# man > pambrighten(1) > **TLDR:** Change a PAM image's saturation and value. > - Increase the saturation of each pixel by the specified percentage: `pambrighten {{-s|-saturation}} {{value_percent}} {{path/to/image.pam}} > {{path/to/output.pam}}` - Increase the value (from the HSV color space) of each pixel by the specified percentage: `pambrighten {{-va|-value}} {{value_percent}} {{path/to/image.pam}} > {{path/to/output.pam}}` *Source: tldr-pages* --- _Pambrighten_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) General Commands Manual _Pambrighten_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) ## NAME pambrighten - change a PPM image's Saturation and Value ## SYNOPSIS **pambrighten **[**-saturation=**[**+**|**-**]_saturation_percent_] [**-value=**[**+**|**-**]_value_percent_] [_netpbmfile_] 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 sep‐ arate an option name from its value. ## DESCRIPTION This program is part of [**Netpbm**(1)](https://www.chedong.com/phpMan.php/man/Netpbm/1/markdown). **pambrighten **increases or decreases the Saturation and Value (from the HSV color space) of each pixel of a Netpbm image. You specify the percentage change for each of those parame‐ ters. You can also remap the colors of the pixels so their Values cover the full range of possible Values. The input image is from the file named _netpbmfile_, or Standard Input if _netpbmfile_ is not specified. The output format is the same as the input format and any extra channels, such as trans‐ parency, are passed through. Hue-Saturation-Value, or HSV, is one way to represent a color, like the more well-known RGB. Hue, Saturation, and Value are numbers in the range from 0 to 1. We always capitalize them in this document when we mean the number from the HSV color space, especially since "value" as a conventional English word has a much more abstract meaning. Value is a measure of how bright the color is, relative to some specified maximum (the Netpbm formats are also defined in terms of a specified maximum brightness -- For the purposes of this program, they are the same). In particular, it is the brightness of the brightest pri‐ mary color component of the color divided by the maximum brightness possible for a component. Zero Value means black. White has full Value. Hue is an indication of the secondary color with the same brightness that most closely ap‐ proximates the color. A secondary color is made of a combination of at most two of the pri‐ mary colors. Saturation is a measure of how close the color is to the color indicated by the Hue and Value. A lower number means more light of the third primary color must be added to get the exact color. Full Saturation means the color is a secondary color. Zero Saturation means the color is gray (or black or white). Decreasing the saturation of a color tends to make it washed out. If it is impossible to increase the Value of a pixel by the amount you specify (e.g. the Value is .5 and you specify +200%), **pambrighten **increases it to full Value instead. If it is impossible to increase the Saturation of a pixel by the amount you specify (e.g. it is already half saturated and you specify +200%), **pambrighten **increases it to full Saturation instead. For a simpler kind of brightening, you can use **pamfunc -multiplier **simply to increase the brightness of each pixel by a specified percentage, clipping each RGB component where the calculated brightness would exceed full brightness. Thus, the brightest colors in the image would change chromaticity in addition to not getting the specified brightness boost. For _de‐_ _creasing_ brightness, **pamfunc **should do the same thing as **pambrighten**. **ppmflash **does another kind of brightening. It changes the color of each pixel to bring it a specified percentage closer to white. This increases the value and saturation. **pambrighten **is meant to replace **ppmbrighten**. It is the same as **ppmbrighten**, except that it recognizes the various Netpbm image formats rather than treating them all as PPM. The output format is the same as the input format and extra channels in a PAM image (such as a trans‐ parency channel) get passed through. If you want to modify the hues in the image, use **pamhue**. ## 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 ## OPTIONS In addition to the options common to all programs based on libnetpbm (most notably **-quiet**, see ]8;;index.html#commonoptions\ Common Options]8;;\ ), **pambrighten **recognizes the following command line options: ### -value=_ 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. ### -saturation=_ 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. ## SEE ALSO [**pnmnorm**(1)](https://www.chedong.com/phpMan.php/man/pnmnorm/1/markdown), [**ppmdim**(1)](https://www.chedong.com/phpMan.php/man/ppmdim/1/markdown), [**pamfunc**(1)](https://www.chedong.com/phpMan.php/man/pamfunc/1/markdown), [**ppmflash**(1)](https://www.chedong.com/phpMan.php/man/ppmflash/1/markdown), [**pamaltsat**(1)](https://www.chedong.com/phpMan.php/man/pamaltsat/1/markdown), [**pamdepth**(1)](https://www.chedong.com/phpMan.php/man/pamdepth/1/markdown), [**pnmgamma**(1)](https://www.chedong.com/phpMan.php/man/pnmgamma/1/markdown), [**pamhue**(1)](https://www.chedong.com/phpMan.php/man/pamhue/1/markdown), [**ppmhist**(1)](https://www.chedong.com/phpMan.php/man/ppmhist/1/markdown), [**ppm**(1)](https://www.chedong.com/phpMan.php/man/ppm/1/markdown) ## HISTORY **pambrighten **was new in Netphm 10.86 (March 2019). It was a PAM conversion of the much older **ppmbrighten**. ## AUTHOR Copyright (C) 1990 by Brian Moffet. Copyright (C) 1989 by Jef Poskanzer. Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in support‐ ing documentation. This software is provided "as is" without express or implied warranty. ## DOCUMENT SOURCE This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at **** netpbm documentation 18 August 2020 _Pambrighten_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown)