# phpman > man > pgmbentley(1)

> **TLDR:** Bentleyize a PGM image.
>
- Apply the Bentley Effect on a PGM image:
  `pgmbentley {{path/to/input_file.pgm}} > {{path/to/output_file.pgm}}`

*Source: tldr-pages*

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[pgmbentley(1)](https://www.chedong.com/phpMan.php/man/pgmbentley/1/markdown)                          General Commands Manual                         [pgmbentley(1)](https://www.chedong.com/phpMan.php/man/pgmbentley/1/markdown)



## NAME
       pgmbentley - Bentleyize a portable graymap

## SYNOPSIS
       **pgmbentley** [_pgmfile_]

## DESCRIPTION
       Reads  a  portable  graymap  as  input.   Performs  The Bentley Effect, and writes a portable
       graymap as output.

       The Bentley Effect is described in "Beyond Photography" by  Holzmann,  chapter  4,  photo  4.
       It's a vertical smearing based on brightness.

## SEE ALSO
       [pgmoil(1)](https://www.chedong.com/phpMan.php/man/pgmoil/1/markdown), [ppmrelief(1)](https://www.chedong.com/phpMan.php/man/ppmrelief/1/markdown), [pgm(5)](https://www.chedong.com/phpMan.php/man/pgm/5/markdown)

## AUTHOR
       Copyright (C) 1990 by Wilson Bent (<whb@hoh-2.att.com>)



                                           11 January 1991                             [pgmbentley(1)](https://www.chedong.com/phpMan.php/man/pgmbentley/1/markdown)