KR100740839B1 - Apparatus and method for correcting analog/digital converter - Google Patents

Abstract

The present invention relates to an analog / digital converter correction apparatus and method for simplifying the process and preventing the occurrence of color deviation. The present invention sets an offset value and a gain value of the analog / digital converter, the color coordinate converter, and the analog / digital converter with respect to the first adjustment pattern, and converts the first and second values converted by the color coordinate converter. The offset correction value and the gain correction value are calculated using the first adjustment pattern and the second adjustment pattern, and the calculated offset correction value and the gain correction value and the preset offset value and the gain value are calculated to calculate the analog values for the second adjustment pattern. It provides an analog / digital converter correction device comprising a control unit for setting the offset value and the gain value of the digital converter. Therefore, the manufacturing process can be simplified, the process time can be reduced, and the image quality can be improved by preventing the occurrence of color deviation.

ADC / Color Coordinates / YUV / Offset / Gain

Description

Apparatus and method for correcting analog / digital converter}

1 is a block diagram showing the configuration of an analog-digital converter correction apparatus according to the prior art

Figure 2 is a block diagram showing the configuration of the analog / digital converter correction apparatus according to the present invention

3 is a flowchart illustrating a method of calibrating an analog / digital converter according to the present invention.

4 is a graph for explaining an analog / digital converter correction method according to FIG. 3.

* Explanation of symbols for main parts of drawings *

21: analog / digital converter 22: color coordinate conversion unit

23: control unit

The present invention relates to an analog / digital converter calibrating device and a method for easily and accurately performing analog / digital converter adjustment for different inputs.

An analog-to-digital converter (hereinafter referred to as an ADC) is a device that converts an input analog signal into a digital signal, and is used to convert an analog video signal input from an external device into a digital video signal for signal processing inside the video device. .

At this time, in the ADC, offset and gain correction is essential in converting an analog image signal to digital. Otherwise, accurate color expression will not be achieved.

That is, the gray level '0' used as the luminance unit of the analog video signal should be recognized as a set voltage (for example, 0V), but if offset correction is not performed, it is recognized as a voltage level other than 0V. As a result, accurate black expression is not achieved.

Therefore, the ADC offset is corrected so that the gray level '0' of the image signal is recognized as the voltage OV.

In addition, the gray level '255' of the analog video signal should be recognized as a set voltage (for example, 0.7V), but if gain correction is not made, it will be recognized as a voltage level other than 0.7V and accordingly, accurate white expression cannot be achieved. .

Therefore, the ADC gain is corrected so that the gray level 255 of the video signal is recognized as 0.7V.

On the other hand, since video equipment can receive video signals in various formats such as RGB and component (YCbCr), it is necessary to calibrate ADC for each of them.

Hereinafter, referring to FIG. 1, the ADC compensator according to the related art will be described.

ADC correction apparatus according to the prior art, as shown in Figure 1, the ADC 11 receives the adjustment pattern consisting of each image signal format, perform the ADC correction operation for each of the adjustment pattern in accordance with the operator control It includes a control unit 12.

Referring to the ADC calibration operation of the prior art described above is as follows.

First, the operator inputs the adjustment pattern RGB and the adjustment pattern YCbCr to the ADC 11 through a separate video generator.

At this time, each adjustment pattern may be a reference analog video signal of 0 to 0.7V corresponding to 0 to 255 gray levels.

Then, the operator selects the RGB input using the adjusting remote controller and instructs the controller 12 to proceed with the ADC calibration.

Subsequently, the ADC 11 converts the input adjustment pattern RGB signal to digital, and the controller 12 corrects the offset so that 0V of the adjustment pattern is converted to the lowest level 0 through the ADC 11, and corrects it. The offset value corresponding to the corresponding input (RGB) and stored in the memory.

The controller 12 corrects the gain so that 0.7 V of the adjustment pattern is converted to the highest level 255 through the ADC 11, and stores the corrected gain value in correspondence with the corresponding input RGB in the memory.

On the other hand, as described above, when the ADC correction operation for the adjustment pattern (RGB) is completed, the operator switches the external input to YCbCr using the remote control, and instructs the controller 12 to proceed with the ADC correction.

Subsequently, the ADC correction operation is performed on the adjustment pattern YCbCr in the same manner as in the case of the adjustment pattern RGB, thereby completing the ADC correction.

However, the ADC compensation technique according to the conventional technique described above has the following problems.

First, ADC adjustment is performed for each image format, which makes the manufacturing process complicated and increases the process time.

Second, the ADC adjustment is performed according to each standard for different image formats, which may cause color deviation.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an analog / digital converter correction apparatus and method for simplifying the process and preventing the occurrence of color deviation.

In order to achieve the above object, the present invention provides an analog / digital converter for converting an input analog video signal into a digital video signal, the color coordinate conversion unit for converting the digital video signal output from the analog / digital converter into a predetermined format, and An offset value and a gain value of the analog-to-digital converter with respect to a first adjustment pattern are set, and an offset correction value is obtained by using the first adjustment pattern and the second adjustment pattern converted by the color coordinate converter. And a control unit configured to calculate a gain correction value, calculate the offset correction value, the gain correction value, the preset offset value, and the gain value to set the offset value and the gain value of the analog / digital converter for the second adjustment pattern. Provided is an analog / digital converter correction device configured to include.

In order to achieve the above object, the present invention comprises the steps of inputting a first adjustment pattern and a second adjustment pattern to the analog / digital converter, the offset value and the gain of the analog / digital converter with respect to the first adjustment pattern ( setting a gain) value, converting and storing the first adjustment pattern and the second adjustment pattern into the same image format, and offset correction using the first adjustment pattern and the second adjustment pattern converted to the same image format. Calculating a value and a gain correction value, and setting an offset and a gain of the analog / digital converter for the second adjustment pattern using the set offset value and the gain value and the calculated offset correction value and the gain correction value. It provides an analog / digital converter correction method comprising a.

As a result, ADC adjustments to different image formats are performed automatically with a single operation, simplifying the manufacturing process and reducing the process time. In addition, the ADC is adjusted according to the same criteria with respect to other image formats, thereby improving the image quality by preventing color deviation.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

2 to 4, an embodiment of an analog / digital converter correction apparatus and method according to the present invention will be described.

First, an embodiment of an analog / digital converter correction apparatus according to the present invention will be described with reference to FIG. 2.

The analog / digital converter correcting apparatus according to the present invention includes an ADC 21, a color coordinate converter 22, and a controller 23.

The ADC 21 is configured to convert an input analog video signal into a digital video signal.

The color coordinate conversion unit 22 converts the digital video signal output from the ADC 21 into the YUV format.

The controller 23 performs ADC adjustment according to the input of the first adjustment pattern RGB to set an offset value and a gain value according to the input of the first adjustment pattern RGB, and according to the input of the first adjustment pattern RGB and the second adjustment pattern YCbCr. Detects the black level and the white level of the output of the color coordinate converter, calculates an offset correction value and a gain correction value using the same, calculates the offset correction value and the gain correction value, and the preset offset value and the gain value. 2 It is a configuration to set the offset value and the gain value according to the adjustment pattern (YCbCr).

Next, an embodiment of an analog / digital converter correction method according to the present invention will be described with reference to FIGS. 3 and 4. At this time, the method of the present invention can be implemented by the apparatus of FIG.

The operator inputs the adjustment pattern RGB and the adjustment pattern YCbCr to the ADC 21 through a separate video generator (S31), and commands the ADC calibration process using the adjustment remote controller.

At this time, each adjustment pattern may be a reference analog video signal of 0 to 0.7V corresponding to 0 to 255 gray levels.

Therefore, the controller 23 performs ADC adjustment on the first adjustment pattern RGB and sets the offset value and the gain value accordingly (S32).

That is, the offset is set to a value obtained by correcting the ADC offset so that the gray level 0 of the video signal is recognized as the voltage OV, and the gain is corrected by the ADC gain so that the gray level 255 of the video signal is recognized as 0.7V. To set it.

Subsequently, the controller 23 stores the YUV value (hereinafter referred to as YUV1) according to the adjustment pattern RGB converted by the ADC 21 and the color coordinate conversion unit 22 (S33).

After the YUV1 storage is completed, the control unit 23 switches the input to the adjustment pattern YCbCr and accordingly stores the YUV value (hereinafter referred to as YUV2) converted through the ADC 21 and the color coordinate conversion unit 22 in the memory. (S34).

Subsequently, the controller 23 detects the black level BL1 and the white level WL1 of the stored YUV1 (S35).

The controller 23 detects the black level BL2 and the white level WL2 of the stored YUV2 (S36).

In this case, the black level corresponds to '0', which is the lowest gray level of the corresponding signal, and the white level corresponds to '255', which is the highest gray level of the corresponding signal.

Subsequently, the controller 23 determines an offset correction value by calculating a difference BL1 -BL2 between the black level BL1 of YUV1 and the black level BL2 of YUV2 (S37).

In this case, since the offset correction is a task of matching the gray level '0' with the voltage value 0V (lowest voltage), the offset correction value is determined by calculating the difference between the black levels.

The controller 23 determines a gain correction value by calculating a difference WL1-WL2 between the white level WL1 of YUV1 and the white level WL2 of YUV2 (S38).

In this case, the gain correction is a task of matching the gray level '255' to a voltage value of 0.7V (highest voltage), and thus, a gain correction value is determined by calculating a difference between white levels.

Subsequently, the controller 23 subtracts the offset correction value determined in the step S37 from the offset value set in the step S32, and determines the result as the offset value of the adjustment pattern YCbCr, and in the step S32 The gain correction value determined in the step S38 is subtracted from the set gain value, and the result is determined as the gain value of the adjustment pattern YCbCr (S39).

As illustrated in FIG. 4, the present invention described above performs ADC correction with respect to RGB and performs offset and gain correction with respect to YCbCr based on this. In addition, the same image format (YUV) is used to perform ADC correction under the same conditions.

The present invention is not limited to the above-described embodiments, and as can be seen in the appended claims, modifications can be made by those skilled in the art to which the invention pertains, and such modifications are within the scope of the present invention.

The effects of the analog and digital converter correction apparatus and method according to the present invention described above are as follows.

First, the ADC adjustment is automatically performed for different image formats with a single operation, simplifying the manufacturing process and reducing the process time.

Second, the ADC is adjusted according to the same criteria with respect to other video formats, thereby improving the image quality by preventing color deviation.

Claims (10)

An analog / digital converter for converting an input analog video signal into a digital video signal; A color coordinate converter converting the digital video signal output from the analog / digital converter into a predetermined format; And An offset value and a gain value of the analog-to-digital converter with respect to a first adjustment pattern are set, and an offset correction value is obtained by using the first adjustment pattern and the second adjustment pattern converted by the color coordinate converter. And a control unit configured to calculate a gain correction value, calculate the offset correction value, the gain correction value, the preset offset value, and the gain value to set the offset value and the gain value of the analog / digital converter for the second adjustment pattern. Analog / digital converter correction device configured to include. The method of claim 1, And a setting format of the color coordinate converter is a YUV format. The method of claim 1, And the first adjustment pattern is an RGB format and the second adjustment pattern is a YCbCr format. The method of claim 1, And the first adjustment pattern and the second adjustment pattern comprise 16 gray levels. In the analog / digital converter correction method, Inputting a first adjustment pattern and a second adjustment pattern to the analog / digital converter; Setting an offset value and a gain value of the analog / digital converter with respect to the first adjustment pattern; Converting and storing the first adjustment pattern and the second adjustment pattern in the same image format; Calculating an offset correction value and a gain correction value using the first adjustment pattern and the second adjustment pattern converted into the same image format; And And setting an offset and a gain of the analog / digital converter for the second adjustment pattern using the set offset value and the gain value and the calculated offset correction value and the gain correction value. The method of claim 5, And the first adjustment pattern is in RGB format and the second adjustment pattern is in YCbCr format. The method of claim 5, And the first adjustment pattern and the second adjustment pattern comprise 16 gray levels. The method of claim 5, And the same image format is a YUV format. The method of claim 5, The step of calculating the offset correction value and the gain correction value using the first adjustment pattern and the second adjustment pattern converted into the same image format may include Detecting a lowest gray level and a highest gray level of each of the first adjustment pattern and the second adjustment pattern; Calculating a difference value between the lowest gray level of the first adjustment pattern and the lowest gray level of the second adjustment pattern as an offset correction value, and And calculating a difference value between the highest gray level of the first adjustment pattern and the highest gray level of the second adjustment pattern as a gain correction value. The method of claim 5, The setting of the offset value and the gain value of the analog-to-digital converter for the second adjustment pattern using the set offset value and the gain value and the calculated offset correction value and the gain correction value may be performed. Setting a difference between the set offset value and the calculated offset correction value as an offset value of an analog / digital converter for a second adjustment pattern, and And setting a difference between the set gain value and the calculated gain correction value as a gain value of an analog / digital converter for a second adjustment pattern.

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