---
name: "percentblack"
section: "1"
platform: "linux"
package: "printbill"
version: "4.1.2-1"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/percentblack"
---

# percentblack(1)

how much coverage is there in a given 8-bit grayscale PNG image.

## NAME

percentblack - how much coverage is there in a given 8-bit grayscale PNG image.

## SYNOPSIS

**percentblack** *filename.png*

## DESCRIPTION

**percentblack** prints a percentage coverage for a given PNG image, to three decimal places. **filename.png** must be 8-bit grayscale, such as is generated by GhostScript's pnggray device. Pixels which are gray make an appropriately scaled contribution to the total percentage.

## EXAMPLE

**percentblack** *filename.png*

yields

	4\.462

indicating that 4.462% of the page is covered in black.

## REQUIREMENTS

**percentblack** only requires libpng to be present on the system.

## INSTALLATION

Please see the accompanying README and INSTALL files for installation instructions. Chances are if you're reading this it's correctly installed.

## AUTHORS

**printbill and the accompanying utilities were written by Daniel** Franklin (d.franklin@ieee.org). The web interface was written by Phil Ciufo (phil@snrc.uow.edu.au).

## AVAILABILITY

You can always grab the latest and greatest version from **http://ieee.uow.edu.au/~daniel/software/printbill**

## SEE ALSO

*[printbill(1)](/printbill/1.md),* *[printbill(8)](/printbill/8.md),* *[printbilld(1)](/printbilld/1.md),* *[printbill\_configure(8)](/printbill_configure/8.md),* *[printbill\_grapher(1)](/printbill_grapher/1.md),* *[percentcolour(1)](/percentcolour/1.md),* *[percent\_cmy(1)](/percent_cmy/1.md),* *[pqcheck(1)](/pqcheck/1.md),* *[printquote(1)](/printquote/1.md),* *[printbill\_printer(1)](/printbill_printer/1.md),* *[printbillrc(5)](/printbillrc/5.md),* *[printcap(5)](/printcap/5.md),* *[init\_from\_passwd(8)](/init_from_passwd/8.md),* *[pqm(8)](/pqm/8.md).*