Get
The Picture - RLE
by Rich Lefko
This will be a discussion of RLE (Run Length Encoded) graphics and how
ADAM owners can utilize them. This will NOT be technical in nature! (I
never discuss DCB's in mixed company.
RLE is a method of transmitting encoded graphics information to your
computer. It was designed as a standard, so many different types of
computers can utilize them, similar to the concept of CP/M. RLE is
composed of a header sequence that tells the program whether a medium
resolution or a high resolution file follows, then a series of ASCII
character pairs, each representing the number of pixels to be background
(turned off) and foreground (turned on). The number of Pixels to be
turned on or off are the "run length". The end of the file is concluded
by another sequence. Now I'm sure you are wondering what that means to
ADAM owners? Well, since ADAM, like most computers, utilizes and
understands ASCII characters, with the proper software you can view or
print pictures created by other computer system and stored in RLE
format.
Now, don't confuse RLE with either Hi-Res or Low-Res BASIC graphics;
they are not the same. For example, you could create a Hi-Res graphics
picture then you would store it in RLE format for any other computer
that could utilize it. Got the idea? Obviously, the advantage of RLE is
its compatability with a wide range of computer systems. Besides
pictures created using Apple or IBM ystems, RLE pictures can also be
digitized images. Simply explained, a video digitizer "reads" horizontal
and vertical sync pulses, and using special software, converts what it
sees" into something the computer can understand and display (RLE) on a
monitor.
One of the best things about RLE pictures is you don't need CP/M, DMP
(Dot Matrix Printer), or any high-priced software to view them. There is
a PD program, written in BASIC, offered in Data library 9 on Compuserve
called "rleviewer" and can be downloaded at a minimal cost. Now you'll
need an RLE picture to view. Again, on Compuserve, type GO PICS and
you'll be in the picture support forum which is the home of RLE
graphics. They also have GIF (Graphics Interchange Format) pictures,
which ADAM owners can NOT use at this time. Go to the data libraries, of
which there are 14, pick one and browse. You'll see at the top left hand
side of each file its name and whether it's in RLE or GIF format. Once
you've found an RLE picture you'd like to download prepare to "capture"
it in the usual fashion and do so. You'll see ASCII characters scrolling
up the screen. When they stop scrolling it means the end of the file so
press the "Undo" key to close it, then press return to continue.
After loqging off CIS, boot SBASIC and run rleviewer, follow the
instructions and that's all there is to itl I've found that I can even
download surface weather maps (Go WEA) from CIS (see examples).
Please note: Sometimes you will see a message which will state that your
'terminal' does not support graphics and it will ask you if you still
want to continue? Obviously, the answer is YES, cause we know better,
don't we? There are a couple of commercial programs that will allow you
to print RLE
graphics on a DMP. GRAPHIXPAINTER ($23.95 M.W Ruth and others)is one
that will convert RLE to "graphicpaint" format and allow various
printing options such as landscape, inverse, or portions.
SHOWOFF I from Digital Express($24.95 members) allows viewing and
printing of RLE formatted pictures, even using the ADAM printer. (I have
NEVER tried using the ADAM printer. If anyone would like to know if this
does indeed work, let me know and I'll try it!) Another Interesting
feature of Showoff I is once you've loaded an RLE picture and have it up
on the screen you can draw on it or alter it in any way yould likel
Certainly, there are MANY options open to ADAM owners concerning RLE
graphics. The Only way to find out in to explore and try itl
ACTUAL RLE PICTURES AS
DOWNLOADED FROM COMPUSERVE
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