JP4355347B2 - Image display apparatus and method, image processing apparatus and method - Google Patents

Description

  The present invention relates to an image display apparatus and method and an image processing apparatus and method having a function of converting a frame rate or a field rate, and more particularly to an image display apparatus and image display method and image using the apparatus that prevent image quality deterioration of a telop portion. The present invention relates to a processing apparatus and an image processing method using the apparatus.

  In contrast to a cathode ray tube (CRT) that has been mainly used for the purpose of embodying moving images, an LCD (Liquid Crystal Display) moves a viewer when a moving image is displayed. There is a so-called motion blur defect in which the outline of a part is blurred and perceived. It has been pointed out that this motion blur is caused by the LCD display method itself (see, for example, Patent Document 1 and Non-Patent Document 1).

  In a CRT that performs display by scanning an electron beam to emit light from a phosphor, the light emission of each pixel is substantially in an impulse shape although there is some afterglow of the phosphor. This is called an impulse type display system. On the other hand, in the LCD, the charge stored by applying an electric field to the liquid crystal is held at a relatively high rate until the next electric field is applied. In particular, in the case of the TFT method, a TFT switch is provided for each dot constituting a pixel, and an auxiliary capacitor is usually provided for each pixel, and the ability to hold stored charges is extremely high. For this reason, light emission continues until the pixel is rewritten by applying an electric field based on image information of the next frame or field (hereinafter referred to as a frame). This is called a hold type display method.

  In the hold-type display method as described above, the impulse response of the image display light has a temporal spread, so that the time frequency characteristic is deteriorated, and the spatial frequency characteristic is accordingly lowered, resulting in motion blur. In other words, since the human line of sight smoothly follows a moving object, if the light emission time is long as in the hold type, the movement of the image becomes jerky due to the time integration effect and looks unnatural.

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

  Conventionally, as a method for converting the frame rate, there are various methods such as simply repeatedly reading out the same frame a plurality of times and frame interpolation by linear interpolation between frames (for example, see Non-Patent Document 2). ). However, in the case of frame interpolation processing by linear interpolation, motion unnaturalness (jerkiness, judder) due to frame rate conversion occurs, and motion blur interference due to the hold type display method described above is sufficiently improved. The image quality was insufficient.

  Therefore, motion compensation processing using motion vectors has been proposed in order to eliminate the influence of the jerkiness and improve the moving image quality. According to this motion compensation processing, since the motion compensation is performed by capturing the moving image itself, it is possible to obtain a very natural moving image without degradation of 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.

  Patent Document 1 described above discloses a technique for improving a decrease in spatial frequency characteristics that causes motion blur by increasing a 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.

  FIG. 15 is a block diagram showing a schematic configuration of an FRC drive display circuit in a conventional liquid crystal display device. In the figure, the FRC drive display circuit interpolates an image signal subjected to motion compensation processing between frames of an input image signal. An FRC unit 100 that converts the number of frames of the input image signal, an active matrix type liquid crystal display panel 103 having a liquid crystal layer and electrodes for applying a scanning signal and a data signal to the liquid crystal layer, and an FRC unit And an electrode driving unit 104 for driving the scanning electrodes and the data electrodes of the liquid crystal display panel 103 based on the image signal whose frame rate is converted by 100.

  The FRC unit 100 includes a motion vector detection unit 101 that detects motion vector information from an input image signal, an interpolation frame generation unit 102 that generates an interpolation frame based on the motion vector information obtained by the motion vector detection unit 101, and Is provided.

  In the above configuration, the motion vector detection unit 101 may obtain the motion vector information using, for example, a block matching method or a gradient method described later, or the motion vector information is included in some form in the input image signal. If this is the case, this may be used. For example, image data compression-encoded using the MPEG method includes motion vector information of a moving image calculated at the time of encoding, and the motion vector information may be acquired.

  FIG. 16 is a diagram for explaining frame rate conversion processing by the conventional FRC drive display circuit shown in FIG. The FRC unit 100 generates an interpolated frame (an image colored in gray in the figure) by motion compensation using the motion vector information output from the motion vector detecting unit 101, and the generated interpolation By sequentially outputting the frame signal together with the input frame signal, processing for converting the frame rate of the input image signal from, for example, 60 frames per second (60 Hz) to 120 frames per second (120 Hz) is performed.

  FIG. 17 is a diagram for explaining an interpolation frame generation process performed by the motion vector detection unit 101 and the interpolation frame generation unit 102. The motion vector detection unit 101 detects the motion vector 105 from the frame # 1 and the frame # 2 shown in FIG. That is, the motion vector detection unit 101 obtains the motion vector 105 by measuring how much and in which direction the frame # 1 and frame # 2 have moved in 1/60 second. Next, the interpolation frame generation unit 102 allocates the interpolation vector 106 between the frame # 1 and the frame # 2 using the obtained motion vector 105. An interpolation frame 107 is generated by moving the object (in this case, an automobile) from the position of frame # 1 to a position after 1/120 second based on the interpolation vector 106.

  In this way, motion compensation frame interpolation processing is performed using motion vector information, and the display frame frequency is increased to change the display state of the LCD (hold type display method) to the display state of the CRT (impulse type display method). It is possible to improve the image quality degradation due to motion blur that occurs when displaying a moving image.

  Here, in the motion compensation frame interpolation process, detection of a motion vector is indispensable for motion compensation. As this motion vector detection method, for example, the pattern matching described in “Television image motion detection method” disclosed in Patent Document 2, “Asymptotic detection method of image motion vector” described in Patent Document 3, and the like. Or the iterative gradient method described in the “image motion amount detection method” disclosed in Patent Document 4 and the “initial displacement method in motion estimation of moving images” disclosed in Patent Document 5, respectively. ing.

  In particular, the latter motion vector detection method based on the iterative gradient method is smaller and more accurate than the pattern matching method, and can detect a motion vector. That is, the motion vector detection method based on the iterative gradient method has a predetermined predetermined size of each frame of a digitized television signal, for example, m × n pixels including m pixels in the horizontal direction and n lines in the vertical direction. By subdividing into blocks, each block is subjected to repetitive gradient calculation based on the signal gradient in the screen and the physical correspondence of the signal difference value between the corresponding screens The amount of motion is estimated.

  By the way, a moving image has high correlation between frames and has continuity in the time axis direction. In many cases, a pixel or block that moves in a certain frame moves with the same amount of motion in a subsequent frame or a frame preceding it. For example, in the case of a moving image in which the ball rolls from right to left on the screen, the ball area moves with the same amount of movement in any frame. That is, there are many cases where motion vectors have continuity between consecutive frames.

  Therefore, by referring to the motion vector detection result in the previous frame, the motion vector detection in the next frame can be performed more easily or more accurately. In Patent Document 5, as an initial value when estimating the amount of motion, the detected block is selected from among motion vector candidates already detected in a plurality of peripheral blocks including the block corresponding to the detected block. By selecting the optimal one for motion vector detection as an initial displacement vector and starting gradient method calculation from a value close to the true motion vector of the detected block, the number of gradient method calculations is reduced, For example, a method for detecting a true motion vector by two gradient method computations has been proposed.

  In addition, in the “motion vector detection circuit” disclosed in Patent Document 6, in order to further improve the accuracy of motion vector detection, an initial displacement vector of motion between each block of an image signal separated by at least one field or one frame or more. A method for detecting the above has been proposed. Furthermore, in the block matching method, it is conceivable to perform efficient motion vector detection by changing the search order with reference to the motion vector detection result in the previous frame. As described above, when a motion vector is detected, by using the already detected motion vector, for example, real-time processing of frame rate conversion becomes possible.

By the way, in television programs and movies, subtitles, so-called telops are often included in image signals. Among them, there is a telop in which characters scroll (move) horizontally or vertically on the screen. According to Non-Patent Document 3, the movement speed of a subject included in a general TV program is mainly distributed to 20 deg / sec or less, and in particular, the frequency of 10 deg / sec or less is high. It can be seen that the scroll speed is 13.8 deg / sec on average and 35.9 deg / sec at the maximum, and the telop appearance frequency of 10 to 20 deg / sec is high. That is, a scrolling telop often moves at a faster speed in a television program than a general subject.
Japanese Patent No. 3295437 Japanese Unexamined Patent Publication No. 55-162683 Japanese Patent Laid-Open No. 55-162684 JP 60-158786 A Japanese Patent Laid-Open No. 62-206980 Japanese Patent Laid-Open No. 06-217266 Shuichi Ishiguro, Taiichi Kurita, “Examination of video quality of hold light emission display by 8 × CRT”, IEICE Technical Report, The Institute of Electronics, Information and Communication Engineers, EID96-4 (1996-06), p. 19-26 Tatsuro Yamauchi, “Television Conversion”, Television Society Journal, Vol. 45, no. 12, pp. 1534-1543 (1991) Fujine, et.al., "Real-Life In-Home Viewing Conditions for FPDs and Statistical Characteristics of Broadcast Video", Digest AM-FPD'06

  Normally, in a moving image, the faster the movement of an object, the larger the change between frames, and it becomes difficult to accurately estimate the motion vector. That is, in FRC, it is more difficult to generate an interpolated image accurately as the object moves faster. As described above, a telop used in a television program often moves at a faster speed than a general subject. Therefore, it can be said that a telop is an object for which it is difficult to accurately generate an interpolated image.

  In general, a subject photographed by a camera includes blur caused by the light accumulation time of the camera (camera blur) when the movement is fast. As described above, motion blur caused by the hold-type display method is less noticeable for an image originally including blur. In addition, when FRC is performed, even if motion vector detection fails and a failure occurs in the interpolated image, the failure is not noticeable. On the other hand, since the telop is an image synthesized later, even if its movement is fast, camera blur is not included. For this reason, motion blur caused by the hold-type display method is conspicuous and the FRC functions effectively. On the other hand, if the motion vector detection of the FRC fails and the interpolated image of the telop part is broken, the failure is Easy to stand out.

  In addition, in order to read the contents of the telop, the viewer watches the telop that scrolls and follows it. For this reason, if the motion vector detection of FRC fails and the failure of the interpolated image appears in the telop portion, there is a problem that the image quality deterioration is particularly noticeable for the viewer.

  The present invention has been made in view of the above problems, and an image display apparatus and method, and an image processing apparatus capable of preventing image quality deterioration of a telop portion caused by a motion compensation type frame rate conversion (FRC) process And to provide a method.

According to a first aspect of the present invention, rate conversion means for converting the number of frames or the number of fields of the input image signal by interpolating an image signal subjected to motion compensation processing between frames or fields of the input image signal. The rate conversion means divides the frame or field of the input image signal into a plurality of blocks having a predetermined size, and at least one frame or one field for each block. A motion vector detection unit that detects a motion vector representing the magnitude and direction of motion between input image signals separated from each other, and the motion vector detection unit detects at least one frame of the detected motion vector detected for each block; A storage unit for storing one field and a shift in a predetermined direction included in the input image signal. And telop information detecting unit for detecting an area and / or the motion vector of a telop which, with an area and / or detection motion vector of the telop detected by the telop information detecting unit, in the region of at least the telop, the storage The initial displacement vector of the detected block from the candidate vector group consisting of motion vectors accumulated by the unit or the candidate vector group obtained by adding the detected motion vector of the telop to the motion vector accumulated by the storage unit As an initial displacement vector selection unit that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop, and by performing a predetermined calculation using the initial displacement vector selected by the initial displacement vector selection unit as a starting point, Obtain and output the motion vector of the detected block And having a motion vector calculating section for storing in the storage unit.

The second invention of the present application, the initial displacement vector selecting unit, wherein in territory Iki以 outside the region of Kite drop before been detected by the telop information detecting unit, the same or close to the candidate vector and the motion vector of the telop The process of preferentially selecting is not performed .

The third invention of the present application, the initial displacement vector selecting unit, wherein in a region other than the region before Kite drop detected by the telop information detecting unit preferentially selects a candidate vector close to the average vector of the entire screen It is characterized by doing.

The fourth invention of the present application, the initial displacement vector selecting unit, wherein in a region other than the region before Kite drop detected by the telop information detecting unit, selecting a candidate vectors close to zero-vector preferentially Features.

The fifth invention of the present application is characterized in that the initial displacement vector selection unit performs processing by adding the detected motion vector of the telop detected by the telop information detection unit to the candidate vector.

According to a sixth aspect of the present invention, the initial displacement vector selection unit detects, for a block corresponding to the telop area detected by the telop information detection unit, the telop information detected by the telop information detection unit. The detected motion vector is processed by being added to the candidate vector.

In a seventh aspect of the present application, the initial displacement vector selection unit performs weighting so that the detected motion vector of the telop in the candidate vector is easily selected in the telop area detected by the telop information detection unit. And performing an initial displacement vector selection process.

Eighth invention of the present application, the motion vector calculation unit, the telop for the information detecting unit block corresponding to the region of the telop detected by the telop information detecting section of the telop detected by the detecting The calculation method is changed so that a vector in the same direction as the direction of the motion vector is obtained.

According to a ninth aspect of the present invention, a rate conversion step of converting the number of frames or the number of fields of the input image signal by interpolating an image signal subjected to motion compensation processing between frames or fields of the input image signal. The rate conversion step divides the frame or field of the input image signal into a plurality of blocks having a predetermined size, and at least one frame or one field for each block. A motion vector detecting step for detecting a motion vector representing the magnitude and direction of motion between the input image signals separated as described above, wherein the motion vector detecting step includes at least one frame of detected motion vectors detected for each block; A storage step for accumulating one field, and the input image signal Included, the telop information detecting step of detecting a region and / or the motion vector of the telop moves in a predetermined direction, with an area and / or detection motion vector of the detected telop, in the region of at least the telop, From the candidate vector group consisting of the motion vectors accumulated in the storage step or the candidate vector group consisting of adding the detected motion vector of the telop to the motion vector accumulated in the storage step As an initial displacement vector, an initial displacement vector selection step that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop, and a predetermined calculation starting from the initial displacement vector selected in the initial displacement vector selection step To determine the motion vector of the detected block And having a motion vector calculation step of Umate output.

According to a tenth aspect of the present invention, the number of frames or the number of fields of the input image signal is converted and output by interpolating the image signal subjected to motion compensation processing between frames or fields of the input image signal. An image processing apparatus comprising rate conversion means, wherein the rate conversion means divides a frame or field of the input image signal into a plurality of blocks having a predetermined size and at least one frame for each block. Alternatively, a motion vector detection unit that detects a motion vector representing the magnitude and direction of motion between input image signals separated by one field or more, and the motion vector detection unit uses at least a detected motion vector detected for each block. A storage unit for storing one frame or one field, and a place included in the input image signal And telop information detecting unit for detecting an area and / or the motion vector of the telop moves in the direction, with the area and / or detection motion vector of the telop detected by the telop information detecting section, at least in the region of the telop , A candidate vector group consisting of motion vectors accumulated by the storage unit, or a candidate vector group obtained by adding the detected motion vector of the telop to the motion vector accumulated by the storage unit, An initial displacement vector selection unit that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop as the initial displacement vector, and performs a predetermined calculation using the initial displacement vector selected by the initial displacement vector selection unit as a starting point To obtain and output the motion vector of the detected block. Together, and having a motion vector calculating section for storing in the storage unit.

According to an eleventh aspect of the present invention, a rate conversion step of converting the number of frames or the number of fields of the input image signal by interpolating the image signal subjected to motion compensation processing between frames or fields of the input image signal. The rate conversion step divides the frame or field of the input image signal into a plurality of blocks having a predetermined size, and at least one frame or one field for each block. A motion vector detecting step for detecting a motion vector representing the magnitude and direction of motion between the input image signals separated as described above, wherein the motion vector detecting step includes at least one frame of detected motion vectors detected for each block; A storage step for storing one field, and the input image Included in the item, the telop information detecting step of detecting a region and / or the motion vector of the telop moves in a predetermined direction, with an area and / or detection motion vector of the detected telop, at least in the region of the telop A candidate vector group consisting of motion vectors accumulated in the storage step or a candidate vector group obtained by adding the detected motion vector of the telop to the motion vector accumulated in the storage step As an initial displacement vector of the block, an initial displacement vector selection step that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop, and an initial displacement vector selected in the initial displacement vector selection step is used as a starting point. By performing the calculation, the motion vector of the detected block And having a motion vector calculation step of outputting seeking.

  According to the present invention, with the above-described configuration, it is possible to more accurately perform motion compensation processing on a telop portion, and as a result, it is possible to improve the image quality of a region where a telop exists.

  Hereinafter, preferred embodiments of an image display device of the present invention will be described in detail with reference to the accompanying drawings. However, the same parts as those of the above-described conventional example are denoted by the same reference numerals, and the description thereof is omitted. 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.

(1) Overall Configuration and Method of Using Telop Information FIG. 1 is a functional block diagram showing an example of a motion vector detection unit provided in the image display device of the present invention. In the FRC unit 100 of the image display device shown in FIG. This is for explaining the internal configuration of the motion vector detecting unit 101 included in detail. The motion vector detection unit 101 of this embodiment includes a frame delay unit 1, an initial displacement vector selection unit 2, a motion vector calculation unit 3, a vector memory 4, and a telop information detection unit 5.

  The motion vector detection unit 101 according to the present embodiment divides an input image signal input for each frame into a plurality of blocks each having a predetermined size, for example, m pixels × n lines (m and n are integers). Then, for each divided block, for example, a motion vector representing the direction and magnitude of motion with the corresponding block in the input image signal one frame before delayed by the frame delay unit 1 is obtained. The candidate vector group selected from the motion vectors already detected and stored in the vector memory 4 and the telop information obtained by the telop information detection unit 5 are used together to obtain an optimal motion vector. An initial displacement vector selection unit 2 for selecting an initial displacement vector in the detected block; and Using the information, and a motion vector calculating portion 3 for obtaining the true motion vector in 該被 detection block correctly by, for example, the gradient method calculation twice.

  In particular, the present embodiment is characterized in that the telop information detection unit 5 is provided and the telop information obtained thereby is used for processing in the initial displacement vector selection unit 2 or the motion vector calculation unit 3. In the initial displacement vector selection unit 2, different processing is performed in the region where the telop exists and the other region, or the initial displacement vector is selected in consideration of the moving speed / direction of the telop, or A combination of both is performed. The motion vector calculation unit 3 performs vector calculation in consideration of the moving speed / direction of the telop in the area where the telop exists. By performing such processing, a more accurate detection vector can be obtained particularly in a region where a telop exists.

  In the telop information detection unit 5, as the telop feature amount (telop information) included in the input image signal, for example, telop area information indicating which motion detection block in the screen corresponds to the telop, and the moving speed / The telop vector information indicating the direction is detected. If there are a plurality of telops in the screen, telop area information and telop vector information may be detected for each of them. Details of the telop information detection unit 5 will be described later.

  Here, an example in which the iterative gradient method is used as a calculation method in the motion vector calculation unit 3 will be described, but the present invention is not limited to this iterative gradient method, and a block matching method or the like may be used.

  More specifically, the motion vector detection unit 101 shown in FIG. 1 includes the initial displacement vector selection unit 2, the motion vector calculation unit 3, the vector memory 4, and the telop information detection unit 5 as described above. It consists of The initial displacement vector selection unit 2 and the motion vector calculation unit 3 are respectively supplied with the current frame signal and the previous frame signal delayed by one frame via the frame delay unit 1.

  The initial displacement vector selection unit 2 selects a value most suitable for the motion of the detected block from the detected motion vectors obtained by the motion vector calculation of the previous frame, for example, a motion vector having a value closest to the motion of the detected block. This is a selection circuit that selects an initial displacement vector as a starting point of the gradient method calculation, and selects an appropriate motion vector from the above-described candidate vector group and telop vector. The initial displacement vector selection unit 2 divides the previous frame signal into blocks of m pixels × n lines as described above, for example, and uses the current frame signal and the previous frame as a reference for selecting the initial displacement vector for each of the divided blocks. Use frame signals.

  For example, as shown in FIG. 2, the initial displacement vector selection unit 2 includes a coordinate conversion unit 2a, a subtraction unit 2b, an absolute value accumulation unit 2c, a selection unit 2d, and a telop vector addition determination unit 2e. . In the initial displacement vector selection unit 2, motion vectors of 8 blocks around the block corresponding to the detected block sequentially read from the vector memory 4, that is, candidate vector groups, and one or more output from the telop information detection unit 5 Telop vector and telop area information, the previous frame signal, and the current frame signal are input.

  The telop vector addition determination unit 2e inputs one or more telop vectors and telop area information, and outputs a telop vector in the telop area to the coordinate conversion unit 2a when the block being processed corresponds to a certain telop area. . When the block being processed corresponds to a plurality of telop areas, the telop vectors in each of the plurality of telop areas, that is, the plurality of telop vectors are output to the coordinate conversion unit 2a.

  Each motion vector of each candidate vector group and one or more telop vectors output from the telop vector addition determination unit 2e are candidates for the initial displacement vector. The initial displacement vector candidates are supplied to the respective coordinate conversion units 2a, and the target block of the previous frame signal supplied from the frame delay unit 1 is displaced by the motion vector to perform coordinate conversion to the current frame. The coordinate conversion result is supplied to each subtraction unit 2b.

  In this embodiment, the candidate vector group uses the motion vector of the previous frame detected in the eight blocks around the detected block as the candidate vector group for selecting the initial displacement vector of the detected block. The candidate vector group is not limited to such an example, but may be configured to be determined from already detected motion vectors in other regions.

  Each subtraction unit 2b performs a subtraction process between the previous frame signal coordinate-converted by the coordinate conversion unit 2a and the input current frame signal to calculate a difference for each pixel. The result is supplied to the absolute value accumulation unit 2c. Each absolute value accumulation unit 2c obtains the absolute value of the difference between the pixels, accumulates the absolute difference for the number of pixels of the block, and selects the accumulated result as an evaluation value of the candidate vector. 2d respectively.

  The accumulated result obtained by the above procedure is called DFD (Displaced Field Difference). The DFD is an index indicating the degree of accuracy of a calculated vector (here, a candidate vector). The smaller the DFD value, the better the matching between the block of the previous frame and the coordinate-converted block of the current frame, Indicates that the corresponding candidate vector is more appropriate.

  Next, the selection unit 2d that has received each accumulated result (DFD) for each block compares the accumulated result (DFD) of each block, and is the candidate vector with the smallest accumulated result (DFD), that is, the most appropriate. The candidate vector which is considered to be detected is detected, the candidate vector is selected as an initial displacement vector, and supplied to the motion vector calculation unit 3. At this time, if the detected block corresponds to a telop area using the telop area information from the telop information detection unit 5, processing is performed so as to preferentially select the telop vector.

  More specifically, for example, when the detected block corresponds to a telop area, weighting is performed so as to reduce the accumulation result (DFD) for the telop vector among the output values from the absolute value accumulation unit 2c. For example, it is possible to use a method of reducing the value of the cumulative result (DFD) for the telop vector by multiplying the cumulative result for the telop vector by a coefficient w (0 <w <1).

  In the above-described embodiment, the method of using both the telop area information and the telop vector information detected by the telop information detection unit 5 in the initial displacement vector selection unit 2 has been described, but only one of the information is used. It does not matter as a configuration to be used. For example, an example of a configuration using only telop area information will be described with reference to FIG. In this configuration, since no telop vector is input, the telop vector addition determination unit 2e in FIG. 2 is excluded. In this example, the selection unit 2d performs weighting on the output of the absolute value accumulation unit 2c to prioritize the average vector or 0 vector of the entire screen when the block being processed is outside the telop area. In the case of a telop area, such weighting is not performed. By performing such processing, a relatively fast vector is easily selected in the telop area. That is, a vector corresponding to a fast-moving telop is easily selected.

  For example, an example of a configuration using only telop vector information will be described with reference to FIG. In this configuration, no telop area information is input. Therefore, the telop vector addition determination unit 2e in FIG. 2 is also unnecessary, and the telop vector is added to the initial displacement vector candidates for all the blocks. Whether or not a vector that is the same as or close to the telop vector exists among the initial displacement vector candidates for the block in which the telop is present depends on the vector detection situation in the previous frame and is not certain. Therefore, it is possible to improve the possibility of selecting a more appropriate initial displacement vector by separately providing a telop vector as a candidate.

  Furthermore, it goes without saying that one or more of the above-described methods for using telop area information and telop vector information may be used in any combination.

  The motion vector calculation unit 3 uses the current frame signal and the previous frame signal to detect a motion vector for each block, and uses the initial displacement vector supplied from the initial displacement vector selection unit 2 as a starting point. This is an arithmetic circuit for obtaining a true motion vector from a frame signal to a current frame signal by gradient method calculation. Note that the motion vector calculation method by the gradient method calculation is detailed in each of the above-mentioned patent documents and non-patent documents, so the description thereof is omitted here, but how the initial displacement vector is used in this embodiment. Is described below using an iterative gradient method as an example.

  For example, in the gradient method calculation, the motion displacement V1 estimated from the coordinate position obtained by displacing the previous frame signal with the initial displacement vector V0 (α, β) as the starting point is represented by the following equation (1). ) And (2).

In equations (1) and (2), Vx is the x-direction component of the difference between the motion vectors V0 and V1, and Vy is the y-direction component of the difference between the motion vectors V0 and V1. Here, Σ represents that a sum is obtained by calculating all coordinates in a block area of m pixels × n lines, for example, 8 pixels × 8 lines. Δx is the gradient in the x direction of the image luminance at the coordinate of interest (difference value with the adjacent pixel in the x direction), Δy is the gradient in the y direction of the image luminance at the coordinate of interest (the difference value with the adjacent pixel in the y direction), DFD (x, y) indicates the inter-frame difference value between the coordinates (x, y) of the previous frame and the coordinates (x + α, y + β) of the current frame, and is the same calculation method as described above. Further, sign (Δx) and sign (Δy) are codes indicating the direction of the gradient represented by any one of +1, −1, and 0, respectively.

  For example, in the case of the two-time iterative gradient method, as shown in FIG. 5, the initial displacement vector is set as V0, the first displacement V1 and the second displacement V2 are obtained, and the motion vector V obtained by adding them to the vector is obtained. Is obtained by the following equation (3).

According to Expression (3), as shown in FIG. 6, the image existing in the block of coordinates (m1, n1) in the previous frame is moved to the block of the coordinate position of coordinates (m1 + α0, n1 + β0) in the current frame. At this time, the amount of motion is obtained as a vector V. Here, FIG. 6 is a schematic diagram for specifically explaining the motion vector V of the image moved between the previous frame and the current frame one frame before.

  In this way, the motion vector V obtained by the motion vector calculation unit 3 in FIG. 1 is stored in the vector memory 4 and is used as a candidate vector for initial displacement vector selection used for motion vector calculation for the next frame and thereafter. Used.

  As described above, by extracting the motion characteristics of the entire screen and applying the initial displacement vector compensated based on the motion characteristics of the entire screen, erroneous detection of the initial displacement vector is prevented, and, for example, a repetitive gradient that is less than twice It is possible to correctly calculate the true motion vector for each block of the current frame signal by the number of operations by the method.

  Here, one or more pieces of telop area information from the telop information detection unit 5 are input to the motion vector calculation unit 3, and special processing may be performed when the detected block corresponds to the telop area. . For example, when the direction of the telop vector is the horizontal direction, the iterative gradient method may be performed using only the x value, and the finally obtained motion vector may be limited to the motion in the horizontal direction. Alternatively, when the direction of the telop vector is the vertical direction, the iterative gradient method may be performed using only the y value, and the finally obtained motion vector may be limited to the vertical motion. This is to make it easier to follow the movement of the telop by performing the calculation according to the direction of the telop vector.

  In the above description, the motion vector calculation method in the motion vector calculation unit 3 employs the iterative gradient method using one or more gradient method operations, but is not limited to this. Or other calculation methods may be used.

  The vector memory 4 is a storage unit including a RAM (Random Access Memory) that accumulates motion vectors for at least one frame that has already been detected for each block, and its input terminal is connected to the output terminal of the motion vector calculation unit 3. Connected and configured to sequentially update and accumulate motion vectors detected by the motion vector calculation unit 3 at addresses corresponding to the positions of the respective blocks divided into 8 pixels × 8 lines, for example. Has been.

  The motion vector detection result for each block is output from the motion vector detection unit 101 by the above-described procedure.

  Then, the interpolated frame generation unit 102 generates an interpolated image using the motion vector detection result for each block. At this time, the interpolation image generation using the motion vector may be performed in the entire area of the screen, the interpolation image generation using the motion vector is performed in the telop area, and the motion vector is used in the other areas. For example, the same image as the previous frame or the subsequent frame may be repeatedly output without generating the interpolated image.

  That is, when a telop is not detected, motion compensation processing is not performed over the entire screen. When a telop is detected, motion compensation processing is performed only for the telop region, and for other regions. The motion compensation process may not be performed.

  As described above, a subject photographed by a normal camera includes blur caused by the light accumulation time of the camera (camera blur) when the movement is fast. If there are many camera blurs that originally exist, even if the motion blur is reduced by FRC, the effect is difficult to understand. On the other hand, since the telop is an image that has been synthesized later, even if the movement is fast, camera blur is not included, and the motion blur improvement effect by FRC is high. Therefore, even if the motion compensation process is performed only in the telop area, a large improvement effect can be obtained visually, and the interpolated image generation process is limited to the telop area, and an interpolated image is generated. Therefore, the processing amount can be reduced.

  In addition, when interpolation image generation by motion compensation is performed only on a telop area in this way, the presence or absence of motion compensation processing may clearly appear in the image at the boundary between the telop area and other areas. . In order to reduce this, the boundary between the telop area and other areas is conspicuous by performing a filtering process such as applying a low-pass filter to continuously change the strength of the motion compensation process. It is desirable to suppress this.

  Here, for regions other than the telop region that is not subjected to motion compensation interpolation processing, as described above, instead of performing motion compensation interpolation processing, the image signals of the same frame are continuously output at high speed, that is, The frame rate may be converted by inserting the image signal of the frame between the frames of the input image signal, or the image generated by the linear interpolation process from the previous and subsequent frames is interpolated, that is, the input The frame rate may be converted by interpolating an image signal subjected to linear interpolation processing between frames of the image signal. In the linear interpolation process, an interpolation frame is obtained from the image signals of the previous and subsequent frames by linear interpolation using the frame interpolation ratio α.

(2) Example of telop information detection method As described above, the telop information detection unit 5 detects telop information using the detected motion vector obtained by the motion vector calculation of the previous frame stored in the vector memory 4. . An example of a specific method for realizing the telop information detection unit 5 will be described in detail below.

  Information that can be used for telop detection is only the motion vector of each motion detection block stored in the vector memory 4 and the texture information of each motion detection block. Among these, since the colors of the telop are various, the texture information can be used only as an auxiliary. For this reason, it is necessary to detect the telop area information and the telop vector information from the motion vector information of each motion detection block.

  In addition to the telop, there are various moving objects such as a person and a car in the video. In some cases, the entire screen is moved relatively by panning the camera. For this reason, it is difficult to make a simple determination, for example, that a fast-moving region is a telop region, that is, whether or not a telop is based on the absolute amount of a motion vector.

  For this reason, in this embodiment, the telop area and the telop speed are detected using statistical information such as the difference between the average vector of the entire screen and the motion vector of each motion detection block, and the average deviation of the motion vectors.

  FIG. 7 shows a state in which an image is decomposed into blocks for vector detection. The overall size of the image is a width Wa pixel and a height Ha pixel. When this image is divided into motion detection blocks having a width of Wb pixels and a height of Hb pixels, the number of blocks is m horizontal blocks and n vertical blocks. Normally, the number of pixels in the entire image is divisible by an integer number of blocks. That is, Wa = Wb × m and Ha = Hb × n.

  For example, if the image has a high-definition resolution (Wa = 1920 pixels, Ha = 1080 pixels) and the block size is 8 × 8 pixels, m = 240 and n = 135. Each motion detection block is called B (i, j), and the motion vector detected by each motion detection block is (V_x (i, j), V_y (i, j)).

  Here, since many telops move in the horizontal direction, in this embodiment, telops that move in the horizontal direction are detected. The telop that moves in the horizontal direction is located in a horizontally long belt-like region on the screen as shown in FIG. Therefore, as shown in FIG. 9, the screen is divided into horizontally long strip-shaped regions L (1) to L (n), and it is determined whether or not each region includes a telop.

  The belt-like region L (j) includes the motion detection blocks B (1, j) to B (m, j) in FIG. When the average vector of motion vectors of the motion detection block included in L (j) is (Vave_x (j), Vave_y (j)),

It is.

  Further, when the average vector (overall average vector) of motion vectors of all motion detection blocks is (Vave_x, Vave_y),

It is.

  Now, as shown in FIG. 10, the screen is divided into a region including a telop and a region other than that. The height of the telop area when the screen height is 1 is k. However, it is assumed that the telop area does not exceed half of the screen. That is,

Assume that The height of the area other than the telop is 1-k. When the area other than the telop is divided into two or more by the telop area, the respective heights are added.

  Next, the average of the motion vectors of the motion detection blocks included in the telop area is (Vt_x, Vt_y), and the average of the motion vectors of the motion detection blocks included in the area other than the telop (referred to as the background area in this specification) is ( Vb_x, Vb_y) between the average vector of the telop area, the average vector of the area other than the telop, and the average vector of the entire screen,

This relationship holds.

  Actually, not all blocks in the telop area have the same motion vector as the moving speed of the telop. For example, a block in a portion where a telop character is interrupted has a motion vector other than the movement speed of the telop. However, in the present embodiment, it is assumed for the time being that all blocks in the telop area have the moving speed of the telop, and the following description proceeds. This assumption will be described later.

  In the present embodiment, since the telop moving in the horizontal direction is a detection target, the following description will be made focusing on the value in the horizontal direction for each average vector, that is, the x value of the vector.

  The relationship among the average vector Vt_x in the telop area, the average vector Vb_x in the area other than the telop, and the overall average vector Vave_x in Expression (9) is as shown in FIGS.

  FIG. 11 illustrates the case of Vb_x <Vt_x. Vave_x is located between Vb_x and Vt_x, and the ratio between the distance between Vb_x and Vave_x and the distance between Vave_x and Vt_x is k: 1-k. This relationship holds regardless of the magnitude or the sign of Vave_x, Vb_x, and Vt_x. Also, from the condition of equation (8),

Always holds. Therefore, the distance between Vb_x and Vave_x is always smaller than the distance between Vave_x and Vt_x.

  FIG. 12 illustrates the case of Vt_x <Vb_x. Vave_x is located between Vt_x and Vb_x, and the ratio between the distance between Vt_x and Vave_x and the distance between Vave_x and Vb_x is 1-k: k. This relationship holds regardless of the magnitude or the sign of Vave_x, Vt_x, Vb_x. Moreover, Formula (11) is always formed from the conditions of Formula (8). Therefore, as in the case of FIG. 11, the distance between Vt_x and Vave_x is always smaller than the distance between Vave_x and Vb_x.

  That is, whether Vb_x <Vt_x or Vt_x <Vb_x, the distance between Vb_x and Vave_x is always smaller than the distance between Vave_x and Vt_x. That means

Always holds.

  Therefore, a certain threshold value T is prepared,

It is determined that Using this threshold value T, the distance between Vave_x (j) and Vave_x and the threshold value T are compared with respect to the average vector x value Vave_x (j) of the motion vectors of the motion detection blocks included in each band-like region Lj in FIG. If it is larger than T, it can be determined that the band-like area Lj is likely to belong to the telop area. That is, regarding a certain band-like region Lj,

Is established, the band-like area is determined as a telop area.

  The problem here is how the threshold value T is set. The method will be described below.

  The setting condition of the threshold T is as shown in Expression (13). From this equation (13), it can be seen that in order to determine the threshold value T, information on | Vb_x-Vave_x | and | Vt_x-Vave_x | is required, but Vt_x and Vb_x cannot be directly obtained. This is because it is not known in advance which area is the telop area.

  Here, | Vb_x-Vave_x | and | Vt_x-Vave_x | are the difference between the global average vector and the average vector of the background area, and the difference between the global average vector and the average vector of the telop area, respectively. It is closely related to the variation of vectors. Therefore, the value of the threshold value T is determined by using an average deviation which is one of the data variation scales.

  Assuming that the average deviation of the average vector Vave_x (j) of each strip region Lj is M, M is

Is calculated by Multiply the average deviation M by a constant α,

And an appropriate constant α is obtained as follows.

  First, consider the case of Vb_x <Vt_x. At this time, when the average deviation M is expressed using Vt_x and Vb_x,

It can be expressed. Substituting equation (9) into equation (17) and rearranging,

Is obtained.

  From Equation (13) and Equation (16),

It is.

  On the other hand, from the condition of Vb_x <Vt_x and the equation (9),

Is obtained.

  Substituting Equation (18), Equation (20), and Equation (21) into Equation (19) and rearranging,

Is obtained.

  Although a detailed description is omitted, Expression (22) is obtained as a conditional expression even when Vt_x <Vb_x.

  The value of the constant α can be determined by assuming the height k of the telop area according to the equation (22). If k = 0.2, substitute it into equation (22)

The condition is obtained. If the constant α is set within this range, a telop area of about k = 0.2 can be detected.

  Also, if k = 0.4, it is similarly substituted into the equation (22),

The condition is obtained. That is, it can be seen that the range in which the constant α can be set becomes narrower in order to cope with the case where a wider telop area exists.

  As described above, the settable range of the constant α can be derived by assuming the value of the height k of the telop area. The actual image is analyzed to determine the tendency of the height k of the telop area to determine k, and the constant α may be determined in accordance with the settable range of the constant α determined thereby.

  If the constant α is determined and the average deviation M is obtained from the equation (15), the value of the threshold T can be determined from the equation (16). Here, it should be noted that the average deviation M is calculated from the detected motion vector. That is, the value of the threshold T changes for each frame depending on the state of the detected motion vector, that is, depending on the motion of the object in the video.

  When the value of the threshold T is obtained, a determination process is performed on the x value Vave_x (j) of the average vector of each strip region Lj according to the equation (14) to determine whether the strip region is a telop region. Can do.

  Further, if each band-like area Lj is determined and it is determined which band-like area is the telop area, the average (Vt_x, Vt_y) of the motion vectors of the motion detection blocks included in the telop area can be calculated. it can. This is the telop vector.

  Here, consideration is given to the assumption that all the blocks in the telop area have the telop speed in the above description. Actually, not all blocks in the telop area have the same motion vector as the telop speed. The more blocks that do not contain telop characters in the telop area, for example, when telop characters exist sparsely, the average vector Vt_x of the telop area is closer to the overall average vector Vave_x than the true telop vector. Become. At the same time, the average vector Vb_x in the area other than the telop is also close to the overall average vector Vave_x. That is, both | Vt_x−Vave_x | and | Vb_x−Vave_x | have smaller values.

  Therefore, the telop area cannot be detected unless the value of the threshold T for which the setting range is limited by the equation (13) or the equation (19) is also set small, that is, unless the value of α is set small. . However, if the threshold value T is reduced, the possibility that a non-telop area is erroneously detected increases.

  On the other hand, when there are few blocks that do not include telop characters in the telop area, for example, when there are dense telop characters, it is possible to expect an operation almost as described above.

  As described above, in actual application, it is necessary to determine the constant α in consideration of how much sparse characters are detected and how much false detection is allowed.

  In the above-described embodiment, the telop is detected on the assumption that the telop moves in the horizontal direction. However, when the telop is moved in the vertical direction or the diagonal direction, it can be detected by the same method. In that case, the method of dividing the band-like region may be set according to the direction to be detected. For example, when it is desired to detect a telop that moves in the vertical direction, the band-like region may be set to a vertically long region.

  Next, a telop information detection method when there are a plurality of telops in the screen will be described. For example, as shown in FIG. 13, the screen is divided into two telop detection areas 1 and 2 at the top and bottom, and the telop area information A, the telop vector information Va and the telop are executed by executing the above-described telop detection method in each area. Two pieces of telop information, that is, region information B and telop vector information Vb can be detected.

  Alternatively, for example, as shown in FIG. 14, horizontal telop detection processing and vertical telop detection processing are executed in parallel, so that horizontal telop area information C, telop vector information Vc, and vertical telop area information are displayed. Two pieces of telop information including D and telop vector information Vd may be detected. Here, the common area between the telop area C and the telop area D corresponds to the case where the block being processed corresponds to a plurality of telop areas in the above description of the vector detection means.

  According to the present embodiment, one or more pieces of telop information can be detected by the procedure as described above. The processing using the detected telop information is as described above.

  Note that the above-described telop information detection means is merely an example, and even when the telop information is detected using other means, it is applicable to the motion vector detection method and the interpolated image generation method in the present invention. Needless to say, this is possible.

  Here, it should be noted that the motion vector of each motion detection block stored in the vector memory 4 is used as an input to the telop information detection unit 5. The motion vector of each motion detection block stored in the vector memory 4 is a motion vector detection result of the previous frame. That is, the processing of the telop information detection unit 5 is performed using the motion vector detection result of the previous frame. Since the telop is usually present at the same position over a plurality of frames, the use of the motion vector detection result of the previous frame as described above is not a big problem.

  As described above in detail, in the motion vector detection method according to the present embodiment, a telop area and a telop vector are detected as telop feature quantities, and the results are reflected in initial displacement vector selection and motion vector calculation to compensate for motion. By controlling the processing, it is possible to more correctly detect the motion vector of the telop area, and as a result, the image quality of the telop area can be improved.

  By the way, in the input image signal, the correlation between successive frames may be interrupted due to a scene change or the like. In this case, referring to the motion vector detection result of the previous frame stored in the vector memory 4 may cause erroneous vector detection. For this reason, when the correlation between successive frames is interrupted due to a scene change or the like, a method of resetting the motion vector detection result in the previous frame has been proposed (for example, JP 2000-333134 A). Publication).

  However, in the case of an input image signal in which a scrolling telop is superimposed on an image in which a scene change exists, if the reset process as described above is performed, the motion vector in the area where the telop exists is also reset, and the telop scrolls smoothly. This makes it impossible to obtain an interpolated image. Therefore, for the area detected as the telop area, even if a scene change occurs in the input image signal, a motion compensation process different from that for other areas is performed to obtain an interpolated image in which the telop scrolls smoothly. It is desirable to be able to.

  More specifically, even if a scene change occurs, the scene detection process is not performed on the telop area, and the vector detection process is continuously performed without performing the above-described reset process of the motion vector detection result. Even when a change occurs, it is possible to obtain an interpolated image in which the telop scrolls smoothly, and for areas other than the telop area, the above reset process is performed when a scene change occurs, resulting in a vector error. Detection can be prevented, and both the image quality of the telop area and the other area can be achieved.

  The image display device of the present invention can be applied not only to a liquid crystal display using a liquid crystal panel as a display panel but also to image display devices having hold type display characteristics such as an organic EL display and an electrophoretic display. . Needless to say, the input image signal is not limited to a television broadcast signal, and may be various image signals such as an image signal reproduced from an external medium.

  In the above description, an example of an embodiment related to the image processing apparatus and method of the present invention has been described. From these descriptions, an image processing program for executing the image processing method as a program by a computer, and the image A program recording medium in which the processing program is recorded on a computer-readable recording medium can be easily understood.

It is a functional block diagram which shows the structural example of the motion vector detection part in the frame rate conversion part with which the image display apparatus which concerns on one Embodiment of this invention is provided. It is a functional block diagram which shows the structural example of the initial displacement vector selection part in FIG. It is a functional block diagram which shows another structural example of the initial displacement vector selection part in FIG. It is a functional block diagram which shows another example of a structure of the initial displacement vector selection part in FIG. It is a vector diagram for demonstrating the calculation method of the motion vector V by the iterative gradient method twice. It is a schematic diagram for specifically explaining a motion vector V of an image moved between the previous frame and the current frame one frame before. It is explanatory drawing which shows a mode that the image was decomposed | disassembled into the some block. It is explanatory drawing which shows the telop which moves to a horizontal direction on a screen. It is explanatory drawing which shows a mode that the screen was divided | segmented into the some strip | belt-shaped area | region. It is explanatory drawing which shows a mode that the screen was decomposed | disassembled into the area | region containing a telop, and the area | region other than that. It is explanatory drawing which shows the relationship with the average vector of the area | region of a telop, the average vector of areas other than a telop, and the average vector of the whole screen. It is explanatory drawing which shows the relationship with the average vector of the area | region of a telop, the average vector of areas other than a telop, and the average vector of the whole screen. It is explanatory drawing which shows an example in the case of detecting two telop information. It is explanatory drawing which shows another example in the case of detecting two telop information. It is a block diagram which shows schematic structure of the FRC drive display circuit in the conventional liquid crystal display device. FIG. 16 is a diagram for explaining frame rate conversion processing by the conventional FRC drive display circuit shown in FIG. 15. It is a figure for demonstrating the interpolation frame production | generation process by a motion vector detection part and an interpolation frame production | generation part.

Explanation of symbols

1 frame delay unit 2 initial displacement vector selection unit 2a coordinate conversion unit 2b subtraction unit 2c absolute value accumulation unit 2d selection unit 2e telop vector addition determination unit 3 motion vector calculation unit 4 vector memory 5 telop information detection unit 100 frame rate conversion (FRC) ) Unit 101 motion vector detection unit 102 interpolation frame generation unit 103 liquid crystal display panel 104 electrode drive unit

Claims (11)

An image display apparatus comprising rate conversion means for converting the number of frames or fields of an input image signal by interpolating image signals subjected to motion compensation between frames or fields of the input image signal. And
The rate conversion means divides a frame or field of the input image signal into a plurality of blocks having a predetermined size, and each block moves motion between input image signals separated by at least one frame or one field or more. A motion vector detection unit for detecting a motion vector representing the size and direction;
The motion vector detection unit includes a storage unit that accumulates at least one frame or one field of detected motion vectors detected for each block;
A telop information detection unit for detecting a telop area and / or a motion vector included in the input image signal and moving in a predetermined direction;
Using the telop area and / or detected motion vector detected by the telop information detection unit, at least in the telop area, a candidate vector group consisting of motion vectors accumulated by the storage unit, or the storage unit Preferentially select a candidate vector that is the same as or close to the motion vector of the telop as the initial displacement vector of the detected block from the candidate vector group obtained by adding the detected motion vector of the telop to the motion vector accumulated by An initial displacement vector selection unit to perform,
A motion vector calculation unit that obtains and outputs a motion vector of the detected block by performing a predetermined calculation using the initial displacement vector selected by the initial displacement vector selection unit as a starting point, and accumulates the motion vector in the storage unit; An image display device characterized by that. The image display device according to claim 1,
The initial displacement vector selection unit does not perform a process of preferentially selecting a candidate vector that is the same as or close to the motion vector of the telop in an area other than the telop area detected by the telop information detection unit. An image display device. The image display device according to claim 2,
The image display apparatus according to claim 1, wherein the initial displacement vector selection unit preferentially selects a candidate vector close to an average vector of all screens in a region other than the telop region detected by the telop information detection unit. The image display device according to claim 2,
The image display apparatus according to claim 1, wherein the initial displacement vector selection unit preferentially selects a candidate vector close to a zero vector in a region other than the telop region detected by the telop information detection unit. The image display device according to claim 1,
The image display apparatus according to claim 1, wherein the initial displacement vector selection unit processes the detected motion vector of the telop detected by the telop information detection unit in addition to the candidate vector. The image display device according to claim 5,
For the block corresponding to the telop area detected by the telop information detection unit, the initial displacement vector selection unit uses the detected motion vector of the telop detected by the telop information detection unit as the candidate vector. An image display device characterized by being additionally processed. In the image display device according to claim 5 or 6,
The initial displacement vector selection unit performs an initial displacement vector selection process by performing weighting so that the detected motion vector of the telop in the candidate vector is easily selected in the telop area detected by the telop information detection unit. An image display device characterized in that: The image display device according to claim 1,
The motion vector calculation unit, for a block corresponding to the telop area detected by the telop information detection unit, has the same direction as the direction of the detected motion vector of the telop detected by the telop information detection unit. An image display device characterized in that the calculation method is changed so that the vector can be obtained. An image display method comprising a rate conversion step for converting the number of frames or fields of an input image signal by interpolating an image signal subjected to motion compensation between frames or fields of the input image signal. And
In the rate conversion step, a frame or field of the input image signal is divided into a plurality of blocks having a predetermined size, and motion between input image signals separated by at least one frame or one field or more for each block. A motion vector detection step for detecting a motion vector representing the magnitude and direction,
Said motion vector detection step, a storing step of at least one frame or accumulated one field detection motion vector detected for each block,
A telop information detection step of detecting a telop area and / or a motion vector included in the input image signal that moves in a predetermined direction;
Using the detected telop area and / or detected motion vector, at least in the telop area, a candidate vector group consisting of motion vectors accumulated in the storage step or accumulated in the storage step An initial displacement vector that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop as an initial displacement vector of the detected block from among candidate vectors obtained by adding the detected motion vector of the telop to the motion vector A selection step;
And a motion vector calculation step of obtaining and outputting a motion vector of the detected block by performing a predetermined calculation using the initial displacement vector selected in the initial displacement vector selection step as a starting point. Method. Image processing comprising rate conversion means for converting and outputting the number of frames or fields of the input image signal by interpolating the image signal subjected to motion compensation processing between frames or fields of the input image signal A device,
The rate conversion means divides a frame or field of the input image signal into a plurality of blocks having a predetermined size, and each block moves motion between input image signals separated by at least one frame or one field or more. A motion vector detection unit for detecting a motion vector representing the size and direction;
The motion vector detection unit includes a storage unit that accumulates at least one frame or one field of detected motion vectors detected for each block;
A telop information detection unit for detecting a telop area and / or a motion vector included in the input image signal and moving in a predetermined direction;
Using the telop area and / or detected motion vector detected by the telop information detection unit, at least in the telop area, a candidate vector group consisting of motion vectors accumulated by the storage unit, or the storage unit Preferentially select a candidate vector that is the same as or close to the motion vector of the telop as the initial displacement vector of the detected block from the candidate vector group obtained by adding the detected motion vector of the telop to the motion vector accumulated by An initial displacement vector selection unit to perform,
A motion vector calculation unit that obtains and outputs a motion vector of the detected block by performing a predetermined calculation using the initial displacement vector selected by the initial displacement vector selection unit as a starting point, and accumulates the motion vector in the storage unit; An image processing apparatus. An image processing method comprising a rate conversion step of converting the number of frames or fields of an input image signal by interpolating an image signal subjected to motion compensation processing between frames or fields of the input image signal. And
In the rate conversion step, a frame or field of the input image signal is divided into a plurality of blocks having a predetermined size, and motion between input image signals separated by at least one frame or one field or more for each block. A motion vector detection step for detecting a motion vector representing the magnitude and direction,
Said motion vector detection step, a storing step of at least one frame or accumulated one field detection motion vector detected for each block,
A telop information detection step of detecting a telop area and / or a motion vector included in the input image signal that moves in a predetermined direction;
Using the detected telop area and / or detected motion vector, at least in the telop area, a candidate vector group consisting of motion vectors accumulated in the storage step or accumulated in the storage step An initial displacement vector that preferentially selects a candidate vector that is the same as or close to the motion vector of the telop as an initial displacement vector of the detected block from among candidate vectors obtained by adding the detected motion vector of the telop to the motion vector A selection step;
And a motion vector calculation step for obtaining and outputting a motion vector of the detected block by performing a predetermined calculation with the initial displacement vector selected in the initial displacement vector selection step as a starting point. Method.