Programming instructions

Intermec Fingerprint v7.61 – Programmer’s Reference Manual Ed. 7 281

Chapter 3 Image Transfer

The following image format is valid for Intelhex, UBI00, UBI01, UBI02,

and UBI03 image transfer protocols, but not for the UBI10 protocol, which

is a combined image transfer protocol and format.

A bitmap picture can be encoded in one of two ways, as a plain bit representation

or encoded with a Run Lenght Limited (RLL) algoritm.

Pictures can be magniﬁ ed, by the printer, up to four times independently

in both x and y directions.

The pictures can be rotated 180 degres by the printer (that is printed

upside-down.) To print a bitmap in all four directions you have to deﬁ ne

two bitmaps, one straight and one rotated 90 degrees. To comply with the

Intermec Fingerprint convention, use the extension .1 for the straight bitmap

and extension .2 for the rotated one.

Bitmap pictures, in both encoding schemes, are printed with the lowest

address ﬁ rst, that is the ﬁ rst row of deﬁ ned data is the ﬁ rst thing out. (This

may be somewhat confusing. The only result, if you misinterpret this, is that

your picture will come out upside-down.)

Bitmap pattern, bit representation

The bitmap picture is encoded word oriented (16 bits), low byte ﬁ rst. The

bits in each byte is read from lsb ﬁ rst (bit 0.)

Bitmap pattern, Run Lenght Limited (RLL)

RLL encoding is a very efﬁ cient way of compressing big bitmaps with

relatively big black and/or white areas.

The RLL encoded picture is encoded byte oriented (8 bits.) Each byte

represents the number of consecutive black or white dots. The sum of bytes

for each row must equal the width of the pattern. The ﬁ rst byte represent

white dots, the second black and so on. The last byte must alter the

color back to white. If the ﬁ rst dot is black just enter a zero ﬁ rst. Valid

values for dot ﬁ elds is 0 to 127 (0 to 7f hex.) To get a row longer then

127, concatenate two rows with zero, for example to get a row of 240

dots, enter 128,0,112.

The next step in our RLL encoding algoritm is to compress identicals rows,

two identical rows are compressed by adding a byte in both ends of the dot row,

the valid range for these bytes are -1 to -128 (ff to 80 hex.)

Image Format