Print Management Service Examples

The DICOM Print Management service facilitates print of images and image related data. There are two Basic Print Management Meta SOP Classes which correspond with the minimum functionality that an implementation of the Print Management service class shall support (i.e at a minimum one of the two Meta SOP Classes must be supported):

• Basic Grayscale Print Management Meta SOP Class which is defined by support of

  • Basic Film Session SOP Class

  • Basic Film Box SOP Class

  • Basic Greyscale Image Box SOP Class

  • Printer SOP Class.

• Basic Color Print Management Meta SOP Class which is defined by support of

  • Basic Film Session SOP Class

  • Basic Film Box SOP Class

  • Basic Color Image Box SOP Class

  • Printer SOP Class.

Which utilise the following SOP Classes:

• Basic Film Session SOP Class, used with N-CREATE, N-SET, N-DELETE and N-ACTION to describe the presentation parameters that are common for all the films of a film session (e.g. all films to be printed)

• Basic Film Box SOP Class used with N-CREATE, N-ACTION, N-DELETE and N-SET to describe the presentation parameters that are common for all images on a given sheet of film (e.g. for a single film).

• Basic Greyscale Image Box SOP Class used with N-SET to describe the presentation of an image and image related data in the image area of a film.

• Basic Colour Image Box SOP Class used with N-SET to describe the presentation of an image and image related data in the image area of a film.

• Printer SOP Class used with N-EVENT-REPORT and N-GET to monitor the status of the printer.

There are also the following SOP Classes that are not included under the Meta Print Management SOP Classes and which may optionally be supported:

• Basic Annotation Box SOP Class used with N-SET to describe the presentation of an annotation on a film.

• Print Job SOP Class used with N-EVENT-REPORT and N-GET to monitor the execution of the print process. Receiving N-EVENT-REPORT requests from the SCP when acting as an SCU is not supported and any such requests will automatically be responded to with a 0x0000 - Success status.

• Printer Configuration Retrieval SOP Class used with N-GET to retrieve key imaging characteristics of the printer.

• Presentation LUT SOP Class used with N-CREATE and N-DELETE to prepare image pixel data for display on devices that conform to the Grayscale Standard Display Function defined in Part 14 of the DICOM Standard.

Grayscale Print SCU

Overview

Over a single association:

1. Send an N-GET request to check the status of the printer.

2. Send an N-CREATE request to create a Basic Film Session SOP Class Instance.

3. Send an N-CREATE request to create a Basic Film Box SOP Class Instance within the Film Session. The SCP will also create one or more of the appropriate Image Box SOP Class Instances (Basic Grayscale or Basic Color) depending on the Meta SOP Class used to create the Film Session.

4. For each of the Image Box SOP Class Instances use N-SET to update its attributes with the image data and image attributes that are to be printed.

5. Use N-ACTION to command the Film Box to be printed or N-DELETE to delete the Film Box.

6. Repeat steps 1-5 as required.

7. Terminate the association to delete the Film Session hierarchy.

A Print SCP may send N-EVENT-REPORT service requests to the Print SCU (under the Printer SOP Class) using one of the following methods, depending on the implementation (check the conformance statement):

1. Over the same association as the Print SCU service request

2. Over a new association initiated by the Print SCP, which requires the SCP be configured with the details of the SCU

3. The next time the SCU associates with the SCP

Depending on which method the Print SCP uses you should:

• For methods 1 and 2, simply bind a handler to evt.EVT_N_REPORT when calling AE.associate()

• For method 3, start an AssociationServer instance with AE.start_server((addr, port), block=False) with a handler bound to evt.EVT_N_EVENT_REPORT

To support minimal conformance for a Print SCU you can just use the handler to return a status of 0x0000 and get the printer’s current status manually by sending an N-GET request.

DIMSE Services Available

DIMSE-N Service	Usage SCU/SCP
Basic Film Session SOP Class
N-CREATE	Mandatory/Mandatory
N-SET	Optional/Mandatory
N-DELETE	Optional/Mandatory
N-ACTION	Optional/Optional
Basic Film Box SOP Class
N-CREATE	Mandatory/Mandatory
N-ACTION	Mandatory/Mandatory
N-DELETE	Optional/Mandatory
N-SET	Optional/Optional
Basic Grayscale Image Box SOP Class
N-SET	Mandatory/Mandatory
Printer SOP Class
N-EVENT-REPORT	Mandatory/Mandatory
N-GET	Optional/Mandatory

Example

Print the image data from a SOP Instance onto a single A4 page. For a real-life Print SCP you would need to check its conformance statement to see what print options (medium types, page sizes, layouts, etc) are supported. This example assumes that the Film Session’s and Film Box’s N-CREATE responses include conformant Basic Film Session SOP Class and Basic Film Box SOP Class instances (which may not always be the case).

We also assume that the Print SCP sends the Printer SOP Class’ N-EVENT-REPORT notifications over the same association (and ignore them).

import sys

from pydicom import dcmread
from pydicom.dataset import Dataset
from pydicom.uid import generate_uid

from pynetdicom import AE, evt, debug_logger
from pynetdicom.sop_class import (
    BasicGrayscalePrintManagementMeta,
    BasicFilmSession,
    BasicFilmBox,
    BasicGrayscaleImageBox,
    Printer,
    PrinterInstance
)

debug_logger()

# The SOP Instance containing the grayscale image data to be printed
DATASET = dcmread('path/to/file.dcm')


def build_session():
    """Return an N-CREATE *Attribute List* for creating a Basic Film Session

    Returns
    -------
    pydicom.dataset.Dataset
        An N-CREATE *Attribute List* dataset that can be used to create a
        *Basic Film Session SOP Class* instance.
    """
    attr_list = Dataset()
    attr_list.NumberOfCopies = '1'  # IS
    attr_list.PrintPriority = 'LOW'  # CS
    attr_list.MediumType = 'PAPER'  # CS
    attr_list.FilmDestination = 'SOMEWHERE'  # CS
    attr_list.FilmSessionLabel = 'TEST JOB'  # LO
    attr_list.MemoryAllocation = ''  # IS
    attr_list.OwnerID = 'PYNETDICOM'  # SH

    return attr_list


def build_film_box(session):
    """Return an N-CREATE *Attribute List* for creating a Basic Film Box.

    In this example we just have a single Image Box.

    Parameters
    ----------
    session : pydicom.dataset.Dataset
        The *Basic Film Session SOP Class* instance returned by SCP in
        response to the N-CREATE request that created it.

    Returns
    -------
    pydicom.dataset.Dataset
        An N-CREATE *Attribute List* dataset that can be used to create a
        *Basic Film Box SOP Class* instance.
    """
    # The "film" consists of a single Image Box
    attr_list = Dataset()
    attr_list.ImageDisplayFormat = 'STANDARD\1,1'
    attr_list.FilmOrientation = 'PORTRAIT'
    attr_list.FilmSizeID = 'A4'

    # Can only contain a single item, is a reference to the *Film Session*
    attr_list.ReferencedFilmSessionSequence = [Dataset()]
    item = attr_list.ReferencedFilmSessionSequence[0]
    item.ReferencedSOPClassUID = session.SOPClassUID
    item.ReferencedSOPInstanceUID = session.SOPInstanceUID

    return attr_list


def build_image_box(im):
    """Return an N-SET *Attribute List* for updating a Basic Grayscale Image Box

    Parameters
    ----------
    im : pydicom.dataset.Dataset
        The SOP Instance containing the pixel data that is to be printed.

    Returns
    -------
    pydicom.dataset.Dataset
        An N-SET *Attribute List* dataset that can be used to update the
        *Basic Grayscale Image Box SOP Class* instance.
    """
    attr_list = Dataset()
    attr_list.ImageBoxPosition = 1  # US

    # Zero or one item only
    attr_list.ReferencedImageBoxSequence = [Dataset()]
    item = attr_list.ReferencedImageBoxSequence[0]
    item.SamplesPerPixel = im.SamplesPerPixel
    item.PhotometricInterpretation = im.PhotometricInterpretation
    item.Rows = im.Rows
    item.Columns = im.Columns
    item.BitsAllocated = im.BitsAllocated
    item.BitsStored = im.BitsStored
    item.HighBit = im.HighBit
    item.PixelRepresentation = im.PixelRepresentation
    item.PixelData = im.PixelData

    return attr_list

def handle_n_er(event):
    """Ignore the N-EVENT-REPORT notification"""
    return 0x0000

handlers = [(evt.EVT_N_EVENT_REPORT, handle_n_er)]

ae = AE()
ae.add_requested_context(BasicGrayscalePrintManagementMeta)
assoc = ae.associate("127.0.0.1", 11112, evt_handlers=handlers)

if assoc.is_established:
    # Step 1: Check the status of the printer
    # (2110,0010) Printer Status
    # (2110,0020) Printer Status Info
    # Because the association was negotiated using a presentation context
    #   with a Meta SOP Class we need to use the `meta_uid` keyword
    #   parameter to ensure we use the correct context
    status, attr_list = assoc.send_n_get(
        [0x21100010, 0x21100020],  # Attribute Identifier List
        Printer,  # Affected SOP Class UID
        PrinterInstance,  # Well-known Printer SOP Instance
        meta_uid=BasicGrayscalePrintManagementMeta
    )
    if status and status.Status == 0x0000:
        if getattr(attr_list, 'PrinterStatus', None) != "NORMAL":
            print("Printer status is not 'NORMAL'")
            assoc.release()
            sys.exit()
        else:
            print("Failed to get the printer status")
            assoc.release()
            sys.exit()
    else:
        print("Failed to get the printer status")
        assoc.release()
        sys.exit()

    print('Printer ready')

    # Step 2: Create *Film Session* instance
    status, film_session = assoc.send_n_create(
        build_session(),  # Attribute List
        BasicFilmSession,  # Affected SOP Class UID
        generate_uid(),  # Affected SOP Instance UID
        meta_uid=BasicGrayscalePrintManagementMeta
    )

    if not status or status.Status != 0x0000:
        print('Creation of Film Session failed, releasing association')
        assoc.release()
        sys.exit()

    print('Film Session created')

    # Step 3: Create *Film Box* and *Image Box(es)*
    status, film_box = assoc.send_n_create(
        build_film_box(film_session),
        BasicFilmBox,
        generate_uid(),
        meta_uid=BasicGrayscalePrintManagementMeta
    )
    if not status or status.Status != 0x0000:
        print('Creation of the Film Box failed, releasing association')
        assoc.release()
        sys.exit()

    print('Film Box created')

    # Step 4: Update the *Image Box* with the image data
    # In this example we only have one *Image Box* per *Film Box*
    # Get the Image Box's SOP Class and SOP Instance UIDs
    item = film_box.ReferencedImageBoxSequence[0]
    status, image_box = assoc.send_n_set(
        build_image_box(DATASET),
        item.ReferencedSOPClassUID,
        item.ReferencedSOPInstanceUID,
        meta_uid=BasicGrayscalePrintManagementMeta
    )
    if not status or status.Status != 0x0000:
        print('Updating the Image Box failed, releasing association')
        assoc.release()
        sys.exit()

    print('Updated the Image Box with the image data')

    # Step 5: Print the *Film Box*
    status, action_reply = assoc.send_n_action(
        None,  # No *Action Information* needed
        1,  # Print the Film Box
        film_box.SOPClassUID,
        film_box.SOPInstanceUID,
        meta_uid=BasicGrayscalePrintManagementMeta
    )
    if not status or status.Status != 0x0000:
        print('Printing the Film Box failed, releasing association')
        assoc.release()
        sys.exit()

    # The actual printing may occur after association release/abort
    print('Print command sent successfully')

    # Optional - Delete the Film Box
    status = assoc.send_n_delete(
        film_box.SOPClassUID,
        film_box.SOPInstanceUID
    )

    # Release the association
    assoc.release()