Feiner notes that advances in digital film conversion and image-processing technologies provides a powerful toolkit for restoration projects. This proved to be a key advantage on the Oz undertaking, given the job's aggressive eight-month schedule.
The picture's fine-grain master was stored at the Library of Congress. Pacific Title/Mirage converted it to digital format with a Kodak digital film scanner at full film resolution. According to Feiner, this process requires 4K x 3K of digital data with 10 bits of log space per pixel. "Some people say 3K, or even 2K, and 8-bit log space per pixel is sufficient, but this film is an important part of our heritage and culture," he says. "Countless millions have seen it on TV. Finally, they can now see it in a cinema the way it is meant to be seen. It would be a crime to cut corners and do anything in a sub-standard manner."
The fine-grain intermediate provided by The Library of Congress showed no visible signs of vinegar syndrome or shrinkage, and it had a stable base. Feiner opted to make a contact liquid-gate dupe negative of the fine-grain IP, which eliminated the worst of the abrasions and emulsion digs. "We test scanned the original fine-grain and the dupe to see if there were discernible differences in resolution, sharpness and overall image quality," he says. "When we scanned our dupe at full film resolution, there was no loss in image quality. If we had scanned from the original fine-grain, we would have copied the abrasion and emulsion digs and that would have required extensive digital paint work.c
If one scans a full-aperture anamorphic frame in full color, the file size would run about 45 megabytes. However, scanning from a black-and-white element at full film resolution yields about 13 megabytes per frame — a rate that allows for more efficient data management at faster speeds.
The digital restoration work was executed on Silicon Graphics 02 platforms and several dual-processor Octanes running Matador Paint and Cineon applications software. The workstations were networked to an SGI Origin 2000 file server that provided high-density image storage and rapid transfer rates. "We elected to use Cineon software for automated dust-busting, with one important provision," says Feiner. "You have to be very careful that you don't lose fine details like highlights in people's eyes. The only way to do that is to compare the processed images on the computer screen to a matching frame of the source material."
The images were stored on the high-speed disk array for display at 2K resolution. The digital artists were then able to flip the display between the source material and the processed images. "We assembled and trained a staff with the appropriate skills and film sensibilities, plus the dedication needed to do the job properly," Feiner says. "The supervisor, Mark Freund, has been a great optical camera operator for us for years."
The dancing Scarecrow sequence was an outtake stored on 250 feet of film — less than three minutes of screen time — in the CRI (Color Reversal Intermediate) format. All of the original three-strip Technicolor film from that period was recorded on a potentially flammable nitrate-based emulsion. Feiner speculates that MGM decided to rid its lot of nitrate-based film sometime in the late Sixties or early Seventies.
When Feiner inspected the Scarecrow scene, the image seemed slightly off. "I noticed that there were two frames, right before the pictures started, with clear lines outside the perforations," he says. "Most people wouldn't have noticed that, but I've worked on a lot of trailers for TV in CRI format. Still, it took me about a day to discover what had happened. One of our people [Vince Roth] had worked in the MGM Labs optical department for 27 years, and he remembered an optical camera operator who had worked on those conversions."
MGM Labs had set up a production line to copy the nitrate film onto CRIs, recording from the emulsion side rather than the base side. That was then considered to be the archival master. When requests were made for duplicate negatives, MGM Labs fashioned a copy from this source. "I realized I had one of the dupes," Feiner says. "Warner Bros. did a diligent search and found the original CRI. That was important, because we wanted to be as close as possible to the original image quality. There's no magic bullet with digital technology — you can only scan in the image quality on the source material."
After scanning, the image quality was cleaned up by the digital artists, who removed dust and dirt spots and painted out the wires used to help actor Ray Bolger to fly in the Scarecrow dance number. The artisans also compensated for yellow dye fading. "It took an aesthetic eye," he explains. "Dorothy is in the scene in question, and we needed to match her skin tones to scenes on either side of the cutting done by the editor."
The digital files for both the Technicolor and black-and-white sequences were converted to intermediate film with a Kodak laser film recorder. "Our goal was simple," Feiner says. "We wanted to provide a pristine internegative which accurately emulates the original Wizard of Oz, and provide an enduring film record for future generations to enjoy."
