Issue Fix for #2958 Transparent backgrounds on PNG images lost in dynamic media Urls

[khanmaroof]

Q	A
Fixed Issues?	Fixes #2958
Patch: Bug Fix?
Minor: New Feature?	Yes
Major: Breaking Change?
Tests Added + Pass?	Yes
Documentation Provided	Yes (markdown)
Any Dependency Changes?
License	Apache License, Version 2.0

Conditional PNG Transparency Detection

Rather than applying fmt=png-alpha to all PNGs (which would cause significant performance issues), we can automatically detect which PNGs actually have transparency using existing DAM metadata.

Key Insight: dam:Bitsperpixel metadata reliably indicates PNG transparency:

• 32 bits = PNG with alpha channel (transparent) → Add fmt=png-alpha
• 24 bits = RGB PNG (opaque) → No format modifier needed
• 8 bits = Indexed PNG (opaque) → No format modifier needed

Implementation: Modify the Dynamic Media URL building logic in ImageImpl.java to automatically prepend fmt=png-alpha only when dam:Bitsperpixel = 32 for PNG assets.

Benefits:

• ✅ Preserves transparency automatically for transparent PNGs
• ✅ Maintains optimal performance for non-transparent PNGs
• ✅ Zero breaking changes - existing manual configurations still work
• ✅ Can be policy-controlled via autoPreservePngTransparency setting

This approach solves the transparency issue while completely avoiding the performance penalty since fmt=png-alpha is only applied when transparency actually exists.

[codecov[bot]]

Codecov Report

:x: Patch coverage is 9.09091% with 40 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
.../core/components/internal/models/v3/ImageImpl.java	4.34%	21 Missing and 1 partial :warning:
.../core/components/internal/models/v2/ImageImpl.java	14.28%	17 Missing and 1 partial :warning:

:loudspeaker: Thoughts on this report? Let us know!

[sonarqubecloud[bot]]

Quality Gate passed

Issues
0 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