JP2010081330A - Signal processing method and apparatus in three-dimensional image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such the problem that a frame memory is needed for both crosstalk countermeasures and scan line conversion/frame rate conversion and an increase in the number of frame memories necessary for a three-dimensional video display system and apparatus is forecast. <P>SOLUTION: When reading a video signal from the frame memory in scan line conversion, a time difference of 1/2 frame is provided between video starting times of a left-eye video signal and a right-eye video signal, the time difference of 1/2 frame is changed into a time difference of 1 frame in frame rate conversion, and the same video signal for both the left-eye video signal and the right-eye video signal is output twice or more, respectively, at the same time. Since there is the time difference of 1 frame between the right-eye video signal and the left-eye video signal, in a crosstalk countermeasure circuit, a frame difference signal is obtained without using any frame memory. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a frame memory reduction method and apparatus in a circuit that performs signal processing using correlation with surrounding frames, such as a crosstalk reduction circuit, in a stereoscopic image display apparatus using an active shutter system.

  Conventionally, as a stereoscopic image display method, a method of displaying video signals for the right eye and the left eye in time series like the active shutter method (FIG. 7) is known. When the right-eye and left-eye video signals are displayed in chronological order as in the active shutter method, the right-eye video is changed to the left-eye video for performance reasons such as display speed and afterglow. There is a problem that image quality deterioration called crosstalk occurs such that the image is leaked or the image for the left eye is leaked into the image for the right eye.

In response to this crosstalk problem, for the video signal for the right eye, the difference from the video signal for the left eye displayed one frame before is taken, and the video signal for the left eye that leaks into the signal for the right eye is obtained. Predict and subtract from the video signal for the right eye in advance. Also, for the video signal for the left eye, the difference from the video signal for the right eye displayed one frame before is taken, and the signal for the left eye is also obtained. Measures have been taken in which the right-eye video signal is predicted in advance and subtracted from the left-eye video signal. (See Patent Document 1)
On the other hand, several formats as shown in FIG. 8 are considered as a method of a video signal transmitted from a video output device such as a broadcast or a video playback device.

  In the side-by-side method, a right-eye video signal and a left-eye video signal having a horizontal resolution of 1/2 are arranged and sent in the right half and the left half of one frame, and as a problem, the horizontal resolution is deteriorated. In the vertical interleaving, the video signals for the left eye and the right eye are multiplexed and transmitted for each line in the vertical direction, and the vertical resolution is deteriorated as in the above system. The checker pattern is a method in which the video signals for the right eye and the left eye are arranged in a staggered pattern for each pixel, and the horizontal resolution and the vertical resolution are also deteriorated in this method.

  On the other hand, in the sequential method, the video signal for the left eye and the video signal for the right eye are transmitted in time series for each frame, and the frame speed is doubled compared to the conventional two-dimensional display. Unlike the above method, a signal having no deterioration in both vertical resolution and horizontal resolution can be obtained.

  The video signal frame rate at this time may be the 120 Hz / 100 Hz interlace method, the 24 Hz / 48 Hz / 50 Hz / 60 Hz progressive method, etc., which are in the current video transmission format.

  Further, in a display device such as a liquid crystal display or a plasma display, a left-eye video signal and a right-eye video signal are displayed in time series by an active shutter system, and thus a progressive signal of 50 Hz, 60 Hz, 24 Hz, or an integral multiple thereof is displayed. When trying to display without reducing the frame resolution, the interlaced input is 120 Hz / 100 Hz (the right-eye video signal and the left-eye video signal have frame resolutions of 60 Hz and 50 Hz, respectively), and the progressive input is twice the input. It is necessary to output at speed. Accordingly, scanning line conversion from interlace to progressive or frame rate conversion is required from the output of the broadcast receiving apparatus or the video reproduction device to the display display.

This scanning line conversion from interlaced signal to progressive signal detects the moving image area, still image area, and the intermediate area between moving image and still image by comparing the input video signal and the field or frame before and after it. For the still image area, the scanning line interpolation is performed using the information of the preceding and succeeding fields, the scanning line interpolation is performed using the information of the upper and lower scanning lines in the moving image area, and the ratio is set in the intermediate area between the moving image and the still image. Accordingly, a technique called motion adaptive scan conversion is performed in which scanning line interpolation is performed using information on the preceding and following fields, the preceding and following frames, and the upper and lower scanning lines. (See Patent Document 2)
As for frame rate conversion, as shown in FIG. 9 as an example of 30 Hz → 60 Hz conversion, the video signal A input to the frame memory is output a plurality of times and A ′ = A frame is inserted, or A → For example, a method of detecting a motion direction of a video signal reaching B and inserting an A ′ frame assuming an intermediate frame between AB and performing smooth motion display is used.
JP-A-11-222255 JP 2000-295581 A

  In the above-described crosstalk countermeasure, for the video signal for the right eye, a difference from the video signal for the left eye displayed one frame before is taken, and the video signal for the left eye that leaks into the signal for the right eye is obtained. Since the process of predicting and subtracting from the video signal for the right eye is performed in advance, it is necessary to store the video signal of the previous frame, and thus a frame memory is required.

  Further, in the above-described scanning line conversion / frame rate conversion, for example, in frame rate conversion, a method of outputting the video signal A input to the frame memory a plurality of times and inserting A ′ = A frame, or A → B It is necessary to store the video signal of at least one frame in advance because it detects the moving direction of the video signal leading to and inserts an A ′ frame assuming an intermediate frame between AB and performs smooth motion display. For this purpose, a frame memory is required.

  In other words, both the above-mentioned countermeasure against crosstalk and the scanning line conversion / frame speed conversion require a frame memory, and an increase in the frame memory required for the stereoscopic image display method and apparatus is expected, and the circuit scale is increased. A problem arises that the manufacturing cost increases as the number increases.

  In order to solve the above problems, in the signal processing apparatus for stereoscopic image display according to the present invention, (1) when the video signal is read from the frame memory in the scanning line conversion, the video start of the left-eye video signal and the right-eye video signal is started. A time difference of 1/2 frame is provided in the time. Next, (2) a time difference of 1/2 frame is set to a time difference of 1 frame in the frame speed conversion, and at the same time, the same video signal is output twice or more for both the left-eye video signal and the right-eye video signal. As a result, (3) since there is a time difference of one frame between the right-eye video signal and the left-eye video signal, the frame difference signal can be obtained without using the frame memory in the crosstalk countermeasure circuit.

  As described above based on the embodiment, by shifting the output of the video signal for the right eye and the processing of the video signal for the left eye by 1/2 × N (Hz), even without having a frame memory as a countermeasure against crosstalk, It is possible to obtain display video signal information of one frame before. In addition, the present invention is not limited to measures against crosstalk, and is an effective means for performing video processing using front and rear frames.

  Embodiments of the present invention will be described.

(Embodiment 1)
FIG. 1 is a schematic block diagram showing an embodiment of a stereoscopic image display apparatus according to the present invention. FIG. 2 shows a video signal at the corresponding block output of FIG. 1 when an input signal is assumed to be a sequential system. The processing timing is described in units of frames. FIG. 3 is a diagram showing the processing contents in the synchronization signal converting means which is one configuration of the stereoscopic image display device, and FIG. 4 is an input / output timing of the video signal to the frame memory which is one configuration of the stereoscopic image display device. Is shown. The stereoscopic image display apparatus of the present invention will be described below with reference to these drawings.

  As shown in FIG. 1, a stereoscopic image display device according to the present invention is connected to a signal dividing unit 1 that divides an input video signal into a left-eye video signal and a right-eye video signal, and to the signal dividing unit 1. A frame memory 2 for storing the right-eye video signal output from the dividing means 1, a frame memory 3 connected to the signal dividing means 1 for storing the left-eye video signal output from the signal dividing means 1, and a frame memory 2 And a scanning line converting means 4 for converting the interlace video signal for the right eye read from the frame memory 2 into a progressive system, and an interlace for the left eye connected to the frame memory 3 and read from the frame memory 3. The scanning line converting means 5 for converting the video signal of the system to the progressive system and the scanning line converting means 4 are connected to the scanning line converting means 4 and outputted from the scanning line converting means 4 Frame rate conversion means 6 for converting the frame rate of the progressive video signal for the eye and the frame rate of the progressive video signal for the left eye connected to the scanning line conversion means 5 and output from the scanning line conversion means 5 The frame rate conversion means 7 for converting the frame rate, the frame memory 8 used for the processing of the frame rate speed conversion means 6 for the right eye, and the frame used for the processing of the frame rate speed conversion means 7 for the left eye The video signal whose right eye frame rate has been converted by the memory 9 and the frame rate conversion unit 6 is enlarged by at least one of the vertical and horizontal directions and the enlargement unit 10 and the frame rate conversion unit 7. , For the left eye frame rate converted video signal, at least in the vertical or horizontal direction One of them is connected to the enlargement means 11 for enlarging the video signal, to the enlargement means 10 and 11, connected to the crosstalk countermeasure means 12 for performing signal processing for preventing image quality deterioration due to crosstalk, and the crosstalk countermeasure means 12. A selector 13 that alternately outputs a video signal for the right eye and a left eye, and a synchronization signal conversion unit 16 that masks (erases) the synchronization signal of the input video signal and generates a new synchronization signal. Hereinafter, specific contents of each component will be described in detail.

  First, the signal dividing means 1 and the frame memories 2 and 3 will be described. The signal dividing means 1 is a signal dividing circuit that writes a video signal input in each format shown in FIG. 8 into a few frame memories while dividing it into a left-eye video signal and a right-eye video signal. As a division method, 2. 2. Only the video signal for the left eye is written to the frame memory of 3. The signal to be written in the frame memory is specified by separately specifying the video area to be written in each frame memory, such as only the video signal for the right eye.

  In the present invention, the frame rate of the input video signal is assumed to be a 120 Hz / 100 Hz interlace method, a progressive method, a 24 Hz / 48 Hz / 50 Hz / 60 Hz progressive method. In FIG. 2, since a sequential input is assumed, a pair of a left-eye video signal (L0) and a right-eye video signal (R0) is input in a cycle of 60 Hz or 50 Hz, and 2 × N = 120 Hz, 100 Hz input. Assumed.

  Next, the frame memories 2 and 3 and the scanning line conversion means 4 and 5 will be described. The scanning line conversions 4 and 5 are scanning line conversion circuits that convert the video signal for the right eye and the video signal for the left eye separately and progressively when the input video signal is an interlaced system. Type scan conversion is performed. Since the scanning line conversion means 4 and 5 need to obtain motion information from video difference signals in a plurality of frames, a few or three frame memories are required. At this time, when signals are output from the frame memories 2 and 3 by the scanning line conversion of 4 and 5, as shown in “4. Output of scanning line conversion” and “5. Output of scanning line conversion” in FIG. The output of the video signal (L0, L1...) And the output of the right-eye video signal (R0, R1...) Are output with a 2 × N (Hz) period shift. That is, when the scanning line conversion means 4 and 5 read out the video signal from the frame memory, a time difference of 1/2 frame is provided between the video start times of the left-eye video signal and the right-eye video signal.

  Next, the frame rate conversion means 6 and 7 and the frame memories 8 and 9 will be described. The frame rate conversion means 6 and 7 output control signals for the frame memories 8 and 9 in order to convert the output signals subjected to the scan conversion by the scan line conversion means 4 and 5 to the final display frame speed. In FIG. 2, a 2 × N (Hz) output frame period is assumed as the minimum frame rate that does not decrease the output frame resolution with respect to the input. However, as will be described later, the output frame period can be 3 × N (Hz), 4 × N (Hz)... M × N (Hz) (M is an integer) depending on the number of frames to be obtained.

  Next, the synchronization signal converting means 16 will be described. The 16 synchronization signal conversion means generates an M × N (Hz) synchronization signal. The relationship between the input vertical synchronization signal and the output vertical synchronization signal in the synchronization signal converter 16 is as shown in FIG. In FIG. 3, the 2 × N (Hz) input vertical synchronization frequency and the N (Hz) output synchronization frequency are assumed as in the above example. The synchronization signal conversion means 16 performs vertical synchronization of the frame of the video signal input earlier in time among the left-eye video signal (L0) and the right-eye video signal (R0) that are the same frame with respect to the input vertical synchronization signal. Let the signal be the output synchronization signal.

  In FIG. 3, assuming that the left-eye video signal (L0) is input earlier, the L0 vertical synchronizing signal is used as an output vertical synchronizing signal as it is. On the other hand, the vertical synchronization signal of R0 is not output as it is, but an output vertical synchronization signal delayed for a certain period is created. Thereby, it is possible to obtain output vertical synchronization having a frequency of input vertical synchronization frequency × ½ with respect to the input synchronization signal.

  Also, the video signal input late in time, that is, the vertical synchronization signal for controlling the right-eye video signal in FIG. 3, is ½ the temporal synchronization signal for controlling the left-eye video signal. Created with a period delay. The delay time of 1/2 cycle at this time can be 1 / M (M is an integer) such as 1/3, 1/4... According to the frame frequency to be output by the frame rate conversions 6 and 7. For example, in the output of the frame rate conversion 6 and 7 this time, 2 frames are output at the same timing, but when 3 frames are output at the same timing, the frame frequency is set to 1/3 and the 22nd frame is the first frame. This can be realized by adding a delay of 1/3 period to the frame and outputting the third frame with a delay of 1/3 period from the second frame.

As described above, by adding a delay of 1/2 cycle to the scanning line conversion 4 and 5 outputs of the left-eye video signal (L0, L1...) And the right-eye video signal (R0, R1...), FIG. As for the inputs to the 8th and 9th frame memories, a difference of 1/2 cycle of the memory input vertical frequency is also produced. (At this time, if the outputs of the scan conversions 4 and 5 are delayed by 1/3, 1/4... 1 / M cycle, the memory cycle also has the same cycle difference.)
The time relationship between the input signal and the output signal of the frame memory 8 must be read so that the output end point (FIG. 4B) of the L0 frame is later than the point when the input signal L0 has finished writing one frame (FIG. 4A). Don't be. Further, regarding the relationship between the input signal and the output signal of the frame memory 9, it is necessary to perform reading so that the output end time of R0 is later than the time when the input signal R0 finishes writing one frame. If writing / reading control (that is, input / output timing control) of the frame memories 8 and 9 is not performed at such timing, control for reading a signal that has not yet been written to the memory is performed, and an incorrect signal is read. Things happen.

  As described above, the timing control for the signal input / output of the frame memories 8 and 9 is performed by the frame rate conversion devices 6 and 7, so that the timing at which L0 is obtained as the output of the frame memory 8 as shown in FIG. Then, R0 is obtained as the output of the frame memory 9, and R0 is obtained as the output of the frame memory 9 at the timing when L1 is obtained as the output of the frame memory 8.

  Since the outputs of the frame rate conversions 6 and 7 are at the same timing as the outputs of the frame memories 8 and 9, the right-eye video signal output (R0) and the left-eye video signal displayed one frame before at the same frame output timing. Output (L0) is output. For the left-eye video signal output (L1), the right-eye video signal output (R0) displayed one frame before is output at the same frame timing.

  Thereafter, the video signal having a small horizontal resolution inputted by the side-by-side method or the checker pattern method is subjected to horizontal enlargement processing by the 10 and 11 horizontal enlargement devices. Here, since no delay is performed in units of frames, 12. The crosstalk countermeasure circuit receives a frame input at the same timing as “6. Output of frame rate conversion” and “7. Output of frame rate conversion” in FIG. That is, a display frame and a video signal displayed one frame before are input, and a video signal in which crosstalk countermeasures are taken is output based on difference information of the video signal.

  13 of FIG. The selector outputs the right-eye video signal and the left-eye video signal in time series.

  As for the configuration, the scanning line conversion and the frame speed conversion shown in FIG. 1 can be realized by the same frame memories 2 and 3 as shown in FIG.

  14 and 15 are apparatuses for simultaneously performing scanning line conversion and frame speed conversion. For the output of the frame memories 2 and 3, “4. Output of scanning line conversion + frame speed conversion” in FIG. The signal output of 2 × N (Hz) is performed as in “+ frame rate conversion output”. In FIG. 6, the output is twice as fast as the input, and the same frame is output twice from the 2-3 frame memory.

  Therefore, when the scanning line conversion and the frame speed conversion are realized in the same frame memory as shown in FIG. 5, the scanning line conversion process is performed while selecting the continuously changing frame necessary for the scanning line conversion once every two times. There is a need to do.

  In the embodiment described above, the case where the video signal is input by the interlace method has been mainly described. However, the present invention is not limited to this, and even when the video signal is input by the progressive method. Applicable. In this case, the configuration of the frame memories 2 and 3 and the scanning line conversions 4 and 5 in FIG. 1 is not necessary, and the signal from the signal dividing means 1 is input to the frame memories 8 and 9, and the synchronization signal conversion 16 It is assumed that the frame memories 8 and 9 are connected. Further, as specific processing, by the progressive method, the right eye video signal and the left eye video signal alternately input in time series at the frequency N (Hz) are divided by the signal dividing means 1 and divided by the dividing means. The right-eye video signal and the left-eye video signal thus stored are stored in the frame memories 8 and 9, and the synchronization signal of the video signal stored in the frame memories 8 and 9 is converted by the synchronization signal conversion means 16, and the synchronization signal conversion means The frame speed of the video signal converted from the synchronization signal is converted by the frame speed conversion means 6 and 7 and output as an M × N (Hz) video signal. The image quality processing of at least the right-eye video signal or the left-eye video signal output from is performed.

  Here, the synchronization signal conversion means delays at least one of the vertical synchronization signal of the right-eye video signal or the left-eye video signal by about 1 / M frame from the other vertical synchronization signal, thereby taking measures against crosstalk. There is no need to have a frame memory.

  The present invention relates to a stereoscopic image display apparatus using an active shutter system, particularly in a circuit that performs signal processing using correlation with a peripheral frame, such as a crosstalk reduction circuit, and a stereoscopic image display apparatus with a reduced frame memory. Regarding the method.

1 is a block diagram of a video signal processing apparatus according to an embodiment of the present invention. The figure which shows the processing timing of the video signal in one embodiment of this invention The figure which shows the process in one embodiment of this invention The figure which shows the process timing in one embodiment of this invention 1 is a block diagram of a video signal processing apparatus according to an embodiment of the present invention. The figure which shows the video signal timing in one embodiment of this invention Diagram showing 3D video display method Diagram showing video signal transmission format for stereoscopic display Diagram showing conventional frame rate conversion

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Signal split device 2 Frame memory 3 Frame memory 4 Scan line converter 5 Scan line converter 6 Frame speed converter 7 Frame speed converter 8 Frame memory 9 Frame memory 10 Horizontal enlargement apparatus 11 Horizontal enlargement apparatus 12 Crosstalk countermeasure apparatus 13 Selector 14 Scan line conversion + frame rate conversion device 15 Scan line conversion + frame rate conversion device 16 Synchronization signal conversion means

Claims (3)

In a stereoscopic image display device that displays a stereoscopic image by a right-eye video signal and a left-eye video signal having parallax,
Dividing means for dividing the right-eye video signal and the left-eye video signal alternately input in time series at a frequency N (Hz);
Recording means for storing the right-eye video signal and the left-eye video signal divided by the dividing means;
Synchronization signal conversion means for converting the synchronization signal of the video signal stored in the recording means;
A frame rate conversion unit that converts a frame rate of the video signal in which the synchronization signal is converted by the synchronization signal conversion unit and outputs the converted video signal as an M × N (Hz) video signal;
Crosstalk countermeasure means for performing image quality processing of at least the right-eye video signal or the left-eye video signal output from the frame speed conversion means,
The three-dimensional image display device characterized in that the synchronizing signal converting means delays at least one vertical synchronizing signal of a right eye video signal or a left eye video signal by about 1 / M frame from another vertical synchronizing signal. . In a stereoscopic image display device that displays a stereoscopic image by a right-eye video signal and a left-eye video signal having parallax,
A dividing unit that divides a right-eye video signal and a left-eye video signal alternately input in time series in an interlaced manner at a frequency of 2 × N (Hz);
Recording means for storing the right-eye video signal and the left-eye video signal divided by the dividing means;
Scanning line conversion means for converting the video signal stored in the recording means into a progressive method of frequency N (Hz);
Synchronization signal conversion means for changing at least one of the synchronization signals of the right-eye video signal or the left-eye video signal with respect to the scanning line conversion means;
A frame rate at which the synchronization signal is converted by the synchronization signal conversion unit, and the frame rate of the video signal of frequency N (Hz) output from the scanning line conversion unit is converted and output as a video signal of M × N (Hz). Conversion means;
Crosstalk countermeasure means for performing image quality processing of at least the right-eye video signal or the left-eye video signal output from the frame speed conversion means,
The three-dimensional image display device characterized in that the synchronizing signal converting means delays at least one vertical synchronizing signal of a right eye video signal or a left eye video signal by about 1 / M frame from another vertical synchronizing signal. . The synchronization signal converting means erases at least one of the right-eye video signal and the left-eye video signal stored in the recording means, and is delayed by about 1 / M frame from the other vertical synchronization signals. The three-dimensional image display device according to claim 1, wherein the synchronization signal is generated.

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