1d.his(1) GRASS GIS User's Manual d.his(1)
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6 d.his - Displays the result obtained by combining hue, intensity, and
7 saturation (HIS) values from user-specified input raster map layers.
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10 display, graphics, color transformation, RGB, HIS, IHS
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13 d.his
14 d.his --help
15 d.his [-n] hue=string [intensity=string] [saturation=string]
16 [brighten=integer] [--help] [--verbose] [--quiet] [--ui]
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18 Flags:
19 -n
20 Respect NULL values while drawing
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22 --help
23 Print usage summary
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25 --verbose
26 Verbose module output
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28 --quiet
29 Quiet module output
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31 --ui
32 Force launching GUI dialog
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34 Parameters:
35 hue=string [required]
36 Name of layer to be used for hue
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38 intensity=string
39 Name of layer to be used for intensity
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41 saturation=string
42 Name of layer to be used for saturation
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44 brighten=integer
45 Percent to brighten intensity channel
46 Options: -99-99
47 Default: 0
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50 HIS stands for hue, intensity, and saturation. This program produces a
51 raster map layer providing a visually pleasing combination of hue, in‐
52 tensity, and saturation values from two or three user-specified raster
53 map layers.
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55 The human brain automatically interprets the vast amount of visual in‐
56 formation available according to basic rules. Color, or hue, is used
57 to categorize objects. Shading, or intensity, is interpreted as
58 three-dimensional texturing. Finally, the degree of haziness, or satu‐
59 ration, is associated with distance or depth. This program allows data
60 from up to three raster map layers to be combined into an image which
61 retains the original information in terms of hue, intensity, and satu‐
62 ration.
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65 This program can be run non-interactively or interactively. It will
66 run non-interactively if the user specifies on the command line the
67 name of a map containing hue values (hue), and the name(s) of map(s)
68 containing intensity values (intensity) and/or saturation values (satu‐
69 ration). The resulting image will be displayed in the active display
70 frame on the graphics monitor.
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72 Alternately, the user can run the program interactively by typing d.his
73 without naming parameter values on the command line. In this case, the
74 program will prompt the user for parameter values using the standard
75 GRASS GUI interface.
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77 While any raster map layer can be used to represent the hue informa‐
78 tion, map layers with a few very distinct colors work best. Only
79 raster map layers representing continuously varying data like eleva‐
80 tion, aspect, weights, intensities, or amounts can suitably be used to
81 provide intensity and saturation information.
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83 For example, a visually pleasing image can be made by using a watershed
84 map for the hue factor, an aspect map for the intensity factor, and an
85 elevation map for saturation. (The user may wish to leave out the ele‐
86 vation information for a first try.) Ideally, the resulting image
87 should resemble the view from an aircraft looking at a terrain on a
88 sunny day with a bit of haze in the valleys.
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90 The brighten option does not truly represent a percentage, but calling
91 it that makes the option easy to understand, and it sounds better than
92 Normalized Scaling Factor.
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95 Each map cell is processed individually. First, the working color is
96 set to the color of the corresponding cell in the map layer chosen to
97 represent hue. Second, this color is multiplied by the red intensity
98 of that cell in the intensity map layer. This map layer should have an
99 appropriate gray-scale color table associated with it. You can ensure
100 this by using the color manipulation capabilities of r.colors. Fi‐
101 nally, the color is made somewhat gray-based on the red intensity of
102 that cell in the saturation map layer. Again, this map layer should
103 have a gray-scale color table associated with it.
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106 The name is misleading. The actual conversion used is
107 H.i.s + G.(1-s)
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109 H is the R,G,B color from the hue map
110 i is the red value from the intensity map
111 s is the red value from the saturation map
112 G is 50% gray (R = G = B = 0.5)
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114 Either (but not both) of the intensity or the saturation map layers may
115 be omitted. This means that it is possible to produce output images
116 that represent combinations of his, hi, or hs.
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118 Users wishing to store the result in new raster map layers instead of
119 displaying it on the monitor should use the command r.his.
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122 g.region raster=elevation
123 r.relief input=elevation output=elevation_shaded_relief
124 d.mon wx0
125 d.his hue=elevation intensity=elevation_shaded_relief brighten=50
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128 d.colortable, d.frame, d.rgb, d.shade, r.colors, r.his, i.his.rgb,
129 i.rgb.his
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132 James Westervelt, U.S. Army Construction Engineering Research Labora‐
133 tory
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136 Available at: d.his source code (history)
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138 Accessed: Saturday Oct 28 18:17:13 2023
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140 Main index | Display index | Topics index | Keywords index | Graphical
141 index | Full index
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143 © 2003-2023 GRASS Development Team, GRASS GIS 8.3.1 Reference Manual
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147GRASS 8.3.1 d.his(1)