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A camera raw image file contains minimally processed data from the image sensor of either a digital camera, image scanner, or motion picture film scanner.〔http://www.luminous-landscape.com/tutorials/understanding-series/u-raw-files.shtml〕 Raw files are named so because they are not yet processed and therefore are not ready to be printed or edited with a bitmap graphics editor. Normally, the image is processed by a raw converter in a wide-gamut internal colorspace where precise adjustments can be made before conversion to a "positive" file format such as TIFF or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent colorspace. There are dozens, if not hundreds, of raw formats in use by different models of digital equipment (like cameras or film scanners).〔(Decoding raw digital photos in Linux )〕 == Rationale == Raw image files are sometimes called digital negatives, as they fulfill the same role as negatives in film photography: that is, the negative is not directly usable as an image, but has all of the information needed to create an image. Likewise, the process of converting a raw image file into a viewable format is sometimes called developing a raw image, by analogy with the film development process used to convert photographic film into viewable prints. The selection of the final choice of image rendering is part of the process of white balancing and color grading. Like a photographic negative, a raw digital image may have a wider dynamic range or color gamut than the eventual final image format, and it preserves most of the information of the captured image. The purpose of raw image formats is to save, with minimum loss of information, data obtained from the sensor, and the conditions surrounding the capturing of the image (the metadata). Raw image formats are intended to capture as closely as possible (i.e. at the best of the specific sensor's performance) the radiometric characteristics of the scene, that is, physical information about the light intensity and color of the scene. Most raw image file formats store information sensed according to the geometry of the sensor's individual photo-receptive elements (sometimes called pixels) rather than points in the expected final image: sensors with hexagonal element displacement, for example, record information for each of their hexagonally-displaced cells, which a decoding software will eventually transform into the rectangular geometry during "digital developing". 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「Raw image format」の詳細全文を読む スポンサード リンク
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