Figure 5.

Retrieving pixel data from DICOM data sets stored in PS3.10 files on disk. (a) Sequence of steps required for loading an individual frame of a multiframe DICOM image from a file on disk into a pixel matrix in memory. First, the file that contains the frame of interest is identified by reading and interpreting metadata (“DICOM header”) of each file. Second, the relative position of the frame within the image is identified using the available metadata. Third, the absolute position of the frame is determined within the encapsulated pixel data element. Fourth, the binary content of the frame item is read into memory. Lastly, the pixel data are decompressed. (b) Software library support for reading images from DICOM files. Selected software libraries available for the Python programming language and their level of support for reading multiframe DICOM images. Only a subset of libraries provides the functionality (check icon) for selectively loading an individual frame into memory. (c) Frame access efficiency for different image compression methods. Shown is the average time (±standard deviation) it takes to identify, read, and decompress an individual frame of a multi-frame DICOM image using an implementation of the algorithm (shown in a) in the pydicom software library