dmb@wam.umd.edu (David M. Baggett) (04/09/90)
A certain magazine which will go unnamed (for now) has printed a version
of the picture formats list nearly verbatim, and this magazine's editorial
staff has taken credit for the compilation and editing of this information.
The editor and many contributors were not given any credit.
It would be irresponsible of me (and probably pointless) to divulge the
name of the publication at this time. There is still the possibility
that an unfortunate error was made and I do not want to malign the
magazine or its staff.
In any case, everyone who is interested in distributing information and/or
software for free should be aware:
There are unethical and/or incompetent people in the world.
Shareware authors: ALWAYS put a copyright notice and a distribution policy
on everything you release. Although these are not legally binding, they
make your intentions clear and will deter individuals of various sorts
from plagiarizing and/or stealing your work. Such contractual statements
can (in theory) make a difference in court as well. (So I am told.)
I have added some legal/contractual stuff to the header of the picture
formats list and humbly request that those of you who have found this
information useful actively seek out and replace old copies of the list
with this new version. Perhaps then the following people will be given
credit in the future for their help in making this document as
popular as it has become:
Phil Blanchfield Jason Blochowiak David Brooks Neil Forsyth
Stefan Hoehn Ken MacLeod Jim McCabe Darek Mihocka David Mumper
George Seto Joe Smith Greg Wageman Roland Waldi Gerry Wheeler
I know old copies exist at terminator and at other FTP sites. Please
get rid of these old versions. It will be _much_ appreciated. Ditto
for the online services (which I unfortunately don't have access too).
The new list is enclosed.
Thanks all,
Dave Baggett
dmb@cscwam.umd.edu
-------------------------------------------------------------------------------
ST Picture Formats
------------------
Edited by:
David Baggett
5640 Vantage Point Road
Columbia, MD 21044 USA
(301) 596-4779
(usenet: dmb@TIS.COM)
(Please report errors or additions)
Copyright (C) 1988, 1989, 1990 by David M. Baggett
Non-profit redistribution of this document is permitted, provided
the document is not modified in any way.
Reproduction of this document in whole or in part for commercial
purposes is expressly forbidden without the prior written consent
of David M. Baggett.
The information presented here is not guaranteed to be correct.
The author and contributors will in no event be liable for direct,
indirect, incidental, or consequential damages resulting from the
use of the information in this document.
This document is the product of many hours of volunteer work by a
large number of people. Please respect this -- do not violate the
distribution policy.
CONTRIBUTORS
Phil Blanchfield Jason Blochowiak David Brooks Neil Forsyth
Stefan Hoehn Ken MacLeod Jim McCabe Darek Mihocka David Mumper
George Seto Joe Smith Greg Wageman Roland Waldi* Gerry Wheeler
Contents
--------
NEOchrome *.NEO
NEOchrome Animation *.ANI
DEGAS *.PI? ? = 1, 2, 3
DEGAS Elite *.PI? ? = 1, 2, 3
DEGAS Elite (Compressed) *.PC? ? = 1, 2, 3
Tiny *.TN? ? = 1, 2, 3, Y
Spectrum 512 *.SPU
Spectrum 512 (Compressed) *.SPC
Art Director *.ART
C.O.L.R. Object Editor Mural *.MUR
Doodle *.DOO
Animatic Film *.FLM
GEM Bit Image *.IMG
Image *.IMG
STAD *.PAC
Imagic Film/Picture *.IC? ? = 1, 2, 3
IFF *.IFF
MacPaint
Introductory Information
------------------------
word = 2 bytes
long = 4 bytes
palette = Hardware color palette, stored as 16 words. First word is
color register zero (background), last word is color register
15. Each word has the form:
Bit: (MSB) 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 (LSB)
-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
0 0 0 0 0 R2 R1 R0 0 G2 G1 G0 0 B2 B1 B0
R2 = MSB of red intensity
R0 = LSB of red intensity
G2 = MSB of green intensity
G0 = LSB of green intensity
B2 = MSB of blue intensity
B0 = LSB of blue intensity
Intensity ranges from 0 (color not present) to 7 (highest
intensity).
Example: { red = 7, green = 3, blue = 5 } -> 0735 (hex)
Caveat: It is wise to mask off the upper four bits of each
palette entry, since a few programs store special
information there (most notably Art Studio).
The Formats
-----------
<NEOchrome> *.NEO
1 long resolution (0 = low res, 1 = medium res, 2 = high res)
16 words palette
12 bytes filename (usually " . ")
1 byte unused (?) (usually either 80 hex or 0)
1 byte color animation limits (4 most significant bits are
left/lower limit; 4 least significant bits are
right/upper limit).
1 byte color animation enabled? High bit set if yes.
1 byte color animation speed and direction
x = 0 means animation stopped
x < 0 means colors cycle to the left (decreasing)
x > 0 means colors cycle to the right (ascending)
Number of vblanks between cycles is |x| - 1
19 longs reserved for expansion
16000 words picture data (screen memory)
-----------
32128 bytes total
<NEOchrome Animation> *.ANI
NOTE: To get this feature on versions 0.9 and later select the Grabber
icon and click both mouse buttons in the eye of the second R in the
word GRABBER.
Interestingly enough, some versions of NEO only require you
to press the right button, not both. Hmmm...
1 long magic number BABEEBEA (hex) (seems to be ignored)
1 word width of image in bytes (always divisible by 8)
1 word height of image in scan lines
1 word size of image in bytes + 10 (!)
1 word x coordinate of image (must be divisible by 16) - 1
1 word y coordinate of image - 1
1 word number of frames
1 word animation speed (# vblanks to delay between frames)
1 long reserved; should be zero
--------
22 bytes total for header
? words image data (words of screen memory) for each frame, in
order
<DEGAS> *.PI1 (low resolution)
*.PI2 (medium resolution)
*.PI3 (high resolution)
1 word resolution (0 = low res, 1 = medium res, 2 = high res)
Other bits may be used in the future; use a simple bit
test rather than checking for specific word values.
16 words palette
16000 words picture data (screen memory)
-----------
32034 bytes total
<DEGAS Elite> *.PI1 (low resolution)
*.PI2 (medium resolution)
*.PI3 (high resolution)
1 word resolution (0 = low res, 1 = medium res, 2 = high res)
Other bits may be used in the future; use a simple bit
test rather than checking for specific word values.
16 words palette
16000 words picture data (screen memory)
4 words left color animtion limit table (starting color numbers)
4 words right color animation limit table (ending color numbers)
4 words animation channel direction flag (0 = left, 1 = off, 2 = right)
4 words 128 - animation channel delay in 1/60's of a second. [0 - 128]
(I.e., subtract word from 128 to get 1/60th's of a second.)
-----------
32066 bytes total
<DEGAS Elite (Compressed)> *.PC1 (low resolution)
*.PC2 (medium resolution)
*.PC3 (high resolution)
1 word resolution (same as Degas, but high order bit is set;
i.e., hex 8000 = low res, hex 8001 = medium res,
hex 8002 = high res). Other bits may be used in the
future; use a simple bit test rather than checking
for specific word values.
16 words palette
< 32000 bytes control bytes
4 words left color animtion limit table (starting color numbers)
4 words right color animation limit table (ending color numbers)
4 words animation channel direction flag (0 = left, 1 = off, 2 = right)
4 words 128 - animation channel delay in 1/60's of a second. [0 - 128]
(I.e., subtract word from 128 to get 1/60th's of a second.)
-----------
< 32066 bytes total
Control byte meanings:
For a given control byte, x:
0 <= x <= 127 Use the next x + 1 bytes literally (no repetition)
-127 <= x <= -1 Use the next byte -x + 1 times
-128 No operation (not used)
Compression Scheme:
Each scan line is compressed separately; i.e., all data for a given
scan line appears before any data for the next scan line. The scan lines
are specified from top to bottom (i.e., 0 is first). For each scan line,
all the data for a given bit plane appears before any data for the next
higher order bit plane.
To clarify: The first data in the file will be the data for the highest
order bit plane of scan line zero, followed by the data for the next lower
order bit plane of scan line zero, etc., until all bit planes have been
specified for scan line zero. The next data in the file will be the data
for the highest order bit plane of scan line one, followed by the data for
the next lower order bit plane of scan line one, etc., until all bit planes
have been specified for all scan lines.
Caveats:
DEGAS Elite's picture loading routine places some restrictions on
compressed DEGAS files:
o Elite uses a 40-byte buffer to store data being decompressed.
o Whenever a control command is encountered, bytes are stuffed
in this buffer.
o The buffer is only emptied when there are EXACTLY 40
characters in it.
The important conclusion here is that
No control command may cause the buffer to have more than 40
bytes in it. In other words, all control commands must end on
or before the 40-byte boundary.
Any picture violating the last condition will cause Elite to get a bus
error when the picture is loaded.
<Tiny> *.TNY (any resolution)
*.TN1 (low resolution)
*.TN2 (medium resolution)
*.TN3 (high resolution)
Several people have reported sightings of mutated Tiny pictures that
do not follow the standard format, so let's be careful out there. What
is described here is the format that David Mumper's original
TNYSTUFF.PRG produces.
1 byte resolution (same as NEO, but +3 indicates rotation
information also follows)
If resolution > 2 {
1 byte left and right color animation limits. High 4 bits
hold left (start) limit; low 4 bits hold right (end)
limit
1 byte direction and speed of color animation (negative value
indicates left, positive indicates right, absolute value
is delay in 1/60's of a second.
1 word color rotation duration (number of iterations)
}
16 words palette
1 word number of control bytes
1 word number of data words
3-10667 bytes control bytes
1-16000 words data words
-------------
42-32044 bytes total
Control byte meanings:
For a given control byte, x:
x < 0 Absolute value specifies the number of unique words to
take from the data section (from 1 to 127)
x = 0 1 word is taken from the control section which specifies
the number of times to repeat the next data word (from
128 to 32767)
x = 1 1 word is taken from the control section which specifies
the number of unique words to be taken from the data
section (from 128 - 32767)
x > 1 Specifies the number of times to repeat the next word
taken from the data section (from 2 to 127)
Format of expanded data:
The expanded data is not simply screen memory bitmap data; instead, the
data is divided into four sets of vertical columns. (This results in
better compression.) A column consists of one specific word taken
from each scan line, going from top to bottom. For example, column 1
consists of word 1 on scanline 1 followed by word 1 on scanline 2, etc.,
followed by word 1 on scanline 200.
The columns appear in the following order:
1st set contains columns 1, 5, 9, 13, ..., 69, 73, 77 in order
2nd set contains columns 2, 6, 10, 14, ..., 70, 74, 78 in order
3rd set contains columns 3, 7, 11, 15, ..., 71, 75, 79 in order
4th set contains columns 4, 8, 12, 16, ..., 72, 76, 80 in order
Note that Tiny partitions the screen this way regardless of resolution; i.e.,
these aren't bitplanes. For example, medium resoltion only has two bitplanes,
but Tiny still divides medium resolution pictures into four parts.
<Spectrum 512> *.SPU
80 words first scan line of picture (unused) -- should be zeroes
15920 words picture data (screen memory) for scan lines 1 through 199
9552 words 3 palettes for each scan line (the top scan line is
not included because Spectrum 512 can't display it)
-----------
51104 bytes total
<Spectrum 512 (Compressed)> *.SPC
1 word 5350 (hex) ("SP")
1 word 0 (reserved for future use)
1 long length of data bit map
1 long length of color bit map
<= 32092 bytes compressed data bit map
<= 17910 bytes compressed color bit map
--------------
< 50014 bytes total
Data compression:
Compression is via a modified run length encoding (RLE) scheme,
similar to DEGAS compressed and Tiny. The data map is stored as a
sequence of records. Each record consists of a header byte followed by
one or more data bytes. The meaning of the header byte is as follows:
For a given header byte, x:
0 <= x < 127 Use the next x + 1 bytes literally (no repetition)
-128 <= x < 0 Use the next byte -x + 2 times
The data appears in the following order:
1. Picture data, bit plane 0, scan lines 1 - 199
2. Picture data, bit plane 1, scan lines 1 - 199
3. Picture data, bit plane 2, scan lines 1 - 199
4. Picture data, bit plane 3, scan lines 1 - 199
Decompression of data ends when 31840 data bytes have been used.
Color map compression:
Each 16-word palette is compressed separately. There are three
palettes for each scan line (597 total). The color map is stored as a
sequence of records. Each record starts with a 1-word bit vector which
specifies which of the 16 palette entries are included in the data
following the bit vector (1 = included, 0 = not included; i.e., stays
the same). The least significant bit of the bit vector refers to
palette entry zero, while the most significant bit refers to palette
entry 15. Bit 15 must be zero, since Spectrum 512 does not use palette
entry 15. Bit 0 should also be zero, since Spectrum 512 always makes the
background color black.
The words specifying the values for the palette entries indicated in
the bit vector follow the bit vector itself, in order (0 - 15).
Yes, it is hideously complex.
<Art Director> *.ART (low resolution only)
16000 words picture data (screen memory)
16 words palette
15 * 16 words 15 more palettes for animation
-------------
32512 bytes total
<C.O.L.R. Object Editor Mural> *.MUR (low resolution only)
16000 words picture data (screen memory)
(palettes are stored in separate files)
-----------
32000 bytes total
<Doodle> *.DOO (high resolution only)
16000 words picture data (screen memory)
-----------
32000 bytes total
<Animatic Film> *.FLM (low resolution only)
1 word number of frames
16 words palette
1 word speed (0 - 99; value is 99 - # vblanks to delay between frames)
1 word direction (0 = forwards, 1 = backwards)
1 word end action (what to do after the last frame)
0 = pause, then repeat from beginning
1 = immediately repeat from beginning
2 = reverse (change direction)
1 word width of film in pixels
1 word height of film in pixels
1 word Animatic version number (major)
1 word Animatic version number (minor)
1 long magic number 27182818 (hex)
3 longs reserved for expansion (should be all zeros)
--------
32 words total for header
? words image data (words of screen memory) for each frame, in order
<GEM Bit Image> *.IMG
2 words upper left x,y of bit image
2 words lower right x,y of bit image
1 word device page width
1 word device page height
1 word device pixel width in microns
1 word device pixel height in microns
1 word NBITSPPXL, (bits per pixel, planes, for color information)
7 words reserved (0)
--------
32 bytes total for header
? bytes data
Format of data
Run-length packet:
+0 [1] run length (1..127)
+1 [1] color index (1..255)
Extended packet:
+0 [1] -1 (opcode, $FF)
+1 [1] extended run length (i.e. *128 pixels)
+2 [1] color index
Raster packet:
+0 [1] -2 (opcode, $FE)
+1 [1] NPXL, # of pixels in stream
+2 [..] packed color indices [NPXL*NBITSPPXL bits]
Raster-run packet:
+0 [1] ? (opcode)
+1 [1] pattern repeat count
+2 [1] NPXL, # of pixels in stream
+3 [..] packed color indices
<Image> *.IMG
1 word version number of image file
1 word length of header in words [8]
1 word number of color planes
1 word pattern length in bytes [2]
1 word pixel width in 1/1000 mm
1 word pixel height in 1/1000 mm
1 word line width in pixels
1 word number of lines
-------
16 bytes total for header
? bytes data
For each byte x in the data section,
x = 0 Pattern/scanline run.
Read the next byte, n (unsigned).
If n > 0 then:
Read a number of bytes equal to the "pattern
length" word in the header. Repeat this
pattern n times.
If n = 0 then:
Scanline run. Data for the next scanline
is to be used multiple times. Read the
following record:
1 word unused (?) [255]
1 word number of times to use
next scanline data
The data for the next scanline follows,
compressed normally.
x = 80 (hex) Uncompressed bit string. The next byte
determines the number of bytes (?) to use
literally. The literal data bytes follow.
otherwise Monochrome run. The value of x determines
what to draw. The high bit specifies the color.
The low 7 bits, taken as an unsigned quantity,
specify the length of the run (the number
of pixels to draw).
<STAD> *.PAC (high resolution only)
4 bytes "pM86" (vertically packed) or "pM85" (horizontally packed)
1 byte id byte
1 byte pack byte (most frequently occuring byte in bitmap)
1 byte "special" byte
-------
7 bytes total for header
? bytes data
The data is encoded as follows. For each byte x in the data section:
x = id byte Read one more byte, n. Use pack byte
n + 1 times.
x = "special" byte Read two more bytes, d, and n (in order).
Use byte d n times.
otherwise Use byte x literally.
<Imagic Film/Picture> *.IC1 (low resolution)
*.IC2 (medium resolution)
*.IC3 (high resolution)
4 bytes "IMDC"
1 word resolution (0 = low res, 1 = medium res, 2 = high res)
16 words palette
1 word date (GEMDOS format)
1 word time (GEMDOS format)
8 bytes name of base picture file (for delta compression), or zeroes
1 word length of data (?)
1 long registration number
8 bytes reserved
1 byte compressed? (0 = no, 1 = yes)
If compressed {
1 byte delta-compressed? (-1 = no, > -1 = yes)
1 byte ?
1 byte escape byte
}
-------
65 bytes total for header (68 bytes if compressed)
? bytes data
Compressed data may be either stand-alone or delta-compressed (relative
to the base picture named in the header). Delta compression involves
storing only how the picture differs from the base picture (i.e., only
portions of the screen that have changed are stored). This is used to
to encode animated sequences efficiently.
Compressed data, stand-alone:
For each byte x in the data section:
x = escape byte Read one more byte, n. (n is unsigned).
If n >= 2, use the next byte n times.
If n = 1, keep reading bytes until a
byte k not equal to 1 is encountered.
Then read the next byte d.
If the number of 1 bytes encountered is o,
use d (256 * o + k) times. I.e.,
if (n == 1) {
o = 0;
while (n == 1) {
o++;
n = next byte;
}
k = n;
d = next byte;
Use d (256 * o + k) times.
}
else {
d = next byte;
Use d (n) times.
}
x != escape byte Use x literally.
Compressed data, delta compressed:
For each byte x in the data section:
x = escape byte Read one more byte, n. (n is unsigned).
If n >= 3, use the next byte n times.
If n = 1, do the same as for n = 1 in
stand-alone compression (above).
If n = 2, then set n = next byte.
If n = 0, end of picture.
If n >= 2, take n bytes from base
picture.
If n = 1, do the same as for n = 1
in stand-alone compression (above),
but take (256 * o + k) bytes from
base picture.
x != escape byte Use x literally.
<IFF Format> *.IFF
4 bytes "FORM"
8 bytes form chunk: 1 long = length (8)
4 bytes = ID ("ILBM")
4 bytes "BMHD"
20 bytes BMHD chunk: 1 long = length (20)
(BitMap 1 word = x width (pixel)
HeaDer) 1 word = y height (pixel)
1 word = x-offset (pixel)
1 word = y-offset (pixel)
1 byte = # bitplanes
1 byte = mask (0=no, 1=impl., 2=transparent,
3=lasso)
1 byte = compressed (1) or expanded (0)
1 byte = 0
1 word = transparent color (for mask=2)
1 byte = x-aspect
1 byte = y-aspect
1 word = page width
1 word = page height
4 bytes "CMAP"
3n+8 bytes CMAP chunk: 1 long = length (3n + 8 for n colors)
(Color 3 words = R,G,B color 0
MAP) ...
3 words = R,G,B color n
4 bytes "CRNG"
8 bytes CRNG chunk: 1 long = length (8)
(Color 1 word = 0
RaNGe) 1 word = animation speed
1 word = active (1) or inactive (0)
4 bytes "BODY"
? bytes body chunk: picture expanded/compressed
Format of body data
An expanded picture is simply a bitmap. The compressed data consists
of records of single control bytes followed by data.
For a given control byte, x:
0 <= x <= 127 Use the next x + 1 bytes literally (no repetition)
-128 <= x <= -1 Use the next byte -x + 1 times
The (decompressed) body data appears in the following order:
line 1 plane 0 ... line 1 plane 1 ... ... line 1 plane m
[line 1 mask (if appropriate)]
line 2 plane 0 ... line 2 plane 1 ... ... line 2 plane m
[line 2 mask (if appropriate)]
...
line x plane 0 ... line x plane 1 ... ... line x plane m
[line x mask (if appropriate)]
The FORM chunk identifies the type of data:
"ILBM" = interleaved bit map
"8SVX" = 8-bit sample voice
"SMUS" = simple music score
"FTXT" = formatted text (Amiga)
Note:
The R,G,B ranges of AMIGA and ST are different (AMIGA 0...15, ST 0...7),
as is the maximum number of bitplanes (AMIGA: 5, ST: 4).
Animation speed of 16384 means 1 full rotation in 1/60's of a second.
<MacPaint>
Word has it that this is wrong. Someone please send me an accurate
description!
header {
1 long version number (if zero, entire header is ignored)
38 * 2 longs pattern data (anyone know how to use this?)
83 longs reserved
} (total 160 longwords for header)
< 51200 bytes compressed bitmap data
-------------
< 51716 bytes total
Bitmap compression:
The bitmap data is for a 576 pixel by 720 pixel monochrome image.
The data is stored as a sequence of records. Each record consists of a
control byte followed by one or more data bytes. The meaning of the
control byte is as follows:
For a given control byte, x:
0 < x < 127 Use the next x + 1 bytes literally (no repetition)
-128 <= x <= 0 Use the next byte -x + 1 times
There are 72 bytes per scan line. Each bit represents one pixel; 0 = white,
1 = black.
-------------------------------------------------------------------------
* Roland Waldi contributed extensive information on the following formats:
GEM, IMG, Doodle, STAD, Imagic Film/Picture, Art Director, IFF
Version of Mon Apr 9 00:24:07 EDT 1990