Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

rawtoppm(1) [minix man page]

rawtoppm(1)                                                   General Commands Manual                                                  rawtoppm(1)

rawtoppm - convert raw RGB bytes into a portable pixmap SYNOPSIS
rawtoppm [-headerskip N] [-rowskip N] [-rgb|-rbg|-grb |-gbr|-brg|-bgr ] [-interpixel|-interrow] width height [imagedata] DESCRIPTION
Reads raw RGB bytes as input. Produces a portable pixmap as output. The input file is just RGB bytes. You have to specify the width and height on the command line, since the program obviously can't get them from the file. The maxval is assumed to be 255. If the resulting image is upside down, run it through pnmflip -tb . OPTIONS
-headerskip If the file has a header, you can use this flag to skip over it. -rowskip If there is padding at the ends of the rows, you can skip it with this flag. -rgb -rbg -grb -gbr -brg -bgr These flags let you specify alternate color orders. The default is -rgb. -interpixel -interrow These flags let you specify how the colors are interleaved. The default is -interpixel, meaning interleaved by pixel. A byte of red, a byte of green, and a byte of blue, or whatever color order you specified. -interrow means interleaved by row - a row of red, a row of green, a row of blue, assuming standard rgb color order. An -interplane flag - all the red pixels, then all the green, then all the blue - would be an obvious extension, but is not implemented. You could get the same effect by splitting the file into three parts (perhaps using dd), turning each part into a PGM file with rawtopgm, and then combining them with rgb3toppm. SEE ALSO
ppm(5), rawtopgm(1), rgb3toppm(1), pnmflip(1) AUTHOR
Copyright (C) 1991 by Jef Poskanzer. 06 February 1991 rawtoppm(1)

Check Out this Related Man Page

rawtopgm(1)                                                   General Commands Manual                                                  rawtopgm(1)

rawtopgm - convert raw grayscale bytes into a portable graymap SYNOPSIS
rawtopgm [-bpp [1|2]] [-littleendian] [-maxval N] [-headerskip N] [-rowskip N] [-tb|-topbottom] [width height] [imagefile] DESCRIPTION
Reads raw grayscale values as input. Produces a PGM file as output. The input file is just a sequence of pure binary numbers, either one or two bytes each, either bigendian or littleendian, representing gray values. They may be arranged either top to bottom, left to right or bottom to top, left to right. There may be arbitrary header information at the start of the file (to which rawtopgm pays no attention at all other than the header's size). Arguments to rawtopgm tell how to interpret the pixels (a function that is served by a header in a regular graphics format). The width and height parameters tell the dimensions of the image. If you omit these parameters, rawtopgm assumes it is a quadratic image and bases the dimensions on the size of the input stream. If this size is not a perfect square, rawtopgm fails. When you don't specify width and height, rawtopgm reads the entire input stream into storage at once, which may take a lot of storage. Otherwise, rawtopgm ordinarily stores only one row at a time. If you don't specify imagefile, or specify -, the input is from Standard Input. The PGM output is to Standard Output. OPTIONS
-maxval N N is the maxval for the gray values in the input, and is also the maxval of the PGM output image. The default is the maximum value that can be represented in the number of bytes used for each sample (i.e. 255 or 65535). -bpp [1|2] tells the number of bytes that represent each sample in the input. If the value is 2, The most significant byte is first in the stream. The default is 1 byte per sample. -littleendian says that the bytes of each input sample are ordered with the least significant byte first. Without this option, rawtopgm assumes MSB first. This obviously has no effect when there is only one byte per sample. -headerskip N rawtopgm skips over N bytes at the beginning of the stream and reads the image immediately after. The default is 0. This is useful when the input is actually some graphics format that has a descriptive header followed by an ordinary raster, and you don't have a program that understands the header or you want to ignore the header. -rowskip N If there is padding at the ends of the rows, you can skip it with this option. Note that rowskip need not be an integer. Amaz- ingly, I once had an image with 0.376 bytes of padding per row. This turned out to be due to a file-transfer problem, but I was still able to read the image. Skipping a fractional byte per row means skipping one byte per multiple rows. -bt -bottomfirst By default, rawtopgm assumes the pixels in the input go top to bottom, left to right. If you specify -bt or -bottomfirst, rawtopgm assumes the pixels go bottom to top, left to right. The Molecular Dynamics and Leica confocal format, for example, use the latter arrangement. If you don't specify -bt when you should or vice versa, the resulting image is upside down, which you can correct with pnmflip . This option causes rawtopgm to read the entire input stream into storage at once, which may take a lot of storage. Ordinarly, raw- topgm stores only one row at a time. For backwards compatibility, rawtopgm also accepts -tb and -topbottom to mean exactly the same thing. The reasons these are named backwards is that the original author thought of it as specifying that the wrong results of assuming the data is top to bottom should be corrected by flipping the result top for bottom. Today, we think of it as simply specifying the format of the input data so that there are no wrong results. SEE ALSO
pgm(5), rawtoppm(1), pnmflip(1) AUTHORS
Copyright (C) 1989 by Jef Poskanzer. Modified June 1993 by Oliver Trepte, 14 September 2000 rawtopgm(1)
Man Page