KR100783817B1 - Video encoder, image processing device and image signal processing method - Google Patents

Abstract

A video encoder, an image processing device and an image signal processing method are provided to reduce color information of a color signal among digital video signals inputted to a video processing unit when variation of a video between frames frequently happens, thereby reducing power consumption of a video processing device. A video encoder includes a synchronization signal control unit, a color information processing unit(390), an image correcting unit(320) and a modulation unit(330). The synchronization signal control unit generates a synchronization signal for adjusting synchronization of an analog video signal. The color information processing unit reduces color information of a pixel inside a frame when the total sum of a frame by frame motion vector is bigger than a threshold value. The image correcting unit corrects image quality of a luminescent signal and generates a second digital video signal. The modulation unit modulates the second digital video signal to a digital signal corresponding to the analog video signal.

Description

VIDEO ENCODER, IMAGE PROCESSING DEVICE AND IMAGE SIGNAL PROCESSING METHOD}

1 is a block diagram showing a configuration of a general digital image processing apparatus, a video encoder, and a TV award period.

2 is a block diagram illustrating a conventional video encoder.

3 is a block diagram illustrating an image processing apparatus according to an embodiment of the present invention.

4 and 5 are graphs showing the sum of motion vectors of a frame.

6 is a conceptual diagram illustrating an image of 8 pixels x 8 pixels before image processing according to an embodiment of the present invention.

6 is a conceptual diagram illustrating an image of one frame including 8 pixels x 8 pixels before color information processing according to an embodiment of the present invention.

7 is a conceptual diagram illustrating an image in one frame before color information processing according to an embodiment of the present invention.

8 is a conceptual diagram illustrating edges and a center point of an image of a specific region in one frame according to an embodiment of the present invention.

9 is a conceptual diagram illustrating a case where an image of a specific region of FIG. 8 is moved in a predetermined direction.

10 to 14 are conceptual views illustrating a process of reducing color information for pixels at a specific position of a specific image in a frame when the sum of the motion vectors of the frame is larger than a predetermined threshold.

FIG. 15 is a conceptual diagram illustrating a process of removing color information of all pixels of an image of a specific region in a frame.

16 is a flowchart illustrating a video signal processing method according to an embodiment of the present invention.

17 is a block diagram illustrating an image processing apparatus according to another exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

120: video encoder 220, 320: image quality correction unit

230, 330: modulator 240, 340: modulated signal generator

330: selection unit 360: motion vector direction detection unit

370: color information extraction unit 390: color information processing unit

380, 1170: image processing unit

The present invention relates to a video encoder, an image processing apparatus, and a video signal conversion method, and more particularly, to a video encoder, an image processing device, and an image signal conversion method that can reduce power consumption when there is a large change in inter-frame images. .

1 is a block diagram showing a configuration of a general digital image processing apparatus, a video encoder, and a TV award period. As shown in FIG. 1, the video encoder 120 converts the digital video signal 112 output from the digital video signal output device 110 into an analog video signal 122 and then converts the digital video signal 112 into an analog video signal 122. Display the image. The digital video signal output device 110 may be a digital camera phone, a memory card, a personal computer (PC), a portable multimedia player (PMP), or the like. The video encoder 120 may be included in the TV receiver 130 or included in the digital video signal output device 110 or may be implemented as an independent device as shown in FIG. 1. In FIG. 1, the video encoder 120 is connected to the TV receiver 130, but the video encoder 120 includes a high definition television (HDTV), a plasma display panel (PDP) TV, and a liquid crystal display (LCD). In addition to the TV receiver 130 such as a TV, it may be connected to a projector and used.

2 is a block diagram illustrating a conventional video encoder.

Referring to FIG. 2, a conventional video encoder includes a synchronization signal controller 210, an image quality corrector 220, a modulator 230, a modulated signal generator 240, and a digital-analog converter 250. .

The synchronization signal controller 210 includes a timing controller 212, a sync signal generator 214, and a blank signal generator 216, and includes a vertical sync signal VSYNC, a horizontal sync signal HSYNC, and a field identifier FIELD_ID. And a synchronization signal SYNC signal 211 and a blank signal (or blanking signal 213) for synchronizing the analog TV signal based on the clock CLOCK.

A blank signal is inserted into the digital image signal passing through the image quality correction unit 220, and a synchronization signal (SYNC signal) is inserted in the retrace period. The horizontal synchronizing signal HSYNC is inserted in the horizontal blanking period, and the vertical synchronizing signal VSYNC is inserted in the vertical blanking period. To synchronize the analog TV signal, an equalizing pulse is inserted before and after the vertical synchronization signal, a serration pulse is inserted within the vertical synchronization signal period, and the back of the horizontal retrace period of the digital video signal. Insert a burst signal into the back porch.

The luminance signal Y, the color signals CB, and CR of the digital image signal 201 pass through the first image quality corrector 222, the second image quality corrector 224, and the third image quality corrector 226, respectively. Oversampled at 222a, 224a, and 226a, and noise components are removed from the low pass filters 222b, 224b, and 226b, thereby improving the quality of the digital video signal.

The modulated signal generator 240 generates a carrier wave for modulating the luminance signal Y 202, the color signal CB 204, and the CR 206 with improved image quality, in order to generate an analog TV signal. Specifically, the modulated signal generator 240 stores the n sampled sine wave sample values and the cosine wave sample values in a memory in advance, reads the sine wave sample values, and generates a sine wave signal 242. Is read to generate a cosine wave signal 244.

The modulator 230 modulates the luminance signal Y 202, the color signal CB 204, and the CR 206 with improved image quality based on the synchronization signal 211, the blank signal 213, and the carrier waves 242 and 244. To generate a digital signal corresponding to the analog TV signal.

The digital-to-analog converter 250 includes three digital-to-analog converters 252, 254, and 256 to digital-analog convert the digital signal output from the modulator 230 to the analog TV signal 258. To convert.

In the video decoding codec that decompresses according to the amount of change between frames by using motion vectors such as H.264 or MPEG4, the motion of the frame of the video signal in the case of a video having a very fast scene change or movement between frames on the video screen. The sum of the vectors increases dramatically compared to the previous frame.

In the conventional video encoder, when the sum of the motion vectors of a frame is larger than a predetermined threshold, many operations are required during the image quality improvement operation by the image quality correction unit 220 for the luminance signal Y and the color signal CBCR. Consumption increases.

When the sum of the motion vectors of the frames is larger than the predetermined threshold, the image quality is reduced when the luminance information of the luminance signal Y input to the image quality correction unit 220 is reduced (or lost) in order to reduce the calculation amount of the luminance signal Y. Can be degraded.

Since human vision is more insensitive to color components than luminance components, when the sum of the motion vectors of a frame is larger than a predetermined threshold, the color signal input to the image quality compensator 220 may be reduced by reducing the computation amount with respect to the color signal CBCR. It is necessary to reduce the color information of the CBCR).

That is, in the conventional video encoder, the color information of the color signal (CBCR) input to the image quality correction unit 220 is reduced in the case of a video having a very fast scene change or movement between frames as described above. In operation 220, it is necessary to reduce power consumption.

Accordingly, a first object of the present invention is to provide a video encoder capable of reducing power consumption when there is a large change in image between frames by adjusting color information of a digital image signal based on the direction of a motion vector.

It is a second object of the present invention to provide an image processing apparatus capable of reducing power consumption when there is a large change in an image between frames by adjusting color information of a digital image signal based on the direction of a motion vector.

In addition, a third object of the present invention is to provide a video signal processing method that can reduce power consumption even when there is a large change in the image between frames by adjusting the color information of the digital video signal based on the direction of the motion vector. will be.

According to an aspect of the present invention, there is provided a video encoder, including: a synchronization signal controller configured to generate a synchronization signal for synchronizing an analog image signal; A color information processing unit for reducing color information of pixels in the frame based on a moving direction of an image of a predetermined region in a frame of an input first digital image signal when the sum of the motion vectors for each frame is larger than a predetermined threshold value; An image quality correction unit configured to generate a second digital image signal by correcting an image quality of a luminance signal of the first digital image signal and one of a color signal of the first digital image signal and the color signal having the reduced color information; And a modulator configured to modulate the second digital video signal into a digital signal corresponding to the analog video signal based on the synchronization signal and the carrier wave. The color information processing section is an estimated area within a predetermined search area having a predetermined search distance in the frame, wherein the estimated area is an area within a predetermined angle range around the direction of the motion vector of the image of the predetermined area within the frame. Color information may be removed for the remaining pixels in the predetermined search area except at least one pixel. The color information processor may increase the number of pixels from which color information in the frame is removed as the sum of the motion vectors of the frame increases. The color information processor may increase the number of pixels from which the color information in the frame is removed as the slope of the sum of the motion vectors of the frame increases. The color information processor may increase the number of pixels from which the color information in the frame is removed as the rate of change of the sum of the motion vectors of the frame increases. The color information processor may include: a motion vector direction detection unit configured to obtain a direction of a motion vector of a predetermined image in the frame; Color information for reducing the color information of the pixels of the frame based on the direction of the motion vector of the predetermined image in the frame when the sum of the motion vectors of the frame is received and the sum of the motion vectors of the frame is greater than a predetermined threshold Extraction unit; And a selector configured to select one of a color signal of the first digital image signal or a color signal having the reduced color information in response to a control signal and provide the selected color signal to the image quality correction unit. The video encoder may further include a digital-to-analog converter configured to convert the modulated digital signal into an analog signal to generate the analog image signal.

According to an aspect of the present invention, there is provided an image processing apparatus according to an aspect of the present invention, in which an image of a predetermined region in a frame of a first digital image signal is input when the sum of motion vectors per frame is greater than a predetermined threshold. A color information processor which reduces color information of pixels in the frame based on a movement direction; An image quality correction unit configured to generate a second digital image signal by correcting an image quality of one of a color signal of the first digital image signal and a color signal having the reduced color information and a luminance signal of the first digital image signal; And an image processor configured to image-process the second digital image signal. The image processor may be an MPEG encoder that encodes the second digital image signal.

According to an aspect of the present invention, there is provided a method of processing a video signal according to an aspect of the present invention, wherein an image of a predetermined region in a frame of a first digital video signal input when a sum of motion vectors per frame is greater than a predetermined threshold. Reducing color information of a pixel in the frame based on a moving direction of the frame; Generating a second digital video signal by correcting an image quality of a luminance signal of the first digital video signal and a color signal having the reduced color information; And image processing the second digital video signal. The reducing of the color information may include estimating an area in a predetermined search area having a predetermined search distance in the frame, wherein the estimated area is within a predetermined angle range around a direction of a motion vector of an image of the predetermined area in the frame. Color information may be removed for the remaining pixels in the predetermined search area except at least one pixel in the area. The image processing of the second digital video signal may include modulating the second digital video signal into a digital signal based on a synchronization signal and a carrier wave to synchronize the analog video signal; And converting the modulated digital signal into an analog signal to generate an analog image signal. The image processing of the second digital video signal may include MPEG encoding the second digital video signal.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. Hereinafter, the same reference numerals are used for the same components in the drawings, and duplicate descriptions of the same components are omitted.

3 is a block diagram illustrating an image processing apparatus according to an embodiment of the present invention.

Referring to FIG. 3, an image processing apparatus according to an embodiment of the present invention includes an image quality correcting unit 320, a color information processing unit 390, and an image processing unit 380. Hereinafter, an example in which the image processing apparatus of FIG. 3 is a video encoder will be described. The image processor 380 includes a synchronization signal controller 310, a modulator 330, a modulated signal generator 340, and a digital-analog converter 350.

The synchronization signal controller 310 includes a timing controller 312, a sync signal generator 314, and a blank signal generator 316. The synchronization signal controller 310 may synchronize the analog image signal based on the vertical synchronization signal VSYNC, the horizontal synchronization signal HSYNC, the field identifier FIELD_ID, and the clock CLOCK. ) And a blank signal (or blanking signal 313). Hereinafter, the analog video signal is a concept including both an analog TV signal for output to a TV receiver or an analog video signal for output to a projector.

The color information processor 390 includes a motion vector directionality detector 360 and a color information extractor 370.

The color information processor 390 adjusts the color information of the digital image signal 301 input to the video encoder based on the sum of the motion vectors for each frame and the directionality of the motion vectors, and provides the color information to the image quality corrector 320. Here, the digital video signal 301 input to the video encoder is called a first digital video signal.

The motion vector directional detector 360 obtains the directionality of the motion vector with respect to the center point of the predetermined image in the frame and provides the directional information 361 of the motion vector to the color information extractor 370.

The color information extracting unit 370 receives the sum 371 of the motion vectors for each frame, and when the sum of the motion vectors of the frames is larger than a predetermined threshold, the directional information 361 of the motion vector with respect to the center point of the predetermined image in the frame. Based on the color information of the pixels of the frame provided to the image quality correction unit 220 is reduced. The sum of the motion vectors for each frame is the sum of the motion vectors of each frame of the digital video signal 301.

For example, when the sum of the motion vectors of the frame is greater than a predetermined threshold, the color information extractor 370 may determine the predetermined search area based on the sum of the motion vectors and the directional information of the motion vector of the center point of the predetermined image in the current frame. Determine an estimation region within the image, remove color information from luminance information and color information of a pixel in the estimation region, and then transmit image data of a frame having pixels from which color information in the estimation region is removed to the image quality correction unit 220; to provide. Therefore, when the sum of the motion vectors of the frames is larger than the predetermined threshold, the color information of the frame input to the image quality correction unit 220 is reduced. Detailed description will be described later.

The selector 330 is one of the digital image signal 301 input to the video encoder in response to the control signal 307 or the color signals 373 and 375 having reduced color information output from the color information processor 390. Is selected and provided to the image quality correction unit 320. The control signal 307 may be activated when the sum of the motion vectors of the frames is greater than a predetermined threshold. Here, the control signal 307 may be input from the outside of the video encoder as shown in Figure 3, the color information processing unit 390 is based on the total sum of the motion vectors of the frame is greater than the predetermined threshold value It can be created to be activated in large cases.

The first selector 332 has a color signal CB or a reduced color information output from the color information processor 390 of the digital image signal 301 input to the video encoder in response to the control signal 307. One of the first color signals 373 is selected and provided to the second image quality correction unit 324. The second selector 334 includes a color signal CR or a reduced color information output from the color information processor 390 of the digital image signal 301 input to the video encoder in response to the control signal 307. One of the two color signals 375 is selected and provided to the third image quality correction unit 326. For example, the first selector 332 and the second selector 334 may be embodied as MUXs, respectively.

The luminance signal Y and the color signals CB and CR output from the selector 330 of the digital image signal are respectively converted into a first image quality corrector 322, a second image quality corrector 324, and a third image quality corrector 326. Through the oversampling unit 322a, 324a, and 326a, the sample is oversampled and noise components are removed from the low pass filters 322b, 324b, and 326b, thereby improving the image quality of the digital video signal. Here, the digital video signals 302, 304, and 306 passing through the image quality correction unit 320 are called second digital video signals.

A blank signal may be inserted into the digital image signals 302, 304, and 306 passing through the image quality correction unit 320, and a synchronization signal 311 may be inserted in the retrace period. The horizontal synchronization signal HSYNC may be inserted in the horizontal blanking period, and the vertical synchronization signal VSYNC may be inserted in the vertical blanking period. Equalizing pulses may be inserted before and after the vertical synchronization signal to synchronize the analog image signals. A serration pulse can be inserted within the period of the vertical synchronization signal. A burst signal may be inserted into the back porch of the horizontal retrace period of the digital video signal.

The modulated signal generator 340 generates a carrier wave for modulating a digital image signal having an improved image quality, for example, a luminance signal Y 302, a color signal CB 304, and a CR 306, to generate an analog image signal. Generate. Here, the modulated signal generator 240 stores the carrier-sine wave signal and the cosine wave signal sampled at a predetermined number of times in a memory in advance, and reads the sine wave sampling value and the cosine wave sampling value stored in the memory, and then stores the sine wave signal. 342 and a cosine wave signal 344.

The modulator 330 modulates the luminance signal Y 302, the color signal CB 304, and the CR 306 with improved image quality based on the synchronization signal 311, the blank signal 313, and the carrier waves 342 and 344. To generate a digital signal corresponding to the analog video signal.

The digital-to-analog converter 250 includes three digital-to-analog converters 352, 354, and 356 to digital-analog convert the digital signal output from the modulator 330 into an analog image signal 358. To convert. The analog image signal 358 may be provided to a TV receiver 130 or a projector such as a high definition television (HDTV), a plasma display panel (PDP) TV, a liquid crystal display (LCD) TV, or the like. have.

Hereinafter, the color information of the color signals CB and CR is based on the sum 371 of the motion vectors of the frame and the directional information 361 of the motion vector with respect to the center point of the predetermined image in the frame according to the embodiments of the present invention. The reduction method is explained in detail.

If the image of the previous frame is similar to the image of the current frame during decoding of the video compression codec, the sum of the motion vectors of the current frame is small. If the image of the previous frame and the image of the current frame are very different, the sum of the motion vectors of the current frame is different. Increases rapidly than the sum of the motion vectors of the previous frame. That is, in the case of a moving image having a very fast transition or movement between frames in a video screen, most of the motion vectors constituting the frame change, so the sum of the motion vectors of the frames increases rapidly.

In the video encoder according to an embodiment of the present invention, in the case of a video having a very fast scene change or movement between frames, power consumption of the video encoder is reduced by reducing color information of pixels of a frame input to the image quality compensator 320. Can be reduced.

In the video encoder according to an embodiment of the present invention, when the scene transition or movement between frames is very fast, the video encoder is input to the image quality compensation unit 320 according to a change rate according to time of the sum of the motion vectors of the frames. The number of pixels from which color information is removed among the pixels of the frame may be changed.

According to one embodiment of the invention, according to the sine values sinα1, sinα2 and sinα3 corresponding to the slope of the sum of the motion vectors of the frames at points A1, A2 and A3 in the graph representing the sum of the motion vectors of the frames of FIG. The number of pixels from which color information is removed among the pixels of the frame input to the image quality compensator 320 may be different from each other. For example, when the sine value sinα corresponding to the slope of the sum of the motion vectors of the frames is between sin 0 ° and sin 30 °, the frame input to the image quality compensator 320 is the first number of color information in the estimation region. When the sine value sinα is between sin 30 ° and sin 60 °, a second number of color information whose frame is input to the image quality compensator 320 is larger than the first number in the estimation region. When the sine value sinα is between sin 60 ° and sin 90 °, a third number of color information in which a frame input to the image quality compensator 320 is larger than the second number in the estimated area is included. May include pixels to be removed.

According to another embodiment of the present invention, the number of pixels from which color information in the estimated area of the frame input to the image quality compensator 320 may be adjusted based on the sum of the motion vectors of the frames. For example, in the graph showing the sum of the motion vectors of the frames of FIG. 5, the estimation of the frame input to the image quality compensator 320 depends on which section the sum of the motion vectors of the frames at points B1, B2, and B3 belongs to. The number of pixels from which color information included in an area is removed may be adjusted. For example, when the sum of the motion vectors of the frames at the points B1, B2, and B3 is between C2 and C3 (B1), color information including the estimated area of the frame input to the image quality compensator 320 is removed. If the number of pixels has a fourth number and is between C2 and C1 (B2), the number of pixels from which color information included in the estimated area of the frame input to the image quality compensator 320 is removed is the fourth number. When the number is less than C1 and less than C1 (B3), the number of pixels from which color information included in the estimated area of the frame input to the image quality compensator 320 is removed is less than the fifth number. Can have

6 is a conceptual diagram illustrating an image of one frame consisting of 8 pixels x 8 pixels before color information processing according to an embodiment of the present invention, and FIG. 7 is an image in one frame before color information processing according to an embodiment of the present invention. Is a conceptual diagram showing.

The luminance information 601 of the specific pixel in the frame of FIG. 6 has the luminance data value of the luminance signal Y of the digital image signal 301 of FIG. 3, and the color information 603 of the specific pixel in the frame of FIG. The color data values of the color signals CB and CR of the digital image signal 301 of FIG. 3 are obtained. When the sum of the motion vectors of the frame is smaller than a predetermined threshold, the image data having the luminance information and the color information of the pixels of the frame of FIG. 6 is provided to the image quality correction unit 320.

FIG. 7 illustrates only a 4 pixel × 4 pixel area 610 in the image of FIG. 6, when the sum of the motion vectors of the frame is smaller than a predetermined threshold, the image data of the pixels of the frame does not decrease color information. Is provided.

Hereinafter, a process of obtaining the directionality of a motion vector of a specific image in a frame when the sum of the motion vectors of the frame is larger than a predetermined threshold, and reducing the color information of the specific image of the frame based on the directionality of the motion vector, for example. Explain.

8 is a conceptual diagram illustrating edges and a center point of an image of a specific region in one frame according to an embodiment of the present invention, and FIG. 9 is a conceptual diagram illustrating a case in which an image of the specific region of FIG. 8 is moved in a predetermined direction.

Referring to FIG. 8, first, image data of one frame is input from a digital image processing apparatus such as a camera phone, a personal PC, or a PMP to detect an outline, that is, an edge, of a specific image in the frame. Edge detection can be obtained by various differential filters that are well known in the art. For example, a Sobel filter may be used to give an edge a more prominent weight at the edge detection so that the edge may be easily detected. A sharper edge may be obtained by passing the blurring filter before the Sobel filter is used. The edge detected through the Sobel filter can be divided into a plurality of stages according to the size. For example, by dividing the size of the edge into four stages can be weighted 0, 1, 2, 3 step by step.

After the edges E1, E2, E3, and E4 are detected by applying the edge detection method as described above, the center point C of the image surrounded by the edges is obtained. For example, the center point can be obtained by obtaining the center of gravity of the image surrounded by the edge.

After the center point C of the image surrounded by the edge is obtained and the center point of the image is moved along the direction of the motion vector M of FIG. 9 in the next frame (C-> C '), the motion of the center point of the image The direction of the vector can be seen as the movement direction of the image.

Accordingly, when the direction of the motion vector of the center point of the specific image is obtained as the movement direction of the specific image, the direction of motion of the pixel at the specific position in the specific image may be viewed as the direction of the motion vector of the center point of the specific image.

10 to 14 are conceptual views illustrating a process of reducing color information for pixels at a specific position of a specific image in a frame when the sum of the motion vectors of the frame is larger than a predetermined threshold.

All or part of the estimated region in the predetermined search region having a predetermined search distance with respect to the direction of the motion vector M11 of the center point of the specific image representing the movement direction of the pixel P11 at the specific position of the specific image in the frame. Color information is not removed for pixels. Here, the search distance may have a pixel unit, the search distance is 3 pixels in FIG. 11, the search distance is 2 pixels in FIG. 12, and the search distance is 1 pixel in FIGS. 13 and 14. Here, the search area indicates an area separated by the search distance with respect to pixels of a specific position of a specific image in a frame. The estimation area represents an area within a predetermined angular range around the direction of the motion vector in the search area. For example, in FIG. 11, the estimation region is within a predetermined angle range around the direction of the motion vector at 12 o'clock in the square search region 1110 having a search distance of 3 pixels about the pixel P11. The area indicated by the dotted line is shown.

Here, as shown in FIG. 10, color information may not be removed for all pixels in the estimation region, and some pixels in the estimation region (P22, P23, P31 of FIG. 11 or P42, P43 of FIG. , P51, or P61 of FIG. 14, the color information may be removed for the remaining pixels in the estimation region without removing the color information.

Alternatively, based on the sum of the motion vectors of the frames, the larger the sum of the motion vectors of the frame (or the slope of the sum of the motion vectors of the frame or the change rate of the sum of the motion vectors of the frame), the more the number of pixels from which the color information in the frame is removed. Can be increased.

Suppose the sum of the motion vectors of a frame (or the slope of the sum of the motion vectors of a frame or the rate of change of the sum of the motion vectors of a frame) has K1, K2, K3, K4 (where K1 <K2 <K3 <K4). 11 shows some pixels in the estimated region of the search region having a search distance of 3 pixels for a pixel at a specific position of a specific image region in the frame when the sum of the motion vectors of the frame has the largest value K4 ( The color information of the remaining pixels except for P22, P23, and P31) is removed, and FIG. 12 shows pixels for a specific position of a specific image area within a frame when the sum of the motion vectors of the frame has the second largest K3 value. FIG. 13 is a view illustrating removal of color information of pixels except for some pixels P32, P33, and P41 in the estimation area among the search areas having a search distance of 2 pixels. If the sum has a value of K3 which is the third largest, except pixels P42, P43, and P51 in the estimated area of the search area having a search distance of 1 pixel with respect to the pixel at a specific position of the specific image area in the frame. 14 illustrates a search region having a search distance of one pixel with respect to a pixel at a specific position of a specific image region in a frame when the sum of the motion vectors of the frame has the smallest value K1. The color information of the remaining pixels except for only one pixel P61 in the estimated region is removed.

12 to 14, the sum of the motion vectors of the frame decreases gradually from FIG. 12 to FIG. 14, and accordingly, from FIG. 12 to FIG. 14, the pixel is searched for a specific position of a specific image area in the frame. It can be seen that the number of pixels from which color information in the area is removed is reduced.

When the color information is removed by changing the search distance and the range of the search area for all the pixels of the image of the specific area in the frame, in FIG. 14, the number of pixels from which the color information in the frame is removed is the lowest. In case of 11, the number of pixels from which color information is removed in a frame is the largest.

FIG. 15 is a conceptual diagram illustrating a process of removing color information of all pixels of an image of a specific region in a frame. As shown in FIG. 15, color information is not removed for pixels in the shaded S2 area of the estimated area in the search area having a search distance of 3 pixels, and color information is applied to the pixels in the remaining area in the estimated area. Removed.

16 is a flowchart illustrating a video signal processing method according to an embodiment of the present invention.

Referring to FIG. 16, first, a sum of motion vectors for each frame of a digital image signal is calculated (step 1610), and it is determined whether the sum of motion vectors of a frame exceeds a predetermined threshold (step 1620). The determination of whether or not the sum of the motion vectors of the frames exceeds the reference value is performed by determining the slope of the sum of the motion vectors of the frames, the rate of change of the slope of the sum of the motion vectors of the frames, or the sum of the motion vectors of the frames. It can be determined as whether or not the threshold is exceeded. In addition, the predetermined threshold value may be a plurality of threshold values or a predetermined interval boundary value instead of one threshold value.

If the sum of the motion vectors of the frames exceeds the threshold, the color information of the pixels in the frames is reduced based on the direction of movement of the image of the predetermined region in the frame of the input digital video signal (step 1630). If the sum of the motion vectors of the frames does not exceed the threshold, the color information of the pixels in the frames of the input digital video signal is not reduced.

Image quality correction is performed by passing an oversampling and lowpass filter on the digital image signal having the color information reduced according to the sum of the motion vectors of the frame (step 1640).

The digital image signal having the corrected image quality is image-processed (step 1650). Here, the image processing is performed by reading a sine wave sampling value or cosine wave sampling value stored in a memory, for example, sampled at a predetermined number of times by a video encoder to generate a carrier, and correcting image quality using a synchronization signal, a blank signal, and a carrier wave. And modulating the digital video signal, and converting the modulated digital video signal into an analog video signal by digital-to-analog conversion. Alternatively, the image processing may include, for example, MPEG compression of the quality corrected digital image signal.

17 is a block diagram illustrating an image processing apparatus according to another exemplary embodiment of the present invention. Referring to FIG. 17, the image processing apparatus includes a color information processor 390, an image quality corrector 320, and an image processor 1700. The image processing apparatus of FIG. 17 illustrates an example in which the color information processing unit 390 of FIG. 3 is applied to an image processing apparatus including an image processing unit such as a general MPEG encoder.

Referring to FIG. 17, the image processor 1700 may include a buffer 1710, a serial-to-parallel converter 1720, a discrete cosine transform 1730, a quantizer 1740, A VLC encoder (Variable Length Code) 1750, a buffer 1760, an inverse quantizer 1770, and an inverse discrete cosine transformer 1780 are included. The image processing apparatus receives the digital image signals 302, 304, and 306 whose color information is adjusted based on the sum of the motion vectors of the frames, buffers them in the buffer 1710, and then converts the serial-to-parallel converter 1720 and discrete code. The compressed image data is output through the Sanin converter 1730, the quantizer 1740, the VLC encoder 1750, and the buffer 1760.

Since the structure of the MPEG encoder in the image processing apparatus of FIG. 17 has the structure of a conventionally known MPEG encoder, a detailed description thereof will be omitted. In addition to the configuration shown in Fig. 17, it may have another configuration of the conventional MPEG encoder.

Although FIG. 17 illustrates an example in which the color information processor 390 of FIG. 3 is applied to an image processing apparatus including an MPEG encoder, the luminance component Y and the color components CB and CR are input from digital image data of a moving image. Of course, if the image processing block to receive and process the color information processing unit 390 according to an embodiment of the present invention can be applied.

According to the video encoder, the image processing apparatus, and the image signal processing method as described above, when the sum of the motion vectors for each frame of the input digital image signal is larger than a predetermined threshold, the image of the predetermined region in the frame of the input digital image signal is Color information of the color signal in the digital image signal input to the image processor is reduced based on the movement direction. In particular, when there is a large change in the image between frames, the color information of the color signal in the digital image signal input to the image processor may be further reduced to reduce power consumption of the image processing apparatus.

 Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

Claims (17)

A synchronization signal controller for generating a synchronization signal for synchronizing the analog image signal; A color information processing unit for reducing color information of pixels in the frame based on a moving direction of an image of a predetermined region in a frame of an input first digital image signal when the sum of the motion vectors for each frame is larger than a predetermined threshold value; An image quality correction unit configured to generate a second digital image signal by correcting an image quality of one of a color signal of the first digital image signal and a color signal having the reduced color information and a luminance signal of the first digital image signal; And And a modulator for modulating the second digital video signal into a digital signal corresponding to the analog video signal based on the synchronization signal and the carrier wave. The apparatus of claim 1, wherein the color information processor is an estimated area in a predetermined search area having a predetermined search distance in the frame, wherein the estimated area is a predetermined angle around a direction of a motion vector of an image of the predetermined area in the frame. And removes color information for the remaining pixels in the given search region except for at least one pixel in the region. Claim 3 was abandoned when the setup registration fee was paid. Claim 4 was abandoned when the registration fee was paid. The video encoder of claim 1, wherein the color information processor increases the number of pixels from which the color information in the frame is removed as the slope of the sum of the motion vectors of the frame increases. Claim 5 was abandoned upon payment of a set-up fee. The video encoder of claim 1, wherein the color information processor increases the number of pixels from which the color information in the frame is removed as the rate of change of the sum of the motion vectors of the frame increases. The method of claim 1, wherein the color information processing unit A motion vector directionality detector for obtaining directionality of the motion vector of the predetermined image in the frame; Color information for reducing the color information of the pixels of the frame based on the direction of the motion vector of the predetermined image in the frame when the sum of the motion vectors of the frame is received and the sum of the motion vectors of the frame is greater than a predetermined threshold Extraction unit; And And a selector configured to select one of a color signal of the first digital video signal or a color signal having the reduced color information and provide the selected color signal to the image quality corrector in response to a control signal. Claim 7 was abandoned upon payment of a set-up fee. The video encoder of claim 1, further comprising a digital-to-analog converter configured to convert the modulated digital signal into an analog signal to generate the analog video signal. A color information processor for reducing color information of pixels in the frame based on a moving direction of an image of a predetermined region in a frame of the first digital video signal input when the sum of the motion vectors for each frame is larger than a predetermined threshold; An image quality correction unit configured to generate a second digital image signal by correcting an image quality of one of a color signal of the first digital image signal and a color signal having the reduced color information and a luminance signal of the first digital image signal; And And an image processor configured to image the second digital image signal. Claim 9 was abandoned upon payment of a set-up fee. The image processing apparatus of claim 8, wherein the image processing unit is an MPEG encoder that encodes the second digital image signal. Reducing the color information of the pixels in the frame based on a moving direction of the image of the predetermined region in the frame of the input first digital image signal when the sum of the motion vectors for each frame is larger than a predetermined threshold; Generating a second digital video signal by correcting an image quality of a luminance signal of the first digital video signal and a color signal having the reduced color information; And And image processing the second digital image signal. The method of claim 10, wherein the reducing of the color information comprises: an estimation area in a predetermined search area having a predetermined search distance in the frame, wherein the estimation area is centered on a direction of a motion vector of an image of a predetermined area in the frame. And removing color information for the remaining pixels in the predetermined search area except at least one pixel in the predetermined angle range. The image signal processing method of claim 10, wherein the reducing of the color information increases the number of pixels from which the color information in the frame is removed as the sum of the motion vectors of the frame increases. The method of claim 10, wherein the reducing of the color information increases the number of pixels from which the color information in the frame is removed as the slope of the sum of the motion vectors of the frame increases. The method of claim 10, wherein the reducing of the color information comprises increasing the number of pixels from which the color information in the frame is removed as the change rate of the sum of the motion vectors of the frame increases. The method of claim 10, wherein reducing the color information Obtaining a direction of a motion vector of a predetermined image in the frame; If the sum of the motion vectors of the frame is greater than a predetermined threshold, reducing the color information of the pixels of the frame based on the direction of the motion vector of the predetermined image in the frame; And And selecting one of a color signal of the first digital image signal or a color signal having the reduced color information in response to a control signal and providing the reduced color information as the reduced color information. Claim 16 was abandoned upon payment of a setup registration fee. The method of claim 10, wherein the processing of the second digital video signal comprises: Modulating the second digital video signal into a digital signal based on a synchronization signal and a carrier wave to synchronize an analog video signal; And And converting the modulated digital signal into an analog signal to generate an analog video signal. Claim 17 was abandoned upon payment of a registration fee. The method of claim 10, wherein the processing of the second digital video signal comprises MPEG encoding the second digital video signal.

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