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Amiga Format AFCD22 (Jan 1998, Issue 106).iso
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GRAPHICS FILE FORMATS
=====================
Within the computer world there are many different ways of
handling and processing graphics electronically. There are also
many more variations of graphic file formats for saving these
permanently to disk.
So lets start with some basic details about common machine-internal
ways of representing computer graphics.
NOTE:
Vectorgraphics support in PMPro (Postscript, EPS, FIG
and CGM) will interpret Postscript files with help from
Ghostscript, so that these may be directly displayed, printed and
of course also converted to bitmap formats (see also chapter
"vector graphics support"). But for this ability, a working installation
of Ghostscript is needed. Unfortunately we cannot offer support for
problems concerning Ghostscript, since we have no influence on
it's development.
Computer graphics in general
----------------------------
In general, it is necessary to represent the colour values of
computer graphics in the form of their single components (red,
green and blue or maybe others).
These may be either RGB-, HSV-, YUV/YCbCr- or also CMYK values,
but outside Desktop Publishing perhaps only RGB values are actually
used and YUV/YCbCr is only significantly used for video processing
(similarities to the PAL/NTSC systems).
For the number of colour scales which can be represented by
RGB-values, the digital "bandwidth" which is available for the
single components is important.
Since these single or complemented values need to be represented
internally as either 8, 16 or 24 Bit, the resolutions that mainly
occur are between 4 and 8 for home and semi-professional usage.
Within the professional area even more bits per vector are used.
It is perhaps important to mention one of the largest restrictions
for computer graphics on home computers. With common computers
and graphic cards it would be a waste of valuable CPU time
and memory to store the complete colour values for any pixel on the
screen. Sometimes for example not more than 16 Colours of the number of
all possible colours are needed which suggests a more simple way of
administration. Because of that, and also because of the highend status
of TrueColour processing in the home business, the spectrum of
representations for computer graphics is mainly split into two
categories: palette-based and TrueColour data representation.
Palette graphics are used for up to 256 Colours since one Byte
may contain values from 0-255 which in this case would
represent the number of a colour palette entry for each pixel.
This would then actually contain the real RGB valuesof the
colour (each one represented by either 4, 6 or 8 Bit for R, G and B).
The byte data may either be available as Bitmap (planar or interleaved
planar organisation) or chunky (which means as a chunk
in a single byte).
TrueColour graphics directly contain RGB values for each pixel.
When making assumptions on how much memory would be needed to access
these numbers of colours via a palette, it can be seen that the
jump to the next higher type of variable to contain the number of the
palette entry (Word) would simply double the required amount of memory.
If you take a word (0-65535), for example, for storing
the colour register number and also storing the actual
RGB values as words, the result would be the opposite of saving memory.
After having just discussed TrueColour representations, here are some
of the most common types (even with 24 Bit graphics sometimes
semi or fully planar representations are used):
Common name R G B values
(DCTV) 4 4 4 0..16
Highcolour 15 Bit (from 16) 5 5 5 0..32 1 Bit unused
Highcolour 15 Bit (from 16) 5 5 5 0..32 1 masking bit
Highcolour 16 Bit (from 16) 5 6 5 0..32/64
TrueColour 24 Bit (from 32) 8 8 8 0..255 1 Byte unused
TrueColour 32 Bit (from 32) 8 8 8 0..255 1 Byte alpha ch.
Additionally, it has to be mentioned that the order of R, G and B
may differ from system to system and that even the use of
24 Bit RGB values for colour space determination, although
claiming to be 8:8:8, sometimes actually only
results in 6:6:6 (mainly with old or low-cost cards with VGA
chips on board).
SVObjects - File formats of the PMPro
=====================================
The following overview indicates which graphics file formats
are supported by PMPro.
Not all of these formats may also be written (converted). The
following table shows whether the single modules are able to not only
read but also able to write these formats.
File Format SVObject Colour Depth Read Depth Write
-------------------------------------------------------------------
IFF-ILBM ILBM up to 8/24 Bit files up to 8/24 Bit
IFF-ACBM ACBM up to 8/24 Bit files up to 8/24 Bit
IFF-DEEP DEEP 24 Bit Files 24 Bit Files
IFF-YUVN YUVN 24 Bit Files 24 Bit Files
OS3-DataTypes (DATATYPES) all graphics (not available)
PCX up to V3.0 PCX up to 8/24 Bit files up to 8/24 Bit
GIF up to 89a GIF up to 8 Bit files up to 8 Bit
BMP (W*nd*ws) BMP up to 8/24 Bit files up to 8/24 Bit
Icon (W*nd*ws) WinIcon 16 Colour Icons (not available)
FBM (*nix) FBM up to 8/24 Bit files up to 8/24 Bit
PNM (*nix) PNM up to 8/24 Bit files always as 24 Bit
C64 (Koala, Doodle) C64 up to 4 Bit Files (not available)
IMG (GEM/Ventura) IMG up to 8 Bit files (not available)
TIFF (V5.0) TIFF up to 8/24 Bit files up to 8/24 Bit
EPS EPS (various) (not available)
Targa Targa up to 8/24 Bit files up to 8/24 Bit
WPG (W*rdP*rf*ct) WPG up to 8 Bit files (not available)
SGI SGI up to 8/24 Bit files 24 Bit Files
SunRaster (RAS) SunRaster up to 8/24 Bit files up to 8/24 Bit
Pictor/PCPaint/PIC Pictor up to 8 Bit files (not available)
MAC (MacPaint) MAC up to 1 Bit Files (not available)
Mac PICT-2 Metafile PICT all (as 24 Bit) (not available)
JPEG (JFIF) JPEG up to 8/24 Bit files always as 24 Bit
PCD PCD 24 Bit Files (not available)
QRT/POV QRT 24 Bit Files 24 Bit Files
PNG (Network Gfx) PNG 8/24Bit Files 8/24Bit Files
CDR CDR Preview Header (not available)
Deegas (Atari) Deegas 2/4/8 Bit (not available)
FIG (Amifig) AmiFIG (various) (not available)
Ghostscript GhostScipt 8/24Bit (not available)
CGM (GPlot) GPlot (various) (not available)
C-Source CSource (not available) 8/24 Bit Files
WMF MetaView (various) (not available)
REFERENCE:
----------
IFF-ILBM
--------
Standard AMIGA graphic file format.
Reading:
- IFF-ILBM uncompressed 1..24 Bit
- IFF-ILBM CmpByteRun1 compressed 1..24 Bit
Writing:
- IFF-ILBM uncompressed 1..24 Bit
- IFF-ILBM CmpByteRun1 compressed 1..24 Bit
Reading/writing from/to Clipboard possible.
Memory usage (RAM): - uncompressed: medium
- compressed: medium to high
Memory usage (Disk: - uncompressed: medium
- compressed: medium to high
speed : - medium
IFF-ACBM
--------
Standard graphic file format for AmigaBASIC.
Reading:
- IFF-ACBM uncompressed
(no 24 Bit)
Writing:
- IFF-ACBM uncompressed
(no 24 Bit)
Reading/writing from/to Clipboard possible.
Memory usage (RAM): - uncompressed: medium
Memory usage (Disk: - uncompressed: medium
speed : - medium
IFF-DEEP
--------
24 Bit format for the video market.
Reading:
- IFF-DEEP 24 Bit RGB 8:8:8, uncompressed
- IFF-DEEP 24 Bit RGB 8:8:8, RLE-encoded
- IFF-DEEP 32 Bit
Writing:
- IFF-DEEP 24 Bit RGB 8:8:8, uncompressed
Reading/writing from/to Clipboard possible.
Memory usage (RAM): - medium to high
Memory usage (Disk: - medium
speed : - fast
IFF-YUVN
--------
24 Bit format for the video market.
Reading:
- IFF-YUVN 24 Bit (Y, 1/4 U, 1/4 V)
Writing:
- IFF-YUVN 24 Bit (Y, 1/4 U, 1/4 V)
Reading/writing from/to Clipboard possible.
Memory usage (RAM): - medium to high
Memory usage (Disk: - medium
speed : - medium
DATATYPES
---------
file format drivers of Amiga OS 3.x
Reading:
- any PICTURE-Datatypes
(with ANYDATATYPES also all the other datatypes)
Memory usage (RAM): - variable
Memory usage (Disk): - variable
speed : - variable
PCX
---
Format of the PC program Paintbrush.
Reading:
2-256 Colours, 24 Bit.
- PCX V2.5 up to 16 Colours
- PCX V2.8a up to 16 Colours
- PCX V2.8b up to 16 Greyscales
- PCX V3.00 up to 256 Colours
- PCX V2.5 - V3.00 with 24 Bit data
Writing:
Dependant on the colour depth of the source the following
is written:
source colours version type destination col.
2 .. 16 PCX V2.8a planar bitmap 16
32 .. 256 PCX V3.00 chunky pixel 256
(24 Bit) PCX V3.00 RGB planar (24 Bit)
Memory usage (RAM): - uncompressed: medium to high
- compressed: medium to high
Memory usage (Disk: - uncompressed: medium to high
- compressed: medium to high
speed : - medium
GIF
---
Previous standard file format of Compuserve; now replaced by PNG.
Reading:
- GIF 87a
- GIF 89a
Writing:
- GIF 87a
- GIF 89a
source colours version type destination colours
2 .. 256 GIF 87/89a chunky pixel 2 .. 256
Memory usage (RAM): - medium
Memory usage (Disk): - slow to medium
speed : - medium to slow
BMP
---
Standard Windows graphic file format.
Reading:
- unencoded in 1, 4, 8 or 24 Bit colour depth
- RLE-encoded in 8 Bit colour depth
Writing:
source colours version type destination colours
2 BMP V3.00 packed chk. pix. 2
4 .. 16 BMP V3.00 packed chk. pix. 16
32 .. 256 BMP V3.00 chunky pixel 256
(24 Bit) BMP V3.00 RGB pixel (24 Bit)
Memory usage (RAM): - uncompressed: medium
- compressed: medium to high
Memory usage (Disk: - uncompressed: medium
- compressed: medium to high
speed : - fast to medium
WinIcon
-------
Standard Windows Icon format.
Reading:
- WinIcons with exactly 16 Colours
Memory usage (RAM): - low
Memory usage (Disk: - low
speed : - fast
FBM
---
Unix graphics file format.
Reading:
FBM 8 Bit, 1 Bitplane FBM 8 Bit, 3 Planes
2..256 Colours; 256 Greyscales 24 Bit
Writing:
FBM 8 Bit, 1 Bitplane FBM 8 Bit, 3 Planes
2..256 Colours; 256 Greyscales 24 Bit
8 Bit will always be written, even for 2..128 colours.
Memory usage (RAM): - low
Memory usage (Disk: - high
speed : - fast
PNM
---
Unix graphic file format.
Reading:
All binary variations (non-ASCII) of the PNM format will be
read (P4/P5/P6), non-binary (ASCII) variations are not
supported (P1/P2/P3).
PBM (P4) PGM (P5) PPM (P6)
black & white 256 Greyscales 24 Bit TrueColour
Writing:
At the moment any input data no matter which colour depth it
has will be written as 24 Bit PPM data (P6).
Memory usage (RAM): - medium
Memory usage (Disk: - high
speed : - fast
C64
---
Various C64 standard formats.
Reading:
Format Size Colours Changed to
Doodle 320x200 2/16 320x200
Koala 160x200 4/16 320x200
Memory usage (RAM): - low
Memory usage (Disk: - low
speed : - fast
IMG
---
Standard graphic format for the GUI system GEM.
Reading:
- IMG, 2..256 Greyscales
Memory usage (RAM): - medium
Memory usage (Disk: - medium
speed : - medium
TIFF
----
Graphic standard for the printing society (scanner, etc.)
Reading:
Compression Code Bytes Planes Max. Depth Int. Repres.
None 1 1 (system) 1*(System) BITPLANE
None 1 8 1,3 8 / 24 ONEPLANE
Mac PackBits 32773 1 (system) 1*(System) BITPLANE
Mac PackBits 32773 4 1 4 ONEPLANE
Mac PackBits 32773 8 1 8 ONEPLANE
LZW 5 8 1,3 8 / 24 ONEPLANE
Writing:
Depth Written as
up to 256 Colours Motorola (MM), uncompressed, 8, 1, ONEPLANE
(24 Bit) Motorola (MM), uncompressed, 8, 3, ONEPLANE
Memory usage (RAM): - uncompressed: variabe
- compressed: variable
Memory usage (Disk: - uncompressed: varaible
- compressed: variable
speed : - variable
EPS
---
Most common format for the printing society (laser printers, etc.)
Reading:
Dependent upon the accompanying previews/thumbnails
(most often in TIFF format)
Memory usage (RAM): - variable
Memory usage (Disk: - variable
speed : - variable
Targa
-----
Proprietary graphic standard for 24 Bit data (also 8, 16 and 32).
Reading:
Colours Depth Organisation RLE-Compression
1 1 planar monochrome supported
256 8 chunky pixel (Colours/grey) supported
(24 Bit) BGR-Pixel supported
Writing:
source colours version type destination col.
2 .. 256 uncompressed chunky pixel 256
(24 Bit) uncompressed BGR (24 Bit)
Memory usage (RAM): - uncompressed: medium
- compressed: medium
Memory usage (Disk): - uncompressed: medium
- compressed: medium
speed : - fast
WPG
---
WordPerfect graphic file format.
Reading:
- WPG BitMap (Greyscales) with 1, 2, 4 or 8 Bit colour depth.
- WPG BitMap (Palette) with 1, 2, 4 or 8 Bit colour depth.
Memory usage (RAM): - medium
Memory usage (Disk: - medium
speed : - medium
SGI
---
Graphics file format for the SGI workstations.
Reading:
Num. of Colours Organisation Compression
256 Colours ( 8 Bit, chunky pixel) uncompressed, RLE
24 Bit (24 Bit, R-G-B) uncompressed, RLE
Writing:
source colours compression type destination colours
(24 Bit) uncompressed 24 Bit RGB (24 Bit)
Memory usage (RAM): - medium
Memory usage (Disk: - medium
speed : - fast
SunRaster
---------
Graphic file format for the SUN workstations.
Reading:
Colours Organisation Compression
2 Colours ( 1 Bit, planar) uncompressed
256 Colours ( 8 Bit, chunky pixel) uncompressed
24 Bit (24 Bit, R-G-B) uncompressed
Writing:
source colours compression type destination col.
2..256 uncompressed Chunky Pixel 256
(24 Bit) uncompressed 24 Bit RGB (24 Bit)
Memory usage (RAM): - medium
Memory usage (Disk): - medium
speed : - fast
Pictor
------
Graphic file format of PC Paint.
Reading:
- files with 1, 4, or 8 Bit colour depth
(monochrome or with EGA- or VGA-Palette).
Memory usage (RAM): - medium
Memory usage (Disk): - medium
speed : - medium
MAC
---
Graphic file format of MacPaint (MacIntosh).
Reading:
- MAC Black/White 576x720
Memory usage (RAM): - slow
Memory usage (Disk): - slow
speed : - fast
Mac PICT-2 (PICT, PCT)
----------------------
Graphic file format of QuickDraw (MacIntosh) and others.
Reading:
- Mac PICT-2 with 1, 2, 4, 8 or 24 Bit colour depth,
but always 24 Bit output.
Memory usage (RAM): - slow to medium
Memory usage (Disk): - slow to medium
speed : - fast
JPEG
----
Standard graphic file format for lossy 24 Bit data compression
(IJG-JFIF).
Progressive JPEG is also supported. When saving graphics in
JPEG format progressive JPEG may also be saved.
Reading:
- JPEG (IJG-JFIF), with output in 256 Colours or 24 Bit
Writing:
- JPEG (IJG-JFIF), from 256 Colours or 24 Bit
Memory usage (RAM): - slow (virtual memory)
Memory usage (Disk: - slow to high (variable compression)
speed : - slow
PCD
---
Format of the pictures on Kodak-Photo-CDs.
Reading:
- BASE/16 BASE/4 BASE
192x128 384x256 768x512
Memory usage (RAM): - medium
Memory usage (Disk: - high
speed : - medium
QRT
---
Raytracer format (Unix).
Reading:
- QRT Dump 24 Bit
Writing:
- QRT Dump 24 Bit
Memory usage (RAM): - medium
Memory usage (Disk: - high
speed : - fast
PNG
---
It supports reading of Portable Network Graphics (PNG) files
In detail these are :
Reading :
- 8 Bit color mapped files
- True color files (16, 24, 32 Bit) as 24 Bit
Writing : 8 / 24Bit Files
C-Source
========
This new saver module will allow you to save graphics as C-source code.
Degas
=====
Had been widely used on the good old Atari computer!
Read:
- uncompressed Degas PI1 320x200: 16 colours
- uncompressed Degas PI2 640x200: 4 colours
- uncompressed Degas PI3 640x400: 2 colours
CDR
===
Vector graphics file format as used with PC program CorelDraw (TM).
Read:
- CDR Preview header, which are included with CDR files
memory usage: low
speed: high
CGM
===
Vector graphics format from the PC. This modules requires Ghostscript
3.53 and GPlot (aminet/gfx/conv/gplot.LHA).
For more information see chapter "vector graphics support".
WMF
===
Vector graphics format from the PC. This modules requires Ghostscript
3.53 and Metaview (aminet).
For more information see chapter "vector graphics support".
EPS
===
The EPS-Module (Encapsulated Postscript) is now able to interpret
EPS graphics in conjunction with Ghostscript. It is also now possible
to save bitmapped graphics in EPS format!
For more information see chapter "vector graphics support".
FIG (Amifig)
============
Vector graphics format used on Unix systems. This module requires
Ghostscript 3.53+ and Amifig (aminet/gfx/edit/amifig.LHA).
For more information see chapter "vector graphics support".
Postscript (Ghostscript)
========================
This module will allow you to display Postscript- and PDF-files and
convert these into bitmapped formats using Ghostscript.
For more information see chapter "vector graphics support".