JPH01272381A - Display picture converting device - Google Patents

Abstract

PURPOSE:To obtain a picture of high quality prevented from being notched at its slashes by composing a prescribed line superposedly read out based upon a specified magnification with its preceding line at a fixed ratio to form an interpolation line in the vertical direction. CONSTITUTION:All line data read out from a memory 1 by a reading control part 2 are multiplied by an interpolation factor k1 in the 1st multiplication part 4 and data delayed from all the data by one line are multiplied by the 2nd interpolation factor k2 in the 2nd multiplication part 5. The outputs of the 1st and 2nd multiplication parts 4, 5 are added by an adder 6 and line data interpolated in the vertical direction are outputted. Respective line data are magnified in the horizontal direction by a clock based upon a specified magnification in a horizontal interpolation control part 7 and outputted.

Description

[Detailed Description of the Invention] [Summary] The present invention relates to a display screen conversion device that converts standard double-sided data to screen data for enlarged display on a display device with higher resolution, without deteriorating the image quality and reducing the circuit scale. The aim is to realize a display screen conversion device that is small and inexpensive and suitable for real-time processing, and includes a frame buffer memory in which one frame of input screen data is written, and a frame buffer memory that reads and specifies the input screen data from the frame buffer memory. a readout control unit that redundantly reads a predetermined line of the screen data according to an enlargement magnification; and a first interpolation coefficient that sets a partial number only for the overlapping line and 1 for other lines among all the lines read from the frame buffer memory. , an interpolation coefficient table storing a second interpolation coefficient of I for the overlapping line out of all lines and O for the other lines in correspondence with the specified enlargement magnification; a first multiplier that multiplies each line data read from the H section by the first interpolation coefficient; A second multiplier that multiplies the interpolation coefficient, an adder that adds the outputs of both multipliers and stores 1947 minutes, and reads out one line of data from the adder using a clock according to the specified enlargement factor to display an enlarged screen. It consists of a horizontal interpolation control section that outputs signals.

[Industrial application field]

The present invention relates to a display screen conversion device, and more particularly to a display screen conversion device that converts standard screen data into screen data for enlarged display on a higher resolution display device.

With the recent diversification of visual devices, screen (image) data for one visual device is being adapted to be displayed on various other visual devices.

In general standard display devices, the display screen is, for example, M, XN, dots (pixels), as shown in FIG. (>M+×N2), so in order to make full use of the display screen, it is necessary to mutually enlarge or reduce the display size.

In addition, the displayed screens are not only still images, but also videos, which are in high demand these days, especially in offices.In the case of videos in particular, real-time processing is required, so the "trackability" of the processing time is important in the market. This is an important point in responding to needs.

[Conventional technology]

Conventional technologies for enlarging videos, for example, include: ■ A method in which the information added for enlarging is simply displayed by repeating the original screen information; ■ A method in which information at the time of enlargement is faithfully interpolated from the original image according to the enlargement magnification. A method of displaying the information was proposed. Among these, the method (3) is particularly adopted by broadcasting stations and the like that require reproduction of images faithful to the original images.

[Problem to be solved by the invention]

The above method (■) simply displays the original image information repeatedly, so it has the disadvantage of deteriorating the screen quality.

To explain this with reference to FIG. 11, a standard screen (frame) consisting of an odd field indicated by a solid line in FIG. 11(a) and an even field indicated by a dotted line is divided into
．． When enlarging 6 times, odd fields "2" and "4"
”, “5” and even field r1) J, rd, , “e”
are displayed repeatedly (overlapping?ji), but since the data from one line before is displayed after the next data, the diagonal lines become jagged and the image quality deteriorates.

In addition, as shown in FIG. 11(c), odd field "2"
, "4", "5" and even fields "b", "d", "
If "e" are repeatedly displayed in succession, it is inappropriate for real-time processing because there is a time difference of 1/60 seconds between fields in a moving image.

On the other hand, method (■) performs enlargement interpolation for the entire screen in real time, so high-speed processing is required.
Large and expensive LS with multiprocessor configuration
There was a problem that it became I.

Therefore, an object of the present invention is to realize a display screen conversion device suitable for real-time processing that does not reduce image quality, has a small circuit scale, and is inexpensive.

[Means to solve the problem]

In order to achieve the above object, the display screen conversion device according to the present invention has a frame buffer memory 1 in which one frame of input screen data is written, as shown in principle in FIG.
and a readout control unit 2 that reads the input screen data from the frame buffer memory l and reads out a predetermined horizontal line of the screen data in an overlapping manner according to a designated enlargement factor;
Among all the lines read from the cough frame buffer memory 1, the partial number is set only for the overlapping line, and 1 is set for the other lines.The first interpolation coefficient is 1, and 1 - the partial number only for the overlapping line among all the lines. A table 3 in which second interpolation coefficients are set to 0 for other lines and stored in correspondence with the specified enlargement magnification, and the readout control unit 2
A first multiplier 4 multiplies all line data read from the first interpolation coefficient by 1, and a first multiplier 4 that multiplies all line data read from the read control unit 2 by one line, and delays all line data read from the read control unit 2 by one line and multiplies the first interpolation coefficient by one a second multiplier 5 that multiplies the interpolation coefficient of 2 by 2; and an adder 6 that adds the outputs of both multipliers 4 and 5 and stores the result for one line.
and a horizontal interpolation control section 7 that reads out one line of data from the addition section 6 using a clock according to the specified enlargement factor and outputs an enlarged screen signal.

[Function] In the display screen conversion device of the present invention, the above number of parts is ro,
5 J, the first and second interpolation coefficients k , k ! in the interpolation coefficient table 3 are The image becomes as shown in FIG. 2(b) depending on the specified magnification. Among these, the interpolation coefficient +
, kg are both 0.5 are overlapping lines, and out of the original image data for one frame stored in the frame buffer memory l in FIG. 2(a), O in FIG.
As shown by the marks, only the original lines "3" and "5" are read out from the memory 1 by the readout control unit 2 so as to overlap.

All the line data read out in this way are multiplied by the interpolation coefficient in the first multiplier 4, and these all line data are delayed by 1947 minutes in the second multiplier 5, and then the second interpolation coefficient k.

is multiplied by

As a result, only the display lines "3" and "6" are output from the second multiplier 5 and added to the output from the first multiplier 4 in the adder 6, as shown in FIG. 2(b). This results in vertically interpolated line data.

Each line data thus interpolated in the vertical direction is enlarged in the horizontal direction by a clock based on a specified enlargement factor by the horizontal interpolation control section 7 and output.

By processing a portion of the original picture in this manner, a display screen as shown in FIG. 3 is obtained. That is, for an odd field, the line ``2°J '''''2Jx0.5 +
r 3 J X O, 5, line "4" = "4" X
o,5 + r5''X O,5, and for even fields the line rb' J = rbJ
o, 5+rCJX0,5, line “d”J = rd”
It can be seen that the interpolation is performed as Xo, 5+reJX0.5, and real-time processing is possible without deteriorating the image quality.

〔Example〕

FIG. 4 shows an embodiment of the vertical interpolation configuration of the display screen conversion device of the present invention shown in FIG. , a line address table 22 which outputs a line address in response to this display timing, and a succession unit 2 which reads out corresponding line data from the frame buffer memory 1 according to the line address output from this table 22.
It is composed of 3. The second multiplier 5 also includes a delay circuit 51 that delays the line data read from the frame buffer memory 1 by one line in response to a write enable signal from the line address table 22, and an interpolation coefficient applied to the output of the delay circuit 51. and a multiplier 52 that multiplies the second interpolation coefficient from table 3 by two. Furthermore, line address table 22 and interpolation coefficient table 3
When the zoom magnification designation signal is given, the system internally selects a table corresponding to the zoom magnification.

FIG. 5 shows an embodiment of the horizontal interpolation system tn unit 7 of the display screen conversion device of the present invention shown in FIG. From the memory 71, the readout control unit 72 of this line buffer memory 71, the display timing generation unit 73 that generates the successive timing of this readout control unit 72, that is, the display timing, and the pixel clock (47MHz) for equal magnification/reduction. Generates clock (30MHz) for enlarged full screen
LL.

a circuit 74; a clock switching section 75 that switches and selects both of these clocks and supplies the clocks to the display timing generating section 73;
This clock switching section 75 and display timing generation section 73
The output section 76 converts the line data from the line buffer memory 71 into a signal to be sent to a display (not shown). The clock switching section 75 and the display timing generation section 73 each operate to generate an enlarged screen according to the full screen setting signal, and the display timing generation section 73 and the readout control section 72 operate to generate an enlarged screen according to the reduction setting signal. operates to generate. Further, the output section 76 performs parallel/serial conversion and D/
It performs A conversion.

Next, the operation of the above embodiment of the present invention will be explained.

First, corresponding tables in the line address table 22 and interpolation coefficient table 3 are selected by the zoom magnification designation signal.

The display timing from the display timing generator 21 is the sixth
The line address table 22 corresponds to the display line number shown in the figure, and in response to this display timing, the line address table 22 is
3 from the frame buffer memory 1 to “A” in FIG.
”.As can be seen from this line data A, the original image lines “3”,
Table 22 so that only "5" is read out in duplicate.
has been created.

The line data read from the frame buffer memory 1 is also input to the delay circuit 51 and input to the multiplier 52 as line data shown at "B" in FIG. 6, which is delayed by one line.

The line data A is multiplied by the interpolation coefficient shown in FIG. 6 (FIG. 2) by the multiplier 4, and the line data B is multiplied by the interpolation coefficient by the multiplier 52. In this example,
As in the case shown in FIG. 2, only the overlapping lines A and B are multiplied by a coefficient of 0.5.

Thereafter, the adder 6 adds the 100 outputs of the multipliers H4 and 52.

As a result, the line data output from the adder 6 is
As shown in the figure, the interpolation line in which only the original lines "3" and "5" are overlapped has a vertical enlargement ratio of 1.6 times.

The line data output from the adder 6 is input to the line buffer memory 71 of the horizontal interpolation sub-door section 7 shown in FIG.

Then, in order to enlarge and display the entire screen, when a full screen setting signal is given to the clock switching section 75 and the display timing generating section 73, the clock from the PLL circuit 74 for full screen is sent to the display timing generating section 73. It will be done. As a result, the display timing generating section 73, as shown in FIG.
The clock frequency is lower than the normal timing of the same size (
The line data is output from the line buffer memory 71 and sent to the display via the output unit 76 by controlling the read control unit 72 to read the line data at the timing for the entire screen (with a long period).

Note that the horizontal interpolation method in the present invention is not limited to the method shown in FIG. 5, and various modifications are possible.

In addition, in the above explanation, we particularly talked about enlarging the screen, but in the case of reduction, the line address table 22 in the vertical embodiment shown in Fig. 4 is thinned out as shown in Fig. 8. and set all 2 to the second interpolation coefficient “
0", and set the first interpolation coefficient to 1" only for the remaining lines as shown in Figure 8.
In the embodiment shown in the horizontal direction, the data may be thinned out as shown in FIG. 9 using the reduction setting signal.

〔Effect of the invention〕

As described above, according to the display screen conversion device of the present invention, a predetermined line that is read out redundantly based on the specified enlargement factor of input screen data is combined with the previous line at a constant ratio, thereby converting the predetermined line into a vertically interpolated line. As shown in Fig. 3, the generated screen can be of good quality without jagged diagonal lines, and can be processed in real time, providing an inexpensive device with a small circuit configuration. can do.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the principle of a display screen conversion device according to the present invention, FIG. 2 is a diagram for explaining a vertical interpolation method in the display screen conversion device according to the present invention, and FIG. A diagram showing an example of both sides of the display by the display screen conversion device of the invention, FIG. 4 is a diagram showing an example of performing vertical interpolation in the display screen conversion device of the invention, and FIG. 5 is a diagram showing the display screen conversion device of the invention. FIG. 6 is a diagram showing an example of the relationship between vertical interpolation lines and interpolation coefficients in the display screen conversion device of the present invention; FIG. Figures 8 and 9 are diagrams to explain horizontal interpolation, Figures 8 and 9 are diagrams to explain screen reduction, Figures 10 and 10 are diagrams showing standard double-sided images displayed on a high-resolution screen, Figure 11 The figure shows an enlarged display screen according to a conventional example.゛In Fig. 1, l... frame buffer memory, 2... readout control unit, 3... interpolation coefficient table, 4... first multiplication unit, 5... second multiplication unit, 6... Addition unit, 7... Horizontal interpolation control unit. In the figures, the same reference numerals indicate the same or corresponding parts. (α) (b)? Figure 2 - Enlarged screen Display screen of the present invention Figure 7 Explanatory diagram of the horizontal direction Figure 7 Reduced horizontal diagram Figure 9 Display screen example Figure 10

Claims (1)

[Scope of Claims] A frame buffer memory (1) into which one frame of input screen data is written; and a frame buffer memory (1) that reads the input screen data from the frame buffer memory (1) and overlaps a predetermined line of the screen data according to a specified enlargement factor. a first interpolation coefficient (k_1) that sets a partial number only for the overlapping line and 1 for other lines among all the lines read from the frame buffer memory (1); The second interpolation coefficient (k_2
) and an interpolation coefficient table (3) that stores the data corresponding to the designated enlargement factor; 1 multiplier (
4), a second multiplication section (5) that delays each line data read from the readout control section (2) by one line and multiplies it by the second interpolation coefficient (k_2); and both multiplication sections. An adder (6) that adds the outputs of (4, 5) and stores one line, and reads one line data from the adder (6) using a clock according to the specified enlargement factor and outputs an enlarged screen signal. A display screen conversion device comprising: a horizontal interpolation control section (7);