KR20040072425A - apparatus for gamma automatic compensation - Google Patents

Abstract

PURPOSE: A device for automatically compensating for a gamma is provided to differently assign the number of data bits to each section, and to transmit the bits to a nonlinear gamma lookup table processor, in order to nonlinearly compensate for the first gamma compensation signal, thereby perfectly removing a contour noise. CONSTITUTION: A gray pattern generator(680) generates H/V synchronous signals and R/G/B signals. A timing controller(620) forms a clock by receiving the H/V synchronous signals. An image processor(600) displays a proper image on an LCD panel by receiving the R/G/B signals. A gamma processor(530) compensates for an image. A gamma comparator/detector(520) automatically senses a degree of a signal change, and nonlinearly detects gamma data. A contour noise controller(550) assigns the gamma data, and removes a contour noise.

Description

Gamma Automatic Compensation Device {apparatus for gamma automatic compensation}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gamma adjustment method of a display, and more particularly, to a gamma automatic correction device for removing contour noise.

1 is a block diagram showing an apparatus for general gamma correction and adjustment.

Referring to FIG. 1, first, the timing controller 13 and the level shifter 15 are configured to receive an H / V synchronization signal from the pattern generator 200 and generate a clock required for the LCD panel 19.

In addition, the image processor 12, the image reversing unit 14, and the sample & holder unit for receiving an R / G / B signal from the pattern generator 200 to display an appropriate image on the LCD panel 19. It consists of 16.

And a gamma processor 17 for correcting an image and a linear gamma look-up table processor 18.

In addition, a camera (image analyzer) 400 which detects image information as light and transmits the image information from the pattern generator 200 and the screen 10 that supplies a signal source, which is essentially configured for gamma adjustment, and transmits the image information. It is composed of a PC 300 that can be compared with the previously set information, calculate and send the data to the CPU (11).

However, since this configuration linearly corrects gamma, contour noise is inevitably generated in a screen section in which a change actually occurs slowly.

Therefore, it is necessary to correct the gamma nonlinearly by automatically allocating a larger number of bits to a signal whose slope of the input image falls below a certain criterion.

Accordingly, an object of the present invention is to provide a method for reducing contour noise due to gamma adjustment.

Another object of the present invention is to reduce the manufacturing cost of the product according to the automation of the adjustment.

Another object of the present invention is to improve the image quality reliability of the product.

1 is a block diagram showing a device for general gamma correction and adjustment

2 is a block diagram showing an apparatus for automatic gamma correction and adjustment according to the present invention

3 is a graph showing a gray waveform for gamma adjustment according to the present invention

4 is a graph illustrating a gamma correction reference signal according to the present invention.

5 is a graph showing gamma data allocation criteria for nonlinear correction according to the present invention.

* Explanation of symbols for main parts of the drawings

510: CPU 520: gamma comparison / detection unit

530: gamma processing unit 540: nonlinear gamma lookup table processing unit

550: CONTERNER NOISE REMOVAL 600: IMAGE PROCESSOR

610: image inversion unit 620: timing control unit

630: Level Shifter 640: Sample & Hold Part

650: LCD panel 660: screen

670: PC 680: Gray Pattern Generator

690: camera

A gamma automatic correction device according to the present invention for achieving the above object is a gray pattern generator for generating an H / V sync signal and R / G / B signal, and the H / V sync signal from the gray pattern generator A timing generator for receiving a R / G / B signal from the gray pattern generator, an image unit for displaying an image suitable for a display, and a gamma processor for correcting an image shown on the display through the image unit. And a gamma comparison / detector for detecting gamma data nonlinearly by automatically detecting a degree of change of a signal according to a signal output from the gamma processing unit, a linear gamma lookup table processing unit, and a gamma detected by the gamma comparison / detection unit. Includes a noise controller to give data to remove contour noise And there consists.

In this case, the display is preferably at least one of an LCD projection TV and an LCD projector, a PDP, a DLP projection TV and a DLP projector.

In addition, the gamma comparison / detection unit is preferably assigned a larger number of bits than a signal input above a reference value for a signal in which a slope of an image signal to which gamma data is input is input below a predetermined reference value.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings.

A preferred embodiment of the gamma automatic correction device according to the present invention will be described with reference to the accompanying drawings.

2 is a block diagram showing an apparatus for automatic gamma correction and adjustment according to the present invention.

Referring to FIG. 2, the LCD panel 19 receives the H / V synchronization signal from the gray pattern generator 680 that generates the H / V synchronization signal and the R / G / B signal, and the gray pattern generator 200. A timing controller 620 and a level shifter 630 for making a clock required for the clock, and an image processor for receiving an R / G / B signal from the gray pattern generator 680 and displaying an appropriate image on the LCD panel 19 600), an image reversal unit 640, and a sample & hold unit 650.

In addition, the gamma processing unit 530, the linear gamma look-up table processing unit 540, and the gamma processing unit 530 for the image correction automatically detect the degree of change in the signal according to the signal output from the non-linear A gamma comparison / detection unit 520 for detecting gamma data, and a contactor noise control unit 550 for removing contour noise by applying gamma data detected by the gamma comparison / detection unit 520. .

In addition, a camera (image analyzer) 690 which detects image information as light from the gray pattern generator 680 and the screen 660 that supplies a signal source, which is essentially configured for gamma adjustment, and transmits the image information as electrical information, and an image to be sent. It consists of a PC 670 that compares the information with previously set information, calculates the data, and sends the data to the CPU 510.

The operation of the gamma automatic correction device according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, upon entering the operation for adjustment, the CPU 510 checks whether the PC 670 has sufficiently stabilized the connection state between the camera 690 and the gray pattern generator 680.

The gray pattern generator 680 then issues a signal output start command for gamma adjustment, and according to this command, as many grays as necessary for system adjustment from black to white are processed at one second intervals. 600 and the timing controller 620.

At this time, the H / V synchronization signal is received from the gray pattern generator 680 to generate a clock required for the LCD panel 650 through the timing controller 620 and the level shifter 630, and the R / from the pattern generator 680. The G / B signal is received and displayed as an appropriate image on the LCD panel 19 through the image processor 600, the image inverting unit 610, and the sample & hold unit 640.

In addition, the CPU 510 receives a signal from the PC 670 that the first basic gamma correction is completed through the gray waveform for gamma adjustment according to the present invention as shown in FIG. 3.

Subsequently, the CPU 510 commands the gamma comparator / 520 to output the first processed gamma signal stored in the gamma processor 530.

In this case, the gamma comparison / detector 520 compares the slope difference for each section between the gamma correction reference signal preset and the gamma signal input from the gamma processing unit 530 as shown in FIG. Output to the remover 550.

The controller noise remover 550 finely compares the input comparison / detection signal (voltage) with the original memorized value once again to finely set the slope section so that the contour noise can be completely removed. do.

In this way, the number of data bits are differently assigned according to the intervals, and then sent to the nonlinear gamma look-up table processing unit 540 to transmit the first gamma correction signal sent from the original gamma processing unit 530. Nonlinear correction by finely allocating data bits for each section according to the slope of the signal makes it possible to completely remove the controller noise.

The gamma automatic correction device according to the present invention as described above has the following effects.

First, by solving the contour noise by the conventional linear gamma correction, it is possible to ensure a clearer image quality, thereby further securing the competitiveness of the product.

Secondly, nonlinear gamma correction can be automatically corrected for the input signal, thereby ensuring the reliability of the product.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

Claims (3)

A gray pattern generator for generating H / V sync signals and R / G / B signals; A timing generator for receiving a H / V sync signal from the gray pattern generator and generating a clock required for display; An image unit for receiving an R / G / B signal from the gray pattern generator and displaying an image suitable for a display; A gamma processing unit and a linear gamma lookup table processing unit for correcting an image displayed on a display through the image unit; A gamma comparison / detection unit which detects gamma data non-linearly by automatically detecting a degree of change of the signal according to the signal output from the gamma processing unit; And a contactor noise control unit for removing contour noise by giving gamma data detected by the gamma comparison / detection unit. The method of claim 1, And the display is at least one of an LCD projection TV and an LCD projector, a PDP, a DLP projection TV and a DLP projector. The method of claim 1, And the gamma comparison / detection unit is configured to allocate a greater number of bits than a signal input over a reference value to a signal having a slope of an image signal to which gamma data is input below a predetermined reference value.