From the review of the new release on thedigitalbits.com
"The production history of The Phantom Menace is a complex one. It was shot mostly on 35 mm photochemical film using Arriflex cameras and Hawk C-Series anamorphic lenses (for an intended aspect ratio of 2.39:1), though it was also one of the first features to utilize footage captured digitally in HDCAM as well (at 1080/24p using the Sony HDC-750—the new Panavision lenses this camera required weren’t ready for principle photography, but were available for re-shoots and second unit photography). Post production was done shot by shot, with original camera negative copied to an interpositive and then to internegative. Footage requiring VFX was scanned at 2K, with VFX produced digitally at sub-2K resolution (state-of-the-art at that time), and the finished shots were printed back out to internegative. The HDCAM footage was likewise printed to internegative. All of this film was then physically edited into a final cut negative, from which a properly color-timed interpositive was created (essentially the finished master element, though an early “Digital Intermediate” was made for pioneering exhibition in theaters by Texas Instruments—presumably a 2K scan of the interpositive). For the film’s original DVD release in 2001, that interpositive was scanned in 10-bit 2K by Lowry Digital, resulting in the creation of a 2K Digital Intermediate (complete with digital VFX tweaks and a color grade supervised by Lucas). This source was used again for the 2011 Blu-ray release, though with a bit more Lowry Digital remastering (and still more digital VFX and color timing tweaks).
For The Phantom Meance’s 3D theatrical release—and to protect Disney’s investment following the studio’s purchase of the Star Wars franchise in 2012—the cut negative (with VFX film-outs) was scanned again in 16-bit 4K by Reliance MediaWorks (formerly Lowry Digital). Lucas once again took the opportunity to tweak the VFX and color timing, resulting in the creation of a new 4K Digital Intermediate. This Ultra HD release (and the recent Disney+ version) was mastered from the 4K DI, with additional color grading for high dynamic range (only HDR10 is available on the disc, but Dolby Vision is available on the Digital version)."