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April 2005
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2005.04.26 16:56 "Re: TIFF Technote 3, draft 2", by Bob Friesenhahn
> Most floating point data have some kind of reference to what 1.0 means, or > simply expect the data representing some physical unit (cd/sqr meter or > the like). The stonits tag make sense with unconverted XYZ data, while XYZ > data are not covered directly by the current tiff spec. Alternatively the > range description, suggestion by Bob, can be extended to add a physical > value to the lower and upper 'normal' bounds. The physical units often have no relationship to ideal default "viewing" parameters for a computer display. For RGB data it is useful to know a recommended "black point" and "white point" for the image. It is also useful to know the normal range of the data. The image data is scaled for display so that values under the black point are "black" and values over the white point are "white". This is of course only a crude approximation but it is better than nothing. Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/