Compuprint 6314 CZL - Manual (Page 31)

CZL – Programmer Manual
 31
where l is the width of the image (in mm), ris the resolution (in dots
⋅mm
-1 ), a the height of the image
(in mm), 8 is the number of bits per byte, and b is the total number of bytes. The result of the
division (l
⋅ris)/8 must be rounded to the next highest whole number.
The number of bytes per line r depends on the width of the image and the printer resolution as
appears in the following formula:
( )
r
ris l
=
⋅
8
From which it is deduced that
( )
ris a r b
⋅ ⋅ =
The hexadecimal code described above for representation of the graphic images involves sending
(and more generally, handling) of files of moderate dimensions.
CZL offers the possibility of reducing file dimensions with a special compression algorithm. More
specifically, it often happens that perfectly equal sequences of hexadecimal codes must be sent (this
corresponds to having extended black parts in the image or recurrent elementary figures). In this
case, the letters after F can be used as a multiplier according to the following table:
G H I J K L M N O P Q R S T U V W X Y
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
When it receives UB, the machine reads (with the identical result) “15 times B”, in other words
BBBBBBBBBBBBBBB.
Likewise for lower case letters:
g h i j k l m N o p q r s t u v w x y z
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400
Sending hB is like sending B: 40 times
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB.
The upper and lower case letters can be combined so that, for example, hUB (or UhB) corresponds
to “55 times B”.
In regard to file compression, CZL specifies the use of several other special characters:
The comma (,) fills the current line (from the right) with pairs (whole bytes) of zeroes (0) from its
position to the end of the line
137 .
The exclamation point (!) does the same thing, filling the line with ones (1).
The colon (:) indicates repetition of the last line.
Since the number of bytes is whole, the hexadecimal characters comprising the representation of the
graphic image are always even in number. Therefore, the action of the comma and exclamation
point characters described above is calculated on the pairs of characters. In other words, to avoid
137
The length of the line is determined by the parameter r.