BCP(1) BCP(1)
NAME
bcp - reformat black-and-white picture files
SYNOPSIS
bcp [ option ... ] [ file1 [ file2 ] ]
DESCRIPTION
Bcp copies black-and-white (B&W) image file1 to file2,
optionally changing the file format and transforming the
image. If file1 is a directory name, then every leaf of its
file tree is processed in turn; and, in this case, if file2
also is specified, it is made the root directory of an iso-
morphic tree of output files. If file2 is not specified,
all output is catenated to stdout.
Bcp can copy among all the B&W picfile(5) formats, and some
others. The default output format is TYPE=ccitt-g4. Image
transformations include trimming, translation, scaling, and
rotation, performed in that order (not in argument order).
Input files in picfile(5) format must begin with an ASCII
TYPE=type header line. Types supported both as input and
output are:
dump One byte/pixel. NCHAN=1 is required. On input,
the grey pixel values are thresholded to B&W; see
option -T. On output, black becomes 0 and white
255.
bitmap One bit/pixel. Essentially Sun rasterfile format,
with a picfile(5) header replacing the Sun binary
header.
ccitt-g4 CCITT Group 4 FAX encoding, strongly compressive on
printed text. Also, ccitt-g31 (Group 3, 1-dim) and
ccitt-g32 (Group 3, 2-dim; see -k).
Other supported types are:
binary One bit/pixel encoding; obsolescent, but needed for
old image archives. Both input and output.
rle Fast run-length encoding; obsolescent, but needed
for old image archives. Input or output, but not
both.
pico Same as dump. Input only.
cdf `Compound document format', used in AT&T FAX Con-
nection product. Input only. Only the first of
BCP(1) BCP(1)
multiple pages is read.
Other formats not using a TYPE=type header, are:
bitfile(9.5) format; tiff 5.0 format; PostScript bitmap for-
mat (output only); and Sun rasterfile format. Input tiff
files may be encoded using the Group 3 or Group 4 schemes,
LZW algorithm, modified Huffman encoding, Apple PackBits, or
uncompressed. Sun rasterfiles may be encoded using no com-
pression, or the byte-length encoding scheme.
The options are:
-B[io] Read/write bitfile(9.5) format (no TYPE=type
header).
-Fc Write tiff format, compression scheme c, where c is
g3 or g31 (1-dim Group 3), g32 (2-dim Group 3), g4
(Group 4), L (LZW compression), P (Apple PackBits),
or N (no compression).
-M Write TYPE=bitmap format.
-P Write Postscript format.
-Rx,y Force output resolutions to x,y (pixels/inch). If
,y is missing, it is taken to be the same as x.
Overrides -xx,y. Requires a RES=x y line in the
header (but, see -Z).
-R= Force the output resolution to be equal to the
greater of the input resolutions.
-S Write Sun rasterfile format (standard encoding).
-Tt Threshold. When reading TYPE=dump, assign black to
grey levels less than t, and white to others.
Default: -T128.
-Zx,y Force input RES=x y.
-b Write TYPE=binary format.
-g4
-4 Write TYPE=ccitt-g4 format. Similarly, -g31 or -31
and -g32 or -32.
-kn Set the `k' for ccitt-g32 encoding on output
(default -k4).
-ox,y Offset (translate) the image by x,y pixels. The
width and height of the picture are not changed.
BCP(1) BCP(1)
-p Write TYPE=dump NCHAN=1 format. Map black to 0,
white to 255.
-r Write TYPE=rle format.
-tl Rotate the image to bring the left edge of the page
to the top. Set top-left corner of the rotated
image at the top-left corner of the image.
-td Rotate the image d degrees counterclockwise about
its center. d is a real number.
-wl,t,r,b
Specify window (trim the image): l,t is the left-
top corner and r,b the right-bottom corner measured
in pixels. If the new margins are outside the
original picture, the new area is set to white. An
argument given as `%' leaves the edge unchanged.
-xx,y Expand/contract (scale) the image, by real factors
x and y. If ,y is missing, y is taken to be the
same as x. May be overridden by -Rx,y. Requires a
RES=x y line in the header (but, see -Z).
SEE ALSO
cscan(1), imscan(1), ocr(1), pico(1), picfile(5)
CCITT facsimile coding standards Rec. T.4(1988) and
T.6(1988).
BUGS
Concatenated pages are supported, but only if each new page
has a complete header.
Scaling is accomplished by naive replication/deletion of
pixels.
Rotation by small angles exhibits aliasing effects, and is
slow.
Rotations -tr and -tb are unfinished.
CCITT FAX `uncompressed' (or, `transparent') mode is not
implemented.
Postscript output is useful only for small images.
WINDOW=l t r b where l or t is non-zero may not be handled
correctly for every combination of file types.
tiff LZW compression may not be working properly (input and
output).
TYPE=rle can't be both input and output.
Should be merged with T. Duff's pcp.