This option is used to specify the transfer function by which the video and frame grabber hardware maps true intensities to intensity values in the frame grabber. Unlike the other mappings in this menu, this hardware transfer function is treated as a static mapping. The quantitative accuracy of the function is less important than its functional form, provided it is applied in a uniform manner to all the images being processed. Normally this mapping would be used to precondition images into an approximately true intensity space in order that basic processing may be undertaken. The dynamic mappings determined by the other options in this menu may then be used to obtain accurate quantitative data.
The transfer function may be applied to an image already acquired by choosing [Y Apply hardware transfer function to buffer], or alternatively the transformation may be applied during acquisition by choosing input look up table 2.
The form of the transfer function should be determined by calibration from a known intensity scale.