KR19980054954A - Contour emphasis processing device of video signal - Google Patents

Abstract

The present invention relates to an apparatus for enhancing contour of a video signal, comprising: a luminance / color signal separation unit (10) for separating a luminance signal component and a color signal component from a video signal, and digital conversion of the luminance signal component in synchronization with a predetermined clock signal. A data conversion section 12, a memory 14 in which the digitally converted luminance data is written, and an abrupt portion of the luminance signal from the luminance data is extracted as an edge, and the slope of the edge is bounded at the edge portion. On the basis of this, the contour emphasis processing section 16 for generating contour enhancement data by subtracting / adding the preceding / following luminance data is provided.

Description

Contour emphasis processing device of video signal

The present invention relates to a contour enhancement processing apparatus for a video signal. More particularly, the present invention relates to an edge enhancement processing apparatus for digitally converting luminance components of a video signal to detect edges depicting contours of the image from the digital luminance data. An apparatus for enhancing contour of an image signal to be subjected to emphasis processing for an image.

As is well known, in the case of a television, a projector, or the like represented as an image processing system for reproducing and outputting a video signal, the sharpness of an image signal displayed on a CRT device or a screen, for example, is reduced on the screen. The boundary (i.e., outline) of the video signal is blurred, resulting in deterioration of image quality.

According to such an image system, in the case of a television, an image processing means (i.e., a chroma IC) is used for the luminance / color signal component from an image signal from a tuner or from an external image signal (e.g., from a video tape reproduced by a video tape recorder). The R / G / B color component of the image signal is obtained and the R / G / B color component is applied to display on the CRT apparatus.

In the case of the projector, the light emitted from the light source is modulated based on the color components of the image signal by an optical modulation means consisting of an LCD (Liquid Crystal Display) panel or an Actuated mirror array (AMA), and is then displayed on the screen through the projection lens. It will work by projecting on the screen.

Here, when the image signal processed by the television or the projector has a high image quality on the CRT apparatus or the screen when the sharpness of the edge portion depicting the contour is high, the image quality of the image signal is improved. When color components are processed in a state of mutual influence between adjacent pixels and displayed on a CRT device or a screen, the description of the contour portion is uncertain and the image quality is deteriorated. In view of this, the image processing system is usually provided with a function for adjusting the sharpness (Sharpness).

However, according to the sharpness adjustment function provided to the image processing system, although the sharpness is expected to be increased to some extent with respect to the contour portion of the image signal, the description of the contour portion of the original image signal processed by the image processing system is uncertain. The sharpness adjustment function also causes a limitation in the sharpness adjustment of the video signal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and separates a luminance / color signal component from a video signal, detects an edge depicting the outline of the image by the brightness signal, and then horizontally (left / right direction) with the edge portion as a boundary. It is an object of the present invention to provide a contour enhancement processing apparatus for an image signal in which the image quality is improved by performing contour enhancement processing by subtracting / adding the luminance data of the preceding and following by a predetermined amount.

In order to achieve the above object, according to a preferred embodiment of the present invention, luminance / color signal separation means for separating the luminance signal component and the color signal component from the video signal, and digitally converting the luminance signal component in synchronization with a predetermined clock signal. Data conversion means, memory means for recording the digitally converted luminance data, and extracting a sharp portion of the luminance change from the luminance data as an edge and subtracting a predetermined amount of the preceding and subsequent luminance data in the horizontal direction with the edge portion as a boundary. There is provided an outline emphasis processing apparatus for a video signal, which is equipped with outline emphasis processing means for generating / adding processing to generate outline emphasis data.

Preferably, the contour emphasis processing means includes a first latch and a buffer in which the luminance data for edge detection are temporarily stored in a forward / rear relation, a delay unit for delaying the luminance data following from the first latch, and the buffer. A second latch into which the preceding luminance data is temporarily stored, a complement processing unit which takes the complement of the Nth luminance data of the second latch, and the complement of the preceding luminance data and the preceding luminance data delayed by the delay unit; An adder, a shifter for undifferentiating the addition result of the adder, a comparator for generating a positive / subdivision signal of a slope by comparing the addition result applied through the shifter with a reference slope, and a count start signal of the digital conversion clock signal. An address generator for counting and generating an address signal in response to the The previous luminance data is added or subtracted by a predetermined amount from the original value and the subsequent luminance data is added or subtracted by a predetermined amount from the original value to generate contour correction data and a recording signal to the memory means. And an address latch / contour correction data generator for generating an address signal of the contour emphasis data.

According to the contour emphasis processing apparatus for a video signal according to the present invention having the above-described configuration, when the brightness signal is separated from the video signal by the brightness / color signal separation means and digitally converted by the data conversion means, the amount of change in brightness in the digitally converted brightness data is obtained. The sharp part is extracted as an edge, and the leading part is added or subtracted by a certain amount in the horizontal direction according to the slope discrimination signal from the comparator, and the subsequent intensity data is added or subtracted by a certain amount in the horizontal direction to emphasize the outline Will be done.

1 is a block diagram of a contour signal processing apparatus of an image signal according to a preferred embodiment of the present invention;

2 is a block diagram showing the configuration of the contour emphasis processing unit shown in FIG. 1;

3 is a schematic diagram for explaining the principle of contour emphasis processing by the contour emphasis processing apparatus for an image signal according to the present invention;

4 is a view for explaining an outline enhancement process performed by the outline emphasis processing apparatus for an image signal according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: luminance / color signal separation unit, 12: data conversion unit,

14: memory, 16: contour emphasis processing,

20: first latch, 22: buffer,

26: the second latch, 28: the maintenance processing unit,

30: adder, 32: shifter,

34: reference slope setting unit, 36: comparator,

38: address generator,

40: Address latch / contour correction data generator.

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

1 is a block diagram of an apparatus for enhancing contour of a video signal according to a preferred embodiment of the present invention.

In the figure, reference numeral 10 denotes a luminance / color signal separator for separating the luminance signal component Y and the color signal component C from the image signal CV, and 12 denotes a separation in the luminance / color signal separator 10. A data conversion section composed of an analog-to-digital converter ADC for digitally converting the luminance signal component Y in synchronization with a predetermined clock signal CLK to output digital luminance data YD.

14 denotes a memory in which the digitally-converted luminance data YD is contour-emphasized and recorded, and 16 denotes an edge portion of the luminance variation YD from the data converter 12 that is abruptly changed in luminance. Extract and add / subtract a predetermined amount of the preceding luminance data and the following luminance data in the horizontal direction with the edge portion as a boundary to generate contour correction data for emphasizing the outline of the edge, and the contour correction data is stored in the memory ( 14 shows an outline emphasis processing section for updating and updating based on the write control signal WE 'and the address signal AD.

FIG. 2 is a block diagram showing an example of the configuration of the outline emphasis processing section 16 shown in FIG. 1, and reference numeral 20 denotes a trailing luminance data for edge detection among the luminance data from the data conversion section 12 (for example, FIG. , The first latch at which the (N + 1) th luminance data) is temporarily stored, and 22 denotes the first latch at the time when the (N + 1) th pixel data is latched to the first latch 20. A buffer is output after the previous luminance data (e.g., the Nth luminance data) is buffered from 20, and 24 is the (N + 1) th output after being temporarily stored in the first latch 20. A delay unit which delays luminance data by a predetermined time for timing matching of signal processing.

26 denotes a second latch 26 in which the N-th luminance data buffered in the buffer 22 and then output is temporarily stored, and 28 denotes a complementary process of the N-th luminance data of the second latch 26 ( That is, the complementation means the result of the subtraction process), and 30 denotes the complement of the (N + 1) th luminance data and the Nth luminance data delayed by the delay unit 24. The adder is shown.

Further, 32 denotes a shifter for shifting the addition result of the adder 30 (that is, the shift means the result of the differential processing), and 34 denotes a reference for detecting the slope from the shift result from the shifter 32. The setting unit in which the slope is set. Reference numeral 36 denotes a comparator for generating a positive (+) / negative (−) discrimination signal of the slope by comparing the shift result from the shifter 32 with the reference slope from the reference value setting section 34. That is, the comparator 36 compares the reference slope and the differential result based on the equation of Y2-Y1 / T2-T1 ≥ X (tilt) in the interval T1, T2 of FIG. In this case, a positive slope discrimination signal is output, whereas when the differential result is smaller than the reference slope, a negative slope discrimination signal is output.

38 denotes an address generator which counts the clock signal CLK in response to the count start signal from the control means (microcom), for example, and generates an address signal, and 40 denotes an inclination discrimination signal from the comparator 36. By adding or subtracting the Nth luminance data (ie, the preceding luminance data in the horizontal direction about the edge portion) from the original value by a predetermined amount from the original value, and the (N + 1) th luminance data (ie, the edge portion). To add or subtract a horizontal amount of trailing luminance data from the original value by a predetermined amount to generate contour correction data and to generate a write signal WE 'and an address signal AD for the memory 14. And an address latch / contour correction data generator.

Next, the operation of the contour emphasis processing apparatus for a video signal having the above-described configuration will be described in detail with reference to FIGS. 3 and 4.

First, the image signal CV is applied to the luminance / color signal separator 10 to be separated into a luminance signal component Y and a color signal component C so that the luminance signal component Y is converted into the data converter 12. The data converter 12 outputs the luminance data YD obtained by digitally converting the luminance signal component Y based on the clock signal CLK. The digital luminance data YD is then output. To be written to the memory 14.

The digital luminance data YD is also applied to the contour emphasis processing section 16, and the first latch 20 of the contour emphasis processing section 16 is configured to detect contours of the luminance data YD. The (N + 1) -th luminance data is latched, and the N-th luminance data latched prior to the first latch 20 is buffered in the buffer 22.

Subsequently, the (N + 1) th luminance data latched in the first latch 20 is applied to the delay unit 24 to be delayed for a predetermined time for timing matching with respect to the processing of the luminance data, and then the adder. And the Nth luminance data buffered in the buffer 22 is output to the second latch 26, latched, and then applied to the maintenance processing unit 28. The processor 28 performs a maintenance process (ie, a subtraction process) on the Nth luminance data and applies it to the adder 30.

Therefore, the adder 30 adds the (N + 1) th luminance data which is delayed for a predetermined time by the delay unit 24 and the Nth luminance data which have been processed.

The addition result of the adder 30 is shifted in the shifter 32 to obtain a differential processing effect and then applied to the comparator 36. The comparator 36 is provided in the reference gradient setting unit 34. The differential result of the luminance data from the shifter 32 is compared based on the reference slope, and the gradient discrimination signal ('+' or '-'; see FIG. 4) is compared with the address latch / contour correction data. It is applied to the generator 40.

The address generator 38 counts the clock signal CLK based on the count start signal to generate an address signal, and the address signal is applied to the address latch / contour correction data generator 40.

Therefore, the address latch / contour correction data generator 40 generates contour correction data according to the comparison result of the comparator 36 in the latched state of the address signal. That is, when the comparison result of the comparator 36 is '+', the address latch / contour correction data generator 40 sets the Nth luminance data at a constant level from the original value with the edge portion of the video signal as a boundary. On the other hand, for the (N + 1) th luminance data, a constant level is added to the original value to emphasize the upward contour. On the other hand, when the comparison result of the comparator 36 is '-', the address latch / contour correction data generator 40 sets the Nth luminance data constant from the original value with the edge portion of the video signal as a boundary. While the level is added, the (N + 1) th luminance data is subtracted by a certain level from the original value to emphasize the downward contour.

When such contour emphasis data is generated, the address latch / contour correction data generator 40 enables the address signal for the portion determined to be the edge and contours corresponding to the preceding address signal AD and the address signal. The correction data DA and subsequent address signals AD and contour correction data corresponding to the address signals are sequentially applied to the memory 14 by the write control signal WE 'to be updated and stored.

Therefore, from the memory 14, the image data in which the outline of the edge portion is emphasized can be accessed.

As described above, according to the contour emphasis processing apparatus for a video signal according to the present invention, a predetermined amount of subtraction and addition processing is performed on the screen by performing a predetermined amount of subtraction and addition processing on the preceding luminance data and the subsequent luminance data around the edge of the edge portion. The sharpness of the displayed image can be significantly improved.

Claims (3)

Luminance / color signal separation means (10) for separating luminance signal components and color signal components from video signals, data conversion means (12) for digitally converting the luminance signal components in synchronization with a predetermined clock signal, and the digitally converted luminance data. A memory section 14 in which the data is recorded and a portion in which the change of the luminance signal is abrupt from the luminance data is extracted as an edge and subtracted / added the preceding / following luminance data based on the slope of the edge with respect to the edge portion; Contour emphasis processing apparatus for an image signal, characterized by comprising a contour emphasis processing means (16) for generating contour emphasis data. 2. The contour emphasis processing means (16) according to claim 1, wherein the contour emphasis processing means (16) is configured to buffer the first latch (20) in which trailing luminance data for the edge detection is temporarily stored and the previous luminance data from the first latch (20). A buffer 22, a delay unit 24 for delaying the trailing luminance data from the first latch 20, a second latch 26 for temporarily storing the preceding luminance data from the buffer 22, A maintenance processing unit 28 that takes the complement of the preceding luminance data of the second latch 26, and an adder 30 that adds the complement of the preceding luminance data delayed by the delay unit 24 and the preceding luminance data. A shifter 32 for differentiating the addition result of the adder 30, a comparator 36 for generating a slope discrimination signal by comparing the derivative result with a reference slope, and counting the digital conversion clock signal in response to the count start signal. To generate an address signal An address latch for generating contour correction data by adding or subtracting the preceding luminance data by a predetermined amount and adding or subtracting the subsequent luminance data by a predetermined amount by the switch generator 38 and the slope discrimination signal. / Contour correction data generator 40, characterized in that configured to include the image signal processing. 3. The address latch / contour correction data generator (40) according to claim 2, wherein the address latch / contour correction data generator (40) is used for address and contour correction data for the preceding luminance data on the edge portion and on the preceding luminance data on the edge portion. Address and contour correction data and a write control signal WE ', so that luminance data corresponding to the contour correction data is updated and recorded in the memory 14, wherein the contour enhancement processing of the video signal is performed. Device.