KR101397045B1 - Apparatus and method for increase video quality by image condition - Google Patents

Abstract

The present invention relates to an apparatus and method for improving picture quality according to a picture state, which improves picture quality factors such as lightness, chroma, and sharpness in a direction in which the state of a TV image is determined and is most effective according to each state. The present invention relates to an image input apparatus, comprising: a video input selection unit for selecting a video input and receiving a selected video signal; An image demodulator for reconstructing a modulated image signal input from the image input selector; An image format processor for converting the image signal reconstructed by the image demodulator into an image format suitable for a resolution of a display and an image format for implementing a display image; An image quality processing unit for determining the frequency and the grayscale of the image and selectively adjusting the contrast, the chromaticity and the sharpness according to the size; An image quality synthesis unit for synthesizing the image adjusted by the image quality processing unit; A data format processor for converting the image synthesized by the image quality synthesizer into a displayable image format; And a display unit for displaying an image processed by the data format processing unit on a screen.

TV, video, contrast, chroma, sharpness, picture quality, improvement, resolution, frequency, gradation

Description

[0001] The present invention relates to an apparatus and method for enhancing image quality according to a video state,

The present invention relates to an apparatus and method for improving image quality, and more particularly, to an apparatus and method for improving image quality according to a video state in which each image quality element is improved by determining a state of a TV image and optimized in accordance with each state .

The present invention relates to an image quality improving apparatus and method, and more particularly, to a system and method for improving image quality by determining a state of a TV image and improving an image quality by an optimized method according to each state, , Chromaticity, histogram, and the like, thereby improving image quality factors such as lightness, chroma, and sharpness in a direction in which the most effective is obtained.

Generally, a display device refers to visual display of data in the form of characters or graphics on a cathode ray tube (CRT) surface, and representative examples thereof include a CRT, a memory type display, a liquid crystal, a light emitting diode, and a projection.

2. Description of the Related Art In recent years, an image quality improvement device has been applied to a display device in order to provide a clearer image quality in accordance with a user's demand.

1 is a block diagram showing a conventional image quality improving apparatus.

As shown in the figure, a conventional image quality improvement apparatus includes a video input selection unit 10, an image demodulation unit 20, an image format processing unit 30, an image quality processing unit 40, a lightness processing unit 41, a chromaticity processing unit 42, A sharpness processing unit 43, a data format processing unit 50, and a display unit 60. [

First, an image input is selected by the image input selection unit 10, and the image signal modulated by the image demodulation unit 20 is restored. The image format processing unit 30 converts the image format into an image format suitable for a display resolution and a scanning method to implement a basic display original image.

Next, the image quality processing unit 40 performs image quality processing. This is not an image processing standard or a standard, but may be slightly different for each TV because it is a task of decorating the image desired by the consumer for a specific purpose. As shown in the figure, in general, the lightness processing unit 41 processes lightness, the chromaticity processing unit 42 processes chromaticity, and the sharpness processing unit 43 processes sharpness.

The image-processed image is converted into a displayable image format in the data format processing unit 50, and is displayed on the screen through the display unit 60.

However, whichever processing method is used, the same processing is applied to the entire screen, so that the same effect is given irrespective of the frequency, color, and level state of the pixel. Therefore, in certain cases, some adverse effects may occur.

For example, in the case of light and dark, it is desirable to improve the discrimination power if the region is high frequency in a low gradation. Therefore, the sharpness should be improved, and if the region is low frequency, the contrast ratio of the whole should be increased to raise the slope of the contrast curve. However, this information needs to determine the frequency, but the histogram that grasps the distribution of the general level does not know the information about the region or the frequency, so that when the contrast curve is raised, the low gradation discrimination power is lost. On the contrary, if the sharpness is raised to utilize the low gradation discrimination power, the overall contrast is lowered and the contrast of the screen is lowered.

In the case of sharpness, if the entire screen is applied in a lump, the sharpness of the data in the high frequency range is improved, but the side effect of amplifying the noise is generated in the low frequency range.

Thus, in the conventional picture quality improvement apparatus, since any picture quality processing such as resolution, contrast, color density, and sharpness of the input signal is applied to the whole of the TV screen in a batch manner, There is a problem that the degree of effect varies with each other.

SUMMARY OF THE INVENTION The present invention has been made to overcome the above-described problems of the related art, and it is an object of the present invention to provide an image quality enhancement method, And an object of the present invention is to provide an improvement apparatus and method.

According to an aspect of the present invention, there is provided an apparatus for enhancing image quality according to a video state, including: a video input selector for selecting a video input and receiving a selected video signal; An image demodulator for reconstructing a modulated image signal input from the image input selector; An image format processor for converting the image signal reconstructed by the image demodulator into an image format suitable for a resolution of a display and an image format for implementing a display image; An image quality processing unit for determining the frequency and the grayscale of the image and selectively adjusting the contrast, the chromaticity and the sharpness according to the size; An image quality synthesis unit for synthesizing the image adjusted by the image quality processing unit; A data format processor for converting the image synthesized by the image quality synthesizer into a displayable image format; And a display unit for displaying an image processed by the data format processing unit on a screen.

Wherein the image quality processing unit comprises: a video division unit for dividing an image region using a frame memory; A gradation determination unit for determining a gradation of the image; A frequency determination unit for determining a frequency of the image using a line memory; A brightness / darkness processing unit for enhancing a brightness / darkness-separating power for high-frequency and low-tone images according to the determination of the frequency determining unit and the tone determining unit, A chroma processor for enhancing the chrominance of the green color in the case of a high frequency image, enhancing the chrominance of the blue color in the case of a low frequency image, and enhancing the color of the skin color in the case of a low frequency image; And a sharpness processor for enhancing the sharpness of the high frequency image and the low grayscale image according to the determination of the frequency determination unit and the grayscale determination unit and for enhancing the edge component of the mid-frequency image.

It is preferable that the sharpness processing unit exclude the skin color series image when the edge component is enhanced with respect to the mid-frequency image.

According to another aspect of the present invention, there is provided an image quality improvement method according to a video state, including: a video input selection step of selecting a video input and receiving a selected video signal; An image demodulating step of reconstructing the modulated image signal received in the image input selecting step; An image format processing step of converting the image signal reconstructed in the image reconstruction step into an image format suitable for a resolution of a display and an image format for implementing a display image; An image quality processing step of determining frequency and gradation of the image, and selectively adjusting contrast, chroma, and sharpness according to the frequency and gradation of the image; An image quality synthesis step of synthesizing the image adjusted in the image quality processing step; A data format processing step of converting the image synthesized in the image quality synthesis step into a displayable image format; And a display step of displaying the image processed in the data format processing step on the screen.

According to the image quality improvement apparatus and method according to the present invention, the state of the TV image is determined in terms of each element of image quality, for example, frequency, signal level, chrominance, histogram, The image quality factors such as contrast, color, sharpness and the like are improved.

In addition, according to the present invention, since the image quality of the TV image can be changed according to the resolution of the input signal and the state of the image (image object area, gradation, frequency, etc.), it is possible to improve the image quality more intelligently and effectively, If the resolution of the input image is smaller than the display resolution, power consumption of the display can be reduced without changing the input resolution.

In addition, the chromaticity processing of the present invention determines whether or not the preferred color processing is applied to the frequency or gradation, and thus the determination of the preferred color application object can be made more accurately.

In addition, according to the present invention, the processing result of the brightness and darkness of the image is reflected to the preferential color processing in the contrast and the preferred color processing result in the processing of the sharpness. Thus, the conventional three kinds of processing can be applied to various side effects Etc.) and to improve edge and high frequency discrimination power effectively.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

It is to be understood that the words or words used in the present specification and claims are not to be construed in a conventional or dictionary sense and that the inventor can properly define the concept of a term in order to describe its invention in the best possible way And should be construed in light of the meanings and concepts consistent with the technical idea of the present invention. Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

FIG. 2 is a block diagram illustrating an image quality improvement apparatus according to an embodiment of the present invention. Referring to FIG.

As shown in the figure, the present invention includes an image input selection unit 100, an image demodulation unit 200, an image format processing unit 300, an image quality processing unit 400, a lightness processing unit 410, a chromaticity processing unit 420, A frame memory 450, a gradation determination unit 460, a frequency determination unit 470, a line memory 480, a resolution determination unit 490, an image quality synthesis unit 500, A data format processing unit 600, and a display unit 700.

The video input selection unit 100 selects a video input and receives a selected video signal.

The image demodulator 200 reconstructs the modulated image signal received from the image input selector 100.

The image format processing unit 300 converts the image signal reconstructed by the image demodulation unit 200 into an image format suitable for a resolution of a display and a scanning method to implement a display image.

The image quality processing unit 400 determines the frequency and the grayscale of the image, and selectively adjusts the contrast, chroma, and sharpness according to the determined frequency and grayscale.

The image quality synthesis unit (500) synthesizes the adjusted image in the image quality processing unit (400).

The data format processing unit 600 converts the image synthesized by the image quality synthesis unit 500 into a displayable image format.

The display unit 700 displays the image processed by the data format processing unit 600 on the screen.

The image quality processor 400 includes a lightness processor 410, a chroma processor 420, a sharpness processor 430, an image divider 440, a frame memory 450, a gradation determiner 460, A line memory 480, and a resolution determination unit 490. The resolution memory unit 470 includes a line memory 480,

The image divider 440 divides the image area using the frame memory 450.

The gradation determination unit 460 determines the gradation of the image.

The frequency determination unit 470 uses the line memory 480 to determine the frequency of the image.

The resolution determination unit 490 determines the resolution of the image.

The brightness / darkness processing unit 410 enhances the brightness / darkness separating power for images of high frequency and low tone levels according to the determination of the frequency determiner 470 and the tone determining unit 460, . In addition, for the high-frequency coarse treble or the medium-frequency treble, the shadows are selectively processed according to the area divided by the image divider 440.

The chroma processor 420 enhances the chrominance of the green color in the case of the high frequency image, the chrominance of the blue color in the case of the mid-frequency image, and the color of the skin color in the case of the low frequency image according to the determination of the frequency determination unit 470.

The sharpness processor 430 enhances the sharpness of the high-frequency and low-tone images and enhances the edge components of the mid-frequency images according to the determination of the frequency determiner 470 and the tone determiner 460. At this time, it is preferable to exclude the red series, that is, the skin color image. In addition, the low-frequency image is not subjected to sharpness processing.

The functions of the present invention are summarized in the following Table 1.

Contrast

Chromaticity
definition
High frequency
Low gradation (bright): Enhancement of discrimination
High gradation: Region classification by image segmentation
Green
Low Gradation: Enhanced
Medium frequency


Area segmentation by image segmentation
Blue system strengthening
Enhancement for edge components (except skin)
Low frequency


Low gradation (dark): Low level
Reinforced red (skin color)
Do not process

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

A preferred color processing unit 830, a chromaticity analysis unit 840, a preferred color application area detection unit 850, and a preferred color application area detection unit 850. The edge detection unit 800, the sharpness applied area detection unit 810, the sharpness processing unit 820, . Here, the image format processor 300 and the image quality synthesizer 500 are as described with reference to FIG.

As shown in the figure, the edge detecting unit 800 detects an edge portion from the image output from the image format processing unit 300, and detects a sharpness applying region through the sharpness applying region detecting unit 810. The sharpness processing unit 820 enhances the sharpness of only the edge portion with respect to the region detected by the sharpness applying region detecting unit 810. [

The preferred color application area detecting unit 850 detects an area excluding the edge area detected by the sharpness applying area detecting unit 810,

The preferred color processing unit 830 processes the preferred color for the area detected by the sharpness applied area detecting unit 810. [

As described above, in applying the sharpness (sharpness) according to the present invention, edge portions are detected and the sharpness is applied only to edge enhancement, and is not applied to the change in chromaticity. Because the edge part is noticeable by enhancing the sharpness, but the chromaticity change can result in an awkward result when applied to the edge part.

In the example of FIG. 3, only the monochrome image data is used to detect the edge, but the color image data may be used for more accurate detection. Here, a method of extracting the preferred color processing region with the sharpness processing region information is described.

FIGS. 4A to 4D are graphs showing changes in the level of application of sharpness according to the present invention. FIG. 4A to FIG. 4D show a method for varying the applicability and level for improving image quality according to various image states in the present invention.

For example, in terms of sharpness, application is classified according to the following image states.

As shown in FIG. 4A, the degree of improvement of the slope of the signal with respect to the luminance and chrominance signals Y and C can be changed according to the vertical and horizontal frequency bands of the image.

Also, as shown in FIG. 4B, the gain amplification of the image can be changed with respect to the luminance and chrominance signals Y and C by the vertical and horizontal frequency bands of the image.

Also, as shown in FIG. 4C, the gradient improvement and the gain amplification can be commonly changed for the luminance and chrominance signals Y and C according to the intermediate level value of the edge.

Also, as shown in FIG. 4D, the gradient improvement and the gain amplification can be commonly changed for the luminance and chrominance signals according to the difference between the starting point and the ending point of the edge.

FIGS. 5A through 5C are graphs showing changes in the level of the preferred color process according to the image frequency according to the present invention.

As a preferred color, since the frequencies of the skin color (red series), sky / sea color (blue series), and grass color (green series) are different from each other, It is possible to know whether it is another object or not.

That is, since the face of the red system is a low frequency signal, and the blue sea and the sky are medium frequency and the green system grass is a high frequency, it is possible to determine whether or not to apply the frequency range to the desired color .

Otherwise, like sand, it is high frequency, but it is similar to face / skin color, so images sometimes have unnatural changes in color due to the preferential color processing of the face.

6A to 6D are diagrams showing an edge tilt improvement degree and a sharpness applying state according to an input image resolution according to the present invention.

As shown in FIG. 6A, adjustment can be made to enhance the rising or falling slope of the edge of the luminance and chrominance signals according to the resolution of the input image. This is called Luminance Transient Improvement (LTI) and Chrominance Transient Improvement (CTI), respectively. The lower the input resolution, the larger the scaling ratio is to match the display resolution in the image format processing unit 300 of FIG. 2 , The influence of the edges of luminance and chromaticity is increased. In other words, if the SD input is input to the Full-HD display, the edge will be collapsed a lot and the tilt compensation must be increased. In this example, the display resolution is Full-HD based on SD (640x480, 704x480, 720x576), HD (1280x720) and Full-HD (1920x1080) inputs.

6B to 6D, when the input resolution is smaller than the display resolution, the image format processor 300 does not convert (enlarge) the resolution of the input signal according to the display resolution in order to prevent image deterioration due to format conversion , It is preferable to display the original input resolution in SD, HD, or Full-HD as it is.

In this way, the screen size is reduced, but the resolution can be maintained at the original resolution, and the size of the screen used in a self-luminous display such as a PDP is reduced, thereby saving power consumption.

7 is a control flowchart illustrating an image quality improvement method according to a video state according to the present invention.

As shown in the figure, the present invention is characterized in that the present invention comprises the steps of selecting an image input step S100, an image demodulating step S200, an image format processing step S300, an image quality processing step S400, an image quality combining step S500, S600), and a display step S700.

The image input selecting step S100 selects an image input and receives a selected image signal.

The image demodulating step S200 reconstructs the modulated image signal received in the image input selecting step S100.

In the image format processing step S300, the image signal reconstructed in the image demodulating step S200 is converted into an image format suitable for the resolution of the display and the scanning method to implement a display image.

In the image quality processing step S400, the frequency and gradation of the image are determined, and the contrast, chromaticity, and sharpness are selectively adjusted according to the determined frequency and gradation.

The picture quality synthesis step (S500) synthesizes the adjusted picture in the picture quality processing step (S400).

The data format processing step S600 converts the image synthesized in the image quality synthesizing step S500 into a displayable image format.

The display step S700 displays the image processed in the data format processing step S600 on the screen.

The image quality processing step S400 includes an image segmentation step S410, a gradation determination step S420, a frequency determination step S430, a darkness processing step S440, a chromaticity processing step S450, S460).

In the image segmentation step S410, the image area is divided using the frame memory 450.

The gradation determination step (S420) determines the gradation of the image.

The frequency determination step S430 uses the line memory 480 to determine the frequency of the image.

In the contrast processing step S440, the contrast discrimination power is enhanced for high frequency and low gradation images in accordance with the determination of the frequency determination step S430 and the gradation determination step S420, Decrease the level. In addition, for the high-frequency coarse treble or the medium-frequency trellis, the shadows are selectively processed in accordance with the divided regions in the image segmenting step S410.

The chroma processing step S450 enhances the chrominance of the green system in the case of the high frequency image, the chrominance of the blue system in the case of the medium frequency image, and the chrominance system chromaticity in the case of the low frequency image, .

The sharpness processing step S460 enhances the sharpness of the high-frequency and low-tone images and enhances the edge components of the mid-frequency images according to the determination of the frequency determining step S430 and the tone determining step S420. At this time, it is preferable to exclude the red series, that is, the skin color image. In addition, the low-frequency image is not subjected to sharpness processing.

As described above, in order to perform the brightness and darkness processing of the image according to the present invention, a frame memory 450 is used to divide a video object and classify gradation and frequency band thereof. Here, the result of the contrast processing of the image is reflected in the preferred color processing, and the result of the contrast and preferred color processing is reflected in the improvement of the sharpness. This is because the result of the improvement of the contrast may affect the improvement of the preferred color. For example, in the high-frequency region of low gradation, the image distinguishing power is important. Therefore, even if the region enters the preferred color region, There is no need to change.

Likewise, the improvement result of the contrast affects the improvement of the sharpness. In the case where the contrast processor 410 is strengthened, the sharpness need not be further strengthened, but only the supplementary line is needed.

In addition, the result of processing the preference color in the chromaticity processor 420 also affects the sharpness processor 430. For example, in a region processed in the skin color, it is not necessary to improve the inclination or gain of the contour line, . This is because the facial part is more important than the need for emphasis, so emphasizing the contour will result in a more unnatural case.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible. Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

1 is a block diagram showing a conventional picture quality improving apparatus.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

3 is a block diagram showing another embodiment of an image quality improvement apparatus according to a video state according to the present invention.

4A to 4D are graphs showing changes in the level of application of sharpness according to the present invention.

5A to 5C are graphs showing changes in level of the preferred color process according to the image frequency according to the present invention.

6A to 6D are diagrams illustrating an edge tilt improvement degree and a sharpness applying state according to an input image resolution according to the present invention.

7 is a control flowchart illustrating a method for improving image quality according to a video state according to the present invention.

Description of the Related Art

100: Image input selection unit 200:

300: image format processing unit 400: image quality processing unit

410: Brightness processing section 420:

430: sharpness processing unit 440:

450: Frame memory 460:

470: Frequency determination unit 480: Line memory

490: resolution discrimination unit 500: image quality synthesis unit

600: Data format processing unit 700:

Claims (6)

A video input selector for receiving a selected video signal; An image demodulator for reconstructing a video signal received from the image input selector; An image format processor for converting the image signal reconstructed by the image demodulator into an image format suitable for a resolution of a display and an image format for implementing a display image; An image quality processing unit for determining a frequency and a gray level of the image to be implemented and adjusting at least one of brightness, chroma and sharpness according to the size; An image quality synthesis unit for synthesizing the image adjusted by the image quality processing unit; A data format processing unit for converting the image synthesized by the image quality synthesizing unit back into an image format suitable for a display resolution and a scanning method; And And a display unit for displaying an image processed by the data format processing unit on a screen. The method according to claim 1, The image quality processing unit, An image divider for dividing an image area using a frame memory; A gradation determination unit for determining a gradation of the image; A frequency determination unit for determining a frequency of the image using a line memory; A brightness / darkness processing unit for enhancing a brightness / darkness-separating power for high-frequency and low-tone images according to the determination of the frequency determining unit and the tone determining unit, A chroma processor for enhancing the chrominance of the green color in the case of a high frequency image, enhancing the chrominance of the blue color in the case of a low frequency image, and enhancing the color of the skin color in the case of a low frequency image; And And a sharpness processing unit for enhancing the sharpness of the high frequency and low gradation images according to the determination of the frequency determination unit and the gradation determination unit and for enhancing the edge components of the mid-frequency image with respect to the image quality. Device. 3. The method of claim 2, The sharpness processing unit And the skin color series image is excluded when the edge component is enhanced with respect to the mid-frequency image. A video input selecting step of receiving a selected video signal; An image demodulating step of restoring a video signal received in the video input selecting step; An image format processing step of converting the image signal reconstructed in the image reconstruction step into an image format suitable for a resolution of a display and an image format for implementing a display image; Determining a frequency and a gray level of the image, and adjusting at least one of brightness, chrominance, and sharpness according to the magnitude; An image quality synthesis step of synthesizing the image adjusted in the image quality processing step; A data format processing step of converting the image synthesized in the image quality synthesis step into an image format suitable for a display resolution and a scanning method; And And a display step of displaying the image processed in the data format processing step on a screen. 5. The method of claim 4, Wherein the image quality processing step comprises: An image dividing step of dividing an image area using a frame memory; A gradation determination step of determining a gradation of the image; A frequency determining step of determining a frequency of the image using a line memory; A brightness / darkness processing step of enhancing a brightness / darkness separating power for high-frequency and low-gradation images according to the determination of the frequency determining step and the gradation determining step, and reducing a light / dark level for low- and low-gradation images; A chroma processing step for enhancing the chrominance of the green system in the case of a high frequency image, enhancing the chrominance in the blue system in the case of a mid-frequency image, and enhancing the chrominance system in the case of a low frequency image; And And a sharpness processing step of enhancing the sharpness of the high-frequency and low-gradation images in accordance with the determination of the frequency determining step and the gradation determining step, and strengthening the edge components of the mid-frequency images with respect to the edge components. Improving image quality. 6. The method of claim 5, Wherein the sharpness processing step comprises: And the skin color series image is excluded when the edge component is enhanced with respect to the mid-frequency image.

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