JP3841105B1 - Signal processing to improve motion blur - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a generated moving image blur while suppressing attenuation of a luminance level of a display image.
A motion amount detection unit detects a motion amount of an entire image represented by read image data for each read image data sequentially read from an image memory. The drive image data generation unit generates drive image data by replacing at least a part of the read image data with mask data generated according to the amount of motion. The mask data is generated by processing the read image data corresponding to the pixel to be replaced with the mask data based on a predetermined parameter determined according to the amount of motion, and the predetermined parameter is The ratio of the mask data to the pixel value of the corresponding read image data is within a range from a ratio at which a predetermined moving image quality characteristic is obtained to 1, and as the amount of motion increases, the amount of motion decreases. It is set to increase as it decreases.
[Selection] Figure 1

Description

  The present invention relates to a signal processing technique for improving blurring of moving images in a storage type display device typified by a liquid crystal display device.

  A liquid crystal display device using a liquid crystal panel has been widely used. This liquid crystal display device is an image display device (hereinafter, referred to as “storage type display device”) in which each pixel is constituted by a storage type display element. The storage-type display device has a low-pass time-frequency characteristic in which a response characteristic at a high frequency of the signal frequency is reduced. For example, when a moving image is displayed on a liquid crystal display device, There is a problem that the image is blurred (hereinafter referred to as “moving image blur” or “moving image blur”) according to the moving speed of the object. In addition, when displaying a moving image on a storage-type display device, there is a problem that blurring of the moving image occurs due to an afterimage on the retina when a human eye observes an object moving on the storage-type display device. is there.

  As a technique for solving this problem, for example, one described in Patent Document 1 below is known.

JP 2002-132220 A

  In the above method, the image data of the original image of each frame sequentially stored in the frame memory is read twice at the double speed of each frame period, thereby generating two video signals of the first field and the second field, respectively. The image corresponding to the original image of each frame is displayed by the display of the image by the video signal of the first field and the display of the image by the video signal of the second field. In the first field, a video signal is generated by replacing the image data of even-numbered horizontal lines among a plurality of horizontal lines with black image data (black image data), and the generated video signal corresponds to the generated first field video signal. Display the image to be played. On the other hand, in the second field, a video signal is generated by replacing the image data of odd-numbered horizontal lines with black image data, and an image corresponding to the generated video signal of the second field is displayed. When attention is paid to a certain horizontal line of the image displayed in this way, at each pixel in the horizontal line, when an image represented by the original image data is displayed in a certain field, a black image is always displayed in the previous field. Will be displayed. Thereby, after resetting each pixel in the horizontal line from the state corresponding to the previously displayed image to the state where the black image is displayed, the next image can be displayed. The influence of the state displayed on the screen can be canceled, and the motion blur can be improved.

  However, in the case of the above method, in each field, half of the horizontal line pixels are black images. Therefore, the luminance of the display image of one frame is theoretically half the luminance of the original image of one frame. The brightness is attenuated and the contrast is lowered.

  The present invention has been made to solve the above-described problems in the prior art, and suppresses the moving image blur generated in the storage-type display device such as the above-described liquid crystal display device from being attenuated in the luminance level of the display image. It aims at providing the technology to improve.

In order to achieve at least a part of the above object, an image data processing apparatus of the present invention provides:
An image data processing device for generating drive image data for driving an image display device,
An image memory for sequentially storing input image data of a plurality of input frames;
For each read image data sequentially read from the image memory, a motion amount detection unit that detects a motion amount of the entire image represented by the read image data;
A drive image data generation unit that generates the drive image data by replacing at least a part of the read image data with mask data generated according to the amount of movement;
The mask data is generated by computing the read image data corresponding to the pixel to be replaced with the mask data based on a predetermined parameter determined according to the amount of motion,
The predetermined parameter is such that a ratio of the mask data to the pixel value of the corresponding read image data is within a range from a ratio at which a predetermined moving image quality characteristic is obtained to 1, and as the amount of motion increases. It is small and is set so as to increase as the amount of motion decreases.

  According to the above image data processing device, moving image blur that occurs in the image display device can be improved by generating drive image data by replacing at least part of the read image data with mask data. Further, mask data to be replaced with the read image data is generated by performing arithmetic processing on the read image data corresponding to the pixel to be replaced with the mask data based on a predetermined parameter determined according to the amount of motion, The ratio of the parameter to the pixel value of the corresponding read image data of the mask data is within a range from the ratio at which a predetermined moving image quality characteristic is obtained to 1, and the amount of motion is small as the amount of motion increases. Since it is set so as to increase as it decreases, it is possible to effectively improve moving image blur while suppressing attenuation of the luminance level of the image displayed on the image display device in accordance with the amount of motion of the image. .

  The predetermined parameter is preferably set so that the ratio is within a range from 0.5 to 1, for example.

  In this way, it is possible to easily improve the motion blur effectively.

  The predetermined parameter is preferably set so that the ratio is within a range in which a predetermined contrast characteristic is obtained.

  In this way, it is possible to effectively suppress the attenuation of the luminance level of the image.

  The predetermined parameter is preferably set so that the ratio is in the range of 0.8 to 1.

  In this way, it is possible to easily suppress the attenuation of the luminance level of the image.

In the image data processing apparatus,
When the amount of movement is larger than a predetermined amount, it is preferable to set the predetermined parameter so that the ratio is 1.

  In this way, in the case of a movement larger than the predetermined amount, it is possible to display an image by determining that it is not a moving image but a still image with a different scene.

  Here, it is preferable that the predetermined amount has a magnitude corresponding to a limit visual angular velocity indicating a speed limit of the following movement of the eyeball.

  In this way, it is possible to set the amount of movement that is easily determined as an image with a different scene.

  Note that an image display system including the image display device can be configured by the image data processing device.

  The present invention is not limited to the above-described aspects of the device invention such as the image data processing apparatus and the image display system, but can also be realized as a method invention such as an image data processing method. Further, there are various aspects such as an aspect as a computer program for constructing a method and an apparatus, an aspect as a recording medium in which such a computer program is recorded, and a data signal embodied in a carrier wave including the computer program. It is also possible to realize in an aspect.

  Further, when the present invention is configured as a computer program or a recording medium that records the program, the entire program for controlling the operation of the apparatus may be configured, or only the portion that performs the functions of the present invention. It may be configured. The recording medium includes a flexible disk, CD-ROM, DVD-ROM / RAM, magneto-optical disk, IC card, ROM cartridge, punch card, printed matter on which a code such as a barcode is printed, an internal storage device of a computer ( A variety of computer-readable media such as a memory such as a RAM and a ROM and an external storage device can be used.

Hereinafter, embodiments of the present invention will be described in the following order based on examples.
A. Example:
A1. Overall configuration of the image display system:
A2. Configuration and operation of drive image data generation unit:
A3. Setting mask parameter characteristics:
A3.1. Video quality characteristics:
A3.2. Contrast characteristics:
A3.3. Mask parameter characteristics:
A4. Effects of the embodiment:
B. Variations:

A. Example:
A1. Overall configuration of the image display system:
FIG. 1 is a block diagram showing the configuration of an image display system to which an image data processing apparatus as an embodiment of the present invention is applied. This image display system DP1 includes a liquid crystal panel 100 as a storage type display device, a signal conversion unit 10, a frame memory 20, a memory write control unit 30, and a memory read control unit 40 as image data processing devices. The computer system includes a drive image data generation unit 50, a motion amount detection unit 60, a liquid crystal panel drive unit 70, a CPU 80, and a memory 90. The image display system DP1 includes various peripheral devices such as an external storage device and an interface provided in a general computer system, but illustration thereof is omitted here.

  The image display system DP1 is a projector, which converts illumination light emitted from the light source unit 110 into light (image light) representing an image by the liquid crystal panel 100, and projects the image light through the projection optical system 120. An image is projected on the projection screen SC by forming an image on the screen SC. The liquid crystal panel driving unit 70 can be regarded as a block included in the storage type display device together with the liquid crystal panel 100 instead of the image data processing device.

  The CPU 80 controls the operation of each block by reading and executing the control program and processing conditions stored in the memory 90.

  The signal conversion unit 10 is a processing circuit for converting a video signal input from the outside into a signal that can be processed by the memory write control unit 30. For example, in the case of an analog video signal, it is converted into a digital video signal in synchronization with a synchronization signal included in the video signal.

  The memory write control unit 30 sequentially synchronizes the image data of each frame included in the digital video signal output from the signal conversion unit 10 with the write synchronization signal WSNK corresponding to the video signal. Write to the frame memory 20. The write synchronization signal WSNK includes a write vertical synchronization signal, a write horizontal synchronization signal, and a write clock signal.

  The memory read control unit 40 generates a read synchronization signal RSNK based on the read control condition given from the memory 90 via the CPU 80, and is stored in the frame memory 20 in synchronization with the read synchronization signal RSNK. Read image data. Memory read control unit 40 then outputs read image data signal RVDS and read synchronization signal RSNK to drive image data generation unit 50. Note that the readout synchronization signal RSNK includes a readout vertical synchronization signal, a readout horizontal synchronization signal, and a readout clock signal. The cycle of the read vertical synchronization signal is set to twice the cycle of the write vertical synchronization signal of the video signal written to the frame memory 20 (frame cycle). The stored image data is read twice during one frame period and output to the drive image data generation unit 50.

  The drive image data generation unit 50 is based on the read image data signal RVDS and the read synchronization signal RSNK supplied from the memory read control unit 40 and the motion amount data signal QMDS supplied from the motion amount detection unit 60. A drive image data signal DVDS for driving the liquid crystal panel 100 is generated via the drive unit 70, and the generated drive image data signal DVDS is output to the liquid crystal panel drive unit 70.

  The motion amount detector 60 includes image data of each frame (hereinafter also referred to as “frame image data”) sequentially written in the frame memory 20 and read image data of each frame read from the frame memory 20 (first field described later). And the read image data of the frame corresponding to the second field) are detected, and the motion amount of the image is detected, and the detected motion amount is output to the drive image data generation unit 50 as the motion amount data signal QMDS. .

  Here, the amount of motion can be detected as follows, for example. Frame image data (target image data) written in the frame memory 20 and frame image data (reference image data) read out from the frame memory 20 are rectangular pixels of p pixels × q pixels (p and q are integers of 2 or more). Divide into blocks. For each block, by obtaining a motion vector between two frames, the magnitude of the motion vector is obtained as the motion amount of each block. The total amount of motion of each block thus obtained corresponds to the amount of motion of the image between two frames. As a method for obtaining a motion vector, for example, various general methods such as a method for obtaining a movement amount of a barycentric coordinate of pixel data (luminance data) included in a block can be used. The detailed explanation is omitted.

  The liquid crystal panel drive unit 70 converts the read synchronization signal RSNK supplied from the memory read control unit 40 and the drive image data signal DVDS supplied from the drive image data generation unit 50 into signals that can be supplied to the liquid crystal panel 100. The liquid crystal panel 100 is supplied.

  The liquid crystal panel 100 emits image light representing an image corresponding to the supplied drive image data signal. Thereby, as described above, the image represented by the image light emitted from the liquid crystal panel 100 is projected and displayed on the projection screen SC.

A2. Configuration and operation of drive image data generation unit:
FIG. 2 is a schematic block diagram illustrating an example of the configuration of the drive image data generation unit 50. The drive image data generation unit 50 includes a mask control unit 510, a first latch unit 520, a mask data generation unit 530, a second latch unit 540, and a multiplexer (MPX) 550.

  Mask control unit 510 is based on read vertical synchronization signal VS, read horizontal synchronization signal HS, read clock DCK, and field selection signal FIELD included in read synchronization signal RSNK supplied from memory read control unit 40. A latch signal LTS for controlling the operations of the first latch unit 520 and the second latch unit 540 and a selection control signal MXS for controlling the operation of the multiplexer 550 are output to control generation of the drive image data signal DVDS. Note that the field selection signal FIELD distinguishes whether the read image data signal RVDS read from the frame memory 20 at double speed is the read image data signal of the first field or the read image data signal of the second field. It is a signal for.

  The first latch unit 520 sequentially latches the read image data signal RVDS supplied from the memory read control unit 40 in accordance with the latch signal LTS supplied from the mask control unit 510, and the read image data after the latch is read image data. The signal RVDS1 is output to the mask data generation unit 530 and the second latch unit 540.

  Based on the motion amount data signal QMDS supplied from the motion amount detection unit 60 and the read image data signal RVDS1 supplied from the first latch unit 520, the mask data generation unit 530 outputs read image data of each pixel. Mask data representing a pixel value corresponding to the represented pixel value is generated, and the generated mask data is output to the second latch unit 540 as a mask data signal MDS1.

  FIG. 3 is a schematic block diagram illustrating a configuration of the mask data generation unit 530. The mask data generation unit 530 includes a calculation unit 532, a calculation selection unit 534, and a mask parameter reference table 536.

  The calculation selection unit 534 receives a mask data generation condition set in advance and stored in the memory 90 in response to an instruction from the CPU 80, and selects and sets a calculation corresponding to the received mask data generation condition in the calculation unit 532. As the calculation executed by the calculation unit 532, various calculations such as multiplication and bit shift calculation can be used. In this embodiment, multiplication (C = A * B) is performed as the calculation executed by the calculation unit 532. Is selected and set.

  In the mask parameter reference table 536, table data indicating the relationship between the normalized motion amount of the image in advance and the value of the corresponding mask parameter (hereinafter also referred to as “mask parameter characteristic”) is stored by the CPU 80. It is stored by being read from the memory 90 and supplied. Thereby, the mask parameter reference table 536 obtains the value of the mask parameter MP corresponding to the motion amount Vm indicated by the motion amount data signal QMDS supplied from the motion amount detection unit 60 by referring to the table data. Data indicating the value of the mask parameter MP is output to the calculation unit 532. In addition, although it demonstrated as table data here, you may be set as the function calculation by the polynomial used as the approximate expression.

  The mask parameter characteristics represented by the table data stored in the mask parameter reference table 536 will be further described later.

  The calculation unit 532 uses the read image data in the input read image data signal RVDS1 as the calculation parameter A, sets the mask parameter MP supplied from the mask parameter reference table 536 as the calculation parameter B, and is selected by the calculation selection unit 534. An operation (A? B :? is an operator indicating the selected operation) is executed. The mask data that is the calculation result C (= A? B) is output as the mask data signal MDS1. Thereby, for each pixel of each frame represented by the input read image data RVDS1, mask data corresponding to the amount of motion of the image of that frame is generated based on the read image data of each pixel.

  For example, as described above, multiplication (C = A * B) is selected and set as the calculation executed by the calculation unit 532, and “0.3” is set as the value of the mask parameter MP by the mask parameter reference table 536. It is assumed that the calculation parameter B is set. At this time, if the values of the read image data in the read image data signal RVDS1 input as the calculation parameter A are “00h”, “32h”, and “FFh”, the calculation unit 532 has “00h”, Mask data having values of “0Fh” and “4Ch” is output as a mask data signal MDS1. That is, the value of the mask parameter MP indicates the ratio (attenuation ratio) of the mask data to the pixel value of the read image data.

  The second latch unit 540 of FIG. 2 sequentially latches the read image data signal RVDS1 output from the first latch unit 520 and the mask data signal MDS1 output from the mask data generation unit 530 in accordance with the latch signal LTS. The read image data after latching is output to multiplexer 550 as read image data signal RVDS2, and the mask data after latching is output as mask data signal MDS2.

  Multiplexer 550 generates drive image data signal DVDS by selecting either read image data signal RVDS2 or mask data signal MDS2 according to selection control signal MXS output from mask control unit 510, and drives the liquid crystal panel. It outputs to the part 70 (FIG. 1).

  The selection control signal MXS includes a field signal FIELD, a readout vertical synchronization signal VS, a readout horizontal synchronization signal HS, and a readout clock DCK so that a pattern of mask data inserted into the readout image data becomes a predetermined mask pattern. , Based on.

FIG. 4 is an explanatory diagram showing generated drive image data. As shown in FIG. 4A, the frame image data of each frame is stored in the frame memory 20 by the memory write control unit 30 (FIG. 1) during a certain period (frame period) Tfr. FIG. 4A shows a case where frame image data FR (N) of N frames (N is an integer of 1 or more) and frame image data FR (N + 1) of (N + 1) frames are stored in the frame memory 20 in order. An example is shown.

  Then, as shown in FIG. 4B, the frame image data stored in the frame memory 20 is converted by the memory read control unit 40 (FIG. 1) into a double speed cycle (field cycle) during the frame cycle Tfr. The data is read twice at Tfi, and sequentially output as read image data FI1 corresponding to the first field and read image data FI2 corresponding to the second field. 4B shows the read image data FI1 (N) and the read image data FI2 (N) of the first field in the N frame, and the read image data FI1 of the first field in the (N + 1) frame. As an example, (N + 1) and read image data FI2 (N + 1) of the second field are output in order.

  Then, as shown in FIG. 4C, the drive image data generation unit 50 has even-numbered horizontal lines (1, 3, 5, 7,...) Of the read image data FI1 of the first field. The pixels (2, 4, 6, 8,...) Forming the vertical lines are replaced with mask data (regions indicated by cross hatching) and the even-numbered horizontal lines (2, 4, 6, 8,. ..) Is generated by replacing the pixels (1, 3, 5, 7,...) Forming the odd-numbered vertical lines with mask data. That is, drive image data having mask data in a checker flag shape is generated. Further, pixels (1, 3, 5, 7,...) Forming odd-numbered vertical lines in the odd-numbered horizontal lines (1, 3, 5, 7,...) Of the read image data FI2 of the second field. .) Is replaced with mask data, and pixels (2, 4, 6, 8,...) Forming even-numbered vertical lines in even-numbered horizontal lines (2, 4, 6, 8,...). Second drive image data in which is replaced with mask data is generated. That is, drive image data having mask data in the form of a checker flag is generated at a pixel different from the position of the mask data in the first field. Also, (1) polarity is applied to FI1 (N) and FI2 (N) in FIG. 4B, and (−) polarity is applied to the next FI1 (N + 1) and FI2 (N + 1). AC drive can also be realized.

  Note that the odd-numbered pixels of the odd-numbered horizontal lines and the even-numbered pixels of the even-numbered horizontal lines of the read image data FI1 of the first field are replaced with mask data, and the odd-numbered pixels of the read image data FI2 of the second field are replaced. The even-numbered pixels of the horizontal lines and the odd-numbered horizontal lines of the even-numbered horizontal lines may be replaced with mask data.

  In addition, the image represented by the image data shown in FIG. 4 appears as a discrete image because the image of one frame is an image of 8 horizontal lines and 10 vertical lines for ease of explanation. Because it has hundreds of horizontal and vertical lines, it is hardly noticeable due to the nature of human vision.

  When driving image data is generated as described above, pixels forming even-numbered vertical lines in odd-numbered horizontal lines and odd-numbered vertical lines in even-numbered horizontal lines are generated for image data in the first field. The read image data corresponding to the pixels forming the pixel is replaced with mask data, and for the image data of the second field, the pixels forming the odd-numbered vertical lines in the odd-numbered horizontal lines and the even-numbered horizontal lines The read image data corresponding to the pixels forming the th vertical line is replaced with mask data. Accordingly, when attention is paid to a certain pixel, mask data and image data are alternately input to the liquid crystal panel in a field cycle. Therefore, before each pixel displays an image corresponding to new image data. In addition, once the image represented by the mask data is displayed, it is possible to suppress the influence of the previously displayed image and display the image represented by the new image data. Can be improved.

A3. Setting mask parameter characteristics:
The mask parameter characteristics represented by the table data stored in the mask parameter reference table 536 are set based on the image quality characteristics and contrast characteristics of the moving image, as will be described below.

A3.1. Image quality characteristics of moving images:
First, the relationship (hereinafter referred to as “moving quality characteristic”) between the mask parameter MP and the moving image quality (hereinafter referred to as “moving quality”) is quantitatively measured by the line scroll method described below.

(1) Line Scroll Method FIG. 5 is an explanatory diagram showing an image quality measurement image used in moving image quality measurement by the line scroll method. This image for image quality measurement is an image in which 10 sets of 2 vertical lines are drawn in 1 [pixel] increments from 1 [pixel] to 10 [pixel] between lines.

  In the line scroll method, the line width and line-to-line values that can be identified when this image quality measurement image is displayed are defined as quantitative values of the image quality, and the moving image is displayed by scrolling the display of the image quality measurement image horizontally. The moving image quality is evaluated by quantifying the moving image quality by determining a set of vertical lines that can be displayed and identified. For example, the quantitative value of the moving image quality is 1 when a line width of 1 [pixel] and a set of two vertical lines between the lines can be identified. The quantitative value of the moving image quality is referred to as “line scroll (LS) value”.

  FIG. 6 is an explanatory diagram showing various measurement conditions when the moving image quality is evaluated by the line scroll method. The screen size for projecting and displaying the image quality measurement image is 50 inches. The viewing distance of the image is 3H (H: length in the vertical direction of the screen) defined in “HDTV Standard Viewing Conditions” by the Institute of Image Information and Television Engineers. The brightness of the video is the brightness in the default setting state of the model to be measured. The resolution of the input signal is assumed to be SVGA (800 × 600) considered as a standard resolution (resolution corresponding to various general displays). The scroll amount is a parameter corresponding to the moving amount Vm of the moving image, and is set in units [pixel / frame] of how many pixels (pixel) are moved during one frame (frame). Then, the line scroll value is measured with six types of scroll amounts of 0, 3, 5, 8, 10, 16 [pixel / frame], and an average value (average line scroll value) of the obtained values is obtained. I will do it. The maximum scroll amount 16 [pixel / frame] is determined as described below.

  The following movement of the eyeball for the viewer to perceive a moving image is defined by a visual angular velocity (unit: [degree / second]). Further, it is said that the maximum speed (limit visual angular velocity) θmax of tracking the eyeball in a short time is 30 [degree / second], and it is considered difficult to recognize a moving image at or above the limit visual angular velocity. .

When this limit visual angular velocity θmax is converted into a scroll amount α [pixel / frame], it is expressed by the following equation.
fv · α · (W / Xn) = 2 · 3H · tan (θmax / 2)
α = 2 · (1 / fv) · (3H / W) · Xn · tan (θmax / 2) (1)

  Here, fv is the frame frequency, H is the vertical length of the display image, W is the horizontal length of the display image, and Xn is the horizontal resolution.

  By substituting 60 [Hz] as the frame frequency fv, (H / W), that is, 3/4 as the aspect ratio, 800 [pixel] as Xn, and 30 [degree / second] as θmax into the above equation (1), About 16 [pixel / frame] is obtained as the scroll amount α. That is, when the scroll amount is changed to be larger than 16 [pixel / frame], the moving image recognition limit is exceeded. Therefore, the maximum value of the scroll amount at the viewing distance 3H is set to 16 [pixel / frame].

  Note that differences in screen size, video brightness, and input image resolution do not affect the line scroll value measured by the line scroll method, and are not limited to the above measurement conditions. Moreover, if the viewing distance is in the range of 0.5H to 5H, the measured line scroll value is not affected.

  In contrast to the line scroll method described above, in recent years, a moving picture response time (MPRT) method has been proposed as a general moving image quality evaluation method. The line scroll method has a correlation with the MPRT method, and it has been confirmed that the same effect as the evaluation by the MPRT method is obtained by the evaluation by the line scroll method.

(2) Moving Image Quality Characteristic FIG. 7 is an explanatory diagram showing moving image quality characteristics representing the relationship between the mask parameter MP and the average line scroll value corresponding thereto.

  This moving image quality characteristic is obtained by measuring the moving image quality by the line scroll method for each of the mask parameters MP from 0 to 1. In the figure, the characteristic indicated by the solid line shows a case where an image with a white background color and a black vertical line is displayed, and the characteristic indicated by a one-dot chain line indicates an image with a black background color and a white vertical line. Shows the case. Thus, the characteristic is different due to the difference in the on / off characteristic of the liquid crystal. For example, in this embodiment, a normally white type liquid crystal panel is used as the liquid crystal panel 100, and thus the characteristics shown in FIG. If a normally black type liquid crystal panel is used, it is expected that the reverse characteristics are exhibited when the background color is white and when it is black.

  As can be seen from FIG. 7, when the value of the mask parameter MP is in the range of 0.5 to 1, the average line scroll value decreases as the mask parameter MP decreases, and the effect of improving the motion blur due to the mask data increases. I understand. In addition, when the value of the mask parameter MP is in the range of 0 to 0.5, the average line scroll value is almost the same regardless of the value of the mask parameter MP, and the moving picture blurring improvement effect by the mask data is almost the same. I understand.

A3.2. Contrast characteristics:
FIG. 8 is an explanatory diagram showing contrast characteristics representing the relationship between the mask parameter MP and the corresponding contrast.

  This contrast characteristic is obtained by measuring the magnitude of contrast for each of the mask parameters MP from 0 to 1.

  As can be seen from FIG. 8, in the range where the value of the mask parameter MP is 0 to 0.5, the magnitude of the contrast is a normal contrast where the value of the mask parameter MP is 1 (in FIG. 8, about 370: 1). It can be seen that the contrast is reduced to about 1/3, and the contrast hardly changes even if the value of the mask parameter MP changes. In addition, in the range where the value of the mask parameter MP is in the range of 0.5 to 1, particularly in the range of 0.6 to 0.8, the magnitude of the contrast increases correspondingly as the value of the mask parameter MP increases. It can be seen that the effect of improving the contrast is enhanced. Further, it can be seen that, in the range where the value of the mask parameter MP is 0.8 or more, the magnitude of the contrast is almost the same as when the value of the mask parameter MP is 1, and there is no decrease in contrast.

A3.3. Mask parameter characteristics:
From the moving image quality characteristics shown in FIG. 7, as described above, the value of the mask parameter MP does not need to be set smaller than 0.5, and the range of the range set according to the movement amount Vm of the mask parameter MP. The minimum value should just be set in the range of 0.5-1.

  However, as can be seen from the contrast characteristics shown in FIG. 8, the mask parameter MP is equal to the normal contrast (the contrast is about 370: 1 in FIG. 8) where the value of the mask parameter MP is 1. As the value decreases, the value drops to about 1/3 at maximum.

  Here, in a normal image display state, a reduction to a contrast level of about 70% is allowed, so the mask parameter MP is in a range corresponding thereto, for example, in the example of FIG. Setting in the range of 65 or more is possible. Further, in the display state in which priority is given to the display of moving images, a reduction to the contrast level of about 50% is allowed. Therefore, the mask parameter MP has a corresponding range, for example, in the example of FIG. Setting in the range of 0.5 or more is possible.

  Therefore, the minimum value of the range set according to the movement amount Vm of the mask parameter MP may be set within the range of 0.5 to 1 depending on how far the contrast can be lowered. .

  As described above, the mask parameter setting condition can be obtained based on the measured moving image quality characteristic and contrast characteristic, and the mask parameter can be set according to the obtained setting condition.

  FIG. 9 is an explanatory diagram illustrating an example of mask parameter characteristics represented by table data stored in the mask parameter reference table 536. As shown in FIG. 5, the mask parameter characteristic indicates the value of the mask parameter MP with respect to the motion amount Vm. The motion amount Vm is represented by a moving speed (unit [pixel / frame]) in which the amount of movement in units of frames is represented by the number of pixels.

  This mask parameter characteristic is set based on the moving image quality characteristic shown in FIG. 7 and the contrast characteristic shown in FIG. That is, as shown in FIG. 9, the value of the mask parameter MP is set to gradually decrease in the range of 1 to 0.5 as the moving image motion amount Vm corresponding to the scroll amount in the line scroll method increases. is doing.

  Note that when the value of the mask parameter MP is close to 1, the line scroll value is increased as shown in the moving image quality characteristic (FIG. 7), and the effect of improving moving image blur is reduced. However, since an image using the value of the mask parameter MP corresponds to a case where the motion amount Vm is small, it is possible to improve the motion blur corresponding to it.

  As described in the description of the line scroll method, when the motion amount Vm is larger than 16 [pixel / frame], the limit visual angular velocity θmax (= 30 [degree / sec]) is exceeded, and the moving image It is difficult to recognize. Therefore, when the motion amount Vm exceeds 16 [pixel / frame], it is treated as a still image, not a moving image, but as a video scene, and the mask parameter MP is set to 1.

A4. Effects of the embodiment:
As described above, in each pixel, before displaying the image corresponding to the read image data, by temporarily displaying the image represented by the mask data, the influence of the previously displayed image is suppressed, and a new image is displayed. The image represented by the read image data can be displayed, and the motion blur can be improved as in the conventional case.

  Further, in the case of the conventional example, before displaying the image corresponding to the read image data, each pixel displays the black level image once, thereby suppressing the influence of the previously displayed image and newly displaying the image. The image was displayed and the motion blur was improved. For this reason, the substantial brightness of the displayed image is attenuated to about half of the theoretical brightness of the image of one frame, resulting in a decrease in contrast. On the other hand, in the case of the present embodiment, the mask data has a gradation level that is higher than the black level according to the amount of motion of the image (the degree of motion). The data is attenuated to a level at which it is possible to obtain a moving image blur improving effect substantially equal to that of the level and to suppress a substantial luminance attenuation of the displayed image. Thereby, in the case of an Example, it is possible to acquire the effect of a moving image blur effectively, suppressing the fall of contrast.

B. Variations:
In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.

B1. Modification 1:
In the above embodiment, the case where the read image data and the mask data are generated alternately for each pixel in the horizontal direction and the vertical direction is shown as an example. However, the read image data is read for each horizontal line. When driving image data is generated such that image data and mask data are alternately arranged, or driving image data is generated so that read image data and mask data are alternately arranged for each vertical line. You may do it.

B2. Modification 2:
In the above-described embodiment and modification 1, the frame image data sequentially written in the frame memory is read at a double speed, and each frame image data is converted into read image data of the first field and the second field as an example. As described above, reading is performed at a speed higher than double speed, and sequentially read image data is alternately read as first field read image data and second field read image data, and corresponding mask data is inserted. By doing so, a drive image data signal may be generated. Further, the frame image data sequentially written in the frame memory is read at the same speed, and the odd-numbered frame image data of the read image data sequentially read is set as the read image data of the first field in the embodiment or the modification 1, and the even number The driving image data signal may be generated by inserting the corresponding frame data as the second frame image data of the second frame image in the embodiment or the modification 1 in the second frame image data.

B3. Modification 3:
In the above embodiment, a projector using a liquid crystal panel is described as an example. However, the present invention can be applied to a direct-view display device instead of the projector. In addition to the liquid crystal panel, various storage type display devices such as PDP (Plasma Display Panel) and ELD (Electro Luminescence Display) can be applied.

B4. Modification 4:
In the drive image data generation unit 50 of the above embodiment, the read image data signal RVDS read from the frame memory 20 is sequentially latched by the first latch unit 520, but in the previous stage of the first latch unit 520. As a configuration including a new frame memory, the read image data signal RVDS is once written in the new frame memory, and the new read image data signal output from the new frame memory is sequentially latched by the first latch unit 520. It may be. In this case, the image data signal input to the motion amount detection unit 60 may be an image data signal written to a new frame memory and an image data signal read from a new frame memory.

B5. Modification 5:
In the above embodiment, the case where the generation of the mask data is executed for each pixel of the read image data has been described as an example. However, the mask data may be generated only for the pixels for which the replacement is performed. In this way, any configuration may be used as long as mask data corresponding to a pixel to be replaced can be generated and mask data can be replaced.

B6. Modification 6:
It is not limited to the mask parameter characteristics described in the above embodiment, and as described in the setting of the mask parameter characteristics, the moving picture quality obtained by obtaining the moving picture quality characteristics and contrast characteristics of the storage type display device to be used. Based on the characteristics and the contrast characteristics, settings may be made so as to obtain a motion blur improvement effect while suppressing a decrease in contrast.

B7. Modification 7:
In each of the embodiments described above, an example is described in which each block of the memory write control unit, the memory read control unit, the drive image data generation unit, and the motion amount detection unit for generating the drive image data is constructed by hardware. However, at least a part of the blocks may be constructed by software so that the CPU reads and executes the computer program.

1 is a block diagram showing a configuration of an image display system to which an image data processing apparatus as one embodiment of the present invention is applied. 3 is a schematic block diagram illustrating an example of a configuration of a drive image data generation unit 50. FIG. 5 is a schematic block diagram illustrating a configuration of a mask data generation unit 530. FIG. It is explanatory drawing shown about the drive image data produced | generated. It is explanatory drawing shown about the image for a quality measurement used in the moving image quality measurement by a line scroll method. It is explanatory drawing shown about the various measurement conditions at the time of evaluating moving image quality by the line scroll method. It is explanatory drawing shown about the moving image quality characteristic showing the relationship between the mask parameter MP and the average line scroll value corresponding to this. It is explanatory drawing shown about the contrast characteristic showing the relationship between the mask parameter MP and the contrast corresponding to this. It is explanatory drawing shown about the mask parameter characteristic which the table data stored in the mask parameter reference table 536 represent.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Signal conversion part 20 ... Frame memory 30 ... Memory write control part 40 ... Memory read-out control part 50 ... Drive image data generation part 60 ... Motion amount detection part 70 .. .LCD panel drive unit 80 ... CPU
DESCRIPTION OF SYMBOLS 90 ... Memory 100 ... Liquid crystal panel 110 ... Light source unit 120 ... Projection optical system 510 ... Mask control part 520 ... Latch part 530 ... Mask data generation part 532 ... Calculation Section 534 ... Operation selection section 536 ... Mask parameter reference table 540 ... Latch section 550 ... Multiplexer (MPX)
DP1 ... Image display system

Claims (8)

An image data processing device for generating drive image data for driving an image display device,
An image memory for sequentially storing input image data of a plurality of input frames;
For each read image data sequentially read from the image memory, a motion amount detection unit that detects a motion amount of the entire image represented by the read image data;
A drive image data generation unit that generates the drive image data by replacing at least a part of the read image data with mask data generated according to the amount of movement;
The mask data is generated by computing the read image data corresponding to the pixel to be replaced with the mask data based on a predetermined parameter determined according to the amount of motion,
The predetermined parameter is such that a ratio of the mask data to the pixel value of the corresponding read image data is within a range from a ratio at which a predetermined moving image quality characteristic is obtained to 1, and as the amount of motion increases. An image data processing apparatus, wherein the image data processing apparatus is set to be small and to increase as the amount of motion decreases. The image data processing device according to claim 1,
The image data processing apparatus, wherein the predetermined parameter is set so that the ratio is in a range from 0.5 to 1. The image data processing device according to claim 1,
The image data processing apparatus, wherein the predetermined parameter is set so that the ratio is within a range in which a predetermined contrast characteristic is obtained. The image data processing apparatus according to claim 3,
The image data processing apparatus, wherein the predetermined parameter is set so that the ratio falls within a range of 0.8 to 1. The image data processing apparatus according to claim 1, wherein:
The image data processing apparatus, wherein the predetermined parameter is set so that the ratio is 1 when the movement amount is larger than a predetermined amount. The image data processing device according to claim 5,
The image data processing apparatus according to claim 1, wherein the predetermined amount has a magnitude corresponding to a limit visual angular velocity indicating a speed limit of the follow-up movement of the eyeball. An image data processing device according to any one of claims 1 to 6,
The image display device;
An image display system comprising: An image data processing method for generating drive image data for driving an image display device,
A step of sequentially storing input image data of a plurality of input frames in an image memory;
Sequentially reading the input image data from the image memory;
Detecting the amount of movement of the entire image represented by the read image data for each read image data sequentially read from the image memory;
Replacing at least a part of the read image data with mask data generated according to the amount of motion, and generating the drive image data,
The mask data is generated by computing the read image data corresponding to the pixel to be replaced with the mask data based on a predetermined parameter determined according to the amount of motion,
The predetermined parameter is such that a ratio of the mask data to the pixel value of the corresponding read image data is within a range from a ratio at which a predetermined moving image quality characteristic is obtained to 1, and as the amount of motion increases. An image data processing method, wherein the image data processing method is set so as to be small and increase as the amount of motion decreases.

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