d.his(1) - f14

1d.his(1)                      Grass User's Manual                     d.his(1)
2
3
4

NAME

6       d.his   - Displays the result obtained by combining hue, intensity, and
7       saturation (his) values from user-specified input raster map layers.
8

KEYWORDS

10       display
11

SYNOPSIS

13       d.his
14       d.his help
15       d.his    [-n]     h_map=string      [i_map=string]       [s_map=string]
16       [brighten=integer]   [--verbose]  [--quiet]
17
18   Flags:
19       -n
20           Respect NULL values while drawing
21
22       --verbose
23           Verbose module output
24
25       --quiet
26           Quiet module output
27
28   Parameters:
29       h_map=string
30           Name of layer to be used for HUE
31
32       i_map=string
33           Name of layer to be used for INTENSITY
34
35       s_map=string
36           Name of layer to be used for SATURATION
37
38       brighten=integer
39           Percent to brighten intensity channel
40           Options: -99-99
41           Default: 0
42

DESCRIPTION

44       his stands for hue, intensity, and saturation.  This program produces a
45       raster map layer providing a  visually  pleasing  combination  of  hue,
46       intensity,  and  saturation  values  from  two  or three user-specified
47       raster map layers.
48
49       The human brain automatically interprets  the  vast  amount  of  visual
50       information available according to basic rules.  Color, or hue, is used
51       to categorize objects.  Shading, or intensity, is interpreted as three-
52       dimensional  texturing. Finally, the degree of haziness, or saturation,
53       is associated with distance or depth. This program allows data from  up
54       to  three  raster map layers to be combined into an image which retains
55       the original information in terms of hue, intensity, and saturation.
56

OPTIONS

58       This program can be run non-interactively or  interactively.   It  will
59       run  non-interactively  if  the  user specifies on the command line the
60       name of a map containing hue values (h_map), and the name(s) of  map(s)
61       containing  intensity  values (i_map) and/or saturation values (s_map).
62       The resulting image will be displayed in the active  display  frame  on
63       the graphics monitor.
64
65       Alternately, the user can run the program interactively by typing d.his
66       without naming parameter values on the command line.  In this case, the
67       program  will  prompt  the user for parameter values using the standard
68       GRASS GUI interface.
69
70       While any raster map layer can be used to represent  the  hue  informa‐
71       tion,  map  layers  with  a  few  very distinct colors work best.  Only
72       raster map layers representing continuously varying  data  like  eleva‐
73       tion,  aspect, weights, intensities, or amounts can suitably be used to
74       provide intensity and saturation information.
75
76       For example, a visually pleasing image can be made by using a watershed
77       map  for the hue factor, an aspect map for the intensity factor, and an
78       elevation map for saturation.  (The user may wish to leave out the ele‐
79       vation  information  for  a  first  try.)  Ideally, the resulting image
80       should resemble the view from an aircraft looking at  a  terrain  on  a
81       sunny day with a bit of haze in the valleys.
82
83       The  brighten option does not truly represent a percentage, but calling
84       it that makes the option easy to understand, and it sounds better  than
85       Normalized Scaling Factor.
86

THE PROCESS

88       Each  map  cell  is processed individually. First, the working color is
89       set to the color of the corresponding cell in the map layer  chosen  to
90       represent  HUE.   Second, this color is multiplied by the red intensity
91       of that cell in the INTENSITY map layer.  This map layer should have an
92       appropriate  gray-scale  color table associated with it. You can ensure
93       this by using the color manipulation capabilities of d.colors or r.col‐
94       ors.   Finally, the color is made somewhat gray-based on the red inten‐
95       sity of that cell in the SATURATION map layer.  Again, this  map  layer
96       should have a gray-scale color table associated with it.
97

NOTES

99       The name is misleading. The actual conversion used is
100         <U>H.i.s + <U>G.(1-s)
101       where
102         <U>H   is the R,G,B color from the hue map
103         i   is the red value from the intensity map
104         s   is the red value from the saturation map
105         <U>G   is 50% gray (R = G = B = 0.5)
106
107
108       Either (but not both) of the intensity or the saturation map layers may
109       be omitted. This means that it is possible  to  produce  output  images
110       that represent combinations of his, hi, or hs.
111
112       Users  wishing  to store the result in new raster map layers instead of
113       displaying it on the monitor should use the program r.his.
114

EXAMPLE

116   Spearfish dataset
117
118         g.region rast=elevation.dem
119         r.shaded.relief map=elevation.dem shad=elev.shad_relf
120         d.mon x1
121         d.his h=elevation.dem i=elev.shad_relf brighten=50
122
123

AUTHOR

129       James  Westervelt,  U.S. Army Construction Engineering Research Labora‐
130       tory
131
132       Last changed: $Date: 2007-05-16 07:17:40 +0200 (Wed, 16 May 2007) $
133
134       Full index
135
136       © 2003-2008 GRASS Development Team
137
138
139
140GRASS 6.3.0                                                           d.his(1)