AppleInsider reports that a patent filed by Apple outlines methods for advanced backlighting to improve picture quality and handle subtitles.
AppleInsider found a patent titled “Dynamic Backlighting Adaptation for Black Bars with Subtitles” filed by Apple only a few months ago, in September of 2011, which outlines a method for improving quality on letterboxed video.
While today’s widescreen displays are in a 16:9 aspect ratio, much of today’s content comes in other proportions, like Panavision’s 2.35:1 ratio. This causes content from Blu-ray, DVDs, and other sources to show black bars above and below the picture. These bars cause problems with image quality due to backlighting issues.
“Many video images are encoded with black bars, e.g., non-picture portions of the video images,” the filing reads. “These non-picture portions complicate the analysis of the brightness of the video images, and therefore can create problems when determining the trade-off between the brightness of the video signals and the intensity setting of the light source. Moreover, these non-picture portions can also produce visual artifacts, which can degrade the overall user experience.”
Cutting them out isn’t entirely plausible, either, as many players show subtitles in those sections, and that further complicates the backlighting issue.
Apple’s patent outlines a solution: dynamic processing. A system could analyze incoming video content and synchronize the backlight to work in tandem with the images shown on screen. The display itself could have multiple backlighting settings, so that the section of the screen showing the images would be backlit properly, but the black bars would be set differently so as to not degrade picture quality.
“The system determines the intensity setting of the light source on an image-by-image basis for the sequence of video images, where the intensity of the given video image is based on the brightness setting and/or brightness information contained in the video signals associated with the given image,” the filing reads. “Then, the system synchronizes the intensity of the setting of the light source with the current video image to be displayed.”
This could also occur over different sections of the screen via mapping functions. Ulrich T. Barnhoefer, Wei H. Yao, Wei Chen, Barry J. Corlett, and Jean-didier Allegrucci were credited with the invention of the system.
Rumors about Apple’s television set have been picking up, and this could be one of the big features that really brings Apple’s offering to the forefront. Apple is rumored to launch their branded Television as early as mid-2012.