JP2010057010A - Image display device - Google Patents

Abstract

An image display apparatus capable of preventing the deterioration of moving image quality due to motion compensation while improving the response of moving images by switching between valid / invalid of motion compensation processing for a large motion image. provide.
An image display device converts a frame number or a field number of an input image signal by interpolating an image signal subjected to motion compensation between frames or fields of the input image signal, thereby displaying a liquid crystal display. An FRC unit 10 for outputting to the panel 16 is provided. The FRC unit 10 includes a motion vector histogram generation unit 11g that generates a histogram of a motion vector detected between frames or fields of the input image signal, and is based on the motion vector histogram generated by the motion vector histogram generation unit 11g. To enable / disable the motion compensation process.
[Selection] Figure 3

Description

  The present invention relates to an image display device, and more particularly to an image display device having a function of converting a frame rate or a field rate.

  Conventionally, a technique for converting a frame rate (the number of frames) by interpolating an image between frames in order to improve motion blur in a hold-type display method such as a liquid crystal display device is known. This technique is called FRC (Frame Rate Converter) and is put into practical use in liquid crystal display devices and the like.

  As a method for converting the frame rate, various methods are known such as repeated reading of the same frame twice and frame interpolation by linear interpolation between frames (linear interpolation). However, in the case of frame interpolation processing by linear interpolation, unnatural motion (jerkiness, judder) associated with frame rate conversion occurs, so that the image quality is insufficient.

  Therefore, in order to eliminate the influence of the jerkiness and improve the moving image quality, motion compensation type frame interpolation processing using motion vectors has been proposed. According to this motion compensation process, since the moving image itself is captured and corrected, it is possible to obtain a very natural moving image without degradation in resolution and without occurrence of jerkiness. Furthermore, since the interpolated image signal is formed by motion compensation, it is possible to sufficiently improve the motion blur interference caused by the hold type display method described above.

  For example, Patent Document 1 describes a technique for improving a decrease in spatial frequency characteristics that causes motion blur by increasing the frame frequency of a display image by generating an interpolation frame adaptively in motion. ing. In this method, at least one interpolated image signal to be interpolated between frames of a display image is formed in a motion adaptive manner from the preceding and following frames, and the formed interpolated image signal is interpolated between frames and sequentially displayed. ing.

  The above-mentioned FRC technology has an effect of improving moving picture response even for an image signal with a low frame rate (15 fps) such as one-segment (one-segment broadcasting), and a mobile phone that supports a double frame rate (30 fps). Has been put to practical use.

  However, in the case of an image of 15 frames per second such as 1Seg, the elements for each frame are skipped, and if the movement is large, the elements that were in the previous frame may not be the next frame or exceed the estimable range. It may end up. In such a case, the estimation destination (end point) of the motion vector of the screen element is not determined, and the screen is broken (error in the interpolated image) for the corresponding part. For this reason, the image quality was deteriorated.

On the other hand, for example, Patent Document 2 describes a motion vector detection circuit capable of detecting a correct motion vector in order to reduce a visual display shift that occurs when a moving image is displayed. This is because the correlation value obtained by the correlation value calculation unit varies due to image fluctuations and noise, and the lowest correlation value S1 (eg, 9) detected by the lowest correlation value detection unit is correlated with an erroneous block far from the origin. When the original minimum correlation value for a block close to the origin changes to S1a (eg, 10) larger than S1, the correlation value conversion unit multiplies the multiplication unit among the correlation values obtained by the correlation value calculation unit. A correlation value equal to or lower than the value (1.5 × lowest correlation value S1) is replaced with 0, and the original lowest correlation value S1a (> S1) before replacement is also included in the detection target range. The motion vector generation unit detects a correlation value 0 (corresponding to S1a before replacement) with respect to a block closest to the origin among a plurality of blocks having a correlation value 0, and starts and ends the block position and origin of the detected correlation value. A correct motion vector is generated and output.
Japanese Patent No. 3295437 Japanese Patent Laid-Open No. 11-45068

  However, in the technique described in Patent Document 2, when the motion of an element in the screen (one frame) is large during the motion compensation type FRC processing, particularly when the element in the previous frame is no longer the next frame. In addition, since there is no correlation between images, a correct motion vector cannot be detected. Therefore, in such a case, the estimation destination (end point) of the motion vector cannot be determined, resulting in a screen failure (interpolated image error) for the corresponding part, and the image quality cannot be improved.

  Also, when shooting while shaking the camera around a moving person or the like, the movement of the background part other than the foreground person increases, so the end point of the motion vector is not fixed in the background part as described above. There will be no. However, the viewer usually watches the person, and there are cases where the screen breakdown is not a concern in the background part other than this person. In such a case, it is preferable to perform motion compensation because the moving image responsiveness of the foreground portion in the vicinity of the person is improved. However, the above-described conventional technology does not solve such a problem.

  The present invention has been made in view of the above-described circumstances, and is caused by motion compensation while improving motion picture responsiveness by switching between valid / invalid of motion compensation processing for a large motion image. An object of the present invention is to provide an image display device capable of preventing deterioration of moving image quality.

  In order to solve the above-described problem, the first technical means according to the present invention interpolates an image signal subjected to motion compensation processing between frames or fields of an input image signal, thereby An image display device comprising rate conversion means for converting the number of frames or the number of fields and outputting the result to a display panel, wherein the motion vector generates a histogram of motion vectors detected between frames or fields of the input image signal Histogram generation means is provided, and the rate conversion means switches between valid / invalid of motion compensation processing based on the motion vector histogram generated by the motion vector histogram generation means.

  The second technical means is the first technical means in which the number of motion vectors outside the preset detection range is greater than or equal to a predetermined value among the motion vectors generated by the motion vector histogram generating means. In addition, the rate conversion means invalidates the motion compensation process.

  According to a third technical means, in the first technical means, when the number of motion vectors near the zero vector is less than or equal to a predetermined value among the motion vectors generated by the motion vector histogram generating means, the rate The conversion means is characterized by invalidating the motion compensation process.

  According to a fourth technical means, in the first technical means, the number of motion vectors outside the detection range set in advance between frames or fields among the motion vectors generated by the motion vector histogram generating means. When the amount of change is equal to or greater than a predetermined amount, the rate conversion unit invalidates the motion compensation process.

  According to a fifth technical means, in any one of the first to fourth technical means, when the rate conversion means invalidates motion compensation processing, the frame is inserted between frames or fields of the input image signal. Alternatively, the number of frames or the number of fields of the input image signal is converted by inserting a field image signal.

  According to a sixth technical means, in the first technical means, the number of motion vectors outside a preset detection range among the motion vectors generated by the motion vector histogram generation means is equal to or greater than a first predetermined value. And the rate conversion means enables the motion compensation processing when both the zero vector and the number of motion vectors near the zero vector are equal to or greater than a second predetermined value. is there.

  According to a seventh technical means, in the sixth technical means, based on the position information of the motion vector generated by the motion vector histogram generating means, the zero vector and the motion vector near the zero vector are near the center of the screen. When it is determined that the position is located at the position, the rate conversion means validates the motion compensation process.

  An eighth technical means is the motion vector according to any one of the first to seventh technical means, wherein the rate conversion means detects motion vector information between consecutive frames or fields included in the input image signal. A detection unit; an interpolation vector allocating unit that allocates an interpolation vector between the frames or between the fields based on the detected motion vector information; and an interpolation that generates an interpolation image signal from the allocated interpolation vector. An image generation unit and an image interpolation unit for interpolating the generated interpolated image signal between the frames or between the fields are characterized.

  According to the present invention, since it is possible to switch between valid / invalid of motion compensation processing for an image with large motion, it is possible to prevent degradation of moving image quality due to motion compensation while improving moving image response. it can.

  Hereinafter, preferred embodiments of an image display device according to the present invention will be described with reference to the accompanying drawings. The image display apparatus according to the present embodiment includes an FRC function that converts a frame rate or a field rate. Although the present invention can be applied to any of a field signal, an interpolated field signal, a frame signal, and an interpolated frame signal, both (field and frame) are in a similar relationship with each other, so A signal and an interpolated frame signal will be described as representative examples.

  FIG. 1 is a block diagram illustrating a configuration example of a motion compensated frame rate conversion unit included in the image display apparatus of the present invention. In the figure, reference numeral 10 denotes a frame rate conversion unit (hereinafter referred to as FRC unit), which corresponds to the rate conversion means of the present invention and detects a motion vector between two consecutive frames included in an input image signal. And a frame generation unit 12 that generates an interpolation frame (interpolated image) based on the detected motion vector. In addition, although the vector detection part 11 shows about the example at the time of using an iterative gradient method for a motion vector detection, it is not limited to this iterative gradient method, A block matching method etc. may be used.

  Here, the feature of the iterative gradient method is that a motion vector can be detected in units of blocks, so that several types of motion amounts can be detected, and a motion vector can be detected even in a small-sized moving object. Also, the circuit configuration can be realized on a small scale as compared with other methods (block matching method or the like). In this iterative gradient method, a method is used in which the gradient method is repeated for the detected block, using the motion vector of a nearby block that has already been detected as an initial displacement vector, and starting from this. According to this method, it is possible to obtain an almost accurate motion amount by repeating the gradient method about twice.

  In FIG. 1, a vector detection unit 11 limits a high frequency band by multiplying an extracted Y signal by LPF and a luminance signal extraction unit 11a that extracts a luminance signal (Y signal) from an input image signal (RGB signal). A preprocessing filter 11b for performing the motion detection, a frame memory 11c for motion detection, an initial vector memory 11d for storing initial vector candidates, and a motion vector detection unit 11e for detecting a motion vector between frames using an iterative gradient method. And an interpolation vector evaluation unit 11f that allocates an interpolation vector between frames based on the detected motion vector.

  Since the calculation of the iterative gradient method uses the differential component of the pixel, it is easily affected by noise, and the calculation error increases if the amount of change in the gradient in the detection block is large. To limit the high-frequency band. In the initial vector memory 11d, motion vectors (initial vector candidates) already detected in the previous frame are stored as initial vector candidates.

  The motion vector detection unit 11e selects a motion vector closest to the motion vector of the detected block from among the initial vector candidates stored in the initial vector memory 11d as an initial vector. That is, the initial vector is selected by the block matching method from the already detected motion vectors (initial vector candidates) in the blocks near the detected block. Then, the motion vector detection unit 11e detects a motion vector between the previous frame and the current frame by gradient method calculation with the selected initial vector as a starting point.

  The interpolation vector evaluation unit 11f corresponds to the interpolation vector allocation unit of the present invention, evaluates the motion vector detected by the motion vector detection unit 11e, and determines an optimal interpolation vector between frames based on the evaluation result. It is allocated to the interpolation block and output to the frame generation unit 12.

  The frame generation unit 12 includes an interpolation frame memory 12a for accumulating two input frames (previous frame and current frame), two input frames from the interpolation frame memory 12a, and an interpolation vector evaluation unit 11f. An interpolation frame generation unit 12b for generating an interpolation frame based on the interpolation vector of time, a time base conversion frame memory 12c for storing input frames (previous frame, current frame), and a time base conversion frame A time base conversion unit 12d that inserts the interpolation frame from the interpolation frame generation unit 12b into the input frame from the memory 12c.

  The interpolation frame generation unit 12b corresponds to the interpolation image generation unit of the present invention, and the time base conversion unit 12d corresponds to the image interpolation unit of the present invention.

  FIG. 2 is a diagram for explaining an example of the interpolation frame generation processing by the frame generation unit 12. The interpolation frame generation unit 12b extends the interpolation vector V assigned to the interpolation block to the previous frame and the current frame, and interpolates each pixel in the interpolation block using pixels near the intersection with each frame. . For example, in the previous frame, the luminance of point A is calculated from three points in the vicinity. In the current frame, the luminance of point B is calculated from the three neighboring points. In the interpolated frame, the luminance at point P is interpolated from the luminance at points A and B. The brightness at point P may be the average of the brightness at point A and the brightness at point B, for example.

  The interpolated frame generated as described above is sent to the time base converter 12d. The time base conversion unit 12d performs a process of converting the frame rate by inserting an interpolation frame between the previous frame and the current frame. As described above, the FRC unit 10 can convert the input image signal (60 frames / second) into the motion compensated output image signal (120 frames / second), and outputs this to the display panel, thereby reducing motion blur. It is possible to reduce and improve the video quality. Here, a case where the frame rate conversion of an input image signal of 60 frames / second to an output image signal of 120 frames / second is described, but for example, output image signals of 90 frames / second and 180 frames / second are obtained. Needless to say, it may be applied to a case.

(First embodiment)
The image display apparatus according to the present invention includes the FRC unit 10 shown in FIG. 1, and when performing the FRC process, switching between valid / invalid of the motion compensation process according to the histogram of the motion vector, thereby degrading the image quality. Is to prevent. The present invention can be applied to all image display devices having hold-type display characteristics such as a liquid crystal display, an organic EL display, and an electrophoretic display. In the following embodiments, a liquid crystal display panel is used as the display panel. A case where the present invention is applied to the liquid crystal display device used will be described as a representative example.

  Note that the frame rate conversion processing according to the present invention can be suitably used not only for watching broadcast waves such as one segment, but also when watching low-quality Internet moving images such as “youtube”.

  FIG. 3 is a block diagram showing a configuration example of a main part of the liquid crystal display device according to the present invention, in which 13 denotes an image processing unit, 14 denotes a control unit, 15 denotes an electrode driving unit, and 16 denotes a liquid crystal display panel. The FRC unit 10 includes a motion vector detection unit 11e, an interpolation vector evaluation unit 11f, a motion vector histogram generation unit 11g, an interpolation frame memory 12a, an interpolation frame generation unit 12b, and a time base conversion unit 12d. Here, only the main configuration according to the present invention is illustrated, and the luminance signal extraction unit 11a, the preprocessing filter 11b, the motion detection frame memory 11c, the initial vector memory 11d, and the time base conversion frame illustrated in FIG. Description of the memory 12c is omitted.

The image processing unit 13 is provided before the FRC unit 10, performs various image processes on the input image signal, and outputs the processed image to the FRC unit 10.
The control unit 14 includes a CPU and a memory for controlling each unit (FRC unit 10, image processing unit 13, electrode driving unit 15, liquid crystal display panel 16) illustrated in FIG. 3, and performs FRC processing in the FRC unit 10. Control.

  The electrode driving unit 15 generates a display timing signal necessary for the liquid crystal display panel 16 under the control of the control unit 14. Further, the electrode driving unit 15 outputs a display control signal necessary for controlling the display operation of the liquid crystal display panel 16. Specifically, the electrode driving unit 15 drives the scanning electrode by the gate driver of the liquid crystal display panel 16 based on the image data converted by the FRC unit 10 and drives the data electrode by the source driver.

  The liquid crystal display panel 16 is illuminated from the back by light from a backlight (not shown). An image is displayed by adjusting the amount of illumination light transmitted through the substrate in accordance with the strength of the electric field applied to the liquid crystal layer having an anisotropic dielectric constant injected between the two substrates.

  In FIG. 3, two input frames (previous frame and current frame) output from the image processing unit 13 are input to the motion vector detection unit 11e and the interpolation frame memory 12a. The motion vector detection unit 11e detects a motion vector between two input frames and outputs it to the motion vector histogram generation unit 11g and the interpolation vector evaluation unit 11f. The interpolation frame memory 12a stores and holds two input frames.

The motion vector histogram generation unit 11g corresponds to the motion vector histogram generation unit of the present invention, generates a histogram based on the motion vector detected by the motion vector detection unit 11e, and outputs the generated histogram information to the control unit 14. .
On the other hand, the interpolation vector evaluation unit 11f evaluates the motion vector detected by the motion vector detection unit 11e, assigns an optimal interpolation vector to an inter-frame interpolation block based on the evaluation result, and inserts an interpolation frame. It outputs to the production | generation part 12b.
For the sake of explanation, the motion vector histogram generation unit 11g and the interpolation vector evaluation unit 11f are shown separately, but the motion vector histogram generation unit 11g may be included in the interpolation vector evaluation unit 11f.

  Based on the motion vector histogram information generated by the motion vector histogram generation unit 11g, the control unit 14 outputs an on / off signal for switching the validity / invalidity of the motion compensation processing to the interpolation frame generation unit 12b. The motion compensation process is validated when the on / off signal is on, and the motion compensation process is invalidated when the on / off signal is off. For example, when the number of motion vectors outside the preset detection range is greater than or equal to a predetermined value among the motion vectors for which the histogram is generated by the motion vector histogram generation unit 11g, the control unit 14 generates an off signal as an interpolation frame. The interpolated frame generation unit 12b invalidates the motion compensation process according to the off signal. In this case, the interpolation frame generation unit 12b reads the previous frame from the interpolation frame memory 12a without performing the interpolation frame generation process for the motion compensation process. A method for determining whether the motion compensation process is valid / invalid based on the histogram will be described with reference to FIGS.

  On the other hand, when the ON signal is input from the control unit 14, the interpolation frame generation unit 12b determines that the motion compensation process is valid, and two input frames (previous frame and current frame) from the interpolation frame memory 12a. And an interpolation frame based on the interpolation vector from the interpolation vector evaluation unit 11f.

  The time base conversion unit 12d performs processing of inserting the interpolation frame or the previous frame from the interpolation frame generation unit 12b into the input frame (previous frame, current frame) from the time base conversion frame memory 12c. That is, the time base conversion unit 12d inserts an interpolated frame between the previous frame and the current frame and performs frame rate conversion processing by motion compensation, or inserts the previous frame between the previous frame and the current frame. The frame rate conversion process is performed by repeatedly outputting the same frame.

  As described above, when invalidating the motion compensation process, the FRC unit 10 converts the number of frames of the input image signal by inserting the image signal of the frame between the frames of the input image signal, in other words, For example, the same frame is sandwiched between the previous frame and the current frame, and frame rate conversion processing is performed by repeatedly outputting the same frame. In the above example, the previous frame is output twice, but the subsequent frame may be output twice.

  FIG. 4 is a diagram illustrating an example of histogram information generated by the motion vector histogram generation unit 11g. This example of the histogram information shows a case where the number of motion vectors outside the detection range set in advance is greater than or equal to a predetermined value among the motion vectors generated by the motion vector histogram generation unit 11g. For example, the motion vector detection range is set to ± 32 pixels, and a motion vector value not included in the detection range, that is, having no end point is set to 40. Note that a setting value set for the frequency (number) of motion vectors is stored in advance in a memory or the like (not shown), and the control unit 14 determines the motion vector value having a motion vector value of 40 based on this setting value. Determine the number. When the number of motion vectors having a motion vector value of 40 exceeds the set value, the control unit 14 outputs an off signal to the FRC unit 10 and controls the FRC unit 10 to repeatedly output the previous frame twice. To do.

  FIG. 5 is a diagram for explaining an example of frame rate conversion processing by the liquid crystal display device according to the first embodiment of the present invention, in which f1 to f3 are input frames, f1 ′ is an interpolation frame, and c Indicates an element (car) in the frame. It is assumed that the automobile c is moving from left to right in the frame. The vehicle c exists in the input frames f1 and f2 in this example, but the vehicle c does not run away in the input frame f3. Therefore, if an attempt is made to detect the motion vector of the automobile c between the input frames f2 and f3, the motion vector value of the automobile c is assigned to the motion vector value 40 having no end point because it is outside the detection range of ± 32 pixels. .

  When the control unit 14 determines that the number of motion vectors having the motion vector value 40 is equal to or greater than the set value, the FRC unit 10 is controlled to repeatedly output the previous frame twice. As a result, the interpolated frame f1 ′ subjected to the motion compensation process is inserted between the input frames f1 and f2, and the input frame f2 is inserted as it is between the input frames f2 and f3.

  Thereby, even when the motion is large and the estimation destination (end point) of the motion vector cannot be determined, screen failure (error in the interpolated image) in the corresponding part (the automobile c in the above example) can be prevented. The FRC process can be performed while maintaining the quality.

  FIG. 6 is a diagram illustrating another example of histogram information generated by the motion vector histogram generation unit 11g. The histogram information of the motion vector is used as an index for grasping the motion of the entire image. For example, as described above, if the motion vector detection range is ± 32 pixels and all the pixels in the frame are included in this detection range, the motion vector histogram is as shown in FIG. . In addition, when the motion is intense and there are few stationary elements, the motion vector near the zero vector decreases, and the motion vector histogram is as shown in FIG. In addition, when the movement is intense and most of the pixels are outside the detection range and there is no end point, the detection range (± 32 pixels) contains a small number of pixels, and the motion vector histogram is as shown in FIG. .

  In the case of the present invention, the motion vector histogram generator 11g generates a histogram with a motion vector detection range of ± 32 pixels and a motion vector value having no end point not included in the detection range as 40. The control unit 14 determines the number of motion vectors having a motion vector value of 40 based on a preset setting value. When the number of motion vectors exceeds the set value, the control unit 14 outputs an off signal to the FRC unit 10 to invalidate the motion compensation process, and controls the FRC unit 10 to repeatedly output the previous frame twice. To do.

  Further, as shown in FIG. 6B, when the number of motion vectors near the zero vector is equal to or less than the set value among the motion vectors generated by the motion vector histogram generation unit 11g, the motion is large. Presumed to be an image. Also in this case, the control unit 14 may output the OFF signal to the FRC unit 10 to invalidate the motion compensation process, and may control the FRC unit 10 to repeatedly output the previous frame twice. It is assumed that the set value at this time is smaller than the set value for the motion vector value 40.

  In addition to the above, among the motion vectors generated by the motion vector histogram generation unit 11g, the change amount of the number of motion vectors outside the detection range set in advance between frames is greater than or equal to a predetermined amount. It is estimated that the image has a large motion. For example, when the number of motion vectors having the motion vector value 40 of the current frame has increased by a predetermined amount or more compared to the previous frame, the control unit 14 outputs an off signal to the FRC unit 10 to invalidate the motion compensation process. And the FRC unit 10 may be controlled so as to repeatedly output the previous frame twice.

  As a method for converting the frame rate without performing the motion compensation process, the output of the motion vector detected by the motion vector detection unit 11e is set to 0 vector, or the interpolation assigned by the interpolation vector evaluation unit 11f is performed. The motion compensation process can be invalidated by setting the vector output to 0 vector. According to this method, since the interpolation vector becomes 0 vector, the same frame is interpolated as a result. In this case, it is not necessary to read the same frame from the interpolation frame memory 12a in the interpolation frame generation unit 12b.

  According to this embodiment, when converting an image with a low frame rate such as one seg to a high frame rate and viewing, even if the image has a large movement, screen disturbance due to an error in the interpolated image is reduced, A high-quality image can be provided.

(Second Embodiment)
FIG. 7 is a diagram for explaining an example of frame rate conversion processing by the liquid crystal display device according to the second embodiment of the present invention, in which 21 is a foreground image (a person in this example), and 22 is a background image. Indicates. Here, one frame is composed of a foreground image 21 and a background image 22. In the present embodiment, the number of motion vectors outside the preset detection range among the motion vectors generated by the motion vector histogram generation unit 11g is equal to or greater than the first predetermined value, and the 0 vector and 0 When the number of motion vectors near the vector is both equal to or greater than the second predetermined value, the motion compensation process is enabled in the FRC unit 10.

  For example, when shooting with a camera shaken about a moving person or the like as shown in FIG. 7A, the foreground image 21 that is a person moves little (substantially still), and the foreground image 21 The motion of the background image 22 other than is increased. Accordingly, the histogram in this case is as shown in FIG. In the first embodiment, since the number of motion vectors having the motion vector value 40 is equal to or greater than a predetermined value (first predetermined value), the previous frame is inserted. However, it is considered that the normal viewer is gazing at the person in the foreground image 21, and the screen failure of the background image 22 that is the other part is not so much concerned.

  Therefore, as shown in FIG. 7B, a second set value is provided for the 0 vector corresponding to the vicinity of the person and the motion vector near the 0 vector, and the number of motion vectors near the 0 vector and the 0 vector is both When the value is equal to or greater than the second set value, an interpolation process based on normal motion compensation is performed. By doing this, even when the number of motion vectors outside the detection range is greater than or equal to the set value, the motion vector of the portion with less motion (that is, the 0 vector and the motion vector near the 0 vector) is greater than or equal to the predetermined number. Since the interpolation process by the normal motion compensation can be performed, it is possible to improve the moving image responsiveness of the portion watched by the viewer.

  Here, in the case of the example shown in FIG. 5, the histogram shown in FIG. 7C is expected. In this example, since the camera is not panned, the number of zero vectors is considered to be the largest if the background of the automobile c is stationary. Therefore, the number of 0 vectors corresponding to the background and the number of motion vectors outside the detection range corresponding to the automobile c are increased. On the other hand, in the case of the example shown in FIG. 7B, since the camera is panning, the person chased by the camera and its surroundings are the 0 vector and the motion vector near the 0 vector, and the other backgrounds are outside the detection range. Since this is a motion vector, the number of motion vectors near the person and the number of motion vectors near the 0 vector and the number of motion vectors outside the detection range corresponding to the other backgrounds are large.

  Thus, in the case of FIG. 7C, since the number of motion vectors near the 0 vector is smaller than the number of 0 vectors, the number of 0 vectors exceeds the set value, but the number of motion vectors near the 0 vector is set. It will be below the value. On the other hand, in the case of FIG. 7B, both the number of 0 vectors and the number of motion vectors near the 0 vector are large, and therefore the number of motion vectors near the 0 vector and the 0 vector both exceed the set value. Become. Note that the motion vector near the zero vector is, for example, a motion vector that falls within a range of ± 10 pixels.

  Therefore, it is possible to discriminate between the image shown in FIG. 5 and the image shown in FIG. 7A by determining whether the number of motion vectors near the zero vector and the zero vector exceeds the set value. .

  In the case of the image shown in FIG. 7A, panning causes the zero vector and the motion vector near the zero vector to concentrate near the center of the screen. Therefore, the control unit 14 acquires the position information of the motion vector for which the histogram is generated by the motion vector histogram generation unit 11g, and based on the acquired position information, the 0 vector and the motion vector around the 0 vector are near the center of the screen. You may determine whether it is located. This makes it possible to more reliably determine the image in FIG. Here, since the motion vector detection unit 11e sees the motion of each pixel when detecting the motion vector, it can acquire the position information of each motion vector. When this position information is input to the control unit 14 and the control unit 14 determines that the zero vector and the motion vector near the zero vector are located near the center of the screen, the FRC unit 10 enables the motion compensation processing. .

  According to the present embodiment, when a camera is shaken around a moving person or the like to take a picture, the viewer pays attention by giving priority to motion compensation of a person (part with less movement) in the image. The moving image quality of the part can be improved and the quality of the entire image can be maintained.

It is a block diagram which shows the structural example of the motion compensation type frame rate conversion part with which the image display apparatus of this invention is provided. It is a figure for demonstrating an example of the interpolation frame production | generation process by a frame production | generation part. It is a block diagram which shows the principal part structural example of the liquid crystal display device which concerns on this invention. It is a figure which shows an example of the histogram information produced | generated by the motion vector histogram production | generation part. It is a figure for demonstrating an example of the frame rate conversion process by the liquid crystal display device which concerns on the 1st Embodiment of this invention. It is a figure which shows the other example of the histogram information produced | generated by the motion vector histogram production | generation part. It is a figure for demonstrating an example of the frame rate conversion process by the liquid crystal display device which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Frame rate conversion (FRC) part, 11 ... Vector detection part, 11a ... Luminance signal extraction part, 11b ... Pre-processing filter, 11c ... Frame memory for motion detection, 11d ... Initial vector memory, 11e ... Motion vector detection part, 11f: Interpolation vector evaluation unit, 11g: Motion vector histogram generation unit, 12 ... Frame generation unit, 12a ... Interpolation frame memory, 12b ... Interpolation frame generation unit, 12c ... Time base conversion frame memory, 12d ... Time Base conversion unit, 13 ... image processing unit, 14 ... control unit, 15 ... electrode drive unit, 16 ... liquid crystal display panel.

Claims (8)

Rate conversion means for converting the number of frames or fields of the input image signal and outputting it to the display panel by interpolating the image signal subjected to motion compensation processing between frames or fields of the input image signal An image display device,
A motion vector histogram generating means for generating a histogram of motion vectors detected between frames or fields of the input image signal;
The image conversion apparatus according to claim 1, wherein the rate conversion means switches between valid / invalid of motion compensation processing based on a motion vector histogram generated by the motion vector histogram generation means.   2. The image display device according to claim 1, wherein the number of motion vectors outside a preset detection range among motion vectors generated by the motion vector histogram generation unit is equal to or greater than a predetermined value. An image display device, wherein the rate conversion means invalidates the motion compensation process.   2. The image display apparatus according to claim 1, wherein when the number of motion vectors near the zero vector is equal to or less than a predetermined value among the motion vectors generated by the motion vector histogram generation unit, the rate conversion unit An image display device characterized by invalidating motion compensation processing.   2. The image display device according to claim 1, wherein a change amount of the number of motion vectors outside a detection range set in advance between frames or fields among motion vectors generated by the motion vector histogram generation unit is between frames. The image display device according to claim 1, wherein the rate conversion means invalidates the motion compensation process when the predetermined amount is exceeded.   5. The image display device according to claim 1, wherein the rate conversion unit invalidates the motion compensation process between frames or fields of the input image signal. An image display device that converts the number of frames or the number of fields of the input image signal by inserting an image signal.   The image display device according to claim 1, wherein the number of motion vectors outside a preset detection range among the motion vectors generated by the motion vector histogram generation unit is equal to or greater than a first predetermined value, In addition, when both the 0 vector and the number of motion vectors in the vicinity of the 0 vector are equal to or greater than a second predetermined value, the rate conversion unit validates the motion compensation process.   7. The image display device according to claim 6, wherein the zero vector and a motion vector near the zero vector are located near the center of the screen based on the positional information of the motion vector for which the histogram is generated by the motion vector histogram generation unit. When judged, the rate conversion means validates the motion compensation process.   8. The image display device according to claim 1, wherein the rate conversion unit includes a motion vector detection unit that detects motion vector information between consecutive frames or fields included in the input image signal. An interpolation vector allocating unit that allocates an interpolation vector between the frames or between the fields based on the detected motion vector information, and an interpolation image generating unit that generates an interpolation image signal from the allocated interpolation vector And an image interpolating unit for interpolating the generated interpolated image signal between the frames or the fields.

Images