JPH04230187A - Video signal processing circuit - Google Patents

Abstract

PURPOSE:To solve a problem of deterioration in the resolution in a line interpolation processing in a conventional video signal processing circuit outputting as it is a preceding field signal by selecting a current field signal at a field switch at a field signal. CONSTITUTION:Inter-line correlation quantity for each line of a preceding field is obtained and a current field video signal is generated from a preceding field video signal by the predetermined signal processing in response to the obtained correlation to generate a video signal by one frame thereby obtaining high resolution even at special reproduction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to video signal processing, and particularly to a video signal processing circuit that improves line interpolation with little deterioration in resolution even when inter-field correlation is small.

0002

[Prior Art] In video equipment, during special playback such as still image playback, the video signal (input signal) of the previous field is
It is used as a signal for the current field after the field. FIG. 2 shows an example of a conventional line interpolation circuit for video equipment. The input signal is delayed by one field in the one field delay circuit 21 and supplied to one input terminal of the field switch 22 . field switch 2
The input signal is supplied as is to the other input terminals 2 without being delayed. The field switch 22 responds to the field signal and outputs the input signal and one field delay circuit 2.
1 and is switched and output as an output video signal.

0003

[Problems to be Solved by the Invention] As mentioned above, the line interpolation process of the conventional video signal processing circuit currently only switches the field signal using the field switch 22 depending on the field signal and outputs the previous field signal as it is. be. Therefore, although there is a signal for one frame, the resolution is the same as displaying only one field, and there is a resolution problem. Therefore, the purpose of this invention is to
It is an object of the present invention to provide a video signal processing circuit that can obtain high resolution even during special playback as described above.

0004

[Means for Solving the Problems] In order to solve the above-mentioned problems, a video signal processing circuit according to the present invention generates a current field video signal from a previous field video signal, and outputs a video signal for one frame. The processing circuit includes a correlation calculation circuit that calculates the inter-line correlation amount for each line of the previous field, a plurality of processing circuits that use different signal processing systems to generate video signals for one frame, and and a switch circuit that outputs a signal generated from one of the plurality of processing circuits according to the calculated correlation value.

[0005]

[Operation] In this invention, the inter-line correlation amount for each line of the previous field is determined, and the current field video signal is generated from the previous field video signal by predetermined signal processing according to the obtained correlation value. By generating video signals, high resolution can be obtained even during special playback.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a video signal processing circuit according to the present invention. The input signal is
The signal V1 is input to the 1-field delay circuit 11 and is delayed by 1 field.
2. The signal V2 delayed by one line by the one-line delay circuit 12 is supplied to an interpolation calculation circuit 13 and a correlation calculation circuit 14. The interpolation calculation circuit 13 receives two consecutive line signals V1 of the previous field signals from the 1-field delay circuit 11 and the 1-line delay circuit 12.
The average value of V2 and V2 is interpolated by (V1+V2)/2, and an average signal V3 is output. In addition, the correlation calculation circuit 14
calculates the amount of correlation between two lines by calculating (V1-V2) using signals V1 and V2, and calculates the correlation signal by comparator 1.
Supply to 5. The comparator 15 compares the correlation signal from the correlation calculation circuit 14 with a predetermined reference value, and generates a switching signal that determines whether to use the previous field signal V1 as it is or to use the interpolation signal V3 depending on the comparison result. Interpolation switch 16
Send to. Interpolation switch 16 supplies signals V1 and V3 to field switch 17 based on the switching signal from comparator 15. The field switch 17 receives the input signal and the signal from the interpolation switch 16, and switches and outputs the signal based on the field signal.

In the above configuration, for example, during special playback, instead of outputting the previous field signal as it is to construct one frame of video, the amount of correlation between the signals of each line of the previous field is determined and the amount of correlation is calculated based on the amount of correlation obtained. One field video is constructed by switching between the previous field signal and the interpolation signal.

[0007]

[Effects of the Invention] As explained above, according to the video signal processing circuit of the present invention, an appropriate signal between the previous field signal and the interpolation signal is outputted based on the correlation value of each line signal of the previous field. Therefore, special playback video without deterioration in resolution can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a video signal processing circuit according to the present invention.

FIG. 2 is a block diagram showing the configuration of a conventional video signal processing circuit.

[Explanation of symbols]

11, 21 1 field delay circuit 12
1-line delay circuit 13 Interpolation calculation circuit 14 Correlation calculation circuit 15 Comparator 16 Interpolation switch

Claims (1)

[Claims] In a video signal processing circuit that generates a current field video signal from a previous field video signal and outputs a video signal for one frame, a correlation calculation circuit that calculates an inter-line correlation amount for each line of the previous field; a plurality of processing circuits that generate video signals using different signal processing systems; and a signal generated from one of the plurality of processing circuits according to a correlation value obtained by the correlation calculation circuit. A video signal processing circuit comprising: a switch circuit;