JPH0723290A - Scroll device - Google Patents

Abstract

PURPOSE:To provide a scroll device where the unnaturalness of the motion of a scroll image (the unidirectional moving of the image) is eliminated and a scroll reproduced image with a smooth motion is obtained. CONSTITUTION:In a scroll device composed by being provided with a frame memory 1 and a scroll control part 2, the device is further provided with a two-dimensional filter 3 and the scroll reproduced image which is unnatural in the motions that the frame memory 1 is converted into an image with smooth motion by performing an interpolation between lines or between picture elements by this two-dimensional filter 3. A correction information generation part 24 and a weighing table 5 are for imparting a weighing coefficient to the weighing circuit of the two-dimensional filter 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll device for scrolling a television image, and more particularly to a scroll device which eliminates the unnatural movement of the scroll image (the image is moving in one direction) and has a smooth movement. This is so that a reproduced image can be obtained.

[0002]

2. Description of the Related Art First, the operation principle of a conventional digital scroll device will be described. Here, in order to facilitate understanding, a scroll display in which an image for three frames moves vertically in 5 seconds, particularly from bottom to top, will be described as an example.

FIG. 1 is a diagram for explaining the operation of scrolling.
For scrolling display of the image signals of 3 frames in 5 seconds, as shown by the vertical line on the right side of the schematic diagram of the image signals of 3 frames, the first position is sequentially shifted by 1 frame. The divided image signals may be sequentially displayed. This shift amount is equal to the image signal (5
A value obtained by dividing the number of lines of the image signal by the number of frames (line / line) when the 25 × n line image signal) is scroll-displayed for τ seconds (the total number of frames is 30 × τ frames).
If you define (frame) as the moving speed of scroll display,
This speed matches. That is, in the case of this example, since the number of lines is 1575 lines and the total number of frames is 150 frames, the moving speed is 10.5 lines / frame, and the shift amount of the start position is 1 when scrolling.
It becomes 0.5 lines / frame.

However, in order to actually perform this using hardware, the image signal is read from the frame memory and displayed. Therefore, the reading is performed in line units (in the case of vertical scrolling) or pixel units (horizontal direction). This can only be done in the case of scrolling), and the shift of the read start position is set to 10 lines and 11 so that the above 10.5 lines / frame can be adjusted by reading the image signals of two frames.
The lines are alternately repeated. According to this, as shown in FIG. 1, when the first (first) television frame signal is generated for the image signals of three frames, the first line (top One frame (that is, 525 lines) from the scan line
1 for the second frame signal, counting from the top scanning line
One frame from the first line (see 2), one frame from the 22nd line counting from the top scanning line on the 3rd sheet (see 3), from the top scanning line on the 4th sheet One frame is counted from the 32nd line (see 4) from the 32nd line, and so on, and the last 150th sheet (see 150) is read while sequentially shifting the read start position. Also, in the case of horizontal scrolling in which the image moves in the left-right direction, it does not differ from vertical scrolling except that lines (scanning lines) are replaced by horizontal pixels.

In the following description, the head position of reading the above television frame signal is referred to as a line address in the frame memory for convenience.

[0006]

As described above, in the conventional scroll device, the scroll control of the scroll image is performed on the basis of the address (vertical scroll: line, horizontal scroll: pixel) corresponding to the head position. The image signals are read out and displayed while sequentially shifting by the number of lines or the number of pixels according to the speed setting.

Further, as described above, the shift amount of the head position when actually reading the image signal using the frame memory is 10 lines / frame (between 1 and 2) and 11 lines / frame (2 and 3). (Between) and 10 lines / frame (between 3 and 4), and so on, a scroll image is displayed by repeating this 10 lines / frame and 11 lines / frame. , The regular display image and the display image shifted by 0.5 line in the vertical direction appear alternately, and the reproduced scroll image is accompanied by a visually unnatural jerky movement.

It is an object of the present invention to read a signal from a frame memory in reproducing a scroll image, even if there is unevenness in the shift amount of the head position as in the prior art. (EN) It is possible to provide a scroll device in which the movement of a display image is smoothed by passing through.

[0009]

To achieve the above object, a scroll device of the present invention comprises a frame memory and a scroll control section, and the scroll control section reads out an image stored in the frame memory. In a scroll device in which the start position is controlled to be sequentially shifted in the vertical or horizontal direction to read out successive television frame signals, the read start position is different from the ideal start position in the case of performing continuous scrolling. In this case, a two-dimensional filter is provided for performing spatial position interpolation in the vertical or horizontal direction of the read television frame signal according to the difference between the read start position and the ideal start position. It is a feature.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 2 is a block diagram showing the basic configuration of the scroll device according to the present invention. In FIG. 2, reference numeral 1 is a frame memory, and 2 is a scroll control unit that controls the frame memory 1 so as to generate a scroll image signal by reading a stored image while shifting the head position from the frame memory 1. The frame memory 1 and the scroll controller 2 are components of a conventional scroll device.

In the above configuration, for example, when an image for 3 frames is scrolled and reproduced for 5 seconds, the signals read from the frame memory 1 are the first, second, third, and fourth signals as described above. About the first image ...
1st line, 11th line, 22nd line, 3 respectively
It is a signal from the second line, ... (Signal at the head position).

On the other hand, the signal of the head position necessary for smoothing the movement of the reproduction scroll image (the image moving in one direction) is 10.5 per frame as described above. Since it is necessary to shift the lines, for the first, second, third, fourth, ... images, the first line, the 11.5th line, and the 2nd line, respectively.
The signals are read from the second line, the 32.5th line, .... In reality, the 11.5 line and 32.5
Since the signal of the line does not exist in the frame memory 1, these lines cannot be read as the line address (head position address).

Therefore, in the present invention, as shown in FIG.
By performing signal processing on the output signal of the frame memory 1 using the dimensional filter 3, the read signals of the second and fourth frames are each as if they were 11.5 lines,
As if read by the line address of 32.5 lines. This technique is known as first-order to higher-order line-to-line interpolating (vertical direction interpolation) using a two-dimensional filter, and a detailed description thereof will be omitted.

FIG. 3 is a block diagram showing an example of a two-dimensional filter used in the present invention. This two-dimensional filter has four 1's
Line (1H) delay element, 20 1 pixel (1P.C.
(Picture Cell) This is a spatial filter of 5 lines × 5 pixels, which is composed of a delay element, 25 weighting circuits (multipliers), and 1 adder as main components, and is composed of multipliers. Coefficient data stored in a coefficient table (ROM) is read out and supplied to the weighting circuit in accordance with correction information described later.

In the configuration of the apparatus of the present invention shown in FIG. 2 again, the scroll image signal obtained from the frame memory 1 and having a jerky motion as it is is the two-dimensional filter 3.
At the same time that the correction information is supplied to the correction information generation unit 4 based on the line address obtained from the scroll control unit 2.
And is supplied to the weighting table 5 (coefficient table (ROM) in FIG. 3). In the weighting table 5, a predetermined weighting coefficient value written in advance in the table is read in accordance with the correction information supplied from the correction information generating unit 4 and is supplied to the two-dimensional filter 3 to perform necessary line-to-line interpolation.

The correction information for reading the weighting coefficient from the weighting table 5 will be described below. Figure 2
In the above, since the scroll control unit 2 actually generates the scroll signal by designating and reading the address of the frame memory 1, the scroll control unit obtains the line address (address of the head position). On the other hand, the line address (ideal start position address) for smoothing the motion of the playback scroll image is also obtained,
The difference between both addresses can be obtained. In the present invention, the obtained difference between the two addresses (in this example, the ideal start position address minus the actual start position address)
Is correction information for determining the weighting coefficient of the two-dimensional filter.

Looking at the case where the image for three frames is scroll-reproduced in 5 seconds, the correction information is
0 line, +0.5 line, 0 line, + for the images of the first, second, third, fourth, ...
0.5 line ... As a result, in this example, the line forming the even-numbered image is +0.5 line,
That is, the pixel information corresponding to the intermediate position between the actual line and the next line (the line after one line) is interpolated by the two-dimensional filter. When the address difference is a negative value, appropriate pixel information between the actual line and the preceding line is interpolated.

FIG. 4 conceptually shows the relationship between the interpolation step between the lines (scanning lines) and the weighting function of the two-dimensional filter. The solid line extending in the vertical direction is the line (-2).
~ (+2), and the four dotted lines between the lines indicate the interpolation steps between the lines. Of the weighting functions shown by the seven lines, the line and the interpolation step are on the horizontal axis, and the relative value of weighting is on the vertical axis. The curve corresponding to interpolation step 0 is a solid line, and the others are dotted lines. These are shown, but these are the solid curves translated left and right in 0.2 interpolation steps.

Referring to FIG. 4, assuming that the correction information is +0.5 as in the above-mentioned example, among the above seven weighting functions, folding is performed at the center position (interpolation step) between line (0) and line (+1). A symmetric weighting function, that is, a curve assumed between the rightmost curve and the first curve from the rightmost curve, is selected, and this curve and lines (-2), (-1), (0) are respectively selected. , (+1) and (+2)
The value (weight) of the intersection point with is supplied to the weighting circuit of the two-dimensional filter shown in FIG.

The various signal processes described above are performed in real time, the weighting function is made constant according to the interpolation step, and this is selectively read from the weighting table to shorten the calculation process. Further, the transmission frame memory 6 in FIG. 2 starts from one frame period in order to compensate for the phase delay of the image signal (5 lines × 5 pixels in the case of the two-dimensional filter shown in FIG. 3) caused by the interpolation processing by the two-dimensional filter. This is for giving a delay obtained by subtracting the phase delay amount to the output image signal of the two-dimensional filter 3.

Although the above-described embodiment relates to the vertical scrolling, in the case of the horizontal scrolling, an interpolation step is set between each pixel in the horizontal direction and the weighting coefficient of the two-dimensional filter is set based on the correction information. The only difference is that interpolation between pixels (horizontal direction interpolation) is performed, and the circuit configuration of the device, signal processing, etc. are essentially the same as those for vertical scrolling.

In the above description, in order to facilitate understanding of the present invention, it is assumed in the description of the prior art that all 525 lines of the image signal for one frame are displayed. Since the generated image signal includes the vertical blacking period (42 lines), the number of displayable scanning lines (the number of effective scanning lines) is 48.
It is 3 lines (= 525 lines-42 lines). As described above, regarding the image signal composed of 525 lines, 3
The moving speed of the scroll display was 10.5 lines / frame when the frame portion was scroll-displayed in 5 seconds, but when the similar scroll display was performed for the image signal composed of 483 lines, the moving speed was 9.66 line. /
It becomes a frame. However, it is not related to the essence of the present invention as to how many lines each frame of the image signal is composed of. It is possible to obtain the correction information based on these various parameters and perform the inter-line or inter-pixel interpolation. Good.

[0023]

According to the present invention, the scroll reproduction image of the jerky motion from the conventional device can be interpolated between lines or pixels by a two-dimensional filter to smooth the motion of the reproduction scroll image. ,
Even in that structure, a large-scale circuit is not required, so that it can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a scrolling operation.

FIG. 2 is a block diagram showing a principle configuration of a scroll device according to the present invention.

FIG. 3 is a diagram showing a configuration of an example of a two-dimensional filter used in the present invention.

FIG. 4 is a diagram conceptually showing the relationship between the interpolation step between lines and the weighting function of the two-dimensional filter.

[Explanation of symbols]

 1 frame memory 2 scroll control unit 3 two-dimensional filter 4 correction information generation unit 5 weighting table 6 transmission frame memory 1H 1 line delay element 1P. C. 1 pixel delay element

Front page continuation (72) Inventor Yutaka Morii 2-2-1 Jinnan, Shibuya-ku, Tokyo Inside the Japan Broadcasting Corporation Broadcasting Center (72) Inventor Hidenori Okada 8-2-56 Nanko East, Suminoe-ku, Osaka-shi, Osaka Eretec Su Co., Ltd.

Claims (2)

[Claims] 1. A frame memory and a scroll controller are provided, and the scroll controller controls to sequentially shift a read start position of an image stored in the frame memory vertically or horizontally. In a scroll device that reads out a television frame signal, if the read start position is different from the ideal start position when performing continuous scrolling, the difference between the read start position and the ideal start position is determined. 2 for performing spatial position interpolation of the read television frame signal in the vertical or horizontal direction, respectively.
A scroll device having a dimensional filter. 2. The scroll device according to claim 1, further comprising a weighting table for controlling a weighting coefficient of the two-dimensional filter according to a difference between the read start position and the ideal start position. Scroll device characterized by.