fix(dicomImageLoader): Fix expected number of LUT entries when tag value is 0

[abustany]

Context

The code was incorrectly interpreting value 0 as 65535 instead of 65536, unlike what DICOM PS3.3 C.11.1.1.1 specifies.

Changes & Results

Fixed the code -> file now decodes fine.

Testing

Tested with an XRay file from a GE scanner I unfortunately can't share here.

Checklist

PR

• My Pull Request title is descriptive, accurate and follows the
  semantic-release format and guidelines.

Code

• [] My code has been well-documented (function documentation, inline comments,
  etc.)

Public Documentation Updates

• [] The documentation page has been updated as necessary for any public API
  additions or removals.

Tested Environment

• OS: macOS
• Node version: 24
• Browser: Firefox 153

Summary by CodeRabbit

• Bug Fixes
  • Corrected lookup table handling for DICOM images when the encoded entry count is zero.
  • Ensures 65,536 entries are used as specified, improving image rendering accuracy.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 7fe5f4ba-cfd2-4e32-9544-c3145475b9fd

📥 Commits

Reviewing files that changed from the base of the PR and between 7034957 and aa3c8e0.

📒 Files selected for processing (1)

• packages/dicomImageLoader/src/imageLoader/wadouri/metaData/getLUTs.ts

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

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📝 Walkthrough

Walkthrough

The DICOM LUT parser now interprets an encoded entry count of zero as 65,536 entries, matching the DICOM specification.

Changes

DICOM LUT parsing

Layer / File(s)	Summary
Correct zero-entry LUT handling packages/dicomImageLoader/src/imageLoader/wadouri/metaData/getLUTs.ts	A zero-encoded LUT entry count now produces 65,536 entries instead of 65,535.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Merge Risk: ⚪ Minimal · up to aa3c8

This localized fix corrects LUT entry handling for a DICOM value of 0; no actionable merge-blocking risk remains beyond normal checks and review.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 1 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the LUT entry-count fix and follows the semantic-release format.
Description check	✅ Passed	The description explains the defect, the correction, the test result, and the tested environment; unchecked documentation items are not critical for this change.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[daker]

already adressed by this PR #2856