04438495 is referenced by 32 patents and cites 4 patents.

Apparatus for applying a gamma correction to digital CT numbers at a selected level and within a window. A memory is loaded sequentially with the gamma correction lookup table. At the start a counter generates a sequence of addresses, in response to clock pulses. These are addresses to another memory. Simultaneously, a variable address generator addresses the gamma lookup table memory to effect transfer of the gamma correction data to the other memory (window-gamma lookup table) at locations that are represented by the ratio of the locations in the gamma lookup table to the address in the window-gamma table. To read out and produce an image, the window black value is subtracted from the stored CT numbers in sequence. The resulting differences constitute addresses to the window-gamma lookup table whose output is then the gamma corrected values for CT numbers in the window. This digitized data is converted to analog video signals for driving a television monitor that displays the image.

Title
Tomography window-level gamma functions
Application Number
6/321008
Publication Number
4438495
Application Date
November 13, 1981
Publication Date
March 20, 1984
Inventor
Nallaswamy Srinivasan
Waukesha
WI, US
Edward W Andrews
Brookfield
WI, US
Arthur K Collins
Waukesha
WI, US
Agent
Fuller House & Hohenfeldt
Assignee
General Electric Company
NY, US
IPC
H04N 5/14
G06F 15/42
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