Lattice: Broken rendering of PNG Hald CLUTs

[janogarcia]

The image below shows how a neutral identity PNG Hald CLUT is rendered when opened via Open LUT….

The Identity LUT was generated by Lattice with the default settings (3D LUT, 33x33x33, 0-1 input bounds), and later exported as a PNG Hald CLUT (64x64x64, 16-bit).

Notes:

• It works as expected if the Hald CLUT is exported as TIFF instead of PNG.
• PNGs also work fine for the other image based LUTs export options (CMS Test Pattern Image, PNG 3D LUT, Unwrapped Cube Image), but not for Hald CLUTs.
• Lattice 1.8.22 (1852) on macOS Sonoma 14.4.

---