HP Pcl 5 Manual

ENRaster Width Command 15-13
Raster Width Command 
The Raster Width command specifies the width in pixels of the raster 
area. Width is in the direction that the raster rows are laid down, 
hence, width is subject to the current raster presentation mode and 
print direction (see Figure 15-8).
E
C* r # S
#  =Width in pixels of the specified resolution 
Default =depends on raster presentation mode -
when presentation mode is 0, width = width of logical 
page - left graphics margin when presentation mode...

15-14   Raster GraphicsEN
Figure 15-8 Maximum Raster Width
Start Raster Graphics Command 
The Star t Raster Graphics command identifies the beginning of the 
raster data and also specifies the left graphics margin.
E
C * r # A 
#  =0- Start graphics at default left graphics margin
X-position 0).
1 - Start graphics at current cursor position (current 
X-position). 
Default =0
Range =0, 1 (values outside the range default to 0)
A value of 0 specifies that the left graphics margin is at the default left...

ENRaster Y Offset Command 15-15 Once in Raster Graphics Mode, PCL commands and text imply an 
End Raster Graphics (
E
C*rC) except for the following commands:
zTransfer Raster Data 
zSet Raster Compression Method 
zRaster Y Offset 
In addition, the following commands are ignored (i.e., locked out) 
while in Raster Graphics Mode and do not imply an End Raster 
Graphics command:
zStart Raster Graphics 
zSet Raster Width 
zSet Raster Height 
zSet Raster Presentation Mode 
zSet Raster Graphics Resolution...

15-16   Raster GraphicsEN
Set Compression Method Command 
The Set Compression Method command allows you to code raster 
data in one of four compressed formats: Run-length encoding, 
tagged imaged file format (TIFF) rev. 4.0, delta row compression, 
and adaptive compression. The choice of compression methods 
affects both the amount of code needed to generate a raster 
graphic image and the efficiency with which the image is printed.
E
C& * b # M 
# =0- Unencoded
1 - Run-length encoding
2 - Tagged Imaged...

ENSet Compression Method Command 15-17
Tagged Image File Format Encoding 
(Method 2)    
Tagged image file format encoding interprets raster data as TIFF 
“Packbits.” This format combines features of methods 0 and 1. A 
control byte precedes the raster data (pattern bytes). The control 
byte identifies whether the pattern byte(s) represent a byte that is to 
be repeated some number of times (up to 127), or represent some 
number of bytes (up to 127) which are to be printed as is (literal).
The sign of...

15-18   Raster GraphicsEN
The range of numbers for the control byte is shown below.
NoteAnother method to calculate the number needed in the control byte 
for some number of repetitions is to subtract the number of desired 
repetitions from 256. For example, the control value for 3 repetitions 
(4 occurrences) of a byte is 256 minus 3 = 253.
A zero or positive value in the control byte means that the subsequent 
byte or bytes are non-replicated bytes of data. The value of the 
control byte plus one...

ENSet Compression Method Command 15-19 TIFF encoding also allows you to include a non-operative (NOP) 
control byte, represented by the value –128. This byte is ignored, 
and the subsequent byte is treated as the new control byte.
NoteIt is more efficient to code two consecutive identical bytes as a 
repeated byte. If these bytes are preceded and followed by literal 
bytes, however, it is more efficient to code the entire group as literal 
bytes.
Examples: Run-length and TIFF Compression   
The following...

15-20   Raster GraphicsEN
TIFF Encoding
E
C*r1A 
E
C*b2m6W(-3)U(0)A(-1)T or E
C*b2m6W(-3)U(2)ATT 
E
C*rC
In the TIFF encoding example above, parenthetical expressions 
are used to identify control bytes. For example, the byte (-3) is shown 
to represent the control byte for a repetition (minus value) of 3. The 
actual value for this position is the decimal value 253. Additional 
“encoded” control bytes in this sequence include: (0) for decimal 0, 
(-1) for decimal 255, and (2) for decimal 2. The raster...

ENSet Compression Method Command 15-21 If more than eight replacement (delta) bytes are needed, additional 
command byte/replacement bytes may be added, as shown below:
E
C*3m#W [(Command Byte)(1 to 8 Replacement 
Bytes)][(Command Byte)(1 to 8 Replacement Bytes)]. . .
In the command byte, the upper three bits identify the number of 
replacement (delta) bytes (which can be 1 to 8 bytes). The lower five 
bits identify the location the replacement bytes are to be positioned. 
This position is identified as...

15-22   Raster GraphicsEN
As mentioned, the offset is contained in the lower five bits of the 
command byte allows for offset values from 0 to 31. Compression 
mode allows offsets larger than 31 bytes as follows:
zAn offset value of 0-30 indicates that the replacement bytes are 
offset from the 1st byte to the 31st byte.
zA value of 31 indicates that the next byte following the command 
byte is an additional offset byte which adds to the first (32) offset 
value. This allows offset values larger than 31....