1 058b0118 2005-01-03 devnull .TH CROP 1
3 058b0118 2005-01-03 devnull crop, iconv \- frame, crop, and convert image
4 058b0118 2005-01-03 devnull .SH SYNOPSIS
48 058b0118 2005-01-03 devnull .I chandesc
53 058b0118 2005-01-03 devnull .SH DESCRIPTION
56 058b0118 2005-01-03 devnull .IR image (7)
57 058b0118 2005-01-03 devnull file (default standard input), crops it, and writes it as a compressed
58 058b0118 2005-01-03 devnull .IR image (7)
59 058b0118 2005-01-03 devnull file to standard output.
60 058b0118 2005-01-03 devnull There are two ways to specify a crop, by color value or by geometry.
61 058b0118 2005-01-03 devnull They may be combined in a single run of
62 058b0118 2005-01-03 devnull .IR crop ,
63 058b0118 2005-01-03 devnull in which case the color value crop will be done first.
67 058b0118 2005-01-03 devnull option takes a red-green-blue triplet as described in
68 058b0118 2005-01-03 devnull .IR color (3).
69 058b0118 2005-01-03 devnull (For example, white
73 058b0118 2005-01-03 devnull .BR 255 .)
74 058b0118 2005-01-03 devnull The corresponding color is used as a value to be cut from the outer
75 058b0118 2005-01-03 devnull edge of the picture; that is, the image is cropped to remove the maximal
76 058b0118 2005-01-03 devnull outside rectangular strip in which every pixel has the specified color.
80 058b0118 2005-01-03 devnull option insets the image rectangle by a constant amount,
82 058b0118 2005-01-03 devnull which may be negative to generate extra space around the image.
87 058b0118 2005-01-03 devnull options are similar, but apply only to the
91 058b0118 2005-01-03 devnull coordinates of the image.
95 058b0118 2005-01-03 devnull option specifies an exact rectangle.
99 058b0118 2005-01-03 devnull option specifies that the image's coordinate system should
100 058b0118 2005-01-03 devnull be translated by
101 058b0118 2005-01-03 devnull .IR tx ,
103 058b0118 2005-01-03 devnull as the last step of processing.
107 058b0118 2005-01-03 devnull option specifies a background color to be used to fill around the image
108 058b0118 2005-01-03 devnull if the cropped image is larger than the original, such as if the
110 058b0118 2005-01-03 devnull option is given a negative argument.
111 058b0118 2005-01-03 devnull This can be used to draw a monochrome frame around the image.
112 058b0118 2005-01-03 devnull The default color is black.
114 058b0118 2005-01-03 devnull .I Iconv
115 058b0118 2005-01-03 devnull changes the format of pixels in the image
117 058b0118 2005-01-03 devnull (default standard input) and writes the resulting image to standard output.
118 058b0118 2005-01-03 devnull Pixels in the image are converted according to the channel descriptor
119 058b0118 2005-01-03 devnull .IR chandesc ,
121 058b0118 2005-01-03 devnull .IR image (7)).
122 058b0118 2005-01-03 devnull For example, to convert a 4-bit-per-pixel grey-scale image to an 8-bit-per-pixel
123 058b0118 2005-01-03 devnull color-mapped image,
124 058b0118 2005-01-03 devnull .I chandesc
125 058b0118 2005-01-03 devnull should be
126 058b0118 2005-01-03 devnull .BR m8 .
128 058b0118 2005-01-03 devnull .I chandesc
129 058b0118 2005-01-03 devnull is not given, the format is unchanged.
130 058b0118 2005-01-03 devnull The output image is by default compressed; the
132 058b0118 2005-01-03 devnull option turns off the compression.
133 058b0118 2005-01-03 devnull .SH EXAMPLE
134 058b0118 2005-01-03 devnull To crop white edges off the picture and add a ten-pixel pink border,
137 058b0118 2005-01-03 devnull crop -c 255 255 255 -i -10 -b 255 150 150 imagefile > cropped
139 058b0118 2005-01-03 devnull .SH SOURCE
140 c3674de4 2005-01-11 devnull .B \*9/src/cmd/draw/crop.c
141 058b0118 2005-01-03 devnull .SH SEE ALSO
142 058b0118 2005-01-03 devnull .IR image (7),
143 058b0118 2005-01-03 devnull .IR color (3)
144 058b0118 2005-01-03 devnull .SH BUGS
145 058b0118 2005-01-03 devnull .I Iconv
146 058b0118 2005-01-03 devnull should be able to do Floyd-Steinberg error diffusion or dithering
147 058b0118 2005-01-03 devnull when converting to small image depths.