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Anamorphic widescreen is a process by which a comparatively wide widescreen image is vertically expanded to fit into a storage medium (photographic film, for example) with a narrower aspect ratio. Compatible play-back equipment (a projector with modified lens) can then recompress the vertical dimension to show the original widescreen image. This is typically used to allow one to store widescreen images on a medium that was originally intended for a narrower ratio, while using as much of the frame - and therefore recording as much detail - as possible.〔(【引用サイトリンク】title=What is Anamorphic Widescreen? )〕 The technique originally comes from cinema. A film would be framed and recorded as widescreen, but the picture would be "squashed together" using a specially crafted concave lens to fit into non-widescreen 1.37:1 aspect ratio film. This film can then be printed and manipulated like any other 1.37:1 film stock, although the images on it will appear to be squashed horizontally (elongated vertically) as in a fun-house mirror. An anamorphic lens on the projector in the cinema (a convex lens) corrects the picture by performing exactly the opposite distortion, returning it to its original width and its widescreen aspect ratio. The anamorphic lens on the projector is a specially crafted convex lens that corrects the picture so that the images on the screen look normal. The optical scaling of the lens to a film medium is considered more desirable than the digital counterpart, due to the amount of non-proportional pixel decimated scaling that is applied to the width of an image to achieve (something of a misnomer) a so-called "rectangular" pixel widescreen image. The legacy ITU Rec. 601 4:3 image size is used for its compatibility with the original video bandwidth that was available for professional video devices that used fixed clock rates of a SMPTE 259M serial digital interface. One would produce a higher-quality upscaled 16:9 widescreen image by using either a 1:1 SD progressive frame size of 640×360 or for ITU Rec. 601 and SMPTE 259M compatibility a letterboxed frame size of 480i or 576i. Similar operations are performed electronically to allow widescreen material to be stored on formats or broadcast on systems that assume a non-widescreen aspect ratio. ==Film== (詳細はanamorphic format for details. Other movies (often with aspect ratios of 1.85:1 in the USA or 1.66:1 in Europe) are made using the simpler matte technique, which involves both filming and projecting without any expensive special lenses. The movie is produced in 1.375 format, and then the resulting image is simply cropped in post-production (or perhaps in the theater's projector) to fit the desired aspect ratio of 1.85:1 or 1.66:1 or whatever is desired. Besides costing less, the main advantage of the matte technique is that it leaves the studio with "real" footage (the areas that are cropped for the theatrical release) which can be used in preference to pan-and-scan when producing 4:3 DVD releases, for example. The anamorphic encoding on DVD is related to the anamorphic filming technique (aka Cinemascope) only by name. For instance, ''Star Wars'' (1977) was filmed in 2.35:1 ratio using an anamorphic camera lens, and shown in theaters using the corresponding projector lens. Since it is a widescreen film, when encoded on a widescreen-format DVD the studio would almost certainly use the anamorphic encoding process. ''Monty Python and the Holy Grail'' was filmed in 1.85:1 ratio without using an anamorphic lens on the camera, and similarly was shown in theaters without the need for the decompression lens. However, since it is also a widescreen film, when encoded on a widescreen-format DVD the studio would probably use the anamorphic encoding process. It doesn't matter whether the filming was done using the anamorphic lens technique: as long as the source footage is intended to be widescreen, the digital anamorphic encoding procedure is appropriate for the DVD release. As a sidenote, if a purely non-widescreen version of the analog-anamorphic ''Star Wars'' were to be released on DVD, the only options would be pan-and-scan or hardcoded 4:3 letterboxing (with the black letterboxes actually encoded as part of the DVD data). If you were to release a purely non-widescreen version of Monty Python, you would have those options, as well as the additional option of an "open-matte" release, where the film footage that was never visible in theaters (due to use of the matte technique in post-production or in the theatrical projectors) is "restored" to the purely non-widescreen DVD release. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「anamorphic widescreen」の詳細全文を読む スポンサード リンク
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