Truevision TGA
From Wikipedia, the free encyclopedia
| Truevision TGA | |
|---|---|
| File name extension | .tga |
| Internet media type | image/x-targa |
| Type code | 'TPIC' |
| Uniform Type Identifier | com.truevision.tga-image |
| Developed by | Truevision |
| Type of format | Raster image file |
Truevision's (now Pinnacle Systems) TGA File Format, often referred to as TARGA File Format, is a raster graphics file format. It was the native format of Truevision Inc.'s TARGA and VISTA boards, which were the first graphic cards for IBM-compatible PCs to support Highcolor/truecolor display. This family of graphic cards was intended for professional computer image synthesis and video editing with PCs; for this reason, usual resolutions of TGA image files match those of the NTSC and PAL video formats.
TARGA is an acronym for Truevision Advanced Raster Graphics Adapter; TGA is an initialism for Truevision Graphics Adapter. Today, most people refer to the format as the "TARGA File Format".
TGA files commonly have the extension ".tga" on PC DOS/Windows systems and Mac OS X (older Macintosh systems use the "TPIC" type code). The format can store image data with 1 - 32 bits of precision per pixel[citation needed], – the maximum 24 bits of RGB and an extra 8-bit alpha channel. Color data can be color-mapped, or in direct color or truecolor format; optionally, a lossless PackBits RLE compression can be employed.
The TGA file format was originally defined and specified by AT&T EPICenter with feedback from Island Graphics Inc in 1984. AT&T EPICenter was an internal spin-off of AT&T created to market new technologies AT&T had developed for color frame buffers. What later became Truevision was the result of a leveraged employee buyout from AT&T in 1987.
EPICenter's first two cards, the VDA (video display adapter) and ICB (image capture board), used the first incarnations of the TGA file format. The file extensions ".vda" and ".icb" implied information about the board specific data contained.
It was later determined by Alan Wlasuk (then head of EPICenter), Brad Pillow (EPICenter) and Steven Dompier (Island's president) that a more codified file format was needed. The file format was created and implemented by Brad Pillow and was developed in response to this need for a less board specific file format. A very simple extension was made to what was already in use, and contained information on width, height, pixel depth, an associated color map and image origin. A label field (up to 255 characters) was also included in the initial spec, but was rarely used.
At the time, another technically superior file format called TIFF also appeared, but its use for true color imaging was initially more limited, as implementation of the TIFF specification was rather involved. The TGA file format's simplistic nature was what led to its widespread adoption at the time.
Initially the TGA file format was used in the ICB-PAINT and TARGA-PAINT programs (what later became known as TIPS) and for several projects in online real estate browsing and still-frame video teleconferencing.
The current version (2.0) includes several enhancements such as "postage stamps" (better known as thumbnails), an alpha channel, gamma value, and textual metadata, and was authored by Truevision Inc.'s Shawn Steiner with direction from Kevin Friedly and David Spoelstra in 1989.
At the time of its launching, it represented the state-of-the-art in digital image processing. Even today, though its maximum color depth is not well suited for high-end pre-press, intensive image processing systems, TGA is still used extensively throughout the animation and video industry because its primary intended outputs are standard TV screens, not color printed pages.
Uncompressed 24-bit TGA images are relatively simple compared to several other prominent 24-bit storage formats: A 24-bit TGA contains only an 18-byte header followed by the image data as packed RGB data. In contrast, BMP requires padding rows to 4-byte boundaries, TIFF and PNG are metadata containers that do not place the image data or attributes at a fixed location within the file.
[edit] Video games using TGA format
Many games create screenshot files in TGA format. The following is a list of the games that use this format, and how it is used in their respective games.
| Video game | How it is used |
|---|---|
| Call of Duty 4 | Screenshots |
| Civilization: Call to Power | General usage |
| Command & Conquer: Generals with Zero Hour expansion pack | In-game buttons, textures and map previews |
| Command & Conquer 3: Tiberium Wars with Kane's Wrath expansion pack | In-game buttons, textures and map previews |
| Command & Conquer: Renegade | Textures |
| Dawn of War | Unit badges and player banners. |
| F/A-18 Hornet Operation Iraqi Freedom | Textures and bitmap graphics |
| Glest | Textures |
| Half-Life | Screenshots and skybox images |
| Half-Life 2 | Screenshots and skybox images |
| Homeworld 2 | Badges on the ships |
| Klondike solitaire on the iPod classic | Allows players to upload custom 39x54 TGA cardbacks to use in the game |
| Medal of Honor: Allied Assault | Screenshots |
| Medieval II: Total War | The majority of the game's map files |
| Messiah | Screenshots are created when F12 is pressed. The TGA files are used as textures but with .001, .002, .003, etc. extensions, and can be discovered using Irfanview |
| Midtown Madness 2 | Landscape textures |
| Neverwinter Nights | Screenshots and textures |
| Quake III Arena | Screenshots |
| Quake III Team Arena | Screenshots |
| Quake IV | Screenshots |
| Rainbow Six | Graphics, such as arm patches |
| Rise of Nations | Structures, military units and landscapes |
| Second Life | Game allows textures to be uploaded/imported as TGA format files |
| Star Trek: Armada | In-game textures |
| Star Trek: Armada II | In-game textures |
| Star Wars Galaxies | Offers options for screenshots in TGA format, as well as JPEG and BMP formats |
| Star Wars Jedi Knight: Jedi Academy | Screenshots (also available in PNG format) |
| Star Wars Jedi Knight II: Jedi Outcast | Screenshots (also available in PNG format) |
| Star Wars: Knights of the Old Republic II - The Sith Lords | Screenshots |
| Sumotori Dreams | Modding |
| Team Fortress 2 | Screenshots |
| Toribash | Textures |
| Trainz Railway Simulator (all versions) | Screenshots and textures (for some models) |
| Warcraft III | Screenshots |
| Warhammer (R) Dawn Of War | Characters and textures |
| Warhammer 40,000: Dawn of War: Soulstorm | Unit badges and player banners |
| World in Conflict | Screenshot files |
| World of Warcraft | Screenshots (before version 2.2, thereafter JPEGs were used) |
[edit] Other media
In the film Earth Girls are Easy, the aliens are given an makeover at the "Curl up and Dye" Salon. There is a short sequence showing the TARGA video card, and TIPS paint software in action.
[edit] External links
- Truevision's TGA file format specification
- Truevision's TGA file format specification – cover pages with title and table of contents
- TGA specification – previous version of the file format taken from the Truevision Technical Guide
- Truevision TGA Specification 2.0
|
|||||||||||||||||||||||||||||||||||||||||||
