Palettes - Revision history

Foxtrot: /* Palette */

2023-01-11T17:16:36Z

‎Palette

Foxtrot: /* Palette */

2023-01-11T17:15:50Z

‎Palette

Dan Tobias: Merge in text/links from Computer Palettes

2023-01-11T16:57:32Z

Merge in text/links from Computer Palettes

Dan Tobias at 16:54, 11 January 2023

2023-01-11T16:54:47Z

Foxtrot: /* Examples */

2023-01-11T15:41:07Z

‎Examples

Foxtrot: /* Game palettes */

2023-01-11T15:40:02Z

‎Game palettes

Foxtrot at 15:39, 11 January 2023

2023-01-11T15:39:43Z

Foxtrot at 15:39, 11 January 2023

2023-01-11T15:39:10Z

Foxtrot: /* Examples */

2023-01-11T15:38:04Z

‎Examples

Foxtrot: /* Examples */

2023-01-11T15:35:51Z

‎Examples

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 * Palettes are often stored as '''tuples''' (1 byte for the red, green and blue component in sequence) or in '''planes''' (1 byte for the red component for each swatch, then 1 byte for the green, then 1 byte for the blue).
 ** Palettes are often loaded directly into memory, and as such, their format usually matches the underlying hardware or system API. For this reason, palettes are often uncompressed and unencrypted.
-** In game formats, the number of bytes allocate for the palette is fixed, even if an image needs fewer colors. This is in contrast to image formats for the web (i.e. [[GIF]]) where a few bytes might be saved by only storing the data which is needed.
+** In game formats, often the number of bytes allocate for the palette is fixed, even if an image needs fewer colors. This is in contrast to image formats for the web (i.e. [[GIF]]) where a few bytes might be saved by storing only the data which is needed.
 * Whilst <code>RGB</code> component ordering is conventional, the components are sometimes ordered differently based on the underlying hardware.
 * If the palette appears dimmer than expected, it might be using less bits per byte in one or all components. It was common to store components using 6-bits (0-63) instead of the full 8-bits (0-255). 6-bit components would need to be multiplied by 4 to map the components back to the expected range of 0-255. Naturally, a 6-bit component would result in loss of precision when converting from 8-bit.

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 * Palettes are often stored as '''tuples''' (1 byte for the red, green and blue component in sequence) or in '''planes''' (1 byte for the red component for each swatch, then 1 byte for the green, then 1 byte for the blue).
 ** Palettes are often loaded directly into memory, and as such, their format usually matches the underlying hardware or system API. For this reason, palettes are often uncompressed and unencrypted.
-** When a format stores 256 colors, but an image fewer colors, the   but still allocate the entire 768 bytes.
+** In game formats, the number of bytes allocate for the palette is fixed, even if an image needs fewer colors. This is in contrast to image formats for the web (i.e. [[GIF]]) where a few bytes might be saved by only storing the data which is needed.
 * Whilst <code>RGB</code> component ordering is conventional, the components are sometimes ordered differently based on the underlying hardware.
 * If the palette appears dimmer than expected, it might be using less bits per byte in one or all components. It was common to store components using 6-bits (0-63) instead of the full 8-bits (0-255). 6-bit components would need to be multiplied by 4 to map the components back to the expected range of 0-255. Naturally, a 6-bit component would result in loss of precision when converting from 8-bit.

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 | colspan="3" style="vertical-align: top;" | <div style="max-width: 500px">The PC game "Dark Reign" has a different palette for each "terrain" tilesets, the colors of which start at index 160. This allows the game's artists to utilize colors for the tilesets that are more suitable to that environment. The colors earlier in the palette largely remain unchanged, as these are used for the game's sprites and interface.</div>
 |}
 [[Category:Elements of File Formats]]
 [[Category:Graphics]]

← Older revision		Revision as of 16:54, 11 January 2023
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		+	{{FormatInfo
		+	\|formattype=electronic
		+	\|subcat=Elements of File Formats
		+	}}
	A '''palette''' is, at its simplest, a lookup-table of colors with their corresponding index that is utilized when displaying computer graphics. Palettes are either:		A '''palette''' is, at its simplest, a lookup-table of colors with their corresponding index that is utilized when displaying computer graphics. Palettes are either:

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	[[Category:Elements of File Formats]]		[[Category:Elements of File Formats]]
		+	[[Category:Graphics]]

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 | style="max-width: 400px; text-align: center;" |  [[File:Game_palette_dr_alien.png]]
 |-
-| colspan="3" style="vertical-align: top;" | <div style="max-width: 500px">The PC game "Dark Reign" has a different palette for each map terrain, starting at index 160. This allows the game's artists to utilize colors that are more suitable to the terrain. The colors earlier in the palette largely remain unchanged, as these are used for the game's sprites and interface.</div>
+| colspan="3" style="vertical-align: top;" | <div style="max-width: 500px">The PC game "Dark Reign" has a different palette for each "terrain" tilesets, the colors of which start at index 160. This allows the game's artists to utilize colors for the tilesets that are more suitable to that environment. The colors earlier in the palette largely remain unchanged, as these are used for the game's sprites and interface.</div>
 |}
 [[Category:Elements of File Formats]]

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 == Structure ==
-Game palettes often comprise a the following chunks of data:
+Game palettes often comprise the following chunks of data:
 * The '''palette''' itself, usually containing 256 ''swatches'', 3 bytes per ''color component'' totaling 768 bytes in length. The 256 limit corresponds to the ''8bpp mode'' (or ''256 color mode'') limitations of personal computers of the time. Whilst a size of 256 was most common, other sizes can be found throughout computing history. See [https://en.wikipedia.org/wiki/List_of_software_palettes List of software palettes].

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 * Any number of '''blending tables''', which store pre-computed transformations on a palette, such as shading or blending. The results refer back to an index in the palette itself.
-----
+=== Palette ===
-−
-The '''palette''':
 * Palettes are often stored as '''tuples''' (1 byte for the red, green and blue component in sequence) or in '''planes''' (1 byte for the red component for each swatch, then 1 byte for the green, then 1 byte for the blue).
@@ Line 33: / Line 31: @@
 * Often, the palette is the first chunk of data within the file. If the palette appears randomized, or ordered by brightness or hue, this is an indication that the palette was generated by graphics software and not used directly by artists. Conversely, if a palette appears structured, the palette itself may have been authored by an graphics artist or the color indices have additional meaning (i.e. an index of 0 or 255 is often used for 1-bit transparency.)
-----
+=== Blending tables ===
 '''Blending tables''' are a lookup-table which stores the pre-computed results of some transformation on the palette. Instead of calculating the changes in real-time (and hindering performance), the game would refer to a blending table of the transformation it wishes to apply.

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 Whilst palettes are common across all media, they are particularly common in games.
 = Game palettes =
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 * The number of tables might be hard-coded for the format or stored as a variable somewhere within the file itself.
-== Examples ==
+= Examples =
 {| class="wikitable"

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 |-
 | style="max-width: 400px; vertical-align: top;" | Example of a palette whose order implies that it was generated by image-editing software, likely, downsampled from a source image with a higher ''color depth''.
-| style="max-width: 400px; vertical-align: top;" | Example of a palette with limited colors but a magnitude of shades. Implying that darkening colors might be important within the game.
+| style="max-width: 400px; vertical-align: top;" | Example of a palette from the PC game ''Duke Nukem 3D''. The palette has limited colors but a magnitude of shades, as the game engine has rudimentary lighting effects. The game utilises blending tables to determine which index to show from the palette, based on the brightness of the area the player occupies.
 |}