# man > pamsumm(1) _Pamsumm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) General Commands Manual _Pamsumm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown) ## NAME pamsumm - Summarize the samples in a Netpbm image arithmetically ## SYNOPSIS **pamsumm **{ **-sum **| **-mean **| **-min **| **-max **} [**-normalize**] [**-brief**] [_imagefile_] All options can be abbreviated to their shortest unique prefix. You may use two hyphens in‐ stead of one. You may separate an option name and its value with white space instead of an equals sign. ## DESCRIPTION This program is part of [**Netpbm**(1)](https://www.chedong.com/phpMan.php/man/Netpbm/1/markdown). **pamsumm **reads a Netpbm image (PNM or PAM) and performs a summary function over all the sam‐ ples in all the rows, columns, and planes and prints the result to Standard Output. **pamsumm **performs the operation on the actual sample values. In the case of a PGM or PPM or PAM equivalent (i.e. a visual image), this is not the same as the light intensities repre‐ sented by those samples. See the format specifications of [**PGM**(1)](https://www.chedong.com/phpMan.php/man/PGM/1/markdown), [**PPM**(1)](https://www.chedong.com/phpMan.php/man/PPM/1/markdown), and [**PAM**(1)](https://www.chedong.com/phpMan.php/man/PAM/1/markdown), for the precise meanings of samples in these formats. If you want to do arithmetic on light in‐ tensities of such a visual image, you can use **pnmgamma **to convert it to one with samples pro‐ portional to light intensity, and then use **pamsumm **on the result. If you want to summarize by column (e.g. add up the columns separately), use **pamsummcol**. If you want to summarize by row, use a combination of **pamsummcol **and **pamflip**. If you want to summarize a particular plane, use **pamchannel **to extract it and then **pamsumm**. ## OPTIONS In addition to the options common to all programs based on libnetpbm (most notably **-quiet**, see ]8;;index.html#commonoptions\ Common Options]8;;\ ), **pamsumm **recognizes the following command line options: You must specify exactly one of **-sum**, **-mean**, **-min**, or **-max**. ### -sum This option makes the summary function addition. ### -mean This option makes the summary function arithmetic mean. ### -min This option makes the summary function arithmetic minimum. ### -max This option makes the summary function arithmetic maximum. ### -normalize This option causes each sample to be normalized to a fraction (in the range 0..1) so the result is independent of the image's maxval. E.g. if you request the mean of an image which has maxval 200 and all the samples have value 50, **pamsumm **will give you 50 as an answer. But **pamsumm -normalize **will give you .25. If instead you want a result that is independent of maxval but still in integers, you can use **pamdepth **to convert the input to some standard maxval and not use **-normalize**. For example, if you want the mean brightness of a PPM image, on a scale of 0 to 99, do pamdepth 99 myimage.ppm | pamsumm -mean This option was new in Netpbm 10.22 (April 2004) ### -brief This option causes **pamsumm **to display the answer as a bare number, rather than in a complete sentence. This option was new in Netpbm 10.22 (April 2004) ## SEE ALSO [**pamsummcol**(1)](https://www.chedong.com/phpMan.php/man/pamsummcol/1/markdown), [**pam**(1)](https://www.chedong.com/phpMan.php/man/pam/1/markdown), ## HISTORY **pamsumm **was added to Netpbm in Release 10.21 (March 2004). ## DOCUMENT SOURCE This manual page was generated by the Netpbm tool 'makeman' from HTML source. The master documentation is at **** netpbm documentation 26 October 2012 _Pamsumm_ _User_ [_Manual_(1)](https://www.chedong.com/phpMan.php/man/Manual/1/markdown)