JP2003058098A - Hold type picture display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of a display picture by performing an edge emphasis while suppressing emphasis of noise components. SOLUTION: A hold type picture display device displaying picture while keeping brightness of display light almost constant for one field period, is provided with an area detection part 21 for detecting a part having varied by a predetermined area or more in a picture to display based on a difference between picture frames, an adding part 24 for performing edge emphasis of the part detected by the area detection part 21 among the pictures to display, a multiplication part 25 and HPF 26, and a display for displaying the edge- emphasized picture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hold type display device (projector), LCD, organic EL, plasma display, LED display, etc., which displays an image while keeping the brightness of display light substantially constant for one field. The present invention relates to an image display device, and more particularly, to a hold-type image display device that enhances edges of an image.

[0002]

2. Description of the Related Art A hold type image display device such as a projection type display device, an LCD, an organic EL, a plasma display, an LED display, etc., which displays an image while keeping the brightness of display light substantially constant for one field, is disclosed in the document "Hold type". Image quality of moving image display on display ”, Taiichi Kurita (Technical Report Vol.23, No.40, P5
5 to P60), there is a problem that a phenomenon called "movement blur" is perceived when displaying a moving image. Further, in the case of a liquid crystal projector, the video signal is generally rewritten at 60 frames / second (1 screen is approximately 16.7 ms), whereas the response of the TN mode liquid crystal widely used in the liquid crystal projector is several tens of halftones. Since it is on the order of ms, the switching response of the liquid crystal is slow, which also contributes to motion blur.

Here, the motion blur is a decrease in which the spatial frequency of the image is visually reduced, and appears in a portion where there is motion in the image. As a conventional hold-type image display device that solves this motion blur, there is known a hold-type image display device that selectively enhances a high frequency region of a spatial frequency, that is, edge enhancement, in a portion where there is a motion in an image. In this hold type image display device, two consecutive image frames are compared with each other, and a portion having a change is determined to be a portion having a motion, and edge enhancement is performed. This hold type image display device is
Video systems such as V (high-definition television) and analog TV (TV
System) input, PC (personal computer) system input, etc.
It has various input sources (input series) and inputs and displays images of various resolutions.

[0004]

However, according to the above-mentioned conventional hold-type image display device, based on the difference between the image frames, all the changed portions are judged to be the moving portions and the edges are detected. Since the emphasis is performed, the noise component of the image source is also emphasized at the same time, which causes a problem that the quality of the displayed image is deteriorated. Especially, MPEG2
For example, when a digital image source that has been digitally compressed is handled, noise due to the compression processing is included in the moving image, so that the effect of noise component enhancement becomes significant.

Further, according to the above-mentioned conventional hold-type image display device, despite having various input sequences having different ratios of moving images, presence / absence of compression, etc., and input images having various resolutions, Since uniform edge enhancement is performed, it is not possible to perform appropriate edge enhancement according to the input sequence and the resolution of the input image, and there is a problem that the quality of the display image is degraded.

The present invention has been made in view of the above, and performs edge emphasis while suppressing noise component emphasis,
A first object is to improve the quality of a display image.
Further, the present invention has been made in view of the above,
A second object is to improve the quality of a display image by performing an appropriate edge enhancement according to the input series and the resolution of the input image.

[0007]

In order to achieve the above object, a hold-type image display device according to a first aspect of the present invention displays a hold-type image while keeping the brightness of display light substantially constant for one field. In the display device, based on the difference between the image frames, an area detection unit that detects a portion of the displayed image that has changed by a predetermined area or more and an area detection unit that detects the area of the displayed image. The image forming apparatus further comprises edge enhancing means for enhancing the edge of a portion, and image display means for displaying the image edge enhanced by the edge enhancing means.

In the hold type image display device according to the present invention, the area detecting means detects the portion of the displayed image which has changed by a predetermined area or more based on the difference between the image frames. The edge emphasizing means performs edge emphasizing on a portion of the displayed image detected by the area detecting means, and the image displaying means displays the image edge-emphasized by the edge emphasizing means. As a result, the probability of edge enhancement of a moving portion while avoiding a noise portion is increased.

According to a second aspect of the present invention, in the hold type image display device for displaying an image while keeping the luminance of display light substantially constant for one field, the absolute value luminance difference between image frames is calculated. Based on the detection result of the difference detection means and the difference detection means, the own pixel has an absolute value luminance difference of a predetermined threshold value or more, and the other pixel having an absolute value luminance difference of the predetermined threshold value or more is an own pixel. Pixel detection means for detecting a predetermined number or more of pixels within a predetermined peripheral area, edge emphasis means for performing edge emphasis on pixels detected by the pixel detection means in an image to be displayed, and edge emphasis means by the edge emphasis means. Image display means for displaying the formed image.

In the hold type image display device according to the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the pixel detecting means detects the absolute value luminance difference between the image frames based on the detection result of the difference detecting means. The own pixel has an absolute value brightness difference of a predetermined threshold value or more, and another pixel having an absolute value brightness difference of a predetermined threshold value or more detects a predetermined number or more of pixels within a predetermined range around the own pixel, and the edge enhancement means Of the images to be displayed, the pixels detected by the pixel detection means are edge-emphasized, and the image display means displays the image whose edges have been emphasized by the edge emphasis means. As a result, the probability of edge enhancement of a moving portion while avoiding a noise portion is increased.

According to a third aspect of the present invention, in the hold type image display apparatus according to the second aspect, at least one of the predetermined threshold value, the predetermined range, and the predetermined number is further changed. The change means is provided.

In the hold type image display device of the present invention, the changing means changes at least one of the predetermined threshold value, the predetermined range and the predetermined number, so that the user appropriately adjusts the edge enhancement. be able to.

According to a fourth aspect of the present invention, there is provided a hold-type image display device which displays an image while keeping the brightness of display light substantially constant for one field. Based on the difference detection means for detecting, the two-dimensional low-pass filter for removing high frequency components of the two-dimensional space in which the absolute value luminance differences detected by the difference detection means are arranged, and the removal result of the two-dimensional low-pass filter Pixel detection means for detecting pixels having an absolute value luminance difference equal to or more than a threshold value, edge emphasis means for performing edge emphasis of pixels detected by the pixel detection means in an image to be displayed, and edge emphasis means for edge emphasis by the edge emphasis means. Image display means for displaying the displayed image.

In the hold type image display device according to the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the two-dimensional low pass filter detects the absolute value luminance detected by the difference detecting means. The high-frequency component of the two-dimensional space in which the differences are arranged is removed, the pixel detection unit detects a pixel having an absolute value luminance difference of a predetermined threshold value or more based on the removal result of the two-dimensional low-pass filter, and the edge enhancement unit Among the images to be displayed, the pixels detected by the pixel detection unit are edge-emphasized, and the image display unit displays the image whose edges have been emphasized by the edge enhancement unit. As a result, the probability of edge enhancement of a moving portion while avoiding a noise portion is increased.

According to a fifth aspect of the present invention, in the hold type image display device which displays an image while keeping the luminance of display light substantially constant for one field, the absolute value luminance difference between image frames is displayed. Based on the removal result of the two-dimensional low-pass filter, the two-dimensional low-pass filter for removing the high-frequency component of the two-dimensional space in which the absolute value luminance differences detected by the difference detection means are arranged, Gain determining means for determining the gain of edge enhancement for each, edge enhancing means for performing edge enhancement based on the determination by the gain determining means, image display means for displaying an image edge enhanced by the edge enhancing means, It is equipped with.

In the hold type image display device according to the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the two-dimensional low pass filter detects the absolute value luminance detected by the difference detecting means. The high-frequency component of the two-dimensional space in which the differences are arranged is removed, the gain determination means determines the edge enhancement gain for each pixel based on the removal result of the two-dimensional low-pass filter, and the edge enhancement means uses the gain determination means. Edge enhancement is performed based on the determination, and the image display unit displays the image that has been edge enhanced by the edge enhancement unit. As a result, the probability of edge enhancement of a moving portion while avoiding a noise portion is increased.

According to a sixth aspect of the present invention, in the hold type image display device according to the second or third aspect, the hold type image display device further includes each pixel based on the other number of pixels within the predetermined range. The edge enhancing means determines the gain of edge enhancement described in 1., and the edge enhancing means performs edge enhancement based on the determination by the gain determining means.

In the hold type image display device according to the present invention, the gain determining means determines the edge enhancement gain for each pixel based on the number of other pixels within the predetermined range, and the edge enhancing means Edge enhancement is performed based on the determination made by the gain determination means. As a result, more appropriate edge enhancement can be performed.

A hold type image display device according to a seventh aspect is the hold type image display device according to any one of the first to fourth aspects, further comprising an input for selecting and setting an image input sequence. A sequence setting means and a gain determining means for determining a gain of the edge enhancement by the edge enhancing means based on the setting by the input sequence setting means.

In the hold type image display device according to the present invention, the input series setting means selects and sets the input series of the image, and the gain determining means sets the edge based on the setting by the input series setting means. Determines the emphasis gain. This makes it possible to perform appropriate edge enhancement according to the input sequence.

Further, a hold type image display device according to an eighth aspect is the hold type image display device according to any one of the first to fourth aspects, further comprising resolution detecting means for detecting the resolution of the input image. Gain determining means for determining the gain of the edge enhancement by the edge enhancing means based on the detection result of the resolution detecting means.

In the hold type image display device according to the present invention, the resolution detecting means detects the resolution of the input image, and the gain determining means determines the gain of edge enhancement based on the detection result of the resolution detecting means. decide. As a result, it is possible to perform appropriate edge enhancement according to the resolution of the input image.

According to a ninth aspect of the present invention, in the hold type image display device for displaying an image while keeping the brightness of the display light substantially constant for one field, the hold type image display device is based on the difference between the image frames. A motion detection unit that detects a portion of the displayed image that has moved, an edge enhancement unit that performs edge enhancement of the portion of the displayed image that is detected by the motion detection unit, and an image input sequence are selected. An input sequence setting means for setting the gain, a gain determining means for determining a gain of edge enhancement by the edge enhancing means based on the setting by the input sequence setting means, and an image displaying an image edge enhanced by the edge enhancing means. And a display means.

In the hold type image display device according to the present invention, the input series setting means selects and sets the input series of the image, and the gain determining means based on the setting by the input series setting means. The edge emphasis gain by the edge emphasis means is determined, the motion detection means detects a part of the image to be displayed which has moved based on the difference between the image frames, and the edge emphasis means detects the part of the image to be displayed. Among them, the edge enhancement of the part detected by the motion detection means,
The image display means displays the image whose edge is emphasized by the edge emphasis means. This makes it possible to perform appropriate edge enhancement according to the input sequence.

According to a tenth aspect of the present invention, in the hold type image display device for displaying an image while keeping the brightness of display light substantially constant for one field, based on the difference between the image frames, Motion detection means for detecting a portion of the displayed image that has moved, edge enhancement means for enhancing the edge of the portion of the displayed image detected by the motion detection means, and detection of the resolution of the input image. Resolution determining means, gain determining means for determining a gain of edge enhancement by the edge enhancing means based on a detection result of the resolution detecting means, image display means for displaying an image edge enhanced by the edge enhancing means, It is equipped with.

In the hold type image display device of the tenth aspect, the resolution detecting means detects the resolution of the input image, and the gain determining means detects the edge by the edge enhancing means based on the detection result of the resolution detecting means. The emphasis gain is determined, the motion detection means detects a portion of the displayed image that has moved based on the difference between the image frames, and the edge emphasis means detects the movement of the displayed image. The detected portion is edge-emphasized, and the image display means displays the image whose edge is emphasized by the edge emphasis means. As a result, it is possible to perform appropriate edge enhancement according to the resolution of the input image.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The present invention is not limited to this embodiment. In the following embodiments, a display device including a display unit (pixel) as shown in (1) or (2) below is referred to as a “hold type image display device”. (1) Display unit (pixel)
Hold each image signal (luminance signal) for one field (or one frame) period, and emit or modulate light based on the held image signal (luminance signal). (2) One display unit (pixel) is at least 1
During the field (or one frame) period, light is continuously emitted or modulated based on the same image signal (luminance signal).

(Embodiment 1) Embodiment 1 of the present invention
Then, based on the difference between two consecutive image frames, a part of the image to be displayed that has changed by a predetermined area or more is detected, and edge enhancement is performed on that part, and the edge enhancement gain α Will be described by taking as an example a liquid crystal projector that is determined according to the input sequence and resolution of an image. 1 is a block diagram showing a schematic configuration of a liquid crystal projector according to a first embodiment of the present invention.

The liquid crystal projector of the first embodiment includes a video signal conversion circuit 2, a liquid crystal display drive circuit 6, a liquid crystal display panel 9, a frame memory 1, a remote controller control unit 4, a CPU 5, and an illumination optical system 10. And a projection optical system 8. The video signal conversion circuit 2, the remote controller control unit 4, the CPU 5, and the liquid crystal display drive circuit 6 are connected to the bus 11. The liquid crystal display panel 9 is substantially uniformly illuminated by the illumination optical system 10, and the image displayed on the liquid crystal display panel 9 is projected on the projection screen 7 by the projection optical system 8. In FIG. 1, the illumination optical system 10 and the projection optical system 8 are shown in a simplified manner.

The video signal conversion circuit 2 AD-converts the input analog image signal AV1, writes the AD-converted image data in the frame memory 1, reads the image data from the frame memory 1, and enhances the edges of the image. Then, the edge-emphasized image data DV2 is output. As the analog image signal AV1, for example, an image signal such as a computer screen display RGB signal output from a personal computer (PC) or a moving image display composite image signal output from a video recorder or a television (TV) is used. Supplied.

The image data DV2 output from the video signal conversion circuit 2 is supplied to the liquid crystal display panel drive circuit 6. The liquid crystal display panel drive circuit 6 displays an image on the liquid crystal display panel 9 according to the supplied image data DV2. The image displayed on the liquid crystal display panel 9 corresponds to the projection optical system 8 and the illumination optical system 10.
Is projected onto the projection screen 7. That is,
Light incident on the liquid crystal display panel 9 by the illumination optical system 10 is modulated according to the image data given to the liquid crystal display panel 9,
Light emitted from the projection optical system 8 causes the projection screen 7
Projected on.

The remote controller control section 4 performs various controls based on commands from the remote controller 3 operated by the user. The control performed by the remote controller control unit 4 includes, for example, control of a parameter relating to edge enhancement processing described later. C
PU5 controls each part of a liquid crystal projector. CPU
The control performed by the control unit 5 is, for example, a PC system or an HDTV.
System, NTSC system, etc. There is switching control of the input system. CPU
Reference numeral 5 selects an input sequence used for display, and outputs input sequence information for notifying the selected input sequence to the video signal conversion circuit 2. The CPU 5 may, for example, select an input sequence based on a signal output from the remote controller control unit 4 in response to an operation of the remote controller 3, or based on a detection result of a detection unit (not shown) that performs connector insertion detection. The input sequence may be selected.

FIG. 2 shows the video signal conversion circuit 2 shown in FIG.
3 is a block diagram showing a schematic configuration of FIG. The video signal conversion circuit 2 includes a sync separation section 12 and 13 and an AD conversion section 14.
And a resolution detector 15 and a video processor 17. The sync separator 12 separates the HDTV composite image signal Sig1 into a sync signal SYNC1 and a component image signal (an analog image signal that does not include the sync signal) and outputs the composite signal. In addition, the sync separator 13
The NTSC composite image signal Sig2 is separated into a synchronization signal SYNC2 and a component image signal and output. These component image signals are RGB 3
It is composed of three color signals representing a color image.

Since the synchronization signal SYNC3 is separately input to the PC RGB signal Sig3, it is not necessary to use the synchronization separation unit. The AD converter 14 uses the RG
The B signal Sig3 and the component image signals output from the sync separation units 12 and 13 are input, and a plurality of AD converters (not shown) in the AD conversion unit 14 convert the color signals into image data DV1. In addition, a plurality of A
The timing of AD conversion by the D converter depends on each sync signal S
Video processor 17 based on YNC1 to SYNC3
It is controlled by the internally generated dot clock DCLK.

The resolution detecting section 15 has a synchronization signal S of each series.
YNC1 to SYNC3 are input, and the input synchronization signal SY
The resolution of the input image is detected based on NC1 to SYNC3. Then, the resolution detection unit 15 determines that the synchronization signal SYN
The resolution information I1 indicating the resolutions of C1 to SYNC3 and the input image is output to the video processor 17. The video processor 17 uses the image data DV from the AD conversion unit 14.
1 is input to control writing and reading of image data to the frame memory 1. In addition, the video processor 17
The resolution information I1 from the resolution detection unit 15, the input sequence information I2 from the CPU 5, and the control signal from the remote control unit 4 are input, and input sequence switching and edge enhancement processing are performed.

FIG. 3 shows the video processor 1 shown in FIG.
7 is a block diagram showing a schematic configuration of No. 7. The video processor 17 includes a first processing unit 18 and a second processing unit 19. The first processing unit 18 inputs the image data DV1, controls writing and reading of the image data to and from the frame memory 1, and outputs the image data DV3. The second processing unit 19 inputs the image data DV3, inputs the resolution information I1 from the resolution detection unit 15, the input sequence information I2 from the CPU 5, and the control signal from the remote control unit 4, and switches the input sequence. And edge enhancement processing.

FIG. 4 is a block diagram showing a schematic configuration of the second processing section 19 shown in FIG. The second processing unit 19 includes an input sequence switching unit 20, an area detection unit 21, and a delay unit 22.
, Gain determining unit 23, adder 24, and multiplier 25
And a high pass filter (HPF) 26. The input series switching unit 20 inputs the image data DV3 from the first processing unit 18, and according to the input series information I2, any one of the input series (PC
System, HDTV system or NTSC system) image data is selected and output.

The input switching control section 14a may be provided in the AD conversion section 14, or may be provided in the input section of the video signal conversion circuit 2, that is, in the video signal conversion circuit 2, and the sync separation section 12, It may be provided in the preceding stage of each of the sync separation unit 13, the AD conversion unit 14, and the resolution detection unit 15.
When the input switching control unit is provided at the input portion of the video signal conversion circuit 2, the HDTV system and the NTSC system can share the synchronization separation unit. That is, HDTV system and N
It is sufficient to provide only one TSC system common sync separation unit. The area detection unit 21 inputs the image data from the input sequence switching unit 20 and the previous image data from the frame memory 1, and these image data (image frame)
Based on the difference between the two, a portion of the displayed image that has changed by a predetermined area or more is detected as a moving portion of the image (portion that has moved).

A portion having a change smaller than the predetermined area is judged to be noise. Note that the area detection unit 21 may detect, as moving portions, all the portions in which the absolute value luminance difference between the image frames is equal to or larger than a predetermined threshold, regardless of the area. The gain determination unit 23 is a LUT described later that associates the edge emphasis gain with the image input sequence and resolution.
(Look Up Table), and the area detection unit 2
The edge emphasis gain for the portion detected by 1 is determined according to the resolution information I1 and the input series information I2.
The gain other than the portion detected by the area detection unit 21 is “0”. Further, the gain determination unit 23 may change the filter characteristic of the HPF 26 according to the resolution information I1 and the input sequence information I2.

The HPF 26 receives the image data from the input sequence switching unit 20 and passes the high frequency portion of the image, that is, the edge portion. The multiplier 25 multiplies the edge portion of the image that has passed through the HPF by the gain determined by the gain determination unit 23. As a result, data of the edge emphasized portion is generated. The adder 24 adds the data from the multiplier to the image data from the delay unit 22. As a result, the edge-emphasized image data DV2 is generated. The delay unit 22 delays the image data from the input sequence switching unit 20 and outputs it to the adder 24, and adjusts the timing of addition by the adder 24.

FIG. 5 is a block diagram showing a schematic structure of the area detection unit 21 shown in FIG. The area detection unit 21 includes an absolute value luminance difference calculation unit 27, a binarization unit 28, and a pixel detection unit 29. Absolute value brightness difference calculation unit 27
Inputs the image data from the input sequence switching unit 20 and the previous image data from the frame memory 1, and calculates the absolute value luminance difference between these image frames. That is, the absolute value of the brightness difference between consecutive image data is calculated. The binarization unit 28 uses the absolute value brightness difference calculation unit 2
The absolute value brightness difference calculated by 7 is input and binarized using a predetermined threshold value. That is, it is determined that the portion having the predetermined threshold value or more is the portion where the image has changed, and the value is set to "1",
The portion less than the predetermined threshold value is determined to be the portion in which the image has not changed and is set to the value “0”.

Further, the binarization unit 28 is the remote control unit 4
The threshold value is changed based on the control signal from. The user
A desired threshold can be set by operating the remote controller 3. The pixel detection unit 29 inputs the binarized data from the binarization unit 28, and a pixel having a value “1”, and a pixel having a value “1” in a predetermined range around the pixel is predetermined. Pixels that are more than the number are detected. In addition, the pixel detection unit 29 changes the predetermined range and the predetermined number based on the control signal from the remote controller control unit 4. The user can operate the remote controller 3 to set a desired predetermined range and a predetermined number.

FIG. 6 is a block diagram showing a schematic configuration of a pixel counting circuit included in the pixel detecting unit 29 according to the first embodiment. The pixel counting circuit included in the pixel detection unit 29 includes four pixel delay elements 31 to 34, five-input adders 39 and 40, and four line delay elements (line memories) 35 to 35.
38 and. Four pixel delay elements 31-34
And the 5-input adder 39 performs addition operation for 5 pixels in the horizontal direction of the binary pixel image from the binarization unit 28. The four line delay elements 35 to 38 and the five-input adder 40 perform addition for five horizontal lines of the binary pixel image.

As a result, it is possible to count the number of pixels having the value “1” in the 5 × 5 range of the binary pixel image.
Further, by adopting such a hardware configuration, memory access can be performed in parallel and real-time processing becomes possible. Further, the pixel delay elements 31 to 34 and the line delay elements 35 to 38 are turned on / off according to a control signal from the remote controller control section 4. This gives 3x
The range of counting pixels, such as 3, can be changed. In this example, the example in which the number of pixels in the range of 5 × 5 at the maximum is counted is described, but the number of pixels in the range of 5 × 5 or more can be counted by increasing the number of pixel delay elements and line delay elements. You may

FIG. 7 is a block diagram showing a schematic structure of the HPF 26 shown in FIG. The HPF 26 is, for example,
Programmable 2D HP with maximum 5 taps x 5 taps
It is an F circuit. The HPF 26 has four pixel delay elements 41.
~ 44 and multipliers 45-49 and 55-59 (coefficient k
h0-kh4 and kv0-kv4), 5-input adders 50 and 60, and four line delay elements 51-54
And are equipped with. Multipliers 45-49 and 55-59
Is a coefficient kh according to the control signal from the gain determination unit 23.
Change 0-kh4 and kv0-kv4.

These coefficients are given as digital information by the LUT, which will be described later, of the gain determining section 23. Coefficients kh0-kh4 of multipliers 45-49 and 55-59
And by changing kv0 to kv4, the HPF
The characteristics of 26 and the number of taps can be changed. For example, the coefficient kh of multipliers 45-49 and 55-59
By setting each of 0 to kh4 and kv0 to kv4 as shown in Expression (1), 2 taps of 3 taps × 3 taps are set.
The dimension HPF can be obtained.

Kh0 = 0, kh1 = -0.5, kh2 =
1, kh3 = -0.5, kh4 = 0, kv0 = 0, kv
1 = -0.5, kv2 = 1, kv3 = -0.5, kv4
= 0 Expression (1) Further, by adopting such a hardware configuration, memory access can be performed in parallel and real-time processing becomes possible. In this example, 5 taps maximum × 5
A two-dimensional HPF circuit with programmable taps has been described as an example, but an HPF of 5 taps × 5 taps or more can be configured by increasing the number of pixel delay elements, multipliers, and line delay elements.

FIG. 8 is a table showing an example of the LUT of the gain determining unit 23 according to the first embodiment. The LUT of the gain determination unit 23 is a PC system, a digital TV (HDTV)
System, analog TV (NTSC) system, etc.
GA (640 x 480), XGA (1024 x 76)
8), SXGA (1280 × 1024), 480i (7
20 × 480), 720p (1280 × 720), 10
80i (1920 x 1080), NTSC (768 x 4)
85, etc.) and the like, and the coefficient k of the HPF 26
It defines h0 to kh4 and kv0 to kv4 and the edge enhancement gain α. Here, the relationship between the image input series and the gain α will be described.

TVs such as digital TVs and analog TVs
When the system and the PC system are compared, since the TV system often handles moving images, the gain α is increased to enhance the motion blur improving effect. On the other hand, in the PC system, since a still image is often handled, the gain α is lowered to suppress the adverse effects such as noise increase. Also, digital TV system and analog T
When compared with the V system at almost the same resolution, MPEG2
A digital TV system that has undergone digital compression, such as, has a lower gain than an analog system that does not perform digital compression. This is to prevent noise components such as block distortion caused by digital compression from being emphasized by high-frequency emphasis. In addition, general analog system is NTS
Although it is C, a high-resolution baseband analog image used for a dedicated purpose such as a business use may be included.

Next, the relationship between the resolution of the input image and the gain α and the characteristics of the HPF 26 will be described. When the resolution of the input image and the display resolution (resolution of the liquid crystal display panel 9) match or approximate to each other, that is, when the difference between these resolutions is within a predetermined value, the difference between these resolutions is equal to or larger than the predetermined value. HP compared to
The peak frequency of F26 is increased and the gain α is increased. This is because unlike the case where the difference between these resolutions is greater than or equal to a predetermined value, since there is no image deterioration component due to scaling (resolution conversion), the adverse effect of high-frequency emphasis is small.

On the other hand, when the resolution of the input image is larger than the display resolution by a predetermined value or more, the gain α is lowered and the peak frequency of the HPF is lowered as compared with the case where these resolutions match or approximate to each other. This is to prevent the interference due to the resolution conversion such as the aliasing distortion from being emphasized by the high frequency emphasis. Further, when the resolution of the input image is smaller than the display resolution by a predetermined value or more, the gain α is lowered and the peak frequency of the HPF is lowered as compared with the case where these resolutions match or approximate to each other. This is to prevent the disturbance due to the resolution conversion such as the jaggedness of the image contour portion from being emphasized by the high-frequency emphasis.

Here, the display resolution is set to 1
It is set to 280 × 720. The substance of the LUT is a ROM. The horizontal characteristic and the vertical characteristic of the HPF 26 change as shown in FIGS. 9 to 11 according to the resolution and the input system of the image indicated by the resolution information I1 and the input series information I2. After the processing of HPF26 by this characteristic, HPF2
The data passed through 6 is further multiplied by the gain α by the multiplier 25.

The area detecting section 21 corresponds to the motion detecting means and the area detecting means of the present invention, the absolute value luminance difference calculating section 27 corresponds to the difference detecting means of the present invention, and the remote controller controlling section 4 A CPU corresponding to the changing means of the present invention
5 corresponds to the input sequence setting means of the present invention, and is an adder 2
4, the multiplier 25 and the HPF 26 correspond to the edge enhancing means of the present invention, and the liquid crystal display drive circuit 6, the projection optical system 8, the liquid crystal display panel 9 and the illumination optical system 10 correspond to the image displaying means of the present invention. .

The operation of the first embodiment having the above configuration will be described with reference to the drawings. FIG. 12 is an explanatory diagram illustrating an operation of the absolute value luminance difference detection unit 27 according to the first embodiment. For example, as shown in FIG.
A graphic 61 and noise N1 are displayed in an arbitrary image frame Pa.
To N3 are included, and as shown in FIG. 12B, the image frame P- (a + 1) next to the image frame P-a includes the graphic 62 and noises N4 to N6. The graphic 62 is the graphic 61 moved to the right. The absolute value brightness difference detection unit 27 uses the image frame P-
The absolute value of the difference between the brightness of each pixel in 1 and the brightness of each pixel in the image frame P- (a + 1) is calculated.

The calculation result of the absolute value brightness difference detection unit 27 is
As shown in FIG. 12C, noises N1 to N3 and N4 to N6 along with the binary pixel image 63 formed by the figures 61 and 62.
2 binary pixel images N11 to N16. Binary pixel image N
11 to N16 are noise portions that are not to be edge-emphasized. Here, the binary pixel images 63 to be edge-emphasized, which are the moving parts, exist in a cluster and have a large area, while the binary pixel images N11 to N16 which are not to be edge-emphasized, which are the noise parts, are scattered. However, the area is small. The pixel detection unit 29 uses this area difference to exclude the binary pixel images N11 to N16 from the edge emphasis targets.

FIG. 13 is an explanatory diagram for explaining the operation of the pixel detection unit 29 according to the first embodiment. Pixel detector 29
Is a two-dimensional space in which the absolute value brightness difference values detected by the absolute value brightness difference detection unit 27 are arranged, and while sweeping the predetermined range, the pixels having the value “1” within the predetermined range are sequentially counted. . Regarding the pixels of the binary pixel images N11 to N16, the number of pixels having the value “1” within the predetermined range around them is small (see A1 in FIG. 13). On the other hand, as for the pixels of the binary pixel image 63, the number of pixels having the value “1” within the predetermined range around them is large (see A2 in FIG. 13). For example, a pixel has a value of "1" and a value of "1" within the surrounding 5 × 5 range.
If the number of pixels is 13 or more, it is determined that the pixel is included in the binary pixel image 63.

FIG. 14 is a flowchart showing the processing procedure of the pixel detection unit 29 according to the first embodiment. When there is a pixel with a value of "1", the pixel detection unit 29 first counts the number of pixels within a predetermined range around it (S1), and determines whether or not it is equal to or larger than a predetermined threshold value (S2). If it is less than the predetermined threshold value, it is determined to be a noise portion (S4), and if it is more than the predetermined threshold value, it is determined to be a moving portion of the image and the gain determination unit 23 is notified (S3). The gain determination unit 23
The area detection unit 29 determines the gain α of the pixel determined to be the moving portion of the image. The gains of pixels in the noise portion and other portions are “0”.

As described above, according to the first embodiment,
Based on the difference between the image frames, the area detection unit 21
A portion of the displayed image that has changed by a predetermined area or more is detected, and the addition unit 24, the multiplication unit 25, and the HPF 26 are detected.
Of the displayed image, the edge of the portion detected by the area detection unit 21 is emphasized, and the liquid crystal display drive circuit 6,
The projection optical system 8, the liquid crystal display panel 9, and the illumination optical system 10 display an edge-emphasized image. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

(Embodiment 2) Embodiment 2 of the present invention
In place of the second processing unit 19 in the first embodiment,
A pixel whose value obtained by binarizing the absolute value luminance difference is “1” (hereinafter,
A second processing unit is provided for determining a gain α of a pixel having a value “1”) based on the number of pixels having a value “1” existing within a predetermined range around the pixel. FIG. 15 is a block diagram showing a schematic configuration of the second processing unit 71 according to the second embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals as those in FIG.

The second processing unit 71 of the second embodiment is present in the second processing unit 19 of the first embodiment, in place of the area detection unit 21, within a predetermined range around the pixel having the value “1”. An area detection unit 72 that notifies the gain determination unit 73 of the number of pixels of the value “1” is provided, and instead of the gain determination unit 23, the gain α of each pixel is determined according to the number of pixels notified from the area detection unit 72. The gain determining unit 73 is provided. Area detection unit 7
2 has the same configuration as the area detection unit 21 of the first embodiment and operates in the same manner, but determines the number of pixels of the value “1” existing within a predetermined range around the pixel of the value “1” as the gain. Notify the unit 73.

The gain determining section 73 has the same structure as the gain determining section 23 of the first embodiment and operates in the same manner.
The gain α of each pixel is determined according to the number of pixels notified from the area detection unit 72. FIG. 16 is a table showing an example of the LUT of the gain determining unit 73 according to the second embodiment. The LUT of the gain determination unit 73 does not associate the input sequence and resolution of the image with the gain α, but the number of pixels of the value “1” existing in a predetermined range around the pixel of the value “1” and the pixel thereof. And the gain α of

For example, when the number of pixels is 0 to 9, the gain α is 0, when the number of pixels is 10 to 14, the gain α is 0.5, and when the number of pixels is 10 to 24. , Gain α = 0.7, and when the number of pixels is 25, gain α = 1. Alternatively, the image input sequence and resolution, the number of pixels, and the gain α may be associated with each other. As a result, in the multiplier 25, the gain α corresponding to the number of pixels of the value “1” existing in the predetermined range around the pixel of the value “1” is given to the pixel. Other configurations and operations are the same as those in the first embodiment.

As described above, according to the second embodiment,
The gain determination unit 73 determines the edge enhancement gain α for each pixel based on the number of other pixels within the predetermined range, and the addition unit 2
4, the multiplication unit 25 and the HPF 26 are the gain determination unit 73.
Edge enhancement based on the decision by This allows
More appropriate edge enhancement can be performed.

(Embodiment 3) Embodiment 3 of the present invention
In the first embodiment, the area detection unit detects a moving portion of an image by removing high frequency components of a two-dimensional space in which absolute value luminance differences are arranged. FIG. 17
FIG. 9 is a block diagram showing a schematic configuration of a second processing unit 81 according to the third embodiment of the present invention. The first embodiment
The same reference numerals as those in FIG. The second processing unit 81 according to the third embodiment is different from the second processing unit 19 according to the first embodiment in that the area detection unit 21 is replaced by removing high-frequency components of a two-dimensional space in which absolute value luminance differences are arranged. An area detection unit 82 for detecting a moving portion of the image is provided.

FIG. 18 is a block diagram showing a schematic structure of the area detection unit 82 according to the third embodiment. The same components as those in the first embodiment are designated by the same reference numerals as those in FIG. The area detection unit 82 is the same as the area detection unit 82 of the first embodiment except that the binarization unit 28 and the pixel detection unit 2 are used.
2D low pass filter (2D LPF) instead of 9
84 and a binarization unit 85 are provided. Two-dimensional L
The PF 84 receives the absolute value brightness difference calculated by the absolute value brightness difference calculation unit 27, and removes the high frequency component of the two-dimensional space in which the absolute value brightness difference is arranged.

As a result, the noise portion, which is a high-frequency component having a small area, is removed, and the moving portion having a large area remains. Further, the two-dimensional LPF 84 changes the characteristics based on the control signal from the remote controller control unit 4. The user can operate the remote controller 3 to set a desired LPF characteristic. The binarization unit 85 inputs the data passed through the two-dimensional LPF 84 and binarizes it using a predetermined threshold value. That is, it is determined that a portion having a predetermined threshold value or more is a portion in which the image has changed, and the value is “1”, and a portion less than the predetermined threshold value is a portion having no change in the image and a value “1”. 0 ”.

Further, the binarizing unit 85 includes a remote controller control unit 4
The threshold value is changed based on the control signal from. The user
A desired threshold can be set by operating the remote controller 3. The two-dimensional LPF 84 is also used for moving parts of the image.
It will be removed to some extent by the
The value conversion unit 85 may set the value of “1” to a value obtained by expanding the value of “1” by a predetermined amount. The binarization unit 85 corresponds to the pixel detection means of the present invention. Other configurations and operations are the same as those in the first embodiment.

As described above, according to the third embodiment, the absolute value brightness difference calculating unit 27 detects the absolute value brightness difference between the image frames, and the two-dimensional LPF 84 detects the absolute value brightness difference calculating unit 27. The high-frequency component of the two-dimensional space in which the absolute value brightness differences are arranged is removed, and the binarization unit 85 detects pixels having an absolute value brightness difference of a predetermined threshold value or more based on the removal result of the two-dimensional low-pass filter. , The adder 24, the multiplier 25, and the HPF 26 enhance the edges of the pixels detected by the binarization unit 85 in the displayed image, and the liquid crystal display drive circuit 6, the projection optical system 8, the liquid crystal display panel 9, and the illumination. The optical system 10 displays the edge-enhanced image. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

(Embodiment 4) Embodiment 4 of the present invention
In the third embodiment, the area detection unit does not perform binarization and outputs the absolute value luminance difference passing through the two-dimensional LPF 84 to the gain determination unit as it is, and the gain determination unit responds to the absolute value luminance difference. The gain α is determined. FIG. 19 shows a second embodiment according to the fourth embodiment of the present invention.
It is a block diagram showing a schematic structure of a processing unit. The same components as those in the third embodiment are designated by the same reference numerals as those in FIG.

In the second processing unit 91 of the fourth embodiment, the absolute value luminance difference that has passed through the two-dimensional LPF 84 is used as it is in the second processing unit 81 of the third embodiment, instead of the area detection unit 82. An area detection unit 92 for outputting to 93 is provided, and instead of the gain determination unit 23, a gain determination unit 93 for determining the gain α according to the absolute value luminance difference from the area detection unit 92 is provided. FIG. 20 is a block diagram showing a schematic configuration of the area detection unit 92 according to the fourth embodiment. The same components as those in the third embodiment are designated by the same reference numerals as those in FIG.

The area detecting unit 92 of the fourth embodiment omits the binarizing unit 85 in the area detecting unit 82 of the third embodiment, and the absolute value luminance difference passing through the two-dimensional LPF 84 is directly input to the gain determining unit 93. It is designed to be output.
FIG. 21 shows L of the gain determining unit 93 according to the fourth embodiment.
It is a chart showing an example of UT. The gain determination unit 93 has an LUT as shown in FIG. 21, which associates the absolute value luminance difference with the gain α, and determines the gain α for each pixel according to the absolute value luminance difference from the area detection unit 92. decide. Other configurations and operations are the same as those in the third embodiment.

As described above, according to the fourth embodiment,
The absolute value brightness difference calculation unit 27 detects the absolute value brightness difference between the image frames, and the two-dimensional LPF 84 detects the high frequency component of the two-dimensional space in which the absolute value brightness difference detected by the absolute value brightness difference calculation unit 27 is arranged. The gain determining unit 93 determines the edge enhancement gain for each pixel based on the removal result of the two-dimensional LPF 84, and the adder 24, the multiplier 25, and the HPF 26 determine the gain by the gain determining unit 93. Edge enhancement is performed, and the liquid crystal display drive circuit 6, the projection optical system 8, the liquid crystal display panel 9, and the illumination optical system 10 display the edge-enhanced image. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

The functions of the video signal conversion circuit and the remote control unit of the first to fourth embodiments may be realized by hardware or may be realized by a computer program. A computer program that realizes the functions of these units is a floppy disk or a CD-RO.
It is provided in a form recorded on a computer-readable recording medium such as M. The computer (liquid crystal projector) reads the computer program from the recording medium and transfers it to an internal storage device or an external storage device.
Alternatively, the computer program may be supplied to the computer from the program supply device via a communication path.

When realizing the functions of the computer,
The computer program stored in the internal storage device is executed by the microprocessor of the computer.
Alternatively, the computer may directly execute the computer program recorded in the recording medium. In this specification, the computer is a concept including a hardware device and an operating system (OS), and means a hardware device that operates under the control of the OS. When the OS is unnecessary and the hardware device is operated by the application program alone, the hardware device itself corresponds to the computer.

The hardware device comprises a microprocessor such as a CPU, and means for reading the computer program recorded in the recording medium. The computer program includes a program code that causes such a computer to realize the above-described functions. Some of the functions described above may be realized by the OS instead of the application program. As the "recording medium" in the present invention, a flexible disk, C
D-ROM, magneto-optical disk, IC card, ROM cartridge, printed matter on which codes such as punch card and bar code are printed, internal storage device of computer (RAM or R
Various media that can be read by a computer can be used, such as a memory such as an OM) and an external storage device.

In addition, in the first to fourth embodiments,
Although the transmissive liquid crystal projector has been described as an example, the configurations of the first to fourth embodiments can be applied to both the transmissive projector and the reflective projector. here,
“Transmissive” means that a light valve such as a liquid crystal light valve is a type that transmits light, and “reflective” means that the light valve is a type that reflects light. ing. The light valve of the reflection type projector may be a liquid crystal light valve or a light valve using a micro mirror.

As the projector, there are a front projector for projecting an image from the direction of observing the projection surface and a rear projector for projecting an image from the side opposite to the direction of observing the projection surface. The configuration of the fourth embodiment can be applied to any projector. Furthermore, the configurations of the first to fourth embodiments are L
It is also applicable to other hold type image display devices such as hold type image display devices such as CDs, organic ELs, plasma displays and LED displays.

[0078]

As described above, in the hold type image display device (claim 1) of the present invention, the area detecting means displays the image among the images displayed based on the difference between the image frames.
The edge enhancement means detects a portion that has changed by a predetermined area or more, and the edge enhancement means performs edge enhancement on the portion detected by the area detection means, and the image display means performs edge enhancement by the edge enhancement means. Display an image. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

Further, in the hold type image display device (claim 2) of the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the pixel detecting means based on the detection result of the difference detecting means. Then, the own pixel has an absolute value brightness difference of a predetermined threshold value or more, and another pixel having an absolute value brightness difference of a predetermined threshold value or more detects a predetermined number or more pixels within a predetermined range around the own pixel, and edge emphasis is performed. The means performs edge enhancement of the pixels detected by the pixel detection means in the image to be displayed,
The image display means displays the image whose edge is emphasized by the edge emphasis means. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

Further, in the hold type image display device (claim 3) of the present invention, the changing means changes at least one of the predetermined threshold value, the predetermined range and the predetermined number.
Since the user can appropriately adjust the edge emphasis, the quality of the display image can be improved according to the user's preference.

In the hold type image display device (claim 4) of the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the two-dimensional low-pass filter detects the absolute value detected by the difference detecting means. The high-frequency component of the two-dimensional space in which the value-brightness differences are arranged is removed, and the pixel detection means detects a pixel having an absolute-value brightness difference of a predetermined threshold value or more based on the removal result of the two-dimensional low-pass filter, and the edge enhancement means. In the image to be displayed, the pixels detected by the pixel detection unit are edge-emphasized, and the image display unit displays the image whose edge is emphasized by the edge emphasis unit. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

Further, in the hold type image display device (claim 5) of the present invention, the difference detecting means detects the absolute value luminance difference between the image frames, and the two-dimensional low-pass filter detects the absolute value detected by the difference detecting means. The high-frequency component of the two-dimensional space in which the value-brightness differences are arranged is removed, the gain determination means determines the edge enhancement gain for each pixel based on the removal result of the two-dimensional low-pass filter, and the edge enhancement means determines the gain. Edge enhancement is performed based on the determination by the means, and the image display means displays the image edge-enhanced by the edge enhancement means. As a result, the probability of performing edge enhancement on a moving portion while avoiding a noise portion is increased, so that edge enhancement can be performed while suppressing enhancement of noise components, and the quality of a display image can be improved.

Further, in the hold type image display device according to the present invention (claim 6), the gain determining means determines the edge enhancement gain for each pixel based on the number of other pixels within the predetermined range, and the edge enhancing means. However, since edge enhancement is performed based on the determination made by the gain determination means, more appropriate edge enhancement can be performed.

Further, in the hold type image display device of the present invention (claim 7), the input series setting means selects and sets the input series of the image, and the gain deciding means is based on the setting by the input series setting means. Determine the edge enhancement gain. As a result, it is possible to perform appropriate edge enhancement according to the input sequence, and thus it is possible to improve the quality of the display image.

Further, in the hold type image display device of the present invention (claim 8), the resolution detecting means detects the resolution of the input image, and the gain determining means performs edge enhancement based on the detection result of the resolution detecting means. Determine the gain. As a result, it is possible to perform appropriate edge enhancement according to the resolution of the input image, and thus it is possible to improve the quality of the display image.

Further, in the hold type image display device of the present invention (claim 9), the input series setting means selects and sets the input series of the image, and the gain determining means sets the setting by the input series setting means. Based on the difference between the image frames, the motion detection means detects the portion of the image to be displayed that has moved, and the edge emphasis means displays it. Of the image, the edge of the portion detected by the motion detection means is emphasized, and the image display means displays the image whose edge is emphasized by the edge emphasis means. As a result, it is possible to perform appropriate edge enhancement according to the input sequence, and thus it is possible to improve the quality of the display image.

Further, in the hold type image display device of the present invention (claim 10), the resolution detecting means detects the resolution of the input image, and the gain deciding means based on the detection result of the resolution detecting means. The edge detection gain is determined, the motion detection means detects a portion of the displayed image that has moved based on the difference between the image frames, and the edge enhancement means detects the motion of the displayed image. The means enhances the edge of the detected portion, and the image display means displays the image edge-enhanced by the edge enhancing means. As a result, it is possible to perform appropriate edge enhancement according to the resolution of the input image, and thus it is possible to improve the quality of the display image.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a liquid crystal projector according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a video signal conversion circuit shown in FIG.

FIG. 3 is a block diagram showing a schematic configuration of the video processor shown in FIG.

FIG. 4 is a block diagram showing a schematic configuration of a second processing section shown in FIG.

5 is a block diagram showing a schematic configuration of an area detection unit shown in FIG.

FIG. 6 is a block diagram showing a schematic configuration of a pixel counting circuit included in the pixel detection unit according to the first embodiment.

FIG. 7 is a block diagram showing a schematic configuration of the HPF shown in FIG.

FIG. 8 is a table showing an example of an LUT of a gain determination unit according to the first embodiment.

FIG. 9 is a diagram showing an example of frequency-gain characteristics of the LPF according to the first embodiment.

FIG. 10 is a diagram showing another example of frequency-gain characteristics of the LPF according to the first embodiment.

FIG. 11 is a diagram showing still another example of frequency-gain characteristics of the LPF according to the first embodiment.

12A, 12B, and 12C are explanatory diagrams for explaining the operation of the absolute value luminance difference detection unit according to the first exemplary embodiment.

FIG. 13 is an explanatory diagram illustrating an operation of the pixel detection unit according to the first embodiment.

FIG. 14 is a flowchart illustrating a processing procedure of a pixel detection unit according to the first exemplary embodiment.

FIG. 15 is a block diagram showing a schematic configuration of a second processing unit according to the second embodiment of the present invention.

FIG. 16 is an LUT of a gain determining unit according to the second embodiment.
It is a chart showing an example.

FIG. 17 is a block diagram showing a schematic configuration of a second processing unit according to the third embodiment of the present invention.

FIG. 18 is a block diagram showing a schematic configuration of an area detection unit according to the third embodiment.

FIG. 19 is a block diagram showing a schematic configuration of a second processing unit according to the fourth embodiment of the present invention.

FIG. 20 is a block diagram showing a schematic configuration of an area detection unit according to a fourth embodiment.

FIG. 21 is a LUT of a gain determining unit according to the fourth embodiment.
It is a chart showing an example.

[Explanation of symbols]

1 frame memory 2 Video signal conversion circuit 3 remote control 4 Remote control unit 5 CPU 6 Liquid crystal display drive circuit 7 Projection screen 8 Projection optical system 9 Liquid crystal display panel 10 Illumination optical system 11 bus 12, 13 Sync separator 14 AD converter 14a Input switching control unit 15 Resolution detector 17 Video Processor 18 First processing unit 19, 71, 81, 91 Second processing unit 20 Input sequence switching unit 21, 72, 82, 92 Area detection unit 22 Delay section 23, 73, 93 Gain determination unit 24 adder 25 multiplier 26 High Pass Filter (HPF) 27 Absolute Value Brightness Difference Calculation Unit 28,85 Binarization unit 29 pixel detector 84 Two-dimensional low-pass filter (two-dimensional LPF)

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) H04N 1/409 H04N 5/208 5/208 1/40 101D F Term (Reference) 2H093 NC41 NC51 ND23 NE06 NG02 5B057 CE03 CE05 CE06 DA08 DA16 DC16 5C021 PA17 PA31 PA38 PA66 PA67 PA78 RA01 XB03 5C077 LL19 MP07 PP02 PP03 PP47 PP61 SS06 TT10 5C080 AA05 AA06 AA07 AA10 BB05 DD30 EE19 EE32 JJ01 JJ02 JJ05 JJ07 KK43

Claims (10)

[Claims] 1. An area detecting means for detecting a portion of a displayed image that has changed by a predetermined area or more, based on a difference between image frames, and an area detecting means for detecting the area of the displayed image. A hold-type image display device, comprising: an edge enhancing unit that enhances edges of the above-described portion; and an image display unit that displays an image that has been edge enhanced by the edge enhancing unit. 2. A difference detecting means for detecting an absolute value luminance difference between image frames, and based on a detection result of the difference detecting means, an own pixel has an absolute value luminance difference of a predetermined threshold value or more, and the predetermined threshold value. Pixel detection means for detecting a predetermined number or more of pixels in a predetermined range around the own pixel having other pixels having the above absolute value luminance difference, and edge enhancement of the pixel detected by the pixel detection means in the displayed image. A hold type image display device, comprising: an edge enhancing unit that performs the above; and an image displaying unit that displays an image that has been edge enhanced by the edge enhancing unit. 3. The hold type image display device according to claim 2, further comprising a changing unit that changes at least one of the predetermined threshold value, the predetermined range, and the predetermined number. 4. A difference detecting means for detecting an absolute value luminance difference between image frames, and a two-dimensional low-pass filter for removing a high frequency component of a two-dimensional space in which the absolute value luminance differences detected by the difference detecting means are arranged. A pixel detection unit that detects a pixel having an absolute value luminance difference of a predetermined threshold value or more based on the removal result of the two-dimensional low-pass filter; and edge enhancement of a pixel detected by the pixel detection unit in an image to be displayed. A hold-type image display device, comprising: an edge enhancing unit that performs the image enhancement; and an image display unit that displays an image that has been edge enhanced by the edge enhancing unit. 5. A difference detecting means for detecting an absolute value luminance difference between image frames, and a two-dimensional low-pass filter for removing a high frequency component of a two-dimensional space in which the absolute value luminance differences detected by the difference detecting means are arranged. A gain determination unit that determines a gain of edge enhancement for each pixel based on a removal result of the two-dimensional low-pass filter; an edge enhancement unit that performs edge enhancement based on the determination made by the gain determination unit; An image display unit for displaying an image whose edge is emphasized by the hold type image display device. 6. The apparatus further comprises gain determining means for determining an edge enhancement gain for each pixel based on the number of the other pixels within the predetermined range, wherein the edge enhancing means is determined by the gain determining means. The edge enhancement is performed based on
Alternatively, the hold-type image display device described in the paragraph 3. 7. An input sequence setting means for selecting and setting an input sequence of an image, and a gain determining means for determining a gain of edge enhancement by the edge enhancing means based on the setting by the input sequence setting means. The hold-type image display device according to claim 1, further comprising: 8. Further comprising: a resolution detecting means for detecting a resolution of an input image; and a gain determining means for determining a gain of edge enhancement by the edge enhancing means based on a detection result of the resolution detecting means. The hold type image display device according to claim 1. 9. A motion detecting means for detecting a portion of the displayed image that has moved based on a difference between the image frames, and edge enhancement of a portion of the displayed image detected by the motion detecting means. An edge enhancing means for performing the above, an input sequence setting means for selecting and setting an input sequence of an image, a gain determining means for determining a gain of edge enhancement by the edge enhancing means based on the setting by the input sequence setting means, An image display means for displaying the image edge-enhanced by the edge emphasis means, and a hold-type image display device. 10. A motion detection means for detecting a portion of the displayed image that has moved based on a difference between the image frames, and edge enhancement of a portion of the displayed image detected by the motion detection means. Edge enhancing means for performing the above, a resolution detecting means for detecting the resolution of the input image, a gain determining means for determining a gain of edge enhancement by the edge enhancing means based on the detection result of the resolution detecting means, and the edge enhancing means. An image display unit for displaying an image whose edge is emphasized by the hold type image display device.