{
    "mode": "man",
    "parameter": "pambrighten",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/pambrighten/1/json",
    "generated": "2026-08-06T15:13:11Z",
    "synopsis": "pambrighten [-saturation=[+|-]saturationpercent] [-value=[+|-]valuepercent] [netpbmfile]\nMinimum  unique  abbreviation of option is acceptable.  You may use double hyphens instead of\nsingle hyphen to denote options.  You may use white space in place of the equals sign to sep‐\narate an option name from its value.",
    "sections": {
        "NAME": {
            "content": "pambrighten - change a PPM image's Saturation and Value\n\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "pambrighten [-saturation=[+|-]saturationpercent] [-value=[+|-]valuepercent] [netpbmfile]\n\nMinimum  unique  abbreviation of option is acceptable.  You may use double hyphens instead of\nsingle hyphen to denote options.  You may use white space in place of the equals sign to sep‐\narate an option name from its value.\n\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "This program is part of Netpbm(1).\n\npambrighten increases or decreases the Saturation and Value (from the  HSV  color  space)  of\neach  pixel  of  a Netpbm image.  You specify the percentage change for each of those parame‐\nters.\n\nYou can also remap the colors of the pixels so their Values cover the full range of  possible\nValues.\n\nThe  input  image  is  from the file named netpbmfile, or Standard Input if netpbmfile is not\nspecified.\n\n\nThe output format is the same as the input format and any  extra  channels,  such  as  trans‐\nparency, are passed through.\n\n\nHue-Saturation-Value,  or HSV, is one way to represent a color, like the more well-known RGB.\nHue, Saturation, and Value are numbers in the range from 0 to 1.  We always  capitalize  them\nin  this  document when we mean the number from the HSV color space, especially since \"value\"\nas a conventional English word has a much more abstract meaning.\n\nValue is a measure of how bright the color is, relative to some specified maximum (the Netpbm\nformats are also defined in terms of a specified maximum brightness -- For  the  purposes  of\nthis  program, they are the same).  In particular, it is the brightness of the brightest pri‐\nmary color component of the color divided by the maximum brightness possible for a component.\nZero Value means black.  White has full Value.\n\nHue is an indication of the secondary color with the same brightness that  most  closely  ap‐\nproximates  the color.  A secondary color is made of a combination of at most two of the pri‐\nmary colors.\n\nSaturation is a measure of how close the color is to the  color  indicated  by  the  Hue  and\nValue.   A  lower number means more light of the third primary color must be added to get the\nexact color.  Full Saturation means the color is a secondary color.   Zero  Saturation  means\nthe color is gray (or black or white).  Decreasing the saturation of a color tends to make it\nwashed out.\n\nIf  it  is  impossible  to  increase the Value of a pixel by the amount you specify (e.g. the\nValue is .5 and you specify +200%), pambrighten increases it to full Value instead.\n\nIf it is impossible to increase the Saturation of a pixel by the amount you specify (e.g.  it\nis already half saturated and you specify +200%), pambrighten increases it to full Saturation\ninstead.\n\nFor  a  simpler  kind  of brightening, you can use pamfunc -multiplier simply to increase the\nbrightness of each pixel by a specified percentage, clipping each  RGB  component  where  the\ncalculated  brightness would exceed full brightness.  Thus, the brightest colors in the image\nwould change chromaticity in addition to not getting the specified brightness boost.  For de‐\ncreasing brightness, pamfunc should do the same thing as pambrighten.\n\nppmflash does another kind of brightening.  It changes the color of each pixel to bring it  a\nspecified percentage closer to white.  This increases the value and saturation.\n\npambrighten  is  meant to replace ppmbrighten.  It is the same as ppmbrighten, except that it\nrecognizes the various Netpbm image formats rather than treating them all as PPM.  The output\nformat is the same as the input format and extra channels in a PAM image (such  as  a  trans‐\nparency channel) get passed through.\n\nIf you want to modify the hues in the image, use pamhue.\n\n\n",
            "subsections": []
        },
        "EXAMPLES": {
            "content": "To double the Value of each pixel:\npambrighten -value=100\n\n\nTo double the Saturation and halve the Value of each pixel:\npambrighten -saturation=+100 -value=-50\n\n\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "In  addition  to  the options common to all programs based on libnetpbm (most notably -quiet,\nsee \u001b]8;;index.html#commonoptions\u001b\\ Common Options\u001b]8;;\u001b\\ ), pambrighten recognizes the following command line options:\n\n\n",
            "subsections": [
                {
                    "name": "-value=_",
                    "content": "This option specifies the amount, as a percentage, by which you want to  increase  the\nValue of each pixel.  It may be negative.\n\nThe default is zero.\n\n"
                },
                {
                    "name": "-saturation=_",
                    "content": "This  option  specifies the amount, as a percentage, by which you want to increase the\nSaturation of each pixel.  It may be negative.\n\nThe default is zero.\n\n\n\n"
                }
            ]
        },
        "SEE ALSO": {
            "content": "pnmnorm(1),  ppmdim(1),  pamfunc(1),  ppmflash(1),  pamaltsat(1),  pamdepth(1),  pnmgamma(1),\npamhue(1), ppmhist(1), ppm(1)\n\n",
            "subsections": []
        },
        "HISTORY": {
            "content": "pambrighten  was new in Netphm 10.86 (March 2019).  It was a PAM conversion of the much older\nppmbrighten.\n\n\n",
            "subsections": []
        },
        "AUTHOR": {
            "content": "Copyright (C) 1990 by Brian Moffet.  Copyright (C) 1989 by Jef Poskanzer.\n\nPermission to use, copy, modify, and distribute this software and its documentation  for  any\npurpose and without fee is hereby granted, provided that the above copyright notice appear in\nall  copies and that both that copyright notice and this permission notice appear in support‐\ning documentation.  This software is provided \"as is\" without express or implied warranty.\n",
            "subsections": []
        },
        "DOCUMENT SOURCE": {
            "content": "This manual page was generated by the Netpbm tool 'makeman' from  HTML  source.   The  master\ndocumentation is at\n\nhttp://netpbm.sourceforge.net/doc/pambrighten.html\n\nnetpbm documentation                       18 August 2020                 Pambrighten User Manual(1)",
            "subsections": []
        }
    },
    "summary": "pambrighten - change a PPM image's Saturation and Value",
    "flags": [
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "This option specifies the amount, as a percentage, by which you want to increase the Value of each pixel. It may be negative. The default is zero."
        },
        {
            "flag": "",
            "long": null,
            "arg": null,
            "description": "This option specifies the amount, as a percentage, by which you want to increase the Saturation of each pixel. It may be negative. The default is zero."
        }
    ],
    "examples": [
        "To double the Value of each pixel:",
        "pambrighten -value=100",
        "To double the Saturation and halve the Value of each pixel:",
        "pambrighten -saturation=+100 -value=-50"
    ],
    "see_also": [
        {
            "name": "pnmnorm",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pnmnorm/1/json"
        },
        {
            "name": "ppmdim",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/ppmdim/1/json"
        },
        {
            "name": "pamfunc",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pamfunc/1/json"
        },
        {
            "name": "ppmflash",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/ppmflash/1/json"
        },
        {
            "name": "pamaltsat",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pamaltsat/1/json"
        },
        {
            "name": "pamdepth",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pamdepth/1/json"
        },
        {
            "name": "pnmgamma",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pnmgamma/1/json"
        },
        {
            "name": "pamhue",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/pamhue/1/json"
        },
        {
            "name": "ppmhist",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/ppmhist/1/json"
        },
        {
            "name": "ppm",
            "section": "1",
            "url": "https://www.chedong.com/phpMan.php/man/ppm/1/json"
        }
    ],
    "tldr": {
        "source": "official",
        "description": "Change a PAM image's saturation and value.",
        "examples": [
            {
                "description": "Increase the saturation of each pixel by the specified percentage",
                "command": "pambrighten {{-s|-saturation}} {{value_percent}} {{path/to/image.pam}} > {{path/to/output.pam}}"
            },
            {
                "description": "Increase the value (from the HSV color space) of each pixel by the specified percentage",
                "command": "pambrighten {{-va|-value}} {{value_percent}} {{path/to/image.pam}} > {{path/to/output.pam}}"
            }
        ]
    }
}