US 6,320,625 B1Granted

Contour emphasizing circuit

AssigneeFujitsu General Limited

InventorsSusumu Suzuki, Masanori Kurita

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Abstract

Since A/D conversion circuits 30r, 30g and 30b to convert for output analog R, G and B signals to digital signals, a phase adjustment circuit 31 to output by delaying in the portion of 1 linc output signals of these A/D conversion circuits 30r, 30g and 30b, a first signal generation circuit 35 to generate Y signals from output signals of A/D conversion circuits 30r, 30g and 30b, a second Y signal generation circuit 37 to generate a Y signal from an output signal of the phase adjustment circuit 31, a contour extracting circuit 39 to extract a vertical contour component and a horizontal contour component from Y signals generated by first and second Y signal generation circuits, and contour adders 34r, 34g and 34b to output signals contour-emphasized adding a vertical contour component and a horizontal contour component extracted by this contour extracting circuit 39 to output signals of the phase adjustment circuit are provided, and since it has been designed that the contour extracting 39 extracts a vertical contour component and a horizontal contour component from Y signals generated by first and second Y signal generation circuits 35 and 37 , provided the line memory ncccssary for the contour extracting circuit 39 is made as 1 piccc, the power consumption can be made smaller, as well the cost can be loared.

A contour emphasizing circuit comprising an A/D conversion circuit for converting input analog color video signals to output digital color video signals, a phase adjustment circuit for delaying by one line the output digital color video signals, a signal processing circuit for processing the delayed output digital color video signals, a first Y signal generation circuit for generating a Y signal from the output digital color video signals, a second Y signal generation circuit for generating a Y signal from the delayed output digital color video signals, a contour extracting circuit for extracting a vertical contour component and a horizontal contour component of the Y signals generated by the first and second Y signal generation circuits and contour adders for adding vertical and horizontal contour components extracted by the contour extracting circuit to the processed delayed output digital color video signals and produce contour-emphasized digital color video signals, wherein the contour extracting circuit comprises a line memory for delaying by one line the Y signal generated by the second Y signal generation circuit, a vertical contour extracting circuit for extracting a vertical component on the basis of the Y signals generated by the first and second Y signal generation circuits and the Y signal delayed by the line memory, a contour emphasizing frequency setting circuit comprising n 1-dot delay elements connected in series for generating two kinds of delayed Y signals consisting of an n-dot delayed Y signal from the nth 1-dot delay element and a 2-dot delayed signal from the second 1-dot delay element for contour emphasizing frequency setting, based on a Y signal generated by said second Y signal generation circuit and n being at least four, a horizontal contour extracting circuit for extracting a horizontal contour component on the basis of the Y signal generated by said second Y signal generation circuit and the two kinds of delayed Y signals and a contour synthesis circuit for synthesizing output contour components from said vertical and horizontal extracting circuits, respectively.

Abstract

Claims5