DICOM: DICOM Print service details, dicomprint

DICOM: DICOM Print service details, dicomprint
Background:

Yesterday, the column published a blog article about DICOM Print DICOM: Comparison and Analysis of PresentationContext negotiation in DICOM Print Service MetaSOPClass and SOPClass. The article starts from the actual situation encountered during deployment, this article analyzes the Association Negotiation in DICOM Print. It can be seen as a supplement to the previous blog post. It re-browses and sorts out the introduction to the DICOM Print Service in the DICOM3.0 standard, deep understanding of DICOM printing.

DICOM Print Service Data Stream:

The PRINT details in DICOM standards are described in appendix H in section 4th. The main concepts are as follows:
Film:In DICOM protocol, Film is collectively referred to as different Hard copies, such as photographic film and paper.
DICOM Print data streams are composedPrint Session,Print Job,Print (hard copy)Is as follows:

DICOM Print Service Relationship

The inclusion relationship diagram between objects in DICOM Print (the objects here represent a specific transaction during the DICOM Print operation, which must be different from the objects in Object-Oriented Programming) is as follows,

Print each part of the above graphPrint Job. However, data needs to be transformed before each part is transmitted to the DICOM Printer. The main process is as follows:

There are three Transformations in Modality and User Sepecific Transformations:

** 1. Modality LUT transformation
2. Mask Subtraction
3. voi lut transformation **

Modalit LUTThe conversion is to convert device-related pixel data into device-independent data;
VOI LUTTransformations are the most common and well-known, and are most often used in practical applications. Similar to the window width and window position adjustment in DICOM image processing, the function is to print the areas of interest to Film. For example, the window for setting soft tissue or bone in CT is printed separately, to facilitate doctors to observe the specified tissue.
PolarityConverts the minimum pixel value to black or white (0, or 255 ). This field (2020,0020) is used with Photometric Interpretation.
Presentation LUTThis is the window width adjustment that is often used in image display. In image display, Presentation LUT converts pixel data into device-specific, human-eye-identifiable display data (Presentation Value, namely P-Value)-soft copy; in DICOM printing middle-aged, presentation LUT uses optical density for printer printing-hard copy.

DICOM Print Service implementation

By constructing the above sections and various transformations, DICOM printing can be implemented. The overall process is roughly as follows,

In addition, the specific implementation process is also provided in part 17th of DICOM3.0, but the problems in the previous blog were encountered because the Association Negotiation section in part 17 was not detailed enough. Therefore, I will describe the DICOM Print process according to the detailed descriptions of DICOM Print in part 1 of DICOM3.0, as follows:

The figure corresponds to the previous"The relationship between various objects in DICOM Print"One-to-one correspondence. One is the relationship between abstract concepts, and the other is the relationship between DICOM printing each part of a specific application. Note the following points:

** 1) ** Basic Film Session SOP Instance the Instance object is created by the SCP server by sending N-CREATE commands to the SCU side;
** 2) ** the Basic Film Box SOP Instance object is created by the SCU end after the Basic Film Session SOP Instance is successfully created, and then the N-CREATE command is sent again, which is created by the SCP server;
** 3) ** after the Basic Film Box SOP Instance is created on the SCP end, the Basic Film Box SOP Instance is associated with the Basic Film Session SOP Instance object of its parent class, at the same time, the Image Display Format parameter in the N-CREATE request in 2) creates the corresponding Image Box SOP Instance for each Image. Therefore, there is no N-CREATE operation in the Image Box SOP Instance, because it was created together when the Basic Film Box SOP Instance was created. [For details, see DICOM3.0 Part 1 H4.2.2.1.3]
** 4) ** the SCU client can set each Image Box SOP Instance object created in 3) by using the N-SET command.
5)When 1)-4) the operation is basically completed, Basic Film Session SOP Instance object through the N-ACTION operation to create a Print Job SOP Instance object, trigger the specific Print operation, after the print operation is completed (or failed), delete it. The specific printing status is reported to the SCU side through the N-EVENT-REPORT operation during the printing process.
** 6) ** Print Job SOP Class can be regarded as a printing operation, and printer sop Instance is the specific hard copy for this printing.

By zssure@163.com
Time: 2015-04-19