System for making standard deviations in quantum noise constant throughout a screen display
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsShinji Badono, Toshimasa Tomoda
Life of this patent
Estimating the term…
Abstract
A loop is constructed in which an output of a two-dimensional integrator is fed back through an exponential function unit for each pixel of a picture signal, a difference between the output and an input picture signal of the corresponding pixel of a next frame is taken and the difference is input to the corresponding element of the two-dimensional integrator, whereby relative standard deviations of quantum noise of an output picture are made constant at all positions of a screen.
Claims9
A picture processor which processes digitized picture signals and displays a picture composed of an array of pixels produced by such signals on a monitor screen, said picture processor comprising a two-dimensional integrator which integrates digitized picture signals in succession and provides integrated signals corresponding to respective pixels, an exponential function unit which receives as inputs the integrated signals and produces output signals that are exponential functions of the integrated signals, and a subtractor which receives the output signals from said exponential function unit as a minus input and input picture signals as a plus input and which subtracts the output signals from the input picture signals for respectively corresponding pixels to produce a difference output which is input to said two-dimensional integrator, said integrated signals being output from said picture processor as integrated and processed picture signals, said integrated and processed picture signals having quantum noise of a constant relative level.
A picture processor which processes digitized picture signals and displays a picture composed of an array of pixels produced by such signals on a monitor screen, said picture processor comprising a two-dimensional memory which stores digitized picture signals in succession and provides signals corresponding to respective pixels, a function converter which receives as inputs time series signals of stored outputs of said two-dimensional memory and substracts from the time series signals exponential transform values of the time series signals to produce output signals, and an adder which receives the output signals from said function converter as a first plus input and picture input signals as a second plus input and which adds the output signals and the picture input signals for respectively corresponding pixels to produce a sum output which is input to a corresponding element of said two-dimensional memory, said time series signals of stored outputs of said two-dimensional memory being output from said picture processor as processed picture signals, said processed picture signals having quantum noise of a constant relative level.
A picture processor which processes digitized picture signals and displays a picture composed of an array of pixels produced by such signals on a monitor screen, said picture processor comprising:
- receiving means for receiving digitized input picture signals;
- two-dimensional means for holding digitized picture signals in succession and for providing signals corresponding to respective pixels, said signals corresponding to respective pixels having a constant relative quantum noise level;
- transforming means for receiving the signals corresponding to respective pixels, for producing exponential transforms of the signals corresponding to respective pixels, and for outputting the exponential transforms as transformed signals;
- combining means for combining the digitized picture input signals with the transformed signals to produce processed signals;
- input means for inputting the processed signals to said two-dimensional means;
- and
- output means for outputting the signals corresponding to respective pixels to a video monitor screen.
Dependencies are inferred from the claim text.