The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
pnmhisteq – histogram equalise a portable anymap Synopsispnmhisteq [-gray] [-rmap pgmfile] [-wmap pgmfile] [-verbose] [pnmfile] Descriptionpnmhisteq increases the contrast of a portable graymap or pixmap through the technique of histogram equalisation[1]. A histogram of the luminance of pixels in the map is computed, from which a transfer function is calculated which spreads out intensity…
pnmgamma – perform gamma correction on a portable anymap Synopsispnmgamma [-ungamma] [-cieramp|-srgbramp] [value [pnmfile]] pnmgamma [-ungamma] [-cieramp|-srgbramp] redgamma greengamma bluegamma [pnmfile] DescriptionPerforms gamma correction on pseudo-PNM images. The PPM format specification specify that certain sample values in a file represent certain light intensities in an image. In particular, they specify that the sample values are…
pnmflip – perform one or more flip operations on a portable anymap Synopsispnmflip [-leftright|-lr] [-topbottom|-tb] [-transpose|-xy] [-rotate90|-r90|-ccw ] [-rotate270|-r270|-cw ] [-rotate180|-r180] [pnmfile] DescriptionReads a portable anymap as input. Performs one or more flip operations, in the order specified, and writes out a portable anymap. OptionsThe flip operations available are: left for right (-leftright or -lr);…
pnmfile – describe a portable anymap Synopsispnmfile [-allimages] [pnmfile …] DescriptionReads one or more Netpbm files as input. Writes out short descriptions of the image type, size, etc. This is mostly for use in shell scripts, so the format is not particularly pretty. Options-allimages Describe every image in each input file. Without this option, pnmfile…
pnmenlarge – read a portable anymap and enlarge it N times Synopsispnmenlarge N [pnmfile] DescriptionReads a portable anymap as input. Replicates its pixels N times, and produces a portable anymap as output. pnmenlarge can only enlarge by integer factors. The slower but more general pnmscale can enlarge or reduce by arbitrary factors, and pbmreduce can…
pnmdepth – change the maxval in a portable anymap Synopsispnmdepth newmaxval [pnmfile] DescriptionReads a portable anymap as input. Scales all the pixel values, and writes out the image with the new maxval. Scaling the colors down to a smaller maxval will result in some loss of information. Be careful of off-by-one errors when choosing the…
pnmcut – cut a rectangle out of a portable anymap Synopsispnmcut [-left leftcol] [-right rightcol] [-top toprow] [-bottom bottomrow] [-width width] [-height height] [-pad] [-verbose] [ left top width height ] [pnmfile] All options may be abbreviated to the shortest unique prefix. DescriptionReads a PBM, PGM, or PPM image as input. Extracts the specified rectangle,…
pnmcrop – crop a portable anymap Synopsispnmcrop [-white|-black|-sides] [-left] [-right] [-top] [-bottom] [pnmfile] All options may be abbreviated to their shortest unique prefix or specified with double hyphens. DescriptionReads a PBM, PGM, or PPM image as input. Removes borders that are the background color, and produces the same type of image as output. If you…
pnmconvol – general MxN convolution on a portable anymap Synopsispnmconvol convolutionfile [pnmfile] DescriptionReads two portable anymaps as input. Convolves the second using the first, and writes a portable anymap as output. Convolution means replacing each pixel with a weighted average of the nearby pixels. The weights and the area to average are determined by the…
pnmcomp – composite (overlay) two portable anymap files together Synopsispnmcomp [-xoff=X | -align={left,center,right}] [-yoff=Y | -valign={top,middle,bottom}] [-alpha=alpha-pgmfile] [-invert] overlay [pnm-input] [pnm-output] Minimum unique abbreviations are acceptable. Descriptionpnmcomp reads two images and produces a composite image with one of the images overlayed on top of the other. The images need not be the same size. The…
pnmcolormap – create quantization color map for a portable anymap Synopsispnmcolormap [-center|-meancolor|-meanpixel] [-spreadbrightness|-spreadluminosity] [-sort] [-square] ncolors|all [pnmfile] All options can be abbreviated to their shortest unique prefix. You may use two hyphens instead of one to designate an option. You may use either white space or an equals sign between an option name and its…
pnmcat – concatenate portable anymaps Synopsispnmcat [-white|-black] -leftright|-lr [-jtop|-jbottom] pnmfile pnmfile … pnmcat [-white|-black] -topbottom|-tb [-jleft|-jright] pnmfile pnmfile … DescriptionReads portable anymaps as input. Concatenates them either left to right or top to bottom, and produces a portable anymap as output. pamdice splits an image up into smaller ones. pnmtile concatenates a single input image…
pnmarith – perform arithmetic on two portable anymaps Synopsispnmarith -add|-subtract|-multiply|-difference|-minimum|-maximum. pnmfile1 pnmfile2 DescriptionReads two portable anymaps as input. Performs the specified arithmetic operation, and produces a portable anymap as output. The two input anymaps must be the same width and height. The arithmetic is performed between corresponding pixels in the two anymaps, as if maxval…
pnmalias – antialias a portable anyumap. Synopsispnmalias [-bgcolor color] [-fgcolor color] [-bonly] [-fonly] [-balias] [-falias] [-weight w] [pnmfile] DescriptionReads a portable anymap as input, and applies anti-aliasing to background and foreground pixels. If the input file is a portable bitmap, the output anti-aliased image is promoted to a graymap, and a message is printed informing…
pnm2ppa – convert portable anymap (PNM) images to HP’s PPA printer format. Synopsispnm2ppa [options] [ -i infile ] [ -o outfile ] DescriptionReads portable anymap (PNM) format as input. Binary PNM formats pnmraw = {ppmraw (color pixmap), pgmraw (graymap), and pbmraw (black-and-white bitmap)} are strongly preferred. Output stream can be locally processed by Hewlett-Packard’s Printing…
pngtopnm – convert a Portable Network Graphics file into portable anymap Synopsispngtopnm [-verbose] [-alpha | -mix] [-background color] [-gamma value] [-text file] [-time] [pngfile] DescriptionReads a Portable Network Graphics as input. Produces a portable anymap as output. The type of the output file depends on the input file – if it’s black & white, a…
pngtopam – convert a PNG image into a Netpbm image Synopsispngtopam [-verbose] [-alphapam | -alpha | -mix] [-background=color] [-gamma=value] [-text=filename] [-time] [-byrow] [pngfile] Minimum unique abbreviation of option is acceptable. You may use double hyphens instead of single hyphen to denote options. You may use white space in place of the equals sign to separate…
pngquant – PNG converter and lossy image compressor Synopsispngquant Aq options [ncolors] file [file … ] pngquant Aq options [ncolors] – < file > file Descriptionpngquant converts 32-bit RGBA PNGs to 8-bit (or smaller) RGBA-palette PNGs, optionally using Floyd-Steinberg dithering. The output filename is the same as the input name except that it ends in…
pngnq – quantize png images Synopsispngnq [-vfhV][-s sample_factor ][-Q dither ][-g gamma ][-e extension ][-d dir ][-n colors ][ inputfiles ] Descriptionpngnq Quantizes a 32-bit RGBA PNG image to an 8 bit RGBA palette PNG using the neuquant algorithm. The output file name is the input file name extended with "-nq8.png" or a specified extension….
PNG driver – driver to create PNG and PPM images (drivers) DescriptionThe PNG driver generates PNG and PPM images from GRASS display commands. Per default PNG files are written with this driver. It is started as ‘pseudo’ monitor (image file instead) and when stopped, all output from previously used display commands are written to the…