.TH i.tape.other
.nh
.SH NAME
\fIi.tape.other\fR \-
An imagery function that extracts scanned aerial imagery (NHAP, etc.)
and satellite imagery (TM, SPOT, etc) from half-inch or 8mm tape.
.br
\fI(GRASS Image Processing Program)\fR
.SH SYNOPSIS
.B i.tape.other
.SH DESCRIPTION
.I i.tape.other
is a generic program that extracts imagery from tape using the tape
description that is input by the user.

This program must be run in a LOCATION_NAME with a x,y coordinate
system (i.e., a coordinate system with projection 0).
For further information regarding 
this LOCATION_NAME refer to the manual entry for \fIimagery\fR.

The first prompt in \fIi.tape.other\fR asks the user for the 
tape device name.  This is sometimes  /dev/rmt0 (for a density of 1600),
but this varies with each machine.

The next prompt is:
.if t \fB
.nf
Please mount and load tape, then hit RETURN -->
.fi
\fR
.SH IMAGE IDENTIFICATION MENU
The first menu in the program asks the user for information about the data.

.if t \fB
.TS
center, tab(|);
c s
l l.
please enter the following information

Tape Identification:|_

Image Description:|_

Title for the Extracted Raster (Cell) Files:|_

.T&
c s.
AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
(OR <Ctrl-C> TO CANCEL)
.TE
\fR
.SH TAPE LAYOUT MENU
The next menu asks for the physical layout of the tape.

.if t \fB
.ne 16
.TS
center, tab(:);
c s
l l.
GENERIC TAPE EXTRACTION:

tape layout
.T&
c l.
0__:number of tape files to be skipped
0__:number of records in the remaining files to be skipped
.T&
l l.
band files
.T&
c l.
0__:number of bands on the tape
.T&
l l.
data format
.T&
c l.
___:band sequential (BSQ)  |  mark one with an x
___:band interleaved (BIL) |
0__:if you select BSQ format and all the bands are in a single file,
   :enter the total number of records in the file. Otherwise enter 0

0__:length (in bytes) of the longest record on the tape
1__:blocking factor of data in the file

.T&
c s.
AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
(OR <Ctrl-C> TO CANCEL)
.TE
\fR

.IP "\fInumber of tape files to be skipped\fR"
If there are files at the beginning of the tape which are not
image data, they can be skipped. Sometimes information that comes
with a tape will indicate the number of header files or records
on the tape.  The GRASS utility \fIm.examine.tape\fR will also
provide this information.  The \fIrecord length\fR is the number of
columns in the image, while the \fInumber of records\fR is the number
of rows in the image (not always correct, see \fIblocking factor of data in 
the file\fR below). NHAP imagery and usually most scanned aerial imagery do 
not have tape header files, but this should be checked.
TM imagery has one header file that contains imagery format of data files
and parameters of data aquisition.
SPOT imagery has two files that should be skipped on the first tape,
and one file to be skipped on the second tape (of a two-tape set).
.IP "\fInumber of records in the remaining files to be skipped\fR"
If the files which contain the image begin with non-image data, these
records can also be skipped.
This is usually 0 for most data types. SPOT imagery stored in 1600bpi
has one header record in the image file on each tape that should be skipped.
.IP "\fInumber of bands on the tape\fR"
Most aerial imagery have 3 bands, but satellite simulator data may have
more.  TM data has seven bands and SPOT has three bands as a standard, 
respectively. The total number of bands on the tape should be specified here, 
not just the number that will be extracted.
.IP "\fIdata format\fR"
The two formats that imagery data are most commonly stored in are 
called \fIband interleaved\fR format (BIL) and \fIband sequential\fR
format (BSQ).
In BIL format, each record on the tape contains one line for one band
of data.  If the data contains three bands, then the first five records
will look like this:  
.nf
.ce 5

band 1, line 1
band 2, line 1
band 3, line 1
band 1, line 2
band 2, line 2

.fi
In BSQ format, all lines of one band are stored together on a
tape, followed by all lines of another band, followed by all
lines of the next band, etc.  These data are stored as if they
were in a one band BIL format:

.nf 12
.ce 12
band 1, line 1
band 1, line 2
band 1, line 3
     .
     .
     .
band 2, line 1
band 2, line 2
     .
     .
band 2, line 156
band 2, line 157
.fi

Each pixel contains one byte and there
is one line per record.  BSQ format is the format that is 
usually created by optical scanning devices when they scan 
photographs, but not all digitized aerial imagery are stored in this
format.  The format of the data is usually written on the 
exterior of the tape;  this should be checked.
.IP "\fIlength (in bytes) of the longest record on the tape\fR"
This must be set to the number of bytes in the longest data record.
It is used to determine how large a buffer to use for reading the
tape. This value can be obtained using
.I m.examine.tape.
.IP "\fIblocking factor of data in the file\fR"
This is the number of lines combining into one physical record on tape.
It is usually one for most of imageries, i.e., one line per physical record. 
However, considering on data compressing and tape memory saving, 
sometimes more than one lines are combined into one physical record on the tape.
This number may be written on the exterior of the tape, otherwise the user need 
to experiment on this number by running of \fIi.tape.other\fR.
.SH BAND EXTRACTION MENU
The user is then asked to mark an \fIx\fR beside the bands to be
extracted.  See the subheading in this entry entitled ROW AND
COLUMN EXTRACTION.

.if t \fB
.ce 1
please mark an x by the bands you want extracted

.nf
.ce 4
_____1
_____2
_____3
_____4


.fi
.ce 2
AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
(OR <Ctrl-C> TO CANCEL)\fR

.SH PREFIX/GROUP NAME
The user is asked to enter the prefix/group for the (raster) band
files to be created.  This name will precede each band file
extracted into GRASS.  For example, if three bands are extracted 
the following three band files will result:

.ce 3
.I prefixname.1
.br
.I prefixname.2
.br
.I prefixname.3

The specified \fIprefixname\fR
will also automatically become the name for the imagery group 
file being created.  Each image (i.e., each run of \fIi.tape.other)\fR
should be given a unique prefix/group name.
.SH ROW AND COLUMN MENU
Finally, the starting row, ending row, starting column and ending
column are required. This allows the user to extract any subset of the
image from the tape.


.if t \fB
.ce 2
EXTRACT
please select desired tape window (geographic region definition) to extract
.nf
.ce 2

start row:_0_
  end row:_0_

.fi
.nf
.ce 2

start col:_0_
  end col:_0_

.fi

.ce 2
AFTER COMPLETING ALL ANSWERS, HIT <ESC> TO CONTINUE
(OR <Ctrl-C> TO CANCEL)\fR

The extraction process will begin by first skipping the number
of specified files, advancing to the starting row, and then reading
the tape.  The percent completion of the extraction is displayed
on the screen.

Following the extraction, the extracted band files
will be listed as raster map layers available in the current MAPSET.
These raster map layers may be displayed individually using the 
GRASS commands \fId.display\fR, \fId.rast\fR or \fIi.points\fR.
.SH NOTES
This program can be used for extraction of TM, SPOT and other types of
data from tape;  however, the user must supply information to the program
on how the image data is laid out on the tape.  For example,
the image data may be padded with surrounding extra rows and/or columns;
the user may wish to skip over these rows and columns and extract only
the actual image data from the tape.  \fIi.tape.other\fR does not
know where image data actually begins on the tape;  the user must
tell the program what portion of the tape data to extract.
Often, information on the orientation and layout of the image data
on tape will be included on a printout accompanying
any tape data received by the user;  however, this may not always be
the case.  The user may need to experiment with various runs
of \fIi.tape.other\fR before extracting the portions of an image
actually desired.
.LP
After extracting an image from tape, the geographic region
in the x,y coordinate LOCATION_NAME will be set, based upon the 
extracted rows and columns from the tape. The relationship between
the image rows and columns and the coordiates bounding the
geographic region is discussed in the \fIimagery\fR manual entry.
.LP
This program is interactive and requires no command line arguments.
.SH ROW AND COLUMN EXTRACTION
The display options in GRASS allow the user to locate rows and
columns on the digital image.  If enough disk space is available, one
band of an entire image, or one band of a portion of an image known to 
contain the area of interest, can be extracted and displayed.  The 
.I measurements 
option in \fId.display\fR, or \fId.where\fR (following a run of \fId.rast\fR)
will echo x and y coordinates to the screen.  (These coordinates will display
negative numbers in the north-south direction but ignoring the negative
sign will yield the row number.  See the \fIimagery\fR manual entry for
further explanation.)

If a photograph of the digital image is available, the rows and columns
to be extracted can be determined from it by associating inches with the 
total number of known rows and columns in the scene.  For example, if 
the total length of the photograph is 12 inches, the total number of rows
on the tape is 2000, and the northwest corner of the area of interest 
begins 2 inches from the top of the photo, then:

.ce 2
12" / 2000 rows \*= 2" / x rows
x \*= 333.333

The northwest corner of the area of interest starts at row 333.  The
starting row, ending row, starting column, and ending column can be 
calculated in this manner.
.SH SEE ALSO
\fIGRASS Tutorial: Image Processing\fR
.LP
.I d.display,
.I d.rast,
.I d.where,
.I i.group,
.I i.points,
.I i.tape.mss,
.I i.tape.mss.h,
.I i.tape.tm,
.I i.tape.tm.fast,
.I imagery,
.I m.examine.tape
.SH AUTHOR
Michael Shapiro, U.S. Army Construction Engineering Research Laboratory
.br
Tao Wen, University of Illinois at Urbana-Champaign, Illinois