Add nvimgcodec GPU accelerated decoder to Pydicom for decoding compressed pixel data

[MMelQin]

This WIP pull request adds a custom pydicom decoder plugin using NVIDIA's nvImageCodec library to accelerate DICOM image decompression for various JPEG and JPEG2000 transfer syntaxes.

Key Changes:

• Implements a new decoder plugin in decoder_nvimgcodec.py supporting 9 DICOM transfer syntaxes (JPEG Baseline, Extended, Lossless, JPEG2000, and HTJ2K variants)
• Integrates the decoder into DICOMSeriesToVolumeOperator to automatically register the plugin during initialization
• Exposes the decoder module through the operators package interface

Special note on testing:

The approach for testing is to compare the decoded pixel values from nvImgCodec against those from the built-in decoders, be it GDCM, libjpeg or else, essentially measuring against the known good ones.

It is observed that the decoded pixels by nvImgCodec for JPEG Baseline 8 bit 1.2.840.10008.1.2.4.50 and HTJ2K 1.2.840.10008.1.2.4.203 are different from those by Pydicom default decoders. The standards allow for some differences on decoding, and assertion is not applied to results with these transfer syntax's, even with comparison tolerances.

For the lossless ones, pixels are exactly matching between nvImgCodec and the default ones (tolerances were not really needed)

See the attached file for details results.
results_PAE_MSE.md

[Copilot]

Pull Request Overview

This PR adds GPU-accelerated DICOM image decompression capabilities using NVIDIA's nvImageCodec library. The implementation creates a custom pydicom decoder plugin that supports 9 JPEG and JPEG2000 transfer syntaxes, automatically registering during the DICOMSeriesToVolumeOperator initialization.

• Implements a new decoder plugin module (decoder_nvimgcodec.py) that integrates with pydicom's pixels backend
• Automatically registers the decoder plugin when creating DICOMSeriesToVolumeOperator instances
• Exposes the decoder module through the operators package interface

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 12 comments.

File	Description
monai/deploy/operators/decoder_nvimgcodec.py	New module implementing nvImageCodec-based decoder plugin with functions for availability checking, frame decoding, plugin registration, and helper utilities for module path resolution
monai/deploy/operators/dicom_series_to_volume_operator.py	Integrates decoder plugin by importing the module and calling registration during operator initialization
monai/deploy/operators/__init__.py	Exposes the decoder module through package imports and adds it to __all__ list

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[sonarqubecloud]

Quality Gate passed

Issues
4 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud