JP3234149B2 - Video signal processing method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a video signal processing method and apparatus for converting an interlaced video signal into a non-interlaced video signal.

[0002]

2. Description of the Related Art NTSC (National Television System)
Committee) system and other television broadcasting scanning systems are premised on the interlaced system, and inevitably the cathode ray tube displays widely used in current television receivers also display images using the interlaced system. It is carried out. On the other hand, in a liquid crystal display (hereinafter, referred to as an LCD), which is expected to spread in the future because of space saving and power saving, as shown in FIG. By displaying images in a non-interlaced manner in which the images are sequentially scanned one by one, an image with less flicker is obtained.

[0003] However, the interlaced system is shown in FIG.
As shown in FIG.
Since n (n is a line number) and the even field On are alternately displayed, the video signal input during one field period is only half of the effective display screen. Therefore, in order to display the video signal on a non-interlaced display, the video signal between scanning lines that are not actually transmitted in the same field is interpolated by some kind of signal processing or the like. Must be converted to non-interlaced format.

[0004] As the above-mentioned interpolation method, there are field interpolation in which pixel data to be interpolated is interpolated by pixel data one field before the current field in which data of the pixel to be interpolated is displayed, and data of the pixel to be interpolated is selected from one of upper and lower adjacent pixels. And line interpolation for interpolating with pixel data of

However, in the field interpolation, since the video signals of two fields having an input time difference are simultaneously displayed on the display, the vertical resolution of the display is increased. A disadvantage is that pixel data is left behind, resulting in distorted display images. For example, FIG.
Reference numeral 2 denotes a display character which moves in the horizontal direction at a speed of 1 pixel / field by field interpolation. Here, although the letter "H" should be displayed, the display image alternates between odd lines and even lines on a field-by-field basis, so that a movement of one pixel indicated by the reference numeral α1 per field occurs. The displayed image is distorted.

On the other hand, the line interpolation is suitable for the reproduction of a moving image because the display image is completely replaced every field, but the same data is displayed over two lines. Is inferior to the above. For example, while FIG. 13 shows a triangle (still image), the display indicated by a broken line of reference numeral α2 (display by field interpolation) and the display indicated by a solid line of reference numeral α3 (display by line interpolation) are compared. Then, it can be seen that the display by the line interpolation is coarser in the display of the oblique line portion, and the resolution in the vertical direction is inferior to the display by the field interpolation.
That is, it can be said that field interpolation is suitable for displaying a still image and line interpolation is suitable for displaying a moving image.

Therefore, as a prior art which utilizes the characteristics of the field interpolation and the line interpolation and uses them together, Japanese Patent Application Laid-Open No. 63-156487 discloses a "non-interlace method in a television receiver". . In the above publication, when converting an interlaced video signal into a non-interlaced video signal, the signal levels of pixel data at the same position in the previous field are compared, and if the difference is smaller than a predetermined value, “no motion” As
Interpolate using pixel data at the same position in the previous field,
If the difference is larger than the predetermined value, it is determined that there is "motion" and interpolation is performed using pixel data of lines above and below the current field. When performing this interpolation, one of the pixel data of the upper and lower lines is used as it is, or the pixel data of the upper and lower lines is averaged and used.

FIG. 14 shows an example of the configuration of a video signal processing device 21 to which the above-described prior art concept is applied. FIG.
, The video signal processing device 21 includes three field memories m1, m2, and m3 connected in series, each of which can store a video signal for one field. Further, the output signal s of the field memory m1
2 and a level difference between an output signal s4 of the field memory m3 and a predetermined threshold value s10, and a motion detection signal s
5, a changeover switch sw1 for switching which video signal is sent to the video signal s6 to be output by the motion detection signal s5, a line memory 11 for storing one line of the video signal s6, A switching switch sw2 for switching which video signal is supplied to the output video signal s11 by the switching signal s9, and a switching signal generating circuit 23 for generating the switching signal s9 from the horizontal synchronization signal s8 of the display are provided.

In the above, the changeover switch sw1 selectively switches the field memory m1 by the motion detection signal s5.
And the video signal s3 from the field memory m2 are output.
The video signal s2 from the field memory m1 and the video signal s from the line memory 11 are selectively provided by the switching signal s9.
7 is output as an output video signal s11.

FIGS. 15 and 16 are diagrams showing the states of the signals of the respective parts flowing in the even-numbered field period, and FIGS. 17 and 18 are diagrams of the signals of the respective parts flowing in the odd-numbered field period. It is a figure showing the state of. In FIGS. 15 and 17, 1H is the input terminal p.
1 indicates one horizontal synchronizing period (one line) of the video signal s1 input, 1h indicates one horizontal synchronizing period of the video signal s11 output from the output terminal p2, and converts the interlaced input video signal into a non-interlaced video signal. , The output video signal s11 has a signal rate twice that of the input video signal s1.

The meaning of the combination of three alphanumeric characters shown in FIGS. 15 and 17 is the same as the first half of the combination of six alphanumeric characters in FIGS. 16 and 18.
First, the leftmost number indicates the order of field entry,
The next letter indicates whether the field is odd or even. O
Denotes an odd number, and E denotes an even number. The next number indicates the input order of the line signal in the field.

Further, in FIGS. 16 and 18, a three-digit number following the above three characters indicates an input order of pixel signal data in a corresponding line. Therefore,
For example, the signal represented by 230002 is the second signal on the third line of the second odd field.

Next, details of the operation of the video signal processing device 21 and the signals flowing through each section will be described. Referring to FIGS. 14 to 16, in field memory m1, input video signal s1 from input terminal p1 is written, and at the same time, video signal s input one field period earlier.
The video signal s1 is read out in the first 1h period of one horizontal synchronization period (= 1H) of the video signal s1 at twice the speed at the time of writing. Further, the write timing and the read timing of the field memories m2 and m3 are also adjusted in accordance with the read timing of the field memory m1.

That is, the video signal s3 read from the field memory m2 is a video signal one field before the video signal s2 read from the field memory m1, and similarly, the video signal s4 read from the field memory m3 is read from the field memory m2. This is a video signal one field before the video signal s3 to be read. Therefore,
The video signal s4 can be said to be a video signal one frame before the video signal s2. The video signal s2 read from the field memory m1 is sent to the changeover switches sw1 and sw2, and at the same time, sent to the comparator 22 for motion detection with the video signal s4 one frame before.

The comparator 22 compares the level difference between the video signal s2 and the video signal s4 with a set threshold s10 input from the input terminal p2, and compares the level difference with the set threshold s10.
If it is larger than the threshold value s10, the level "H" is output as the motion detection signal s5. If the level difference is equal to or smaller than the set threshold s10, the level "L" is output as the motion detection signal s5. I do. Thus, the motion detection signal s5 obtained from the comparator 22 by the above method is sent to the changeover switch sw1 as a changeover signal of a pixel to be interpolated.

In the above, when the motion detection signal s5 outputs the level "H", the changeover switch sw1 selects the video signal s2 which is the read output of the field memory m1, and the motion detection signal s5 has the level "L". When outputting, the changeover switch sw1 is set to the field memory m.
The video signal s3, which is a readout output of No. 2, is selected and output to the line memory 11 as a video signal s6. In the line memory 11, writing is performed at the timing of the video signal s6, reading is performed in the latter half 1h of the same 1H period of the horizontal synchronizing signal of the video signal s1, and output as the video signal s7 to the changeover switch sw2.

In the changeover switch sw2, based on the changeover signal s9 generated by the changeover signal generation circuit 23 from the horizontal synchronization signal s8 of the display input from the input terminal p3, the first half of one horizontal synchronization period of the video signal s1. During the 1h period, the video signal s2 is selected. During the last 1h period, the video signal s7, which is the readout output of the line memory 11, is selected as the interpolated pixel signal, and sent to the subsequent display (not shown) as the output video signal s11. At this time, if the source of the video signal s11 is the video signal s2 read from the field memory m1, the interpolation method for this pixel is line interpolation. If the source of the video signal s3 is the video signal s3 read from the field memory m2, the interpolation method for this pixel is used. The method can be called field interpolation. It should be noted that motion detection of video is performed in pixel units, and pixel interpolation is also performed accordingly.

The above is for explaining the state of the signal in the even-numbered field period.
7 and FIG. 18. By detecting “presence or absence of motion” as described above, and switching between field interpolation and line interpolation based on the detection result, it is intended to realize both a high-resolution still image and a distortion-free moving image.

[0019]

However, the interpolation by the above-described motion detection method has a problem that when the display image moves in the horizontal direction, the contour of the display image is distorted. For example, assuming that the line interpolation is performed by the pixel immediately above, a window 31 of 3 × 3 pixels is moved rightward at a speed of 1 [pixel / field] on the display 30 shown in FIGS. Consider the case of horizontal movement. In the figure, XE is displayed on the display 30.
Lines from 2 to XE4 (X is optional) and 2nd to 8th
The area up to the pixel is shown, and the arrow in the figure indicates the direction in which the pixel is interpolated.

As shown in FIG. 19A, in the first field, since the window 31 is in a stationary state, there are no pixels for which motion is detected, and the display on the display 30 is all field-interpolated. In the next second field, as shown in FIG.
1 horizontally moves rightward by one pixel from the state of the first field. At this time, since the field is an even field, X
Only the lines O2 and XO3 are updated, and the other lines are interpolated. At this time, since motion is detected in the pixels XO2003, XO2006, and XO3006, the pixels XE3003, XE3006, and XE4006 below the pixel are respectively set to the pixels XO2003,
The interpolation is performed by the video signals of XO2006 and XO3006, and the window 31 is distorted by the pixel XE4006.

In the next third field, FIG.
As shown in (c), the window 31 further horizontally moves rightward by one pixel from the state of the second field. At this time, since the field is an odd field, XE2, XE
3, only the line XE4 is updated and the other lines are interpolated. Therefore, the pixel XE4006 is erased and motion is detected in the pixels XE3004 and XE3007.
4. XO3007 is interpolated by the video signals of pixels XE3004 and XE3007, respectively. However, since no motion is detected in the line XE2, the line XO2 remains displayed in the second field, and the pixels XO2004 and XO2007 cause the window 3 to be displayed.
1 is distorted. As described above, the contour of the image is distorted due to the horizontal motion of the displayed image only by the pixel interpolation based on the conventional motion detection.

An object of the present invention is to provide a video signal processing method and apparatus capable of preventing distortion of a displayed video when converting an interlaced video signal into a non-interlaced video signal.

[0023]

According to a first aspect of the present invention, there is provided a video signal processing method, wherein a non-interlaced image is compared with an interlaced current field with respect to an interlaced current field. In the video signal processing method for converting an interlaced video signal of two fields and one frame supplied from a video signal source into a non-interlaced video signal by comprising the interpolation data, the first pixel on the interpolation data In contrast, a pixel at the same position in the previous field on the non-interlaced image of the first pixel is defined as a second pixel,
In the non-interlaced image, a pixel on the line immediately before the line to which the first pixel belongs in the current field, and a pixel adjacent to the first pixel is a third pixel, and one line of the line to which the first pixel belongs When a pixel on the subsequent line and adjacent to the first pixel is a fourth pixel, the second pixel on the same line as the second pixel
When the outline of the image is detected between the pixels located on both sides of the pixel, and at least one of the third pixel and the fourth pixel detects the motion with respect to the previous frame, the third pixel and the fourth pixel are detected. It is characterized in that the signal level of the first pixel is interpolated based on the signal level of the pixel on the side on which motion detection has been performed among the fourth pixels.

As described above, when the first pixel is interpolated, if both the contour detection of the image and the motion detection of the image are performed, the interpolation is performed by the pixel on the side where the motion detection is performed. By doing so, even when the image is moved in a direction parallel to the line, it is possible to suppress the disturbance of the contour in the direction intersecting the line.

According to a second aspect of the present invention, in order to solve the above-mentioned problem, a non-interlaced image is composed of an interlaced current field and interpolated data for an interlaced current field. In the video signal processing apparatus for converting a 2-field 1-frame interlaced video signal supplied from a video signal source into a non-interlaced video signal,
A second pixel signal deriving means for deriving a signal level of a second pixel existing at the same position of the first pixel in the interpolation data one field period before, and a same pixel as the first pixel on a non-interlaced image On top, first
A third pixel signal deriving unit that derives a signal level of a third pixel adjacent to the first pixel while being on a line one line before the line to which the pixel belongs, and a line one line after the line to which the first pixel belongs A fourth pixel signal deriving means for deriving a signal level of a fourth pixel adjacent to the first pixel is provided, and the signal level of the second pixel and the fourth pixel signal deriving means are determined on the same line as the second pixel. A contour detection means for comparing the signal level of a pixel adjacent to the pixel and outputting a contour detection when the difference is equal to or greater than a predetermined threshold value; and a signal level of the third pixel and a pixel one field before the third pixel. First comparing means for comparing the signal levels of the fourth pixel and the signal level of the pixel one field before the fourth pixel and outputting the detection of the motion when the difference is equal to or greater than a predetermined threshold value. Compare with Interpolating the signal level of the first pixel on the basis of the detection results of the contour detection means and the first and second comparison means, the second comparison means outputting motion detection when the difference is equal to or greater than a predetermined threshold value. An interpolation signal switching means for switching a pixel to be provided is provided. As the signal level for interpolating the first pixel, the interpolation signal switching means detects the contour of the contour detecting means and operates the first and second comparing means. If not all or only at most one of the three detection results is detected, the second
When the signal level of the pixel is selected, and when both the first and second comparing means detect the motion, the signal level of the third pixel or the fourth pixel is selected, and the contour detecting means detects the contour, When only one of the first and second comparison means detects a motion, the signal level of the pixel whose motion is detected is selected from the third pixel and the fourth pixel.

In the above arrangement, the outline of the image is detected by the outline detecting means, and the movement of the pixel which belongs to the adjacent line and is directly adjacent is detected by the comparing means. Interpolation by two pixels, that is, field interpolation, is applied to obtain high image quality.
Alternatively, interpolation by the fourth pixel, that is, line interpolation is applied. At this time, in the second pixel, which is the pixel before the first pixel, the presence or absence of the contour of the image with respect to the previous and next pixels on the same line is determined. The presence / absence of motion detection at the third and fourth pixels for interpolation is detected. When both the contour detection and the motion detection of the video are performed, one of the third and fourth pixels is detected. The interpolation based on the signal level of the pixel on which the motion is detected, that is, the line interpolation is performed, so that a moving image whose contour formed in the direction parallel to the line in the video is not disturbed can be obtained. In either case, high-quality display can be realized.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a video signal processing device 1 according to an embodiment of the present invention.
For example, it is used for a liquid crystal television device, and therefore, a reception signal of an NTSC television broadcast is separated from R, G or B color signals and input from an input terminal P1. The same configuration as 1 is provided in common for three sets. Note that such video signal processing may be performed with the composite video signal as it is.

In order to obtain a video signal to be interpolated, the video signal processing device 1 is capable of storing video signals for one field each, and has three field memories M1 connected in series with each other. , M2, M3, and delay circuits 2-5 for delaying the video signal for one pixel, respectively.
And a line memory L capable of storing video signals for one line
1 to L5.

In the video signal processing device 1,
H: h = 1: 1 between the horizontal synchronization cycle H of the input video signal and the horizontal synchronization cycle h of the output video signal.
There are two relationships. In the field memory M1, when a video signal is supplied, the input video signal is input at the same time as the input of the video signal at twice the speed as when the video signal input one field period ago is input. The signal is output in the latter half 1h of the 1H period, and the input / output timing of the field memories M2 and M3 is synchronized with the output timing from the field memory M1. On the other hand, the line memories L1 to L1
Since L5 has a memory for one line, the video signal output for the input video signal is the video signal of the previous line. However, in the line memory L2, since the output signal has a period of 1h, the same video signal is output twice.

First, when the input video signal S1 is input to the input terminal P1 to the field memory M1, as described above,
The video signal S2 is output at twice the speed. The video signal S2 is input to the field memory M2 and the delay circuit 2. At this time, the video signal S3 one field period before the video signal S2 is output from the field memory M2 at the above timing, while the delay is output. The circuit 2 outputs a video signal S5 one pixel before the video signal S2, and inputs the video signal S5 to the line memory L2. As a result, the line memory L
2 outputs a video signal S6 one line before the video signal S5. Further, the video signal S6 is stored in the line memory L
3 and a video signal S7 one line before the video signal S6 is output.

On the other hand, the video signal S3 output from the field memory M2 is input to the field memory M3 and the line memory L1. At this time, a video signal S4 one field before the video signal S3 is output from the field memory M3, while a video signal S8 one line before the video signal S2 is output from the line memory L1.
The video signal S8 is input to the delay circuit 4 to obtain a video signal S9 one pixel before the video signal S8. Further, the video signal S9 is input to the delay circuit 3 and one pixel before the video signal S9. Is obtained.

On the other hand, the video signal S4 output from the field memory M3 is input to the delay circuit 5. And
From the delay circuit 5, a video signal S11 one pixel before the video signal S4 is output and input to the line memory L4.
As a result, 1 of the video signal S11 is output from the line memory L4.
The video signal S12 before the line is output. Further, the video signal S12 is input to the line memory L5, and a video signal S13 one line before the video signal S12 is output.

As described above, for the input video signal S1,
Video signals S2 to S13 are obtained. These video signals S
In order to determine the interpolated pixel data S17 to be described later using 2 to S13, the video signal processing apparatus 1 includes an edge detector 6, an interpolation data switching circuit 7, comparators 8 and 9, and a switching signal generation circuit 10 And a changeover switch SW1. Then, the video signal processing device 1 switches between the video signal S6 and the interpolated pixel data S17 to output the output video signal S2.
As 3, output from the output terminal P6.

The operation for obtaining the interpolated pixel data S17 will be described below. First, video signals S8 to S10 are input to the edge detector 6, and a set threshold S20 is input from an input terminal P3. The video signal S9 corresponds to a signal one field before the video signal S6. At this time, for example, if the video signal S6 exists in the even field, the video signal S9 exists in the odd field, and the display position where each is displayed is the display position. The image signal S6 is shifted by one line above, and the image signal S6 is shifted by one line.
Corresponds to the pixel immediately below. Similarly, the video signal S7
Corresponds to the pixel immediately above the video signal S9. The video signal S9 corresponds to the video signal one field before the pixel to be interpolated.

Each of the video signals S8 to S10 is a video signal shifted by one pixel, and can be regarded as video signals adjacent on the same line when considered as pixel-based video signals obtained at the same timing. On the display of a general display, the video signal S10 is compared with the video signal S10.
Represents the pixel on the left and the video signal S8 corresponds to the pixel on the right.

In the above description, if one of the differences between the video signal S9 and the video signals S8 and S10 adjacent on both sides is larger than the set threshold value S20, the signal level of the pixel to be interpolated is on either side of the pixel to be interpolated. There are different pixels,
That is, since there is an edge of the image, it is determined that “the edge of the image is detected”. If the edge is small, there is no difference between the signal levels on both sides of the pixel to be interpolated. No detection "is determined. Thus, it can be seen that the motion of the image may occur in the line to be interpolated. At this time, if it is determined that “the image has an edge detected”, the edge detection signal S1
The level "H" is output as "4", and when it is determined that "there is no video edge detection", the level "L" is output as the edge detection signal S14.

On the other hand, although the video signal S6 and the video signal S12 are input to the comparator 8, the video signal S12 is a video signal one frame before the video signal S6. The difference between the signal levels of the signals is the set threshold S
If it is larger than 21, it is determined that there is movement, and if it is smaller, it is determined that there is no movement. This makes it possible to detect the motion of the video image in the downward direction. At this time, when it is determined that there is "motion", the level "H" is output as the motion detection signal S15, and when it is determined that "no motion", the level "L" is output as the motion detection signal S15. Is done.

Although the video signal S7 and the video signal S13 are input to the comparator 9, the video signal S13 is also the video signal one frame before the video signal S7. If the difference between the signal levels of the video signals is larger than the set threshold value S22, it is determined that “there is motion”,
If smaller, it is determined that there is no movement. This makes it possible to detect the motion of the video in the direction directly above. At this time, if it is determined that there is "motion", the level "H" is output as the motion detection signal S16, and if it is determined that "no motion", the level "L" is output as the motion detection signal S16. Is done. Note that the set thresholds S20, S2
1, S22 are both set to predetermined values,
It can be changed arbitrarily.

Then, the edge detection signal S obtained above is obtained.
14, the motion detection signals S15 and S16, and the video signal S
6, S7 and S9 are input to the interpolation data switching circuit 7,
One of the video signals S6, S7, and S9 is output as the interpolated pixel data S17 according to the combination of the edge detection signal S14 and the motion detection signals S15 and S16.

As described above, the video signals S6 and S7 are video signals corresponding to the upper and lower positions, respectively, with respect to the video signal S9 at the same position one field before the pixel to be interpolated. If any of the video signals S6 and S7 is selected as S17, line interpolation has been performed, and if the video signal S9 has been selected, field interpolation has been performed.

The switching signal generating circuit 10 generates a switching signal S19 for switching between the video signal S6 and the video signal S17 from the horizontal synchronizing signal S18 of the display used for display. S19
Thus, the video signal S6 and the video signal S17 are switched as the video signal output as the output video signal S23.

FIG. 2 shows an example of an interpolation data switching circuit 7 configured by a logic circuit and performing the above operation. In this figure, when the levels “H” and “L” of the edge detection signal S14 and the motion detection signals S15 and S16 are respectively combined, the obtained interpolation pixel data S17 is
It is as shown in the following table.

[0043]

[Table 1]

From the above, the video signal processing device 1
The operation in the even-numbered field period when the input video signal S1 is input to the input terminal P1 will be specifically described with reference to FIG. 1 and FIGS. Here, FIGS. 4 and 5 show the respective video signal sequences at the timings indicated by A and B in FIG. 3, and the vertically arranged signals are output at the same timing in each video signal. It is shown that.

The meanings of the numbers indicated by the signals in FIGS. 3 to 5 are, for example, in the case of 230002, the leftmost number indicates the order of field input. The next alphabet indicates whether the field is odd or even, where O indicates odd and E indicates even. The next number indicates the input order of the line signal in the field. Subsequent three-digit numbers indicate the order of input of pixel signal data in the line. That is, the signal indicated by 230002 is the second signal of the third line of the second odd field. 1H is the input video signal S1
Indicates one horizontal synchronization period, and 1h indicates a video signal S2 to be output.
3 indicates one horizontal synchronization period, and the output video signal S23
Is twice the signal rate of the input video signal S1.

First, as shown in FIG. 3, when the input video signal S1 input in the horizontal synchronization period H is 2E4 in the even field period, the field memory M1 outputs the horizontal synchronization period H as the video signal S2. 1h
During the period, the signal 2O4 one field before is output.
Similarly, the signal 1E4 one field before the video signal S2 is output as the video signal S3 from the field memory M2, and the signal 1O4 one field before the video signal S3 is output from the field memory M3 as the video signal S3.
Is output as

On the other hand, as the video signal S6 one pixel before the video signal S2 and one line before, 2O3 is output twice during the period 1H. In the video signal S6, the video signal S6 output in the first 1h period of the 1H period of the video signal S1
Is output from the output terminal P6 as the output video signal S23 when the switching signal S19 is at the level "H".

When the switching signal S19 is at level "L", the interpolated pixel data S17 output from the output terminal P6 as the output video signal S23 is, for example, an edge detection signal S14 in the first pixel row in FIG. Is at the level “H”, and when both the motion detection signals S15 and S16 are at the level “L”, according to Table 1, the pixel signal of the video signal S9, that is, the second signal of the third line of the first odd field The second signal, that is, the signal of 1E3002 is input. Similarly, the interpolation pixel data S17 is
It is determined according to Table 1 by the edge detection signal S14 and the motion detection signals S15 and S16. In the odd field period, referring to FIGS.
Similarly, the interpolation pixel data S17 can be obtained.

Based on the above configuration and operation, the display 1 is displayed on the basis of FIG.
Consider a case where the 3 × 3 window 12 on 1 moves in the horizontal direction.

In the figure, on the display 11,
Lines from XE2 to XE4 (X is the number of frames) and 2
The area from the ninth pixel to the eighth pixel is shown, and the frame drawn by a bold line indicates the window 12, and
The arrows in the figure indicate the directions in which the pixels are interpolated. In addition,
The signal levels of the pixels in the window 12 and the window 12
The difference from the signal level of the outside pixel is sufficiently set threshold value S20,
It is assumed to be larger than S21 and S22.

First, in the first field shown in FIG. 9A, since the window 12 is in a stationary state, a field is interpolated. Therefore, it can be said that one field before the first field is in the same stationary state. In the next second field, as shown in FIG. 9B, the window 12 horizontally moves by one pixel to the right from the state of the first field, but since it is an even field, the lines XO2 and XO3 are It will be updated and the other lines will be interpolated. At this time, since the difference in signal level between the pixel XE3003 and the adjacent pixel XE3002 in FIG. 9A is equal to or greater than the set threshold S20, the level “H” is output as the edge detection signal S14.

On the other hand, the signal level of the pixel XO2003 in FIG.
(The same state as (a)) is larger than the set threshold value S21, so that the level “H” is output as the motion detection signal S15. Further, the signal level of the pixel XO3003 and its 1
The difference from the signal level before the frame is similarly determined by the set threshold S22.
Since it becomes larger, the level “H” is output as the motion detection signal S16.

Therefore, the signal level of the pixel XE3003 is
According to Table 1, interpolation is performed based on the signal level of the pixel in the video signal S7, that is, the pixel XO2003 immediately above. Similarly, the signal level of the pixel XE3006 is also interpolated by the signal level of the pixel XO2006 located immediately above.

On the other hand, the pixel XE4006 in FIG.
Since the signal levels of the adjacent pixels XE4005 and XE4007 are equal, the difference between the signal levels should be smaller than the set threshold value S20. Therefore, the level “L” is output as the edge detection signal S14. Further, the pixel XE in FIG.
The difference between the signal level of 4006 and the signal level one frame before is that the signal level should not change.
It becomes smaller than the set threshold value S21, and outputs a level “L” as the motion detection signal S15. At this time, regardless of the motion detection signal S16, the signal level of the pixel XE4006 is
The signal level of the pixel XE4006 at the same position one field before,
That is, interpolation is performed based on the signal level of the pixel XE4006 in FIG. As a result, even when the image moves from the first field to the second field, the window 12 is not disturbed.

Further, in the next third field, FIG.
As shown in (c), the window 12 horizontally moves by one pixel to the right from the state of the second field, but since it is an odd field, the lines XE2, XE3, and XE4 are updated, and the other lines are changed. Interpolated. At this time, the difference in signal level between the pixel XO2004 and the pixel XO2003 in FIG. 9B and the difference in signal level between the pixel X and the pixel XO3004 and the pixel XO3003 are all equal to or larger than the set threshold value S20. Therefore, the level “H” is output as the edge detection signal S14 in each case.

Since the difference between the signal levels of the pixel XE3004 and the pixel located one frame before at the same position as the pixel XE3004 is larger than the set threshold value S21 with respect to the pixel XO2004 in FIG. Level “H” as S15
Is output, and the difference between the signal levels of the pixel XE2004 and the pixel located one frame before at the same position as the pixel XE2004 is the set threshold S.
Therefore, the level “L” is output as the motion detection signal S16. Conversely, for pixel XO3004,
Since the difference between the signal levels of the pixel XE4004 and the pixel one frame before at the same position as the pixel XE4004 becomes smaller than the set threshold value S21, the level “L” is output as the motion detection signal S15, while the pixel XE3004 and the pixel 1 at the same position as XE3004
The difference between the signal levels of the pixels before the frame is equal to the set threshold S22.
Since it becomes larger, the level “H” is output as the motion detection signal S16.

As a result, the signal levels of the pixels XO2004 and XO3004 are both interpolated by the signal level of the pixel XE3004. This means that the pixels XO2007, XO3007 and XE
The same applies to the relationship with 3007. Therefore, even when the video shifts from the second field to the third field, the window 12 is not disturbed.

As described above, in the video signal processing apparatus 1 of the present invention, when converting the interlaced video signal S1 to the non-interlaced video signal S23, the video signal is processed one field before the pixel to be interpolated. In addition to detecting whether or not there is an outline of a video based on a difference in signal level between adjacent pixels, pixels above and below the pixel that supplies a signal level to be interpolated are changed by a change in signal level from one frame before. By detecting motion and switching between the signal level of the pixel one field before the pixel to be interpolated and the signal level of the upper and lower pixels based on the detection result, distortion of the displayed image is reduced. Can be.

[0059]

As described above, the video signal processing method according to the first aspect of the present invention comprises forming a non-interlaced image from the interlaced current field with the current field and the interpolated data for the interlaced current field. A video signal processing method for converting a 2-field 1-frame interlaced video signal supplied from a video signal source into a non-interlaced video signal, wherein the first pixel on the interpolation data is The pixel at the same position in the previous field on the non-interlaced image is a second pixel, and is located on the line one line before the line to which the first pixel belongs in the current field on the non-interlaced image. A pixel adjacent to one pixel is defined as a third pixel, and one of the lines to which the first pixel belongs
When a pixel on the line after the line and adjacent to the first pixel is defined as a fourth pixel, an image of the image is placed between the second pixel and a pixel located on both sides of the second pixel on the same line. When the contour is detected and at least one of the third pixel and the fourth pixel performs the motion detection with respect to the previous frame, the side of the third pixel and the fourth pixel on which the motion detection is performed is performed. In this configuration, the signal level of the first pixel is interpolated by the signal level of the pixel.

Therefore, when the first pixel is interpolated, the outline of the image between the second pixel and the pixels before and after the second pixel on the same line is detected, In addition, when the motion detection is performed on the third and fourth pixels that are directly adjacent to each other, the interpolation is performed by the pixel on which the motion is detected among the third pixel and the fourth pixel. In the case where the image is moved in a direction parallel to the above, the effect that the contour of the image formed in the parallel direction can be suppressed from being disturbed.

As described above, the video signal processing apparatus according to the second aspect of the present invention comprises a non-interlaced image composed of the current field and the interpolation data for the current field of the interlaced system. In a video signal processing apparatus for converting a two-field one-frame interlaced video signal supplied from a source into a non-interlaced video signal, the first pixel in the interpolation data is located at the same position one field period before. A second pixel signal deriving unit for deriving a signal level of the second pixel; and a non-interlaced image on the same field as the first pixel and on a line one line before the line to which the first pixel belongs. A third pixel signal deriving unit for deriving a signal level of a third pixel adjacent to the first pixel; Fourth pixel signal deriving means for deriving a signal level of a fourth pixel adjacent to the first pixel on a line one line after the line to which the element belongs is provided. Contour detection means for comparing the signal levels of the pixels adjacent to the second pixel on the same line with the front and rear, and outputting a contour detection when the difference is equal to or greater than a predetermined threshold value; And first signal comparing means for comparing the signal level of the pixel one field before the third pixel and outputting a motion detection when the difference is equal to or greater than a predetermined threshold value. A second comparing means for comparing the signal level of a pixel one field before the pixel with a signal level and outputting a motion detection when the difference is equal to or greater than a predetermined threshold value; and a contour detecting means and the first and second comparing means. Based on detection results Interpolating signal switching means for switching a pixel to be interpolated with the signal level of the first pixel, wherein the interpolation signal switching means detects the contour of the contour detecting means as a signal level for interpolating the first pixel; If not all or at most one of the three detection results, that is, the detection of the movement of the first and second comparing means, is selected, the signal level of the second pixel is selected, And if both the second and third comparing means detect a motion, the signal level of the third pixel or the fourth pixel is selected, the contour detecting means detects the contour, and any one of the first and second comparing means. When only one of the pixels detects motion, the signal level of the pixel for which motion has been detected is selected from the third pixel and the fourth pixel.

Therefore, when the image is stationary,
High image quality is obtained by field interpolation, and line interpolation is applied when the video is moving. At this time, the second pixel, which is the pixel before the first pixel, is on the same line as the second pixel. The presence or absence of the contour of the image for the previous and next pixels and the first
Detecting the presence or absence of motion detection at the third pixel and the fourth pixel adjacent to the pixel, and when both the contour detection and the motion detection are performed, the signal level of the pixel on which the motion detection is performed Line interpolation is performed, and especially when the video is moved in a direction parallel to the line, the contour formed in the parallel direction is not disturbed. There is an effect that image quality display can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a video signal processing device according to the present invention.

FIG. 2 is a logic circuit diagram showing a configuration example of an interpolation data switching circuit shown in FIG.

FIG. 3 is a timing chart illustrating an operation when a video signal of an odd field is input to the video signal processing device of FIG. 1;

FIG. 4 is a timing chart for explaining the operation of a signal flowing through each section during a horizontal synchronization period 1h indicated by reference numeral A in FIG. 3;

FIG. 5 is a timing chart for explaining the operation of a signal flowing through each section during a horizontal synchronization period 1h indicated by reference numeral B in FIG. 3;

FIG. 6 is a timing chart illustrating an operation when a video signal of an even field is input to the video signal processing device of FIG. 1;

FIG. 7 is a timing chart for explaining the operation of a signal flowing through each section during the horizontal synchronization period 1h indicated by reference numeral C in FIG. 6;

8 is a timing chart illustrating the operation of a signal flowing through each section during a horizontal synchronization period 1h indicated by reference numeral D in FIG.

9 is an explanatory diagram showing a display state on a display when an image moves in the image signal processing device of FIG. 1;

FIG. 10 is an explanatory diagram showing a display display procedure in a non-interlace system.

FIG. 11 is an explanatory diagram showing a display display procedure in the interlaced mode.

FIG. 12 is an explanatory diagram showing a problem in field interpolation when converting an interlaced video signal into a non-interlaced video signal.

FIG. 13 is an explanatory diagram showing a problem in line interpolation when converting an interlaced video signal into a non-interlaced video signal.

FIG. 14 is a block diagram showing a conventional video signal processing device that converts an interlaced video signal into a non-interlaced video signal.

FIG. 15 is a timing chart illustrating an operation when a video signal of an even field is input to the video signal processing device of FIG. 14;

16A and 16B are timing charts for explaining signals flowing through the respective units during the horizontal synchronization period 1h in FIG. 15; FIG. 16A is a timing chart during the horizontal synchronization period 1h indicated by reference numeral F; 4B is a timing chart during the horizontal synchronization period 1h indicated by reference numeral G.

FIG. 17 is a timing chart illustrating an operation when a video signal of an odd field is input to the video signal processing device of FIG. 14;

18A and 18B are timing charts for explaining signals flowing through each section during the horizontal synchronization period 1h in FIG. 17, and FIG. 18A is a timing chart during the horizontal synchronization period 1h indicated by reference numeral I; 4B is a timing chart during the horizontal synchronization period 1h indicated by reference numeral J.

19 is an explanatory diagram showing a display state on a display when an image moves in the image signal processing device of FIG. 14;

[Explanation of symbols]

Reference Signs List 1 video signal processing device 2 delay circuit (second pixel deriving means / third pixel deriving means) 4 delay circuit (previous pixel signal deriving means) 6 edge detector (contour detecting means) 7 interpolation data switching circuit (interpolated pixel switching means) 8) Comparator (first comparing means) 9 Comparator (second comparing means) M1 field memory (previous pixel signal deriving means / second pixel deriving means / third pixel deriving means) M2 field memory (previous pixel signal deriving means) L1 line memory (previous pixel signal deriving means) L2 line memory (second pixel deriving means / third pixel deriving means) L3 line memory (third pixel deriving means)

Claims (2)

(57) [Claims] 1. A two-field one-frame interlaced video signal supplied from a video signal source, comprising a non-interlaced image composed of the current field and interpolation data for the interlaced current field. A non-interlaced video signal, wherein a pixel at the same position in a previous field on the non-interlaced image of the first pixel is a second pixel with respect to the first pixel on the interpolation data. And a pixel adjacent to the first pixel on the line immediately before the line to which the first pixel belongs in the current field on the non-interlaced image, and a pixel adjacent to the first pixel, and the line to which the first pixel belongs On the line one line after
When the pixel adjacent to the pixel is the fourth pixel, the second pixel
An image outline is detected between the pixel and a pixel located on both sides of the second pixel on the same line, and at least one of the third pixel and the fourth pixel performs motion detection with respect to the previous frame. A video signal processing method of interpolating a signal level of a first pixel based on a signal level of a pixel on which motion detection has been performed among the third pixel and the fourth pixel. 2. A two-field one-frame interlaced video signal supplied from a video signal source is provided by forming a non-interlaced image from the current field and interpolated data for an interlaced current field. A video signal processing device for converting a video signal into a non-interlaced video signal; a second pixel signal deriving means for deriving a signal level of a second pixel existing at the same position one field period before the first pixel in the interpolation data; , On the same field as the first pixel on the non-interlaced image,
A third pixel signal deriving unit that derives a signal level of a third pixel adjacent to the first pixel while being on a line one line before the line to which the pixel belongs, and a line one line after the line to which the first pixel belongs And a fourth pixel signal deriving means for deriving a signal level of a fourth pixel adjacent to the first pixel is provided, while a signal level of the second pixel and a fourth pixel signal deriving means are arranged on the same line as the second pixel. A contour detection means for comparing the signal level of a pixel adjacent to the pixel and outputting a contour detection when the difference is equal to or greater than a predetermined threshold value; and a signal level of the third pixel and a pixel one field before the third pixel. First comparing means for comparing the signal levels of the fourth pixel and the signal level of the pixel one field before the fourth pixel and outputting the detection of the motion when the difference is equal to or greater than a predetermined threshold value. Compare with Then, based on the detection results of the second comparing means for outputting the detection of the motion when the difference is equal to or greater than a predetermined threshold value, the contour detecting means and the first and second comparing means, the signal level of the first pixel is calculated. Interpolation signal switching means for switching a pixel to be interpolated is provided. As the signal level for interpolating the first pixel, the interpolation signal switching means detects the contour of the contour detecting means, and detects the first and second contours.
If not all of the three detection results of the detection of the movement of the comparison means or at most one detection result is obtained, the signal level of the second pixel is selected and the first and second signal levels are selected.
When both of the comparing means detect the motion, the signal level of the third pixel or the fourth pixel is selected, the contour detecting means detects the contour, and only one of the first and second comparing means is selected. A video signal processing device, wherein when a motion is detected, a signal level of a pixel in which the motion is detected is selected from the third pixel and the fourth pixel.