CN1725814A

CN1725814A - ADC bias regulation method for top-set box of TV

Info

Publication number: CN1725814A
Application number: CNA2004100530061A
Authority: CN
Inventors: 李宗宪
Original assignee: Shanghai LG Electronics Co Ltd
Current assignee: Shanghai LG Electronics Co Ltd
Priority date: 2004-07-20
Filing date: 2004-07-20
Publication date: 2006-01-25

Abstract

A method for regulating ADC bias of TV set - top box includes setting ADC initial value according to regulating mode, fetching pixel value of ADC output digital image after initial value is set , comparing pixel value of ADC output digital image with required pixel value and transferring to next channel if compared result is in range of convergence condition or adjusting regulation mode if compared result is not satisfied to convergence condition .

Description

The ADC deviation method of adjustment of TV set-top box

Technical field

This is the invention about TV set-top box; TV set-top box ADC deviation method of adjustment in this invention can be adjusted in the analog input all patterns of essential ADC ((analog to digital converter) Analog toDigital) chipset automatically.

Background technology

Common TV set-top box is exported after receiving outside input such as aberration terminal (Component) or NTSC again; And in the exploitation of this TV set-top box,, use the analog to digital converter (ADC) that the analog image signal is converted into numerical data as essential chipset.

Above-mentioned ADC chipset is made of analog module and digital module, and analog signal is converted in the process of numerical data, and its chip deviation is big relatively.And this deviation is because the error of the loop of ADC chipset or peripheral manual element etc. can more and more become big.

During therefore with these ADC exploitation TV set-top box, must adjust the inner parameter of TV set-top box ADC, thereby adjust overall color.

Fig. 1 adjusts the connection status figure that uses the peripheral hardware generator for existing TV set-top box ADC.

With reference to Fig. 1, according to the outside input modes of TV set-top box or equipment, the analog image signal that input mode standard generator produces, and be that standard is adjusted the ADC color with this signal.

Press input style, the interval of its output is also different; Therefore, after distinguishing by pattern usually, adjust the color-values of ADC.

Said method needs to buy separately the high price mode generator; To the input pattern that will adjust, the user will reset mode generator.

If a large amount of production can be caused user's error and the low phenomenon of operating rate in above-mentioned adjustment process.And, if do not possess above-mentioned environment, can't adjust.

Summary of the invention

The purpose of this invention will solve above-mentioned variety of problems exactly; To provide by this invention and need not to utilize signal generator also can independently adjust the method for adjustment of TV set-top box ADC deviation.

Other purposes of this invention just provide the TV set-top box deviation method of adjustment that can adjust whenever and wherever possible, can simplify the step that the script user sets by input pattern by said method.

In order to achieve the above object, the TV set-top box ADC deviation method of adjustment in this invention comprises following step: in the stage one, set the ADC initial value by adjustment modes; Stage two, set above-mentioned initial value after, read ADC output digitized video pixel value; In the stage three, above-mentioned ADC output digitized video pixel value and required pixel value compare, and just carry out the transition to next channel in the condition of convergence scope if be in, if do not satisfy the condition of convergence, just adjustment modes are adjusted.

At first, the vision signal kind that is input to TV set-top box can be divided into aberration terminal (Component) and compound terminal (Composite).

Compound terminal signals is that Y ((brightness) Luminance) and C ((colourity) Chrominance) composition are compounded in a signal in the channel; The aberration terminal signals is made of 3 channels such as Y ((brightness) Luminance)/Pb/Pr ((color difference signal) Color Difference Signal).

Tell about as the front, from the adjustment aspect of the chipset ADC of TV set-top box or equipment, this invention more has operating efficiency than existing method.

And need not the standard set-up of high price when adjusting, see on aspect the expense merely and can bring the cost savings effect, and be not subjected to time and controlled restriction.

Description of drawings

Fig. 2 is the ADC deviation method of adjustment explanation drawing of TV set-top box system in this invention.

Fig. 3 is the explanation algorithm of TV set-top box system ADC deviation method of adjustment in this invention.

Fig. 4 is the module map that TV set-top box system ADC deviation is adjusted signal in this invention.

Embodiment

With reference to the accompanying drawings, formation and the effect to this invention example describes.

Fig. 2 is the ADC deviation method of adjustment explanation drawing of TV set-top box system in this invention; The figure illustrates the digital conversion values of automatic adjustment with standard signal.

With reference to Fig. 2, the 100IRE colour band is made up of white (White:WHT) yellow (Yellow:YEL), cyan (Cyan:CYN), green (Green:GRN), aubergine (Magenta:MGT), red (Red:RED), blue (Blue:BLU), black 8 kinds of colors such as (Black:BLK).

And can learn that each colour band becomes the digital value of standard by each channel of YpbPr.

This standard signal is input under the state of TV set-top box, adjusts the ADC parameter, makes the output valve of ADC trend towards standard value.

When following table is gain (Gain) and side-play amount adjustment, press the standard color that channel is distinguished.

When [table 1] gain is adjusted

Signal	The use pattern	Remarks
Signal	The use pattern	Remarks	Y	Black	Utilize black signal to adjust the Y offset value.
Cb	Black, white	If the black and white signal because the Cb value is identical, just utilizes this signal.	Y	Black	Utilize black signal to adjust the Y offset value.
Cb	Black, white		Cr	Black, white	If the black and white signal because the Cr value is identical, just utilizes this signal.

When [table 2] side-play amount is adjusted

Signal	The use pattern	Remarks
Signal	The use pattern	Remarks	Y	Black, white	Utilize the white of Y maximum and the black signal difference of Y minimum
Cb	Yellow, blue	Utilize the yellow of Cb minimum and the blue signal difference of Cb maximum	Y	Black, white
Cb	Yellow, blue		Cr	Cyan, redness	Utilize the cyan of Cr minimum and the danger signal difference of Cr maximum

Carry out before the computing, at first gain initial value and the side-play amount initial value of ADC will be set at 128 and 64 separately.

If image data mean value (μ _i) surpass admissible error, will move to side-play amount adjustment end (S12); If be included in the range of allowable error, just move to gain and adjust in the end (S14).(S11)

When above-mentioned image data mean value surpassed admissible error, the difference between above-mentioned image data mean value and the target average was multiplied by with the variable quantity of side-play amount coefficient (β), upgrades present offset value with this.And if differed bigger between the target average, the side-play amount variable quantity will strengthen; If differ smaller, the side-play amount variable quantity will dwindle.

ADC side-play amount or gain adjustment value can only be suitable for positive number, therefore sometimes about the side-play amount of positive, can surpass the admissible error condition of S11.

Therefore, as the disengaging condition of above-mentioned situation, count by the interior counter of establishing; If present offset value and the difference of having upgraded between the offset value are 1 o'clock, will judge that convergence has error, and make internal counter increase by 1 value.(S13)

If differing of two offset values is 1 when above, just being judged as does not have convergence error, and present Counter Value is reset to 0.

If Counter Value is 10, though just can judge that the mean variation of adjusting according to side-play amount not in range of allowable error, is restrained; Then carry out the transition to the following gain adjusting stage.(S15)

If Counter Value is littler than 10, just can judge that its convergence situation can't be determined about changing side-play amount.(S16)

At this moment, with according to the image frame update that changes the output of ADC side-play amount, open and re-execute side-play amount adjustment (S12).(S17)

By above step, set ADC with initial initial value, and under this state, read ADC output digitized video pixel value from memory.

Required pixel value and the pixel value in the actual storage compare, if be included in the condition of convergence, just carry out the transition in the next channel; If do not satisfy the condition of convergence, adjust after gain (gain) or the side-play amount, under this state, read ADC output digitized video pixel value again from memory.

Carry out said process repeatedly, when the gain of integral body and side-play amount do not change, finish this program.

From algorithm, the gain or the condition of convergence of offset value be included in-0.5＜e＜0.5 in the time, just finish this program.Most of ADC can satisfy the condition of convergence on certain gain or offset value, but part A DC, on particular delta or offset value, can't satisfy the above-mentioned condition of convergence, if under the state that can't satisfy, continue change, O O+1 will take place, G G+1.

Therefore, can't satisfy the ADC gain of the above-mentioned condition of convergence or the changing pattern of offset value is O O+1, during G G+1, just utilizes internal counter that changing pattern is counted; If above-mentioned changing pattern occurs about 10 times, just be judged as termination condition, so just can avoid phenomenon infinitely repeatedly.

Fig. 4 is the module map that TV set-top box system ADC deviation is adjusted signal in this invention; Can carry out the outside input of aberration terminal (DVD) and compound terminal (A/V) here, and the data requirement of TV set-top box or equipment also can adopt aberration terminal (DVD) and compound terminal (A/V) output format.

General method is that the output of external perimysium reference equipment is finished with the input of TV set-top box or equipment, and is adjusting before.In other words, must adjust separately two inputs, so the user is provided with external device (ED), needs some times and workload when adjusting TV set-top box or equipment, this brings inconvenience on using to the user undoubtedly; And in this invention, directly in display routine, generate close beta figure, and can carry out the inside input by AC.

For example, the HDTV chipset can be from line output close beta figure.This resolution chart is that chip self generates, and is therefore higher than its reliability of standard device.And need not be connected with external equipment, TV set-top box or equipment self can generate resolution chart, can also be to external feedback; Because above-mentioned characteristic can utilize software mode that 2 inputs are handled automatically.

By above-mentioned description, those skilled in the art can carry out various change and modification fully in the scope that does not depart from this invention technological thought.Therefore, the technical scope of this invention can not be confined to the detailed description on the specification; Must determine its technical scope according to the scope of patent application.

Claims

1, a kind of TV set-top box ADC deviation method of adjustment is characterized in that comprising with the next stage content: in the stage one, set the ADC initial value by adjustment modes; Stage two, set above-mentioned initial value after, read ADC output digitized video pixel value; In the stage three, above-mentioned ADC output digitized video pixel value and required pixel value compare, and just carry out the transition to next channel in the condition of convergence scope if be in, if do not satisfy the condition of convergence, just adjustment modes are adjusted.