# 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.

## Filter Lookup Table Data Attribute

Tag (003A,032E) Required (1) FilterLookupTableData 1 Other Double String (OD)

Lookup Table Data.

See Section C.10.13.1 for further explanation.

## Section C.10.13.1

#### C.10.13.1 Lookup Table Data

Lookup Table Data consist of n triplets of double values: the first value is the input frequency. The second value is the magnitude. The third value is the phase shift of the signal resulting from filtering.

The input frequency values in the Lookup Table shall cover all frequencies from 0 to ½ of the sampling frequency. For input frequencies between two values in the Lookup Table an interpolation between the neighboring values can take place.

Frequency Encoding Code Sequence (003A,032C) defines the encoding of the first value, which could be:

• frequency given in Hz

• frequency given in radians per second

• normalized frequency, which is frequency in Hz divided by ½ of the sampling rate

• or angular frequency, which is frequency in Hz divided by ½ of the sampling rate and then multiplied by π (pi).

Magnitude Encoding Code Sequence (003A,032D) defines the encoding of the second value, which could be:

• dB microvolts, dB millivolts

• normalized magnitude

• absolute magnitude in millivolt or microvolt.

Normalized magnitude is (ω - |H(ω)|)/ ωmax, which is the input signal amplitude minus the filter output signal amplitude both divided by the maximum input signal amplitude, and has a value between 0-1; (no units, because it is the ratio of input and output amplitudes).

The phase shift is given in degrees.