Secondary Capture


Secondary Capture Images Composite Instances which are the “lowest common denominator” images available in DICOM. Whilst there is sufficient information to identify the patient, date and institution, they do not contain any scaling, or other modality information, so are effective “just pictures”. They are commonly used for:

  • Screen captures
  • Scanned request forms
  • etc.

Whilst the original secondary capture object definition was minimally defined and originally allowed a huge variety of DICOM bit-depths etc., the newer versions with defined colour spaces and bit depth are much better defined and therefore more functional.

Secondary capture objects may be created in DicomObjects by using the Import method to import from JPEG, MPEG etc.

API file import call to import external images:

COM:

DicomImage.FileImport

.NET:

For Windows standard Images like Bmp, JPEG, PNG etc. you can use the DicomImage’s constructor: DicomImage(Bitmap Bitmap)

Or you can call the DicomImage.Import method.

Please note all group and element numbers below are in Hex format.

Contents

  1. Attributes already set by DicomObjects during File Import:
  2. Attributes you need to set before writing the Image out: 2.1 Type 1 attributes 2.2 Type 2 attributes

Attributes already set by DicomObjects during File Import:

  
 (0008,0018) : SOP Instance UID
 (0020,000D) : Study Instance UID
 (0020,000E) : Series Instance UID
 (0028,0002) : Samples per Pixel
 (0028,0004) : Photometric Interpretation
 (0028,0006) : Planar Configuration
 (0028,0010) : Rows             
 (0028,0011) : Columns      
 (0028,0100) : Bits Allocated
 (0028,0101) : Bits Stored
 (0028,0102) : High Bit
 (0028,0103) : Pixel Representation
 (0028,1050) : Window Centre
 (0028,1051) : Window Width
 (7FE0,0010) : Pixel Data

Attributes you need to set before writing the Image out:

Type 1 attributes

(MUST be present and MUST have valid value):

 
(0008,0016) : SOP Class UID: 1.2.840.10008.5.1.4.1.1.7
(0008,0064) : Conversion Type: 
	DV = Digitised Video
	DI = Digital Interface
	DF = Digitised Film
	WSD = Workstation
	SD = Scanned Document
	SI = Scanned Image
	DRW = Drawing
	SYN = Synthetic Image

Type 2 attributes

(MUST be present but can have null value)

  
(0010,0010) : Patient Name
(0010,0020) : Patient ID
(0010,0030) : Patient Date of Birth
(0010,0040) : Patient Sex
(0008,0020) : Study Date
(0008,0030) : Study Time
(0008,0050) : Accession Number
(0008,0090) : Referring Physician's Name
(0020,0010) : Study ID
(0020,0011) : Series Number 
(0020,0013) : Instance Number 
(0020,0020) : Patient Orientation

See Creating Secondary Capture Image for complete sample code.

Note:

For anybody who wishes to import external images and write them out as DICOM image files, we strongly suggest you to use DVT to validate your output files before you starting to use them or send them elsewhere.