Crate gdcm_conv[−][src]
Expand description
An easy-to-use Grassroots DICOM Library wrapper designed to convert DICOM files transfer syntaxes and photometric interpretation.
Usage
You need CMake to build GDCM Library.
Linux Ubuntu:
sudo apt-get install cmake
Windows & MacOS:
Download CMake directly from www.cmake.org/download page.
Quickstart
Copy this code and make sure you have a DICOM file to test (DICOM file samples).
use std::io::prelude::*; use std::fs::File; use gdcm_conv::{TransferSyntax, PhotometricInterpretation}; // Read input file let mut ibuffer = Vec::new(); let mut ifile = File::open("test.dcm").unwrap(); ifile.read_to_end(&mut ibuffer).unwrap(); // Transcode DICOM file let obuffer = match gdcm_conv::pipeline( // Input DICOM file buffer ibuffer, // Estimated Length None, // First Transfer Syntax conversion TransferSyntax::JPEG2000Lossless, // Photometric conversion PhotometricInterpretation::None, // Second Transfer Syntax conversion TransferSyntax::None, ) { Ok(t) => t, Err(e) => { eprintln!("{}", e); return; } }; // Create output file and save let mut ofile = File::create("output.dcm").unwrap(); ofile.write_all(&obuffer).unwrap();
How it works
The gdcm_conv library takes as input the content of the DICOM file. It reuse the source vector allocating an estimated size to avoid cloned memory. The default estimad length is 3 times the input file size, the worst case, changing from a compressed image (like JPEG2000) to raw. Is recommended to use an estimated calculation, to minimize memory allocation.
If the allocated size is not enough, the library will re-allocate to the correct size and execute the FFI function again.
To estimate the output length you could use this aproximation:
- (0028,0100) bits_allocated
- (0028,0004) photometric_interpretation
- (0028,0008) number_of_frames
- (0028,0010) rows
- (0028,0011) columns
// MAX HEADER SIZE const MAX_HEADER_SIZE: usize = 5000; let a = match bits_allocated { 8 => 1, 16 => 2, }; let b = match photometric_interpretation { "MONOCHROME1" => 1, "MONOCHROME2" => 1, _ => 3, }; let estimad_length = (a * b * rows * columns * number_of_frames) + MAX_HEADER_SIZE;
The library works as a pipeline with a first transfer syntax conversion (PRE-TRANSFER), a photometric conversion and a final transfer syntax conversion (POST-TRANSFER). If you set to None it don’t execute the step. Usually, you will use only the first and/or second step.
I setup this way because in some cases is needed two transfer syntax transcoding like this example:
The conversion from JPEG Baseline (Process 1) 1.2.840.10008.1.2.4.50 with YBR_FULL or YBR_FULL_422 to JPEG2000 lossles, you need to change to Explicit Little Endian transfer syntax, then to an RGB photometric interpretation and finally to JPG2000, to avoid GDCM color interpretation issue.