Intermec EasyCoder 3440 User Manual page 13

You can significantly reduce the amount of time necessary to download and
image a graphic by using Direct Graphics mode. Direct Graphics mode allows
the printer to receive a compressed bitmap graphic and image it directly into
the image bands without storing it in the printer.
Before you download the graphic, you must compress it into run-length
encoded (RLE) data. The data compression greatly reduces the amount of data
to download and the rasterized graphic requires minimal processing to image
it into the image bands. You no longer need to store the graphic in Program
mode and then set up a format in Print mode.
When you download a direct graphic to the printer, the printer stores the
graphic in the image bands until you:
clear the label data.
set up another format.
enter Program mode or Test and Service mode.
When printing a label with direct graphics, you must have enough dynamic
RAM installed in your printer to contain the entire label. Intermec printers
normally reuse image bands which enables you to print long labels with
standard RAM. However, when you download direct graphics, the printer
retains no information regarding the existence of the graphic in its image
bands. Therefore, the printer cannot reuse those image bands when you
download a direct graphic.
With standard dynamic RAM, you should be able to print almost any label up
to 6 inches long. For longer labels you may need to install expanded dynamic
RAM.
Run-length encoding (RLE) is a method of compressing bitmap graphics. RLE
efficiently compresses graphics that have repeated runs of white or black dots
in a column and reduces the amount of time required to download the graphics
to a printer.
RLE sends a series of commands that define each bitmap column of a graphic.
It takes advantage of a series of repeated dots within a column by encoding
them as transition commands. Instead of sending the entire column of bitmap
data, it sends commands telling the printer how many series of black and white
dots to image. If columns are identical, a command can instruct the printer to
repeat the last column. RLE is ideal for bar code graphics or designs with
simple patterns.