Relation to digital imaging

Relation to digital imaging

Digital photography refers to a quantized (finite) word length, i.e. to pixel quantities that are usually integers. Conversely, what is expected of computational photography is pixel quantities that are floating point numbers in acquisition, processing, storage, and display. This is done through file formats that represent floating point values quantimetrically, i.e. on some known (to within a constant scale factor) tone scale. Examples of quantimetric scales include, but are not limited to the following:

• Linear in the quantity of light received, up to a single unknown multiplicative constant for the entire image;
• Logarithmic in the quantity of light received, up to a single unknown additive constant for the entire image.

A recent paper, entitled "Being Undigital" attempted to define the essence of computational photography as an "undigital" capture of images. Ideally, computational photography captures, as best as possible, an array of real numbers rather than integers, while maintaining the ability to store, wirelessly send, process, and display the image on a continuous tone scale.
First simultaneous estimation of projection (homography) and gain change, together with composite of multiple differently exposed pictures to generate a high dynamic range image, 1991:



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