JPH0470078A - Scanning transforming device - Google Patents

Abstract

PURPOSE:To smoothly and accurately display an oblique line by increasing the number of picture elements in the vertical direction of a display device by an interpolation arithmetic circuit. CONSTITUTION:Interpolation arithmetic circuits 15-17 which prepare an interpolation data to increase the number of operating lines, and a control circuit 14 which prepares a control signal necessary for the arithmetic processing of the interpolation arithmetic circuits 15-17, are added to this device. Then, an almost intermediate interpolation data of each of the scanning lines of the field is prepared during the field period of a television signal, and the interpolation data for the prescribed number of the scanning lines are prepared between the interpolation data and the adjacent scanning line. Then, the interpolation data corresponding to the number of the scanning lines of a displaying device is selected from these interpolation data. Thus, the oblique line on a screen can be always smoothly and continuously displayed regardless of the number of the scanning lines of the display device.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a scan conversion device used when digitally processing a television signal and reproducing it on a display device such as a large-sized display or a flat display. be.

[Conventional technology]

FIG. 2 is a block diagram showing the general configuration of a scan converter for displaying, for example, an NTSC television signal (hereinafter referred to as NTSC signal) on a flat display using a different scanning method. In the figure, 1 is an NTSC signal input terminal, 2 is an NTSC decoder that receives the NTSC signal arriving at input terminal 1, 3 is a clock/control pulse generator that receives the output of NTSC decoder 2, and 4.5° 6 is R and G output from the NTSC decoder 2;

An A/D converter converts the B signal into digital data using the clock generated by the clock/control pulse generator 3; 7 is a memory control unit that receives the output of the clock/control pulse generator 3; 8, 9.10 are A/D converter 4, 5.
An image memory 11, 12, and 13 is an image memory 8, in which writing and reading of digital R, G, and B signals outputted from 6 are performed under the control of a memory control unit 7;
9゜100 output terminal, R signal output terminal, G
These are a signal output terminal and a B signal output terminal.

Next, the operation will be explained.

The analog NTSC signal arriving at input terminal 1 is N
The signal is input to the TSC decoder 2. The NTSC decoder 2 demodulates the input NTSC signal and converts it into analog amounts of R, G,
Outputs a B signal and a synchronization signal. The above synchronization signal output is
The signal is input to the clock/control pulse generator 3. The clock/control pulse generator 3 outputs clocks and control pulses synchronized with the input NTSC signal to the A/D converters 4 to 6 and the memory controller 7. R signal output terminal 11, G signal output terminal 12. A display device (not shown) that displays the output signal of the B signal output terminal 13 is an NTSC
It is assumed that the signal aspect ratio of 4:3 is satisfied, and the number of pixels is 4n×3n (where n is a positive integer).

The horizontal effective scanning rate of the NTSC signal is 83 (because it is a punishment, the NT
When the horizontal scanning frequency of the SC signal is fH, the clock frequency fB given to the A/D converters 4 to 6 is determined by the following equation.

fs = 4n x (100/83) xfH--
--= (1) From fs K in equation (1), the R signal output, G signal output, and B signal output output from the NTSC decoder 2 are converted into digital signals by A/D converters 4 to 6, respectively. be done. This digital R, G, B signal is
Each field is written into the image memories 8-10. This writing is controlled by the memory control section 7.

The number of effective scanning lines of the NTSC signal is 490 in one frame (two fields). Since the number of pixels in the vertical direction of the display device is 3n, scan conversion from 490 pixels to 3n pixels is required. This scan conversion is performed by controlling reading of the image memories 8 to 10. In general, it is difficult for display devices to perform interlaced scanning, so one frame screen must be constructed by non-interlaced scanning using two fields of original signals for each field. Therefore, consider scan conversion using 490 screens in which one scanning line is scanned twice. That is, among the data written in the image memories 8 to 10, data corresponding to the second scanning line (DM(6)) and data corresponding to the second scanning line of the display device (D
o(k)) is defined by the following equation, and linear conversion is performed.

Dofk)=DM(1+INTC244X(k 1)
/(3n-1)))-(2) However, #=1, 2,
..., 245. = 1.2°..., 3n, INT
() indicates integerization of [].

By controlling the reading of the image memories 8 to 10 by the memory control unit 7 according to equation (2),
The R, G, and B signals scan-converted to the book are output terminals 11 to 1.
Obtained in 3.

In addition, as prior art related to this invention, for example, Japanese Patent Application Laid-Open No. 61-225978 and Japanese Patent Application Laid-Open No. 61-23977
There is a technique disclosed in Publication No. 9.

[Problem to be solved by the invention]

Since the conventional scan conversion device is configured as described above, the number of vertical pixels (number of scanning lines) of the input signal to the rirJ image memories 8 to 10 is constant, and the number of vertical pixels is greater than this number of vertical pixels. When displaying on a display device, the same pixel is read out and written twice from the image memories 8 to 10, and when displayed on a display device with fewer vertical pixels than the input signal, Since pixels are read out by excluding every few pixels (thinning), there are problems such as diagonal lines in the image being displayed discontinuously.

This invention was made to solve the above-mentioned problems, and provides a scan conversion device that can display diagonal lines smoothly and accurately by increasing the number of pixels in the vertical direction of a display device using an interpolation calculation circuit. With the goal.

[Means to solve the problem]

The scan conversion device according to the present invention creates interpolation data approximately in the middle of each scanning line of the field during a field period of a television signal, and also creates predetermined interpolation data between each interpolation data and the scanning line adjacent to the interpolation data. Interpolation data for the number of scanning lines is created, and interpolation data corresponding to the number of scanning lines of the display device is selected from these interpolation data.

[For production]

The scan conversion device according to the present invention can obtain data for a large number of interpolated scanning lines from scanning line data of an input signal,
By selecting appropriate data from these data according to the number of scanning lines of the display device, the diagonal lines on the screen are always displayed smoothly and continuously regardless of the number of scanning lines.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, blocks having substantially the same functions as those in FIG. 2 are given the same reference numerals, and their explanations will be omitted.

In FIG. 1, reference numerals 15, 16, and 17 are interpolation calculation circuits for creating interpolation data for increasing the number of scanning lines from the outputs of the A/D converters 4 to 6, respectively, and each output is Written to 10. Reference numeral 14 denotes a control circuit that creates control signals necessary for the arithmetic processing of the interpolation arithmetic circuits 15 to 17 based on the clock and control pulses from the clock/control pulse generator 3.

Note that the memory control section 7 and the image memories 8 to 10
This constitutes a selection means for selecting interpolation data corresponding to the number of scanning lines of the display device from the interpolation data created by the interpolation calculation circuits 15 to 17.

Next, the operation will be explained. The outputs of the A/D converters 4 to 6 are input to interpolation calculation circuits 15 to 17, respectively. Interpolation calculation circuit 15 ~ in the first field (odd field)
The 245 scanning line data input to DI (2V
-1), and the 245 scanning line data input to the interpolation calculation circuits 15 to 17 in the second field (even field) are DI (2V) (where V=1, 2, .
..., 245). First, in the first field, the interpolation calculation circuits 15 to 17 calculate interpolation data DI (2y) having the same vertical phase as the scanning line data Dr (2y) of the second field by calculating the following equation (3). , and in the second field, the above first
Interpolated data Dx (2y+1) having the same vertical phase as the scanning line data Dr (2y+1) of the field is created.

DI'(2y)=-Dr(2y-1)+"Dx(2y+
1)・・・・・・・・・・・・(3)Dx (2y+
1 ) = −Dr (2y) +' Dr (2y+
2) -.-(4) According to equations (3) and (4) above, interpolated data between two scanning lines can be obtained in each field.

Next, the interpolation calculation circuits 15 to 17 perform D in the first field.
From I(2y+1) and DI(2y), and from I)r(2y+1) and DX(2y) in the second field, interpolated data (x(1)
, x(2), ..., x(m)). That is,
m interpolated scanning lines are created between each of the interpolated data obtained using equations (3) and (4) above and the next scanning line.

This interpolation method is shown in the following equation.

(1) First field x(1)=Dr(2y) xm/(m+1)+Dr(2
y+1)/(m+1)x(2)=DI(2y)x(m
-x)/(m+1)+-Dr(2y+1)x2/(m+
x )x(m)=DI(2y)/(m+i)+I)r
(2y+1)xm/ (m+1)...(5)
(11) Second field x(i)=])+(2y) xm/(m+1)+Dr(
2y”l)/(ml)x (2)= DI (2y
)x (m-x)/(m+1)+DI(2y+1) x
2/(m+1)x6n)=pr(2y)/(m+D
+pr(2y+1) Xm/(m+1) −(s
) x(1) to x(m
) is data of m scanning lines whose vertical phases are shifted by equal intervals, and is suitable as data of interpolated scanning lines. In the control circuit 14, the interpolation calculation circuits 15 to 17 satisfy the above equation (5
).

It outputs the control signals necessary to perform the calculation in (6).

During one field period, the interpolation calculation circuits 15 to 17 have 24
Since data corresponding to five effective scanning lines are respectively input, data corresponding to (490+489m) scanning lines is obtained as an output.

These are written into the image memories 8 to 10 under the control of the memory control unit 7, respectively.

The number of pixels in the vertical direction of the display device is 3n, so (490+
A scan conversion from 489m) lines to 3n lines is required. This is done by controlling the reading of the image memories 8-10. That is, among the data written in the image memories 8 to 10 during one field period, the data corresponding to the th scanning line (DM'(t)) and the data written to the th scanning line of the display device. The relationship with the data Do(k) corresponding to is defined by the following equation (7), and linear conversion is performed.

Ddk) = Dy'(1+INT[(489+489
m)x(k-1)/(3n-1)))
7) The memory control unit 7 controls reading of the image memories 8 to 10 according to the above equation (7). In this way, R, G, B was scan-converted into 31 lines! The numbers are output terminals 11 to 13
are obtained respectively.

Note that in the above embodiment, (49
0+489m) scanning line data to image memories 8 to 1
0 and selects the data of 30 scanning lines required for the display device when reading, but the above (490 + 48
9m) After selecting data of 30 scanning lines in advance from the data of 30 scanning lines, it may be written in the image memories 8 to 10, and the same data may be read out.

Further, in the above embodiment, the case of NTSC signal was shown, but PAL, SECAM, and HDTV are also applicable.

Even when displaying a video signal generated by a combinator, the same effects as in the above embodiments can be achieved by applying the present invention.

〔Effect of the invention〕

As described above, according to the present invention, interpolation data approximately in the middle of each scanning line of the field is created during a field period of a television program signal, and a predetermined interval is created between each interpolation data and the scanning line adjacent to the interpolation data. Interpolated data for the number of scanning lines is created, and interpolated data corresponding to the number of scanning lines of the display device is selected from these interpolated data. From the data of 245 scanning lines of the input signal, (245+4
'89m) It is possible to create data for a large number of interpolated scanning lines with accurate phases, so even if the number of pixels in the vertical direction of the display device increases, diagonal lines on the screen can be displayed continuously and smoothly. Effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a scan conversion device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional scan conversion device. 1 is an NTSC signal input terminal, 7 is a memory control section, 8, 9.10 is an image memory, 14 is a control circuit, 15
．． 16 and 17 are interpolation calculation circuits. In the figures, the same symbols indicate the same or equivalent parts.

Claims (1)

[Claims] During a field period of a television signal, interpolation data is created approximately in the middle of each scanning line in that field, and interpolation data for a predetermined number of scanning lines is created between each interpolation data and the adjacent scanning line. A scan conversion device comprising: an interpolation calculation circuit; and selection means for selecting interpolation data according to the number of scanning lines of a display device from the interpolation data created by the interpolation calculation circuit.