# DICOM Standard Browser

Built with by Innolitics, a team of medical imaging software developers.

Data synced with official DICOM standard on 18 April 2024. The DICOM Standard is under continuous maintenance, and the current official version is available at http://www.dicomstandard.org/current/. DICOM Parts 3, 4, and 6, © NEMA. Please note that the most recent PDF version of the standard is the official reference, and should checked when making technical decisions.

## Table of Y Break Points Attribute

Tag (0018,6054) Conditionally Required (1C) TableOfYBreakPoints 1-n Double (FD)

An array of Y values used to create the piece wise linear curve.

Required if Pixel Component Organization equals 0 or 1. Otherwise not used.

See Section C.8.5.5.1.9 for further explanation.

## Section C.8.5.5.1.9

###### C.8.5.5.1.9 Table of X Break Points and Table of Y Break Points

Table of X Break Points (0018,6052) and Table of Y Break Points (0018,6054) are individual arrays of coordinates that interpreted together are used to create a piecewise linear curve. Each X value from the Table of X Break Points is matched with the corresponding Y value from the Table of Y Break Points yielding an (X,Y) coordinate. The set of (X,Y) coordinates describes a piecewise linear curve mapping the value of a pixel component to its actual physical value (in units defined in Pixel Component Physical Units (0018,604C)).

The X direction on the curve has no units, and represents actual pixel component values. If the Pixel Component Organization (0018,6044) is "Bit aligned positions", and the width of the Pixel Component Mask is n bits then the X coordinates are in the range 0 through 2n-1. If the Pixel Component Organization is Ranges, then the X coordinates are in the range 0 through 2 number of bits in the composite pixel- 1.

### Note

The X value is NOT relative to the Pixel Component Range Start (0018,6048). Not all possible X values in the range need be covered by the curve.

For any pixel component value in the range of the curve described by this table, the corresponding Y value is the actual physical value for that pixel, in units specified in Pixel Component Physical Units (0018,604C). If the pixel component value is NOT within the range of specified X values for the curve, then no pixel calibration is defined by this region. It may be possible for pixel calibration to be defined by other spatial regions intersecting this one.