---
name: "dchist"
section: "1"
platform: "linux"
package: "dicom3tools"
version: "1.00~20240118131615-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/dchist"
---

# dchist(1)

ACR/NEMA DICOM PS3 ... DICOM PS3 - DICOM image statistics

## NAME

dchist - ACR/NEMA DICOM PS3 ... DICOM PS3 - DICOM image statistics

## SYNOPSIS

**dchist** \[ **-h\|histogram** \] \[ **-csv** \] \[ **-withhighbits\|highbitsonly** \] \[ **-v\|verbose** \] \[ **-filename** \]

## DESCRIPTION

**dchist** reads the named dicom or acr-nema input file and describes the statistics of the image pixel data. The primary intent is to determine the zero order entropy of the image.

The description and verbose output go to standard error.

The basic input switches are described in [dcintro(1)](/dcintro/1.md). Options specific to this program are:

- **-h\|histogram**

  Display table of pixel value, frequency, probability, contribution to zero order entropy, and cumulative zero order entropy. May generate a LOT of output !

- **-csv**

  Display only a comma separated value pair of pixel value and frequency, one line per value, e.g., for import into a statistical program or spreadsheet

- **-withhighbits**

  Include as well the values that are above Bits Stored and within Bits Allocated, such as might be overlay bits (regardless of whether or not there are any 60xx group elements).

- **-highbitsonly**

  Use instead the values that are above Bits Stored and within Bits Allocated, such as might be overlay bits, and treat all valid pixel values below Bits Stored inclusive as zero (regardless of whether or not there are any 60xx group elements).

- **-v\|verbose**

  Display byte offset from file start and message start, in hexadecimal, and dump contents while reading and once read.

- **-filename**

  Show the name of the file supplied in the arguments; a hyphen will be reported if no filename was supplied.

## ENVIRONMENT

## EXAMPLES

% dchist expmeta.dc3

9\.02366 Zero order entropy (bits per pixel)

0x0     Smallest symbol value

0       Smallest symbol length (bits)

0x6e9   Largest symbol value

11      Largest symbol length (bits)

% dchist -h expmeta.dc3

\[0x0\]   392 p=0.00598145  e=0.0441747   cum=0.0441747

 ...

\[0x6e9\] 1   p=1.52588e-05 e=0.000244141 cum=9.02366

9\.02366 Zero order entropy (bits per pixel)

0x0     Smallest symbol value

0       Smallest symbol length (bits)

0x6e9   Largest symbol value

11      Largest symbol length (bits)

## FILES

## SEE ALSO

**[dcstats(1)](/dcstats/1.md)**, **[dcintro(1)](/dcintro/1.md)**

## AUTHOR

Copyright (c) 1993-2022, David A. Clunie DBA PixelMed Publishing. All rights reserved.

## BUGS