JPH0693773B2 - How to increase the number of scanning lines - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for enlarging the number of scanning lines of a component video signal to an integral multiple, and a system for displaying a single enlarged screen using a plurality of video monitors at an event site or the like. For the enlargement processing of the video signal used in the above, or for the digital signal processing of the video signal in the enlargement apparatus that restores the reduced image in combination with the apparatus that reduces the image provided on the transmission side to improve the transmission efficiency of the image data. Can be applied.

[0002]

2. Description of the Related Art A video system has been developed which can provide a video with a high effect by dividing a video image of a television broadcast or the like onto a plurality of video monitors and projecting it to form one large screen as a whole. Has been done. When supplying a video signal to such a system, it is necessary to enlarge the length and width of the screen according to the number of combinations of video monitors.

Since the amount of information in the signal component of the screen is large in the horizontal direction, it is relatively uncomfortable even if the sampling frequency is appropriately set and the signal is magnified to obtain a screen of a desired magnification. It is easy to get a magnified screen that is not natural. However, in the vertical direction, the number of scanning lines is as small as 525 in the case of the standard television system of Japan, for example, and since one screen is divided into two fields, the information density is further halved. In the case of enlarging, it is necessary to newly generate a number of scanning lines according to the magnification based on such a small amount of information. So if you want to get an enlarged screen,
The main point is how to process vertical information, which has an extremely smaller amount of information than horizontal information, while keeping image deterioration to a minimum.

Conventionally, there are two methods for increasing the number of scanning lines.
There are two methods, that is, one field expansion and 60 frame expansion every 60 Hz, which will be described below.

First, a conventional field enlarging method will be described with reference to FIGS. 9 and 10. Figure 9
(A) shows a part of the scanning lines forming one field, and in reality, 262.5 scanning lines are formed per field. It should be noted that each scanning line is exaggerated and schematically shown for the sake of clarity.

In order to double the number of scanning lines based on the scanning lines of FIG. 9 (a), as shown in FIG. 9 (b), adjacent scanning lines are interpolated to be adjacent to each other. One new scan line is generated between the scan lines. That is, for example, each scan line is 1 / th between the first scan line and the second scan line.
A new one is created by adding 2 to these.

In order to triple the number of scanning lines based on the scanning line of FIG. 10A, as shown in FIG. 10B, the upper scanning is performed between adjacent scanning lines. One line is obtained by adding 2/3 of the line and 1/3 of the lower scanning line, and one line is obtained by adding 1/3 of the upper scanning line and 2/3 of the lower scanning line. .

According to this method, for example, in the case of doubling, the same scanning line is simply made to appear once for each scanning line to make a total of two, so that the number of scanning lines is doubled. Compared with other primitive methods, each newly generated scan line contains a part of the original scan line component, so that an image having a correlation with the original field scan line can be obtained. is there.

Next, a method of enlarging one frame will be described with reference to FIGS. 11 to 13. In this method, the first field at the time of enlargement is created based on one frame composed of the first and second fields, and then the second field is created based on this first field.

FIG. 11 shows the case of double processing.
The doubled first field is the original scanning line of the first field (shown by the solid line) and the original scanning line of the second field (shown by the broken line) as they are, as shown in FIG. , The doubled second field is generated by performing interpolation with the average of two adjacent 525 scanning lines of the doubled first field as shown in FIG. .

FIG. 12 shows the case of triple processing.
As shown in FIG. 10A, the original scanning lines (solid lines) of the original first field are output as they are in the first field which is three times as large as that of the original scanning lines of the original first field. Three
And a scan line of 1/3 of the original second field immediately below and a scan line of 1/3 of the scan line of this original second field and the scan of the original first field immediately below Line 2
And scan lines added with / 3 are generated, and as a whole, 1.5 times the number of scan lines in the original 1 frame, that is, 3 times the number of scan lines in the first and second fields is generated. Will be made. As shown in FIG. 12B, the triple field is generated by interpolating the average of two adjacent scanning lines of the triple field.

Similarly, FIG. 13 shows the case of the quadruple processing. In the quadruple first field, the original scanning line of one frame is output as it is, and the average of two adjacent scanning lines is obtained. By interpolating in, the number of scanning lines in terms of the number of scanning lines in the field is four times as large.
The second field, which is 4 times larger, is 4 times as shown in FIG.
It is generated by performing interpolation with the average of two adjacent scanning lines of the doubled first field.

As described above, the method of enlarging one frame is as follows.
By generating the number of scanning lines that is half the magnification to be enlarged from one frame as the first field and further generating the second field from this first field, an image with very high resolution can be obtained especially for still images. It is what is done.

[0014]

By the way, in the above-mentioned enlargement method, the enlargement method in the field does not correlate with each other in the enlarged field. Therefore, when an interlaced video signal is inputted, the enlargement is performed. Pitch jitter, which appears as a phenomenon in which an image shakes in the vertical direction, occurs, and the deterioration of the resolution becomes large.

On the other hand, in the method of enlarging by the frame, the pitching jitter generated in the method of enlarging in the field does not occur, and an image in which the resolution of the still image is less deteriorated can be obtained. However, for moving images, distortion of the moving distance between fields occurs according to the enlargement ratio. That is, for example, when an image in which a vertical straight line moves laterally is magnified, the vertical straight line is displayed in a form of a sawtooth wave having a mountain whose height is proportional to the magnification.

In order to prevent such distortion from occurring in a moving image, the moving image / still image is discriminated, the still image is enlarged by the above-mentioned frame, and the in-field interpolation is performed for the moving image. Although a method of using it has been proposed, it is very costly to realize such a method because the circuit scale in hardware becomes large, and it is very difficult to distinguish between moving images and still images Has not been found, resulting in unnatural motion screens when switching between those methods.

The present invention has been made in view of the above circumstances, and provides a method for enlarging the number of scanning lines which is capable of obtaining a sufficiently enlarged image for both moving images and still images and which is advantageous in terms of hardware and cost. The purpose is to provide.

[0018]

For the above object, according to the present invention, the interlaced continuous scanning line signals of the first field and the second field are taken into a frame memory, and based on the signals in this memory. A non-interlaced frame obtained by averaging image movements is generated for each field, and then (N-1) scan lines (N-1) are provided between the scan lines forming the non-interlaced frame.
Is an integer) to increase the number of scanning lines by N times, and these (N-1) scanning lines generated at this time are converted into signals of continuous scanning lines forming a non-interlaced frame. There is provided a method for enlarging the number of scanning lines, which is characterized in that a product obtained by multiplying a weight according to a distance from is added and generated.

[0019]

According to the above-mentioned means, the non-interlaced 1 which is obtained by averaging the motions of the image from the first field and the second field of the interlace system stored in the frame memory.
A frame is created for each field, and one frame is expanded and interpolated based on this non-interlaced one frame.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the method of enlarging the number of scanning lines according to the present invention illustrated in FIGS. 1 to 8 will be described in detail below.

According to the present invention, first, before performing the enlargement processing, the movement of the image is averaged so that the movement of the moving image at the time of enlargement does not become unnatural. Therefore, the scan line signals of the first field and the second field are
Capture it into a memory that can store frames,
Remake into one non-interlaced frame in which motions are averaged for each field (for example, every 60 Hz). An example of the method will be described with reference to FIG.

In FIG. 1A, the scanning line (shown by a solid line) of the first field and the second scanning line are stored in the memory for easy understanding.
Field scan lines (indicated by dashed lines) alternate 1
It is shown as forming a frame. Based on this one frame, the averaging of the motion is performed by adding the halved scanning lines of the first field and the halved scanning lines of the second fields located on the upper and lower sides thereof. By doing so, one scanning line is formed, and this is sequentially repeated to form a scanning line for one frame as shown in FIG. In a non-interlaced frame in which motions are averaged by this method, the luminance center in the vertical direction does not move, and there is little blurring in the moving image, which makes the image always look hazy. Note that this process is
This is performed for three RGB signals. The same applies to the case of the luminance signal and the color difference signal.

FIG. 2 shows another embodiment for performing the averaging process of the motion of the image. FIG. 2A shows the scanning for one frame in the non-interlaced form stored in the memory as in the case of FIG. A line is shown. Based on this one frame, motion averaging is performed by simply averaging two adjacent scanning lines from the top to form one scanning line, and scanning for one frame is performed as shown in FIG. Make a line. In the frame made by this method, the shift of the luminance center is 1 in the input field.
/ 4, which is practically fully usable.

Now, in the case of increasing the number of scanning lines, FIG.
Alternatively, it is performed on the basis of a non-interlaced frame every 60 Hz created by the method of FIG. Hereinafter, the enlargement method at various magnifications will be described.

FIG. 3 shows an embodiment in the case of magnifying twice, in which (a) shows the non-interlaced frame made in FIG. 1 or 2, and (b) and (c). Indicates a first field and a second field formed on the basis of them, respectively. Here, in order to make the description easy to understand, the scanning lines forming the non-interlaced frame are denoted by symbols, ...

In the case of the 2 × enlargement processing, the scanning lines of the non-interlaced frame and the scanning lines formed by multiplying two adjacent scanning lines by ½ weights and adding them are sequentially output. , The number of scanning lines is doubled, and the odd-numbered scanning lines constitute the first field, and the even-numbered scanning lines constitute the second field.

FIG. 4 shows an embodiment in which the image is enlarged three times. In the case of the 3 × enlargement processing, the scanning lines of the non-interlaced frame and the two scanning lines newly inserted between these scanning lines are output, but the two scannings inserted at this time are output. The lines are obtained by multiplying the scan lines above them, for example, the components of by 2/3, 1/3, and the scan lines below them, by the weights of 1/3, 2/3, and adding them. Note that in the embodiment of FIG. 4, 3/8 and 5/8 are used as the weights, but this is a constraint due to the configuration of the hardware that executes these 1/3 and 2/3 calculations. For example, a simple 8
This is because the values are approximated to 1/3 and 2/3 that can be calculated by bit shift after addition using a bit shift register.

FIG. 5 shows an embodiment in the case of magnifying 4 times, in which scanning lines of a non-interlaced frame and three scanning lines newly inserted between these scanning lines are output. It shows the situation. Each newly generated scan line has the components of the scan lines above them 3/4, 2/4, 1 /
4 by 4 and scan line components below them by 1/4, 2
It is assumed that the weights are multiplied by / 4 and 3/4 and added.

FIG. 6 shows an embodiment in the case of magnifying 5 times. Essentially, in the same manner as described above, four scanning lines obtained by multiplying the weights inversely proportional to the distances from the scanning lines and adding them are inserted between the scanning lines of the non-interlaced frame. It can be generated. However, in the case of the embodiment shown in FIG. 6, the data created at the time of quadrupling and the scanning lines of the non-interlaced frame are output two by two. This is because with a magnification of 5 times or more, it is practically sufficient without having to newly generate the number corresponding to the magnification up to 4 times, and since the data at 4 times can be used as is, The reason is that a great simplification can be realized.

FIG. 7 shows an embodiment in the case of enlarging by 6 times. Two scanning lines of a non-interlaced frame are used, and data at 4 times and data in the middle at 4 times are twice. The desired number is realized by outputting.
By adopting the method of using the data at 4 times as it is, the data of the non-interlaced frame at 8 times and the three data generated at 4 times are used twice respectively. Then, after 9 times, some use the same data three times.

Therefore, in the case of magnifying ten times as shown in FIG. 8, two are used three times and two are used twice.

[0032]

As described above, according to the present invention, a non-interlaced frame in which the motion of an image is averaged for each field is created from the interlaced first field and second field, and this is used as a basis. Since the enlargement interpolation processing is performed as described above, it is possible to obtain a sufficiently enlarged image for both still images and moving images.

In the preferred embodiment of the present invention, the weights at the time of 3 times enlargement are set to 5/8 and 3/8, and the calculation approximate to 2/3 and 1/3 is realized by simplified hardware. can do.

Further, in the preferred embodiment of the present invention, at the time of enlarging by 5 times or more, at least one of the scanning lines of the non-interlaced frame and the scanning line generated at the time of 4 times is used by overlapping. The hardware can be greatly simplified.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a method of averaging image movements in a method of enlarging the number of scanning lines according to the present invention.

FIG. 2 is an explanatory diagram showing another method for averaging the movement of an image in the method of enlarging the number of scanning lines according to the present invention.

FIG. 3 is an explanatory diagram showing a method of doubling an image in the vertical direction in the method of enlarging the number of scanning lines according to the present invention.

FIG. 4 is an explanatory diagram showing a method of enlarging an image three times in the vertical direction in the method of enlarging the number of scanning lines according to the present invention.

FIG. 5 is an explanatory diagram showing a method for magnifying an image four times in the vertical direction in the method for enlarging the number of scanning lines according to the present invention.

FIG. 6 is an explanatory diagram showing a method of magnifying an image five times in the vertical direction in the method of expanding the number of scanning lines according to the present invention.

FIG. 7 is an explanatory diagram showing a method of enlarging an image six times in the vertical direction in the method of enlarging the number of scanning lines according to the present invention.

FIG. 8 is an explanatory diagram showing a method of enlarging an image 10 times in the vertical direction in the method of enlarging the number of scanning lines according to the present invention.

FIG. 9 is an explanatory diagram showing a conventional method of enlarging an image twice in the vertical direction by a field enlarging method.

FIG. 10 is an explanatory diagram showing a conventional method of enlarging an image three times in the vertical direction by a field enlarging method.

FIG. 11 is an explanatory diagram showing a conventional method of enlarging an image by a factor of 2 in the vertical direction by a frame enlarging method.

FIG. 12 is an explanatory diagram showing a conventional method of enlarging an image three times in the vertical direction by a frame enlarging method.

FIG. 13 is an explanatory diagram showing a conventional method of enlarging an image four times in the vertical direction by a frame enlarging method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 5/68 C 9068-5C

Claims (6)

[Claims] 1. A non-interlaced frame obtained by averaging the interlaced scanning line signals of the first field and the second field into a frame memory and averaging the motion of the image based on the signal in this memory. , And then generate (N-1) scan lines (N is an integer) between the scan lines forming the non-interlaced frame to increase the number of scan lines by N times. , (N-1) scanning lines generated at this time are generated by adding signals obtained by multiplying the signals of continuous scanning lines forming a non-interlaced frame by a weight corresponding to the distance from these scanning lines. A method for enlarging the number of scanning lines characterized in that. 2. The method according to claim 1, wherein a non-interlaced frame obtained by averaging the motion of an image has a scan line of a first field and a scan line of a second field alternately arranged in the memory. Assuming that a frame is formed, a signal obtained by adding the signal obtained by halving the nth scanning line and the signal obtained by halving the (n-1) th scanning line and the (n + 1) th scanning line in the memory is added. Is set as the n-th scanning line, the method for enlarging the number of scanning lines. 3. The method according to claim 1, wherein a non-interlaced frame obtained by averaging motions of an image has a scan line of a first field and a scan line of a second field alternately arranged in the memory. Assuming that a frame is formed, the nth scan line and the (n + 1) th scan line in the memory are each 1 /
2. A method for increasing the number of scanning lines, wherein the number of scanning lines is increased by adding the signal set to 2 to the nth scanning line. 4. The method according to claim 1, wherein the weight is on the nth scanning line with respect to the (n-1) th scanning lines generated before and after the nth scanning line of the scanning lines forming the non-interlaced frame. (N-1) / N, (N-2) / N, in order from the closest one
... A method of increasing the number of scanning lines, which is set to 1 / N. 5. The method for enlarging the number of scanning lines according to claim 4, wherein the weights when N = 3 are 5/8 and 3/8. 6. The method according to claim 1, wherein when N ≧ 5, the weights are 3/4, 2/4, and 1/4, and the scan lines of the non-interlaced frames are formed. At least one of the scan lines generated in between is the same as one of the scan lines forming the non-interlaced frame and / or one of the scan lines generated from the scan lines forming the frame. And a method for increasing the number of scanning lines.