Robert A. Harris, who led a team that famously restored the Oscar-winning 1964 film version of “My Fair Lady” for its 30th anniversary, wasn’t thrilled when he took a look at the classic musical’s high-definition home-video debut four years ago. To put it mildly.

Blasting what he termed “the worst Blu-ray of 2011” in a review for Home Theater Forum, Harris accused the film’s owner, CBS, of “purposely destroying one of our greatest films . . . I would not waste a single coin on this release.”

Despite those very harsh words, CBS hired Harris to do a whole new digital restoration for the film’s 50th anniversary. He also oversaw a new digital master that will premiere in theaters nationwide on Sunday ahead of the Oct. 27 release of a new Blu-ray that looks and sounds what Audrey Hepburn’s Eliza Doolittle would call positively “loverly.”

“There were no hard feelings by CBS about the review,” says Harris, whose credits include acclaimed restorations of “Vertigo,” “Lawrence of Arabia” and “Spartacus.” “They knew they needed to bring me back in, because this is by far the most valuable of their feature-film assets.” (The beloved winner of eight Oscars, including Best Picture, was produced by Warner Bros., but ownership reverted to CBS, which backed the original stage show, decades ago.)

Harris says he always knew that “My Fair Lady,” which he originally restored primarily through photochemical techniques when digital restoration was in its infancy 20 years ago, would need another face-lift.

“We knew it would need to be done again when the technology improved,” says Harris. “And CBS was great about it, paying for a new 8K scan of the original negative [and other elements] and a full 4K restoration.” (A regular Blu-ray player displays 2K of resolution.) He declines to provide a price tag, but says such high-end restorations “can easily hit seven figures.”

There were tears in the bulky original 70mm negative, and ghosting and other technical challenges in the positive color-separation elements (one for each primary color) used to supplement the negative. Computers were used to remove around 12 million glitches in the images, including dust, scratches, tears and splices, a painstaking process that took six months.

Faded colors were brought back to their original vibrancy using digital techniques, with an archival print from the Motion Picture Academy serving as a reference. Improvements in technology will make it possible for audiences to hear the full range of the original music tracks for the first time since the film’s original release in 1964.

Harris says that because modern-day computers can pull more information from the negative than were seen in relatively grainy original 70mm release prints, there was a danger that 21st-century audiences would be seeing things that the filmmakers never intended — like Audrey Hepburn’s fillings when Eliza fully opens her mouth during her pronunciation drills.

“Everything shows in an 8K scan, and we were shocked when we saw her dental work the first time we watched it on a 25-foot screen,” Harris says. “Jack L. Warner [the film’s producer] would never have permitted this to be seen, so we digitally removed her fillings. Though if you look really hard for it, you might catch a glimpse of the adhesive on Rex Harrison’s toupee in some shots.”