Home > Views > Industry Views > Film and High Definition Resolution

Film and High Definition Resolution

Jun 11th, 2008
The impact of digital noise reduction

As regular readers know who’ve followed my home theater design, build, and upgrades in my long running series, Mr. Blandings Builds His Dream Theater, my stated goal is to bring the motion picture theater experience to the home (sans the sticky floors and noisy patrons). I purchased my first serious front projector in 1994 and, since then, I’ve been drawn to the movie theater only four times to see films I simply couldn’t wait to appear on disc: once for each of the Star Wars prequels (well, twice for Episode 1 - I reported for the site on the quality of experimental digital cinema in two theaters in the New York area); and most recently, for Indiana Jones and the Kingdom of the Crystal Skull. (Wow, that film wasn’t what I expected; a critique will have to wait for the release on DVD and Blu-ray Disc.)

This was my first visit to a theater in three years and I chose a THX certified theater hoping to enjoy the finest possible presentation. My wife and I sat at a screen distance that yielded about the same viewing angle I enjoy in my home theater, about 43 degrees. (Blandings readers will recall that my standard of measurement is the “Ramer,” the angular distance between the tips of splayed thumb and pinky held at arm’s length directly in front of the body.) Since I installed HD DVD a little over two years ago and BD six months after that, I was extremely curious to compare the theater’s visual presentation with the images I project at home with 1080p resolution on an eight-foot wide screen in a room with no ambient light. I was very surprised that the visual presentation in the THX certified theater was not as revealing or detailed as in my home theater. Even my technically forgiving wife commented on that without being prompted.

When I spoke with a TXH executive several years ago concerning the deficiencies of the Episode 1 DVD (soft and badly contaminated with halos), he mentioned in a different context that release prints have about the same resolution as DVDs. I found the comment ludicrous at the time, but didn’t challenge his assertion. Now, I’m beginning to understand why he feels that way. I know that film gets softer with each generation and release prints are four generations from the original negative (negative to interpositive to internegative to release print), but I didn’t know by how much the images deteriorated. I did a little research and found a couple of scientific white papers that addressed the subject. A distribution print’s resolution is, on average, 48% percent below that of the original negative. Compound that with the wear the film is subjected to as it’s repeatedly run through a projector, and add any incorrect settings in the projection booth and the result is that high definition 1080p has measurably more spatial resolution. It’s no wonder that George Lucas pioneered the use of 1080p24 cinema video cameras and is an advocate of 1080p projection in the motion picture theater.

I also can attest to the remarkable clarity of 1080p digital images projected on a motion picture theater-sized screen. During last fall’s Blu-ray Festival in Hollywood, both Panasonic and Fox used a large-venue Panasonic 3-chip DLP projector to demonstrate BDs. The image clarity and detail were quite extraordinary. So we now have the ability to project visuals at home that exceed the quality of 35 mm film in the motion picture theater; we’re now coming closer to what the filmmakers see when they view a first generation copy.

By now, you’re probably asking yourself what this has to do with the subject of digital noise reduction (DNR). Readers (and our own Dave Boulet) have expressed concerns over the use of DNR since it tends to soften the image, robbing it of very finely grained textures and imparting an unnatural look to skin textures. What seems like excessive pancake makeup is one possible visual clue that DNR has been applied. One kind reader brought to my attention a demonstrative comparison. This is a single frame from Pan’s Labyrinth. By moving your mouse on and off the image, it will switch back and forth between screencaps from the U.K. BD release and the U.S. BD release. Note the lack of texture on the young actress’s face and the visual suppression of individual hairs in front of her ears in the U.S. version.

Now, I wasn’t about to make an issue of this unless I was convinced that this problem is genuine, so I purchased the U.K. BD release of the film and did an A/B comparison of that disc and my U.S. release. I even sought out and paused the frame in the film you can see by clicking on the above link. And indeed, I saw precisely what that webpage demonstrates. The U.K. release is visually superior, with better finely grained textures and a more film-like appearance.

But there are several potential reasons for what I was seeing. Pan’s Labyrinth has a very generous set of supplements. If the bit budget required that the film be a bit more compressed to accommodate the content, the video would have been low-pass filtered to prevent problems with a higher level of compression. But with the exception of substituting a PAL interview of the director for the NTSC roundtable discussion on Charlie Rose, the supplements are identical. Perhaps it’s the CODEC. AVC yields more pleasing and more revealing visuals than VC-1, but both discs use the same CODEC. Additional audio tracks might consume bits, but there are no differences there either. The running times are the same. Perhaps a different generation of film was used for the telecine work. For example, when Lowry Digital Images prepares important titles, the company scans the original negatives, not a duplicate; that provides the highest level of detail and the lowest amount of grain. But the Pan’s Labyrinth BD from the U.K. has more grain and more detail. So I’m forced to conclude that my concerned readers are absolutely correct: New Line applied DNR and Britain’s Optimum Home Entertainment did not. And since there does not seem to be any rational justification for the application of DNR other than to homogenize the appearance of the American transfer, I’m concerned… no, I’m angry.

Blu-ray Disc has the ability to deliver a presentation that exceeds the qualities found in the motion picture theater. It’s inexcusable to cripple the resolution of the presentation with a process that softens the image by acting like a low pass video filter. This particular example seems to be a wrongheaded attempt to remove film grain; but, unless the motion picture was shot digitally, grain is a natural part of the film experience. To remove it and adversely affect the resolution and the film-like presentation is inexcusable.

DVDfile has always fought for the best quality in disc releases for our readers. We fought for anamorphic transfers. We object to edge halos. I personally communicated with no fewer than three compressionists to better understand the causes and effects that diminish image quality. I’ve tried to stimulate change. Now, the question becomes do we have another quality issue to bring to our readers’ attention and to the studios’ attention? Is it time to draw the sword once more? Alas, it would seem to be.

I’ll be attending the Home Media Expo in Las Vegas later this month. I plan on discussing this issue with New Line representatives. If you are aware of any title from any studio that has been crippled by DNR, please let me know and I’ll speak with those studios as well.

Comments (0)

Write comment

smaller | bigger