Desktop usage (RiscOS version only)
Pretty straightforward. Run !InterGif; drag your sprite file, Draw
file, or Animator file onto the left-hand bit of the window; set any
options you want in the middle bit of the window; and save your GIF
(or sprite) out from the right-hand bit of the window.
All Rites Reversed --
Copy What You Like
- Produce an interlaced GIF: in other words, one which a Web
browser can render quickly at a low resolution, filling in the
details later as they arrive.
- Looping animation
- Normally an animated GIF plays through once and stops. If you
tick this option, you'll get an animated GIF that plays over and
over again. This is a Netscape extension to the GIF format, but
hopefully it will become a popular one -- both MSIE and Fresco now
support it too.
- Join input files
- This option causes InterGif to look for only one frame in the
file you give it, and then look for the next frame in another file
with the numeric part of the file incremented. For instance, you
could have three files called frame000, frame001, and frame002 and
create an three-frame animation by dragging frame000 onto the
InterGif window and choosing Join input files.
- Set delay
- This lets you override the frame rate, in centiseconds.
sets the frame rate in the output file as follows:
- If Set delay is ticked, the given value is used.
- If not, and the input file specifies a frame rate, that
is used for the output file. You can change frame delays
individually in Animator files in the usual way (in
Animator, press F7) or in sprite files by giving the
frames sprite names with "delay" in them: for instance, a
sprite called "037delay25" will be given a delay of 25
centiseconds. (Anything before the word "delay" is
This is the
only way to get different delays on different frames.
- If the input file doesn't specify a frame rate (i.e.
it's a Draw file, or a sprite file without special
names), InterGif uses a default of 8 centiseconds per
frame (12.5 frames per second).
- Choose None to get a wholly opaque GIF (no
masking), Auto to get InterGif to use the sprites'
masks (or the film's background
colour); or you can specify a transparent pixel-value directly.
(Hint: to find out what pixel-value a sprite pixel has, load the
sprite into Paint, ensure its palette window is showing, click
Menu over the pixel you want, and choose Paint->Select
- This tells InterGif to remove any wholly
transparent rows or columns from the edges of the input
image. (If the input is an animation, it only removes rows or
columns that are blank on every frame.) This means
that the output image may be a different size from the input
one, which is otherwise never the case.
ticks itself automatically if you're making a transparent,
interlaced GIF: for the reason why, see the section on
Netscape Navigator 4.
probably want to tick this if you're converting a Draw file,
as these often end up with one or two transparent rows and
columns at the edges.
- Split output
- This splits up the input file into one output file per frame.
Not, I admit, terribly useful, unless you need to import something
into an application that expects lots of one-frame GIFs -- for
instance, Sun's Java Animator applet. The names of the files are
taken from the one you give, with any numeric part incremented as
needed, so if you save a three-frame animation as frame001/gif,
you also get frame002/gif and frame003/gif.
- This icon opens the Palette Options window, giving you the
following further options:
Palette options are ignored when importing a Draw file:
for Draw files, InterGif always acts as if you specified
- Use existing
- This does the same as versions of InterGif prior to
6.00: it discards palette entries that aren't actually
used, but keeps all the others. With this option
selected, an error will be given if you give InterGif a
deep sprite (one with 32,000 or 16,000,000 colours): to
convert such an image, use one of the other palette
- Acorn standard 256
- 216 cube
- These map all colours in the input onto the nearest ones
in either the standard Acorn 256-colour "mode 15" palette, or
the Macintosh/PC standard 216-entry colour cube (also known as
the "Web safe" palette). This is
useful, for instance, for reducing the size of 256-greyscale
that very few colours are present in both
palettes: only white, black, the four intermediate greys
(#333333, #666666, #999999, and #CCCCCC) and a few others
(#0000CC, #00CC00 etc., and #3333FF, #33FF33 etc.).
- 16 greys
- 256 greys
- Produces 16- or 256-colour output with grey scales only. This
is much like supplying a greyscale palette with "from file",
except that error diffusion (if selected) is done entirely
in greyscale. This avoids colour fringing.
- From file
- You can also map colours to those in any Acorn palette
file (such as one saved from !Paint).
- Find best
- This is the most powerful option: selecting this makes
InterGif calculate the optimal palette for displaying the
input images, and then map to that. You can tell it to
calculate any size palette from 2 to 256 entries. InterGif
uses the "median cut" algorithm to calculate the palette.
- Error diffusion (dithering)
this option makes InterGif dither, rather than map,
its input file to the required palette. This only works on
16bpp and 24bpp input files (and Draw files). This feature was
contributed by Martin Würthner.
- This icon opens the InterGif calling ChangeFSI window,
which gives you the option of pre-processing InterGif's
input file with Acorn's ChangeFSI image
manipulation program. This is mainly useful for importing
files in formats which InterGif doesn't understand
directly: for instance, the "Targa" files output by
InterGif can give
ChangeFSI any of a large range of command-line options:
most of the time you probably want this set to
-- which tells ChangeFSI to
convert things to 256-colour sprites. For details of the
other options you can apply, see the "FSIuse" text file
inside the !ChangeFSI directory.
If the icons in this
window are greyed out, this means <ChangeFSI$Dir>
isn't set: you should make sure !ChangeFSI has been seen
by the filer. If you don't have
ChangeFSI at all, or if you've got a version older
than 1.12, you can get 1.12 from Acorn's FTP site.
You can find out more
about using ChangeFSI with InterGif on the Hints and Tips page.
- Sprite options...
- This icon opens the Sprite options window, which gives
you some special options for sprite output.
- Force new sprite format
- By default, InterGif, just like Paint, will produce old
format sprites that are understood by all versions of
RiscOS. With this option ticked, InterGif produces new
format sprites, which are limited to RiscOS 3.5 or
higher but have much more efficient masking information
(for a 256 colour sprite, only 1/8 of the size of that
needed by the corresponding old format sprite). In
addition, using the new format allows you to specify the
horizontal and vertical sprite resolutions. Choosing the
180dpi options results in "hi-res" sprites for so-called
"EX0" screen modes supported by RiscOS 5.