A raw image file contains minimally processed data from the image sensor of either a digital camera, image or motion picture film scanner. Raw files are so named because they are not yet processed and therefore are not ready to be used with a bitmap graphics editor or printed. Normally, the image is processed by a raw converter in a wide-gamut internal color space where precise adjustments can be made before conversion to a "positive" file format such as TIFF, DPX or JPEG for storage, printing, or further manipulation, which often encodes the image in a device-dependent color space. These images are often described as RAW image files based on the erroneous belief that they represent a single file format. In fact there are dozens if not hundreds of raw image formats in use by different models of digital equipment.
A raw digital image may have a wider dynamic range or color gamut than the eventual final image format, and is usually the one "closest" to the real picture in the sense that it preserves most of its details. Raw image formats' purpose is to faithfully record both 100% of exactly what the sensor "saw" or "sensed" (the data), and the conditions surrounding the recording of the image.
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