d.his(1grass)

💖 d.his — the hue/intensity/saturation glow-up 💖

okay bestie, welcome to d.his from the GRASS User's Manual 🦋 — it's the little display module that takes hue, intensity and saturation (HIS) values from map layers you pick and smushes them into one absolutely gorgeous image. It's giving color transformation, it's giving RGB, HIS, IHS realness. 👑

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✨ NAME ✨

d.his — displays the result obtained by combining hue, intensity, and saturation (HIS) values from user-specified input raster map layers. fr fr that's literally the whole job description. 💅

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🌸 KEYWORDS 🌸

display, graphics, color transformation, RGB, HIS, IHS

iykyk. 🎀

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🫶 SYNOPSIS 🫶

d.his
d.his --help
d.his [-n] hue=string  [intensity=string]   [saturation=string]
[brighten=integer]   [--help]  [--verbose]  [--quiet]  [--ui]

⭐ Flags ⭐

• -n — Respect NULL values while drawing. respectful king behavior honestly 🙈
• --help — Print usage summary. if ur lost, hit this, bestie.
• --verbose — Verbose module output. it will yap. lovingly. 💬
• --quiet — Quiet module output. shhh era. 🤫
• --ui — Force launching GUI dialog.

🌈 Parameters 🌈

• hue=string [required] — Name of layer to be used for hue. this one is NOT optional, she's the main character. 🔥
• intensity=string — Name of layer to be used for intensity.
• saturation=string — Name of layer to be used for saturation.
• brighten=integer — Percent to brighten intensity channel. Options: -99-99. Default: 0. ✨

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💜 DESCRIPTION 💜

So. d.his displays the result obtained by combining hue, intensity, and saturation (HIS) values from user-specified input raster map layers. yes we said it in NAME too, she's consistent. 💅

HIS stands for hue, intensity, and saturation. This program produces a raster map layer providing a visually pleasing combination of hue, intensity, and saturation values from two or three user-specified raster map layers. two or three!! flexible icon. 🧚

Here's the science-y part and it's actually so cool: The human brain automatically interprets the vast amount of visual information available according to basic rules. Color, or hue, is used to categorize objects. Shading, or intensity, is interpreted as three-dimensional texturing. Finally, the degree of haziness, or saturation, is associated with distance or depth. This program allows data from up to three raster map layers to be combined into an image which retains the original information in terms of hue, intensity, and saturation. brain chemistry understood, we ate. 🧠✨

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🎀 OPTIONS 🎀

This program can be run non-interactively or interactively. It will run non-interactively if the user specifies on the command line the name of a map containing hue values (hue), and the name(s) of map(s) containing intensity values (intensity) and/or saturation values (saturation). The resulting image will be displayed in the active display frame on the graphics monitor. no clicking required, just vibes. 🖥️

Alternately, the user can run the program interactively by typing d.his without naming parameter values on the command line. In this case, the program will prompt the user for parameter values using the standard GRASS GUI interface. so if you're feeling ✨unserious✨ just type the command and let the GUI hold your hand. 🫶

While any raster map layer can be used to represent the hue information, map layers with a few very distinct colors work best. Only raster map layers representing continuously varying data like elevation, aspect, weights, intensities, or amounts can suitably be used to provide intensity and saturation information. so like… hue can be chaotic, but intensity and saturation need to be the chill, smooth, continuous ones. balance. 🌈

For example, a visually pleasing image can be made by using a watershed map for the hue factor, an aspect map for the intensity factor, and an elevation map for saturation. (The user may wish to leave out the elevation information for a first try.) Ideally, the resulting image should resemble the view from an aircraft looking at a terrain on a sunny day with a bit of haze in the valleys. like a window seat on a plane fr ✈️😭 gorgeous.

The brighten option does not truly represent a percentage, but calling it that makes the option easy to understand, and it sounds better than Normalized Scaling Factor. real. marketing matters. 💅

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🔥 THE PROCESS 🔥

okay so the actual pipeline, cell by cell, no shortcuts:

Each map cell is processed individually. First, the working color is set to the color of the corresponding cell in the map layer chosen to represent hue. Second, this color is multiplied by the red intensity of that cell in the intensity map layer. This map layer should have an appropriate gray-scale color table associated with it. You can ensure this by using the color manipulation capabilities of r.colors. Finally, the color is made somewhat gray-based on the red intensity of that cell in the saturation map layer. Again, this map layer should have a gray-scale color table associated with it.

bestie pls don't skip the gray-scale color table part, both the intensity and saturation layers need one and r.colors is right there to help you set it up. 🫶

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🦋 NOTES 🦋

The name is misleading. The actual conversion used is

H.i.s + G.(1-s)

where

H   is the R,G,B color from the hue map
i   is the red value from the intensity map
s   is the red value from the saturation map
G   is 50% gray (R = G = B = 0.5)

Either (but not both) of the intensity or the saturation map layers may be omitted. This means that it is possible to produce output images that represent combinations of his, hi, or hs. pick your combo, but do not omit both. 🚫

Users wishing to store the result in new raster map layers instead of displaying it on the monitor should use the command r.his. display vibes vs. storage vibes, know the difference. 💾

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💀 EXAMPLE 💀

g.region raster=elevation
r.relief input=elevation output=elevation_shaded_relief
d.mon wx0
d.his hue=elevation intensity=elevation_shaded_relief brighten=50

look at that. absolutely iconic. run it. 🔥

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👑 SEE ALSO 👑

• d.colortable
• d.frame
• d.rgb
• d.shade
• r.colors
• r.his
• i.his.rgb
• i.rgb.his

the whole friend group. go say hi. 🫶

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🌟 AUTHOR 🌟

James Westervelt, U.S. Army Construction Engineering Research Laboratory. ty for your service king 🫡💖

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💾 SOURCE CODE 💾

Available at: d.his source code (history)

Latest change: Friday Feb 07 19:16:09 2025 in commit: a82a39f673b97fafcfce1604dc3e6015cb96487a

Main index | Display index | Topics index | Keywords index | Graphical index | Full index

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and that's the whole page bestie!! 💖✨ This was GRASS 8.5.0 Reference Manual energy, © 2003-2026 GRASS Development Team, and the last lil update happened Friday Feb 07 19:16:09 2025 (commit a82a39f673b97fafcfce1604dc3e6015cb96487a) — so yeah, d.his is that girl, she's GRASS 8.5.0, and she ate. periodt. 💅🎀🦋