| 摘要 |
The invention is related two a new kind of pre-processing for plasma display panel control. The plasma display technology has the drawback of a reduced grey scale portrayal. This is due to the fact that contrarily to CRTs where luminance is approximately quadratic to the applied cathode voltage, luminance is linear to the number of discharge pulses in PDPs. Therefore, an approximately quadratic degamma function has to be applied to the input video signal components R,G,B before sub-field coding can be done. Truncation to 8-bit video data is required, so that the effect of the degamma function cannot be fully maintained. Especially in the region of small video levels, where the eye sensitivity is high, the grey scale portrayal is poor. According to the invention it is proposed to use a new kind of dithering, adapted to the PDP specialities to improve the grey scale portrayal. These adaptation includes three dithering specialities which can he used singly or in combination. These are: cell-based dithering, i.e. to each colour component R, G, B of a pixel separate dithering numbers are added; object/region-based dithering, i.e. the set of disposable dithering numbers is made dependent on the region/object in the video picture; the set of disposable dithering numbers is made dependent on the video (signal) level.
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