&#160;&#160;&#160;&#160;&#160;'
            s += 'G&#160;&#160;&#160;&#160;&#160;&#160;B</th>\n'
            s += '</tr>\n'
            return s

        def MakeTD(self, name):
            s = '<tr>\n'
            s += '<td colspan="2" style="background:whitesmoke;'
            s += 'color:slategray;text-align:left"><big><b>' + name
            s += '</b></big></td>\n'
            s += '</tr>\n'
            return s

        def MakeTR(self, name, rgb, textColor):
            """
              Use when the name is a color name known to the web browser.
            """
            s = '<tr>\n'
            s += '<td style="background:' + name + ';color:' + textColor
            s += '">' + name + '</td>\n'
            s += '<td style="background:' + name + ';color:' + textColor
            s += '"><tt>' + FormatRGBForHTML(rgb) + '</tt></td>\n'
            s += '</tr>\n'
            return s

        def MakeVTKTR(self, name, nameColor, rgb, textColor):
            """
              Use when the name is not a color name known to the web browser.
            """
            s = '<tr>\n'
            s += '<td style="background:' + nameColor + ';color:'
            s += textColor + '">' + name + '</td>\n'
            s += '<td style="background:' + nameColor + ';color:'
            s += textColor + '"><tt>' + FormatRGBForHTML(rgb) + '</tt></td>\n'
            s += '</tr>\n'
            return s

        def FindLongestColorName(self):
            """ Find the longest color name. """
            maxLength = -1
            for key, value in self.cn.items():
                for val in value:
                    if len(val) > maxLength:
                        maxLength = len(val)
            for key, value in self.vtkcn.items():
                for val in value:
                    if len(val) > maxLength:
                        maxLength = len(val)
            return maxLength

        def MakeWebColorTables(self):
            res = ''
            for key in self.cnOrder:
                if key in self.cnStartTable:
                    res += '<td>\n'
                    res += '<table>\n'
                    res += self.MakeTableHeader()
                # Add in the name of the group in the color table.
                res += self.MakeTD(key + ' colors')
                values = self.cn[key]
                for name in values:
                    rgb = self.nc.GetColor3ub(name)
                    Y = RGBToLumaCCIR601(rgb)
                    textColor = '#000000'  # Black
                    if Y < 255 / 2.0:
                        textColor = '#ffffff'  # White
                    # Make the row for each color in the group.
                    # Here we use the name to set the background color
                    #  as it is known to the web browser.
                    res += self.MakeTR(name, rgb, textColor)
                if key in self.cnEndTable:
                    res += '</table>\n'
                    res += '</td>\n'
            return res

        def MakeVTKColorTables(self):
            res = ''
            for key in self.vtkcnOrder:
                if key in self.vtkcnStartTable:
                    res += '<td>\n'
                    res += '<table>\n'
                    res += self.MakeTableHeader()
                # Add in the name of the group in the color table.
                res += self.MakeTD(key)
                values = self.vtkcn[key]
                for name in values:
                    rgb = self.nc.GetColor3ub(name)
                    Y = RGBToLumaCCIR601(rgb)
                    textColor = '#000000'  # Black
                    if Y < 255 / 2.0:
                        textColor = '#ffffff'  # White
                    # We must set the background color to a specific
                    # HTML color as the color name may not be a standard
                    # name known to the web browser.
                    nameColor = RGBToHTMLColor(rgb)
                    # Make the row for each color in the group.
                    res += self.MakeVTKTR(name, nameColor, rgb, textColor)
                if key in self.vtkcnEndTable:
                    res += '</table>\n'
                    res += '</td>\n'
            return res

        def MakeSynonymColorTable(self):
            syn = self.nc.GetSynonyms()
            # Convert to a list where each element is a list of the
            #  color and its synonyms.
            syn = syn.split('\n\n')
            synonyms = []
            for ele in syn:
                synonyms.append(ele.split('\n'))
            cn = list()
            for key, value in self.cn.items():
                cn = cn + value
            # Create a dictionary where the key is the lowercase name.
            d = dict()
            for n in cn:
                d.update({n.lower(): n})
            res = '<td>\n'
            res += '<table>\n'
            res += self.MakeSynonymTableHeader()
            for colorNames in synonyms:  # colors.GetSynonyms():
                for idx, name in enumerate(colorNames):
                    if name in d:
                        colorNames[idx] = d[name]
                colorNames.sort()
                name = ", ".join(colorNames)
                rgb = self.nc.GetColor3ub(colorNames[0])
                Y = RGBToLumaCCIR601(rgb)
                textColor = '#000000'  # Black
                if Y < 255 / 2.0:
                    textColor = '#ffffff'  # White
                # We must set the background color to a specific
                # HTML color  names is just a list of
                # synonyms for that particular color.
                nameColor = RGBToHTMLColor(rgb)
                # Make the row for each color in the group.
                res += self.MakeVTKTR(name, nameColor, rgb, textColor)
            res += '</table>\n'
            res += '</td>\n'
            return res

        def MakeWebColorPage(self):
            res = self.MakeHTMLHeader()
            res += '<body>\n'
            res += '<h1>Colors available in vtkNamedColors</h1>\n'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<caption style="background:lightgrey">Web Color Names'
            res += '</caption>\n'
            res += '<tr valign="top">\n'
            res += self.MakeWebColorTables()
            res += '</table>\n'
            res += '</body>\n'
            return res

        def MakeVTKColorPage(self):
            res = self.MakeHTMLHeader()
            res += '<body>\n'
            res += '<h1>Colors available in vtkNamedColors</h1>\n'
            res += '<p>The web colors take precedence over colors of the same'
            res += ' name in VTK Color Names.</p>\n'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<caption style="background:lightgrey">VTK Color Names</caption>\n'
            res += '<tr valign="top">\n'
            res += self.MakeVTKColorTables()
            res += '</table>\n'
            res += '</body>\n'
            return res

        def MakeSynonymColorPage(self):
            res = self.MakeHTMLHeader()
            res += '<body>\n'
            res += '<h1>Synonyms in vtkNamedColors</h1>\n'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<caption style="background:lightgrey"></caption>\n'
            res += '<tr valign="top">\n'
            res += self.MakeSynonymColorTable()
            res += '</table>\n'
            res += '</body>\n'
            return res

        def MakeCombinedColorPage(self):
            res = self.MakeHTMLHeader()
            res += '<body>\n'
            res += '<h1>Colors available in vtkNamedColors</h1>\n'
            res += '<p>The class vtkNamedColors provides color names and their'
            res += ' values for the convenience of the user.</p>\n'
            res += '<p>The following tables show the available colors along with'
            res += ' their red, green and blue values.</p>\n'
            res += self.MakeHTMLIndex()
            res += '<h2><a id="WebColorNames">Web color Names</h2>'
            res += 'These colors correspond to those in'
            res += ' <a href="http://en.wikipedia.org/wiki/Web_colors"'
            res += ' title="Web Colors">Web Colors</a>.\n'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<tr valign="top">\n'
            res += self.MakeWebColorTables()
            res += '</table>\n'
            res += '<h2><a id="VTKColorNames">VTK color Names</h2>'
            res += '<p>The colors mainly correspond to those in vtkColors.txt.\n</p>\n'
            res += '<p>The web colors (above) take precedence over colors of the'
            res += ' same name in vtkColors.txt.</p>\n'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<tr valign="top">\n'
            res += self.MakeVTKColorTables()
            res += '</table>\n'
            res += '<h2><a id="Synonyms">Synonyms</h2>'
            res += '<table style="font-size:90%" cellpadding="4">\n'
            res += '<tr valign="top">\n'
            res += self.MakeSynonymColorTable()
            res += '</table>\n'
            res += '</body>\n'
            return res

    if __name__ == "__main__":
        requiredMajorVersion = 6
        if vtk.vtkVersion().GetVTKMajorVersion() < requiredMajorVersion:
            print("You need VTK Version 6 or greater.")
            print("The class vtkNamedColors is in VTK version 6 or greater.")
            exit(0)
        ncp = HTMLTableMaker()
        res = ncp.MakeCombinedColorPage()
        f = open("VTKNamedColorPatches.html", "wt")
        f.write(res)
        f.close()