"Dyslexia is punishment for taking the name of Dog in vain."
ST NEWS SOFTWARE REVIEW: "SPEED OF LIGHT" VERSION 3.8
by Mark Stephen Smith
(Taken from his Atari Web Pages, with permission)
"Speed of Light" has been around for many years now on the
Atari. Starting off as a GIF viewer it has developed into a
powerful picture viewer and colour editor. Its latest incarnation
is version 3.8 containing mainly bug fixes over previous
versions. "Speed of Light", or SOL as I will refer to it from now
on, is Shareware and whilst perfectly useable has some of the
more advanced options crippled in such a way as to encourage
registration. The whole set of tools and their use is too great
to go into in detail, even in an review this large, I will
however try and give a flavour of their use and power so you can
get a feel for the program as a whole.
What is SOL and what does it offer?
SOL firstly is a picture viewer, within the program however it
sports a wide variety of features so as to get the best out of
your pictures. It works on all Atari formats (ST, Falcon, TT,
Mega) and works in all resolutions in up to 256 colours. It
supports a wide variety of formats and is one of the fastest GIF
file handlers on an Atari. SOL now supports the DSP in the Falcon
for JPEG decoding. It is MultiTos compatible and recommended for
maximum speed to be run in conjunction with NVDI or Warp.
Registering the Program
This review is based upon the registered version of "Speed of
Light". To register is simple, just start the program (see
"Getting Started" below). Upon loading you will be greeted with a
screen allowing you to enter your registration details. Enter
your details and choose "Print EZForm", this will create a
document which can be printed or saved to disk with your details
which you send to the author (or local registration handler)
along with the registration fee. They in turn will generate your
Once you have received this key, load the program and enter it
along with your details, the program then becomes the registered
version and will work without any features being disabled. You
only have to register once, with subsequent loads taking you
straight to the main menu.
This form of registration is quick and easy and your details and
keycode only have to be entered into future versions for you to
receive a full registered upgrade.
The program is available from many PD libraries, FTP sites,
Stuart Denman's and my Atari Web pages, as well as making an
appearance on several Atari magazine cover disks. What you get is
the un-registered version of the program, with all the
documentation, supporting files and image files.
Using the shareware version without registering offers all the
facilities you get with the full version with the difference that
some of the more advanced features such as warping will have
blank lines in the pictures at regular intervals, and that you
are limited to only loading one JPEG image per session. Other
than these limitations placed to encourage you to register you
have full access to the program.
Running the program couldn't be simpler. Just click on the
program file "SPOFLT38.APP", after a short while you will be
asked to enter your registration details, if you don't have any
you can continue by choosing "Cancel". This will now take you to
the main options screen.
Whatever resolution you load in will be the screen size used by
the program, and the number of colours in that resolution will be
used (up to 256 colours). On all machines but the Falcon however
you do have the option to change the resolution from within the
Main Options Screen
From the main options screen all the options and access to the
more advanced options are available. Here's a quick summary of
the main options screen features (starting from the top left),
some of which I'll describe in greater detail later:
Picture Statistics - Various information on the picture such as
name, size and palette size.
"H" Button - Histogram of current image.
"P" Button - Optimises image palette.
Machine Specifications - Various machine information such as
computer being used, resolution, palette, and the number of
"Delta" Button - Allows the changing of resolution on ST's and
TT's within the program.
"3-Bars" Button - Allows setting of preferences and true colour
Picture Number Slider - A slider to easily move through the
pictures in memory.
Display Mode Menu - A pop-up menu that allows you to select
between colour or shades (grey scale). On the TT "TTGrey" mode is
available which allows 256 shades of grey.
Downward Arrow Button - Makes image as close to original as
possible by setting sliders to zero and histograms to 1-to-1
"Complex" Button (Colour Transformations) - Toggles between the
additive colour transformation options and the histogram colour
Additive Colour Transform Slider - Available when "Complex" is
not selected. These three sliders one for each of the prime
colours allow you to add to or subtract the RGB elements of the
picture. If moved equally together can be used to brighten or
darken the picture.
Colour Reduction Menu - If the picture contains more colours
than the display this can be used to decide how the palette will
be reduced. "Frequency" is the default with "By Rank" and
"Influence" being the other choices.
Colour Rank "Button" - This switches to the colour rank
histogram editor so you can define the ranks of the RGB
Complex "Button" (Colour Reduction/Selection) - Toggles between
simple contrast slider bars and histogram colour contrast.
Colour Contrast/Separation Slider - These three sliders define
the minimum seperation between the chosen colours used to display
Horizontal/Vertical Size - Allows you to enter the horizontal
and vertical pixel sizes for the images to be scaled to.
Axis Effect Menu - Allows you to choose horizontal, vertical or
both with respect to how the buttons (below) effect the axes.
"O" Button - Sets scaling to original size of image.
"A" Button - Calculates the aspect ratio based on the effected
axis when scaling.
"-" Button - Halves the selected axis.
"+" Button - Doubles the selected axis.
"Fltr" Button - Toggles filtered scaling on/off.
"Set" Button - Takes you to the filtered scaling dialogue for
setting filter type and scaling.
"Fit" Button - Makes the image fit the current resolution in
size as best as possible whilst maintaining the aspect ratio.
"Mous" Button - When highlighted the mouse will be displayed on
the display screen, otherwise it is hidden.
"SmDr" Button - Toggles on/off "Smooth Draw" mode. This is where
flickering is used to increase number of colours you choose to
turn it on or off when the image is being drawn to speed up image
"Warp" Button - Takes you to the Warp dialogue where you can set
the warping and stretching effects.
Flicker Contrast Slider - Sets the maximum contrast allowed
between flickering colours. When on the far left flickering is
Dither Pattern Menu - This menu allows you to select different
"Set" Button - Takes you to the dithering dialogue to give
detailed control over dithering.
"Desk" Button - Allows access to accessories or to other
programs when under MultiTOS. Options for SOL are also available
as drop down menus.
"?" Button - Displays credits, shareware information and amount
of free memory.
"Purge" Button - Allows you to remove the current image freeing
memory. When double clicked on removes all images.
"Colours" Button - Takes you to the colour editor (not allowed
in Shades, Greyscale mode or any resolution using less than 16
">>" Button - Takes you to the slideshow dialogue where you can
set the different slideshow parameters such as start and end
images, pause length between images, and forwards or backwards
play. Once set up choosing "Display" from the main options screen
will go through the images for the slideshow. Turn the slideshow
off to view single images again.
As you can see the program is packed to the brim with features
with these just being a brief summary of the options available
from the main menu, that's before we even start to look at the
You may think that with all these features it difficult to use,
but the control for the most part is straightforward and
intuitive leaving the user only having to reference the manual to
look at some of the more advanced features and to see some of the
possible shortcuts and tips available to achieve better
Using SOL for the first time
Upon loading SOL you are most likely going to want to load some
images, to do this you select the "Add" button. You will be
presented with the file selector where you can choose an image or
use wild cards to load multiple images. Getting files into SOL is
very easy. Apart from the methods mentioned above it is also
possible to load images by dragging the files over the SOL
program icon on the desktop (on later versions of TOS), therefore
starting the program with several loaded images. There is even
support for other file selectors such as Selectric allowing
multiple images to be selected and loaded in one operation.
SOL supports the following image formats for loading:
Degas Uncompressed (.PI?)
Degas Compressed (.PC?)
Prism Paint (.PNT)
GEM (X) Image Format (.IMG)
and the following for saving:
GEM (X) Image Format
The speed at which it handles GIF files is excellent and Falcon
owners are catered for with DSP JPEG decoding (although the
reduction from true colour to 256 colours does slow this down).
Once you have an image you will most likely want to view it.
Selecting the "Display" button will bring the image to the
screen. If the image is larger than the screen you can scroll the
screen by moving the mouse pointer from the centre of the screen.
The further you move it from the centre the faster the screen
scrolls in that direction.
Pressing the right button returns you to the main options
screen. If you want to see the whole image at once clicking on
the "Fit" button will shrink the image proportionally to the
screen. If the image uses more colours than you have available
SOL uses clever techniques to expand the palette, however if the
results still aren't good enough then it is possible to improve
the picture in a number of ways.
The first way to improve the image when lacking colours is to
adopt one of the many dither patterns. Clicking on the "Dither
Patrn:" box will bring up a menu with a choice of dither patterns
with the default being no dither pattern. This menu has two empty
slots into which you can load dither patterns. To access the
dither options and to load a pattern into one of the slots select
the "Set" button next to "Dither Patrn:", this will take you to
the dither options screen.
SOL comes with 3 standard dither patterns with the option of
loading additional dither patterns as provided with the package.
These dither patterns are in the same format as that used by
GemView and are therefore interchangeable.
Once at the dither options screen you can do a number of things.
You have the choice of changing options on the FIS (Filtered
Image Scaling) or normal dithering patterns. The Filter (FIS)
options allows you to either choose no pattern, one of the
defaults or to load one of the files available. The normal dither
options has the same options plus the addition of being able to
change the gradient steps and contrast of the pattern chosen.
Other options that can be adopted to improve the image quality
when the current resolution doesn't support enough colours is to
use the "Flicker Contrast" slider. When moving this slider will
define the contrast level of the flicker and therefore the degree
of flicker visible. When moved to the far left it is off with
possible values up to 255. Using this increases the palette
available and gives you extra colours in which to display the
picture. The disadvantage is a degree of flicker is introduced
into the image when viewed and it slows draw time if flicker is
not turned off with the "SmDr" button.
There are many shortcuts available in SOL but keyboard shortcuts
are not available generally as a rule in the window and option
screens. This has been done deliberately so as not to clash with
programs that provide shortcuts automatically. However whilst
viewing an image using the "Display" button short cuts to perform
a number of simple tasks and to take you to different parts of
the program become available. This includes everything from
changing what image is being viewed and flipping or scaling it,
to calling up the colour editor.<p>
A thing that people often miss when viewing a picture is that
pressing and holding the left mouse button will bring up a list
of features available for manipulating the currently viewed
image. This list includes the keyboard shortcuts were applicable
and makes the program very user friendly as it saves time
flipping between the picture and options screens.
The tools provided by SOL for colour editing and enhancing are
its most powerful features, and is what makes it stand out from
other picture viewers.
Colour editing is divided between the RGB additive sliders that
add or subtract from the RGB elements of an image in a linear
fashion, the complex RGB controls which use the histogram method
of alterering the RGB balance throughout the image, and the
colour editor which gives you direct control over the palette
used and the colours within it.
I will look in further detail now at the later two elements of
the package. Namely the "Histogram Editor" and the "Colour
The Histogram Editor
This is available for use to control either the colour or
contrast of a picture. I will look at its use when applied to the
colour aspect of an image. To access the Histogram Editor you
must select the "Complex" button in the colour options area. This
replaces the RGB sliders with 3 histograms, one for each of the
RGB elements. Clicking on any one of the histograms will take you
the the Histogram Editor.
On this screen the histogram of the colour selected is enlarged
to fill a large portion of the screen. Moving the mouse over the
histogram and clicking sets the level at that point. If the left
mouse button is held down whilst moving over the histogram you
effectively draw the histogram for that colour. Switching between
the histograms for changes to the three colours is easy using the
three buttons at the top of the screen to take you to the
appropriate colour. These are the "Red", "Green" and "Blue"
Along the bottom of the screen are several buttons for editing
the shape of the histogram, these are the "Stretch", "Squash",
"Invert", "Flip" and arrow buttons (where the arrow buttons
scroll the histogram). You can also "Copy" and "Paste" histograms
to any of the other histograms therefore copying the shape to one
of the other colours. It is possible to double click on the
"Copy" button to automatically copy the current histogram to the
other two. All changes can be reversed with the use of the "Undo"
button. It is also possible to automatically define the shape
using either the "Linear" or "Gamma" buttons.
Linear creates a step from left to right with a one-to-one slope
and gives you the shape you usually see, namely a triangle.
When you select Gamma for gamma correction you will have to
enter the gamma value into the popup dialogue. Selecting the
"Generate" button does the correction with values greater than
one darkening the image, and less than one brightening the image.
Gamma correction does this without creating washout in the
Once you are happy with your changes you can select the "OK"
button to accept them and return the the main options screen or
the "Cancel" button to reject all changes made and return to the
There are several histograms available for you to load and try
The Colour Editor
To enter the Colour Editor from the main options screen you
select the "Colours" button. Once selected you will be taken to
the Colour Editor screen. Across the top of the screen ten
colours are displayed with the colour value above them. Using the
"VDI Order" button you can toggle between the colours being
displayed in VDI order or Device-Dependent order. You can scroll
the ten colours through the image palette by either using the
Arrows at either side of the colour boxes, or by using the Slider
Bar just below the colour boxes.
Colours can be selected for editing by clicking on them in their
boxes (selected colours are highlighted with an inner box). To
alter a selected colour you move the three Slider Bars for the
RGB elements. Boxes marked with an "X" in the palette are unused
Buttons in this editor are divided into two areas, the upper-
left buttons for manipulating two or more colours (known as the
"Toolbox"), and the lower left/right hand buttons which are for
switching to other dialogue boxes, undoing, or for other global
Buttons within the Toolbox are used in the same way. You must
select the range of colours you wish to apply the tool to.
Colours selected are reffered to as "hot" colours and once
selected the tool will perform the operation over the set of
Tools available are:
"Copy" - Copies first colour to second.
"Swap" - Exchanges two colours.
"Fill" - Fills whole range with the first colour.
"<" Rotate - Rotates the palette left with wrap around.
">" Rotate - Rotates the palette right with wrap around.
"Sort Group" - Sorts the colours within the range into groups
based on their RGB values.
"Gradient" - Fills in all the colours in the range blending the
colour from the first to the last.
"Sort DK > LT" - Sorts the range from the darkest to the
"Sort LT > DK" - Sorts the range from the lightest to the
The functional buttons are the other group of buttons associated
with the Colour Editor. The functional buttons include:
"Match" - Toggle on/off. This causes SOL to match changes in the
image to the new palette. If it doesn't use one of the colours in
the map it will mark it with an X. When not selected changes will
appear in the displayed image.
"Display" - Display the picture.
"Undo" - Undoes any palette changes.
"Cpy/Swp" - Allows you to copy or swap the palette with another
"Image" - Allows you to edit another image's palette.
"Rescan" - Reverts back to the orignal palette.
"Select" - Allows you to click on any pixel in the image and
return to the editor with that colour selected for editing.
"Take" - Works the same as Select but colour currently being
edited takes on the colour that pixel had in the original image.
"Load" - Loads a .PAL palette file into the current colour map.
"Save" - Saves current palette in .PAL file.
"Cancel" - Aborts any changes made and returns to previous
"Options" - Goes to the Options Dialogue.
Filtered Image Scaling
Filtered Image Scaling (FIS) is used to smooth out or alter
images that have been enlarged or reduced, whilst it will help
improve images that are scaled in this manner it has the drawback
that it is very calculation intensive and therefore takes a long
time to draw. As such it is not a quick way to view images but
can be used to improve them.
To use filtering you must turn the filter on by selecting the
"Fltr" button and use the "Set" button to go to the FIS option
screen. Once on the option screen you will be presented with a
selection of menus, buttons and editable fields.<p>
The first menu is the "Filter Type" which can be either
"Standard" or "Enhancing". The second menu is "Filter Curve"
which has the options of "Box", "Triangle", "Cubic", "B-Spline",
"Lancos3", "Mitchell" or "Nelson". With each offering a different
filter curve. Other options include toggle switches for
"Filtering On/Off", "Flip Horizontal" and "Flip Vertical", "Wrap
Image at Edges" and "Scale Filter". Editable fields are for the
"Height", "Horizontal" and "Vertical". Information is also given
on the amount of memory required for the filter.
When the enhancing Filter Type is selected the Filter Curve menu
contains different filters specifically for enhancing the image.
These are "Sharpening", "Quad-Step", "Raised Edge", "Smooth
Bias", "Sharp Bias", "Linear Bias" or "Diffusion". Enhancing
filters generally work better when image scaling is a multiple of
the original image. Often you will get banding due to the
inability of these filters to shift phase.
Some filters such as Sharpening and Diffusion work best on the
original image whereas others work best on enlarged images. Some
of these other filters can be used to create interesting effects
on the pixels themselves such as the Sharp Bias filter which
produces a 3D pixel effect. Some of the filters are assymetric
and can therefore be flipped. Filters can also be wrapped at the
edge of the image or faded. Both have drawbacks in that fading
will darken the edge of the image whilst wrapped edges can
produce duplicate pixels close to the edges.
When reducing an image without FIS image quality is lost.
Standard filters are used to accurately take into account lost
lines and improve detail. When "Scale Filter" is selected it is
possible to blur filters. Small scaling values will not blur the
filter but larger values will increase level of blurring. Values
less than one produce a weird patterned darkening effect.
Filtering is a powerful tool within SOL and as such requires a
lot of experimentation to achieve the best results along with a
lot of patience. When working with FIS on large images it is
ideal to have a lot of memory available.
(Please note that image warping cannot be used in conjunction
Clicking on the "Warp" button will take you to the warp option
screen. Here you can enter a variety of values for "Width",
"Horizontal Shift", "Height" and "Vertical Centre". Along side
these options are the menus "Warping Pattern" and "Repeat". The
first menu contains the following list of warp transformations:
Off (No warping)
The Repeat menu has the options of "Once" or "Periodic". Using
Warping scan lines are stretched and shifted in various ways in
order to make an interesting change in the image. All numbers
entered are relative to the image itself so if the image is
enlarged twice the warping figures will be scaled likewise. The
warping is centred around what is reffered to as the "bulge" and
can be repeated using the periodic bulge. This centre is usually
the peak or lowest point of the curve when warping.
Whilst the distortions provided prove no real practical value
they are fun to try and are worth experimenting with to achieve
some interesting effects.
SOL has the ability to read special scripts which can be created
by the user, which are to be used in conjunction with the
slideshow. With these simple scripts it is possible to assign
individual times for images to stay on screen, as well as to
select whether loaded images stay in memory or are loaded each
time to save memory. You can even select files with wildcards for
use in the slideshow.
You also have the option of viewing one image whilst the next is
being loaded and decompressed. Other features include the ability
to define how the image will look when displayed by making use of
warping, scaling, truecolour reduction, etc. SOL will follow all
these commands from a script without the user having to do
This is a very useful and welcome additional feature within SOL.
SOL is an excellent program, with a wealth of features it will
keep you experimenting with it for some time to come. All the
features are very fast and provide excellent results. SOL must
have the most comprehensive set of colour features I've seen in a
single package and this alone makes it worthwhile to use. Combine
this with it's speed and compatibility and you have a package
that every Atari owner who likes to view pictures should support.
Of course there are some limitations. There is no true colour
support and there is a limited number of picture formats
supported. JPEG's are memory hungry and can be slow but when put
against the positive things it has to offer these seem to fade
away. This package is a winner.
Ease of Use = 82
Although designed well with many shortcuts and a good intuitive
design this doesn't score as high as it could due to the nature
of the package. Many of the more advanced features are difficult
to use and take a long time to master and although the program is
well done these problems can't be overcome with anything other
than experimentation to achieve the right results.
Features = 91
For a picture viewer this program is packed with features and
represents excellent value for money. Colour-wise nearly every
option is supported that you could ever want and each area
implemented has been thought out very well and is very
comprehensive. This said there are some features in this current
version that have yet to be implemented and with these the score
would be higher.
Use of Computer = 90
Despite the fact it is not aimed at any one machine and
therefore allowing for clever programming and optimisations for
that machine this does an excellent job of taking advantage of
the extra facilities of whatever machine you are on. This is
shown by the support for the TT and the DSP in the Falcon, making
its use of machine excellent with most operations being lightning
fast whatever the system.
Compatibility = 96
What can I say it works with and makes the most of all the Atari
range. This review is based on the time I spent on the package on
both the ST and the Falcon. In all the time I spent on both
machines the only problem I ever had was on the Falcon and that
turned out to be a problem with the Overscan software I was
running. It evens supports file selectors, screen accelerators,
MultiTos, and some graphics cards such as the NOVA.
Speed = 92
Everything with the exception of FIS scaling is very fast
(although considering the intensive nature of this it is to be
expected). Warping can take a little time as can JPEG decoding
but again this is to be expected. "Speed of Light" certainly
lives up to its name.
Documentation = 84
Overall the documentation is good but being included as a text
file on disk for you to print out does limit its ability to
illustrate some things clearly. The ability to see more
screenshots and illustrations of use along with some small
tutorials would help more. Reading the manual on it's own can be
a little confusing at times unless sat in front of the computer
trying everything out. Also some areas are skimmed over two
quickly in the manual.
Overall = 91
An absolute must for anyone with an Atari who views pictures and
has a need to enhance the palette or clear up pictures. With only
a few minor flaws, it is an excellent package with good support
fast times for use, very comprehensive tools, a well thought out
design and excellent cross platform compatibilty. Get this and
register it now; you won't regret it!
The text of the articles is identical to the originals like they appeared in old ST NEWS issues. Please take into consideration that the author(s) was (were) a lot younger and less responsible back then. So bad jokes, bad English, youthful arrogance, insults, bravura, over-crediting and tastelessness should be taken with at least a grain of salt. Any contact and/or payment information, as well as deadlines/release dates of any kind should be regarded as outdated. Due to the fact that these pages are not actually contained in an Atari executable here, references to scroll texts, featured demo screens and hidden articles may also be irrelevant.