(2) background technology
Fig. 1 is common plane display interior system module figure.
As shown in Figure 1, analog rgb (red green blue tricolor) signal and simulation YpbPr signal by the outside input are converted to digital RGB and digital YpbPr signal by A/D converter 1; In addition, the simulation y/c signal by the outside input is converted to digital YUV signal by decoder 2.
And above-mentioned digital RGB and digital YpbPr signal and the digital YUV signal changed by scaler 3, is output as required image.
At this moment, the input of the number of above-mentioned scaler 3 finally is combined as RGB output on display screen; And,, in the process of the light and shade, gray scale and the color reprodubility that determine final picture, play important effect by the color mixture of this combination. therefore, to set standard input accurately and gain (gain) in the above-mentioned scaler 3.
In addition, the DTV signal can receive the input value of rgb color coordinate and YpbPr; Here, the RGB input is to utilize common PC to handle.
Therefore, can be suitable for, carry out related setting to the automatic setting of existing standard input signal with to the method for automatically programing of gain (gain).
Following mathematical expression 1 is the mathematical expression that YUV is converted to RGB.
[mathematical expression 1]
R=1Y+1.402V
G=1Y-0.344U-0.714V
B=1Y+1.772U
What above-mentioned mathematical expression 1 was represented is that the YpbPr and the y/c signal of input finally are output as in the process of RGB necessary color conversion matrix in above-mentioned scaler 3.
As telling about the front, digital RGB that above-mentioned scaler 3 will be by A/D converter 1 output and digital YpbPr signal and the digital YUV signal by decoder 2 outputs are converted to rgb signal; Because the error diffusion of input signal is the error of rgb signal, therefore can export diverse light and shade, gray scale and color reprodubility.
For all the foregoing reasons, be necessary to develop can be at the front end of above-mentioned scaler 3 to the I/O of vision signal than the method for accurately setting.
(3) summary of the invention
Purpose of the present invention is exactly in order to address the above problem, and a kind of optimal input range automatic setting device that can accurately set the digital video signal of digital video signal I/O ratio is provided.
Another object of the present invention is exactly to provide and can search the whole optimal input range automatic setting method that is transfused to the digital video signal of analog signal range.
Another object of the present invention is exactly to search white balance accurately.
Another object of the present invention is exactly to provide the operator to utilize the method for automatically operating of the accurate data of numerical value operation search.
In order to achieve the above object, the architectural feature of the optimal input range automatic setting device of the digital video among the present invention (DT) signal is as follows: by analog rgb, simulation YpbPr and simulation y/c signal with outside input be converted to digital RGB, digital YpbPr signal A/D converter and, be converted to the pattern generator that the decoder of digital YUV signal is formed; By signal formatization, the digital signal of above-mentioned pattern generator generation is shown as the chromacoder of picture; Signal formatted in the above-mentioned chromacoder is presented at display screen on the picture; Measure the gray scale analyzer of above-mentioned display screen display frame gray scale; Control above-mentioned gray scale analyzer, transmit the increase and decrease command signal of gain (gain) and standard (bias) to above-mentioned pattern generator, and by with the communication of above-mentioned chromacoder, the transmission data are set yield value and the peaked PC of standard value separately with this.
And, in order to achieve the above object, the optimal input range automatic setting method of the digital video among the present invention (DTV) signal will be divided following step: step 1, judge that the digital signal that is input to chromacoder is the DTV pattern, if not the DTV pattern, just convert the DTV pattern to; Step 2 is utilized and has been set gain (gain) value and standard (bias) value, and the above-mentioned digital signal that has been converted to the DTV pattern is carried out initializing set; Step 3, increase the standard value of the above-mentioned Y of an initializing set value after, read control and use the PC signal; Step 4, can read the increase signal of standard value in the PC signal in above-mentioned control, just increase a bias value, and then read again to control and use the PC signal, if above-mentioned control is with the non-increase signal that reads standard value in the PC signal, just reduce the bias value of a Y value, and then read control PC signal; Step 5 reads bias value in the PC signal in above-mentioned control and reduces signal, just reduces by a standard value, read control PC signal again, if read the non-minimizing signal of bias value in the PC signal in above-mentioned control, just increase a standard value, will be worth now again and be defined as standard value; Step 6 behind the yield value of an above-mentioned Y value of increase, reads control PC signal; Step 7 reads the non-increase signal of yield value in the PC signal in above-mentioned control, just increases a yield value, read control PC signal again, if above-mentioned control just reduces the yield value of a Y value again with the increase signal that reads yield value in the PC signal, read control PC signal again; Step 8 reads the non-minimizing signal of yield value in the PC signal in above-mentioned control, just reduces by a yield value, reads control PC signal again; Step 9 reads the minimizing signal of yield value in the PC signal in above-mentioned control, just increases the yield value of a Y value, more present yield value is defined as the maxgain value of Y.
And, above-mentioned institute in steps in, till its operating process proceeds to gain (gain) and standard (bias) value repeatedly and restrains.
In addition, above-mentioned gain yield value and standard value will be changed with color space converter CSC (Color SpaceConverter).
Embodiment effect of the present invention:
As noted earlier, the optimal input range automatic setting device and the method for the digital video among the present invention (DTV) signal have following effect.
The first, because the maximum of each gain (gain) value of automatic setting can accurately show white balance.
The second, owing to set maximum, therefore 256 gray scales can all show.
Three, slope gain (gain) states different to each input value carry out revisal and handle, and can prevent thus because of can't holding maximum magnitude, and the light and shade that causes contrast low phenomenon.
Four, aspect color reprodubility, show its maximum magnitude by input signal, the error minimize that produces in the time of therefore vision signal can being converted to rgb signal.
For further specifying above-mentioned purpose of the present invention, design feature and effect, the present invention is described in detail below with reference to accompanying drawing.
(5) embodiment
With reference to the accompanying drawings, the optimal input range automatic setting device of digital video of the present invention (DTV) signal and the embodiment of method are elaborated.
Fig. 2 is a DTV signal optimal input range automatic setting device displayed map among the present invention.
In order to realize setting by the automatic input of white balance assignment procedure, as Fig. 2, to possess following structure: by analog rgb, simulation YpbPr and simulation y/c signal with outside input be converted to digital RGB, digital YpbPr signal A/D converter and, be converted to the pattern generator 10 that the decoder of digital YUV signal is formed; By signal formatization, the digital signal of above-mentioned pattern generator 10 generations is shown as the chromacoder 30 of picture; Formatted signal in the above-mentioned chromacoder 30 is presented at display screen 20 on the picture; Measure the gray scale analyzer 40 of above-mentioned display screen 20 display frame gray scales; Control above-mentioned gray scale analyzer 40, and by with the communication of above-mentioned chromacoder 30, transmit the control PC50 of data.
At this moment, above-mentioned display screen 20 preferably uses plasma display (PDP).
And, above-mentioned PC50 as shown in Figure 5, transmit the increase and decrease command signal of gain (gain) and standard (bias) to above-mentioned pattern generator 10: { I}^{2}C, and in the transmission of the scaler in above-mentioned chromacoder 30 data sets the maximum of yield value and standard value separately with this.
In addition, in order to grasp the characteristic of dull and stereotyped nixie display, to set required data in advance.In the said determination method, without chromacoder 30, when directly utilizing above-mentioned pattern generator 10 to import, the data that obtain are as follows:
The highest gray scale of A, complete white (full white) pattern;
B, red, the highest gray scale of green, full blue pattern entirely entirely;
The highest gray scale of C, peak white (peak white) pattern;
The highest gray scale of D, peak white, green, blue pattern;
Fig. 3 is the A/D converter internal module figure that becomes digital YpbPr signal among the present invention in the maker internal conversion.
The input signal of YpbPr is exported digital YpbPr signal behind clamp circuit, gain circuitry, A/D converter.
As shown in Figure 3, the simulation YpbPr signal input rank of outside input be 0.0V to 0.7V, and in the A/D device, this level of signal is converted to the digital signal till 0 to 255.
What next mathematical expression 2 showed is the formula of above-mentioned A/D converter.
[mathematical expression 2]
OutPr=OffsetPr+GainPr?x?InPr
OutY=OffsetPr+GainY?x?InY
OutPb=OffsetPb+GainPb?x?InPb
That is:
Output Pr=biasing Pr+ gain Pr * input Pr
Output Y=biasing Y+ gain Pr * input Y
Output Pb=biasing Pb+ gain Pb * input Pb
In the above-mentioned mathematical expression 2, the output valve of each YpbPr signal according to standard input (bias) and gain items such as (gain), is stipulated its standard point and scope.
And according to the standard input value and the gain slope of input signal condition enactment, the output valve of logarithmic code signal forms influence.
If the standard input value of input signal is than the standard input value height of having set, hydro-planing will appear in picture; If the standard input value of input signal is than the established standards input value is low, will exports identical value below certain grade, and not have differentiation between the grade. therefore, the part that color is darker all is shown as identical color.
In addition, the ratio of gains of input signal has been set the yield value height, and picture will be in saturation condition, and does not have the branch of light and shade; If it is low that the slope ratio of input signal has been set slope, at this moment just can not export whole 256 gray scales, just show a part, so gray scale (contrast) is than descending to some extent.
Fig. 4 is the flow chart of display system internal signal stream among the present invention.
In the YUVtoRGB color space converter (ColorSpace Converter:CSC) of YpbPr signal in chromacoder 30, change/be output as rgb signal.
Following mathematical expression 3 is fundamental formulars of color space converter (CSC).
[mathematical expression 3]
R=C0*(Y+Bias)+C1*U+C2*V
G=C3*(Y+Bias)+C4*U+C5*V
B=C6*(Y+Bias)+C7*U+C8*V
The coefficient of above-mentioned color space converter (coefficient) is C0-C8, and the factor of fundamental matrix (matrix) is and above-mentioned mathematical expression 3 value accordingly.
And, when being suitable for the gain (gain) be equivalent to the YpbPr value and standard (bias), will use color space converter CSC.
Fig. 5 is a displayed map of having set gain and input signal relation among the present invention.
When Fig. 5 was suitable for corresponding to the standard value of YpbPr and gain, (CSC) used by color space converter.What represent among Fig. 5 is corresponding to the standard value of YpbPr and the input range of gain, the relation of gain and input signal when respectively giving gain and side-play amount (offset).
Fig. 6 is the displayed map of DTV signal optimal input range automatic setting method among the present invention.
As shown in Figure 6:
S10 judges that the digital signal that is input to chromacoder 30 is engineering adjustment modes, i.e. Installation Modes.
S20 is if the pattern that need not to adjust is just undertaken by original program.
S30, and above-mentioned judged result is the engineering adjustment modes that needs adjustment, just needs to judge that the digital signal that is input to is the DTV pattern, i.e. the YpbPr pattern.
At this moment S40, if the digital signal that is input to is not the DTV pattern, will convert input value to the DTV pattern.
S50, the digital signal of above-mentioned DTV pattern is initialized as gain (gain) value and standard (bias) value set.At this moment initialization value is the set point that indicates among Fig. 6.
S60, then, chromacoder 30 increases the standard value of a Y value, reads control PC50 signal then.
At this moment S70, need to judge whether can read standard value in above-mentioned control in the PC50 signal is the increase signal.
S80 is to increase signal if can read standard value in the PC50 signal in above-mentioned control, and above-mentioned chromacoder 30 just increases a bias value, and then reads control PC50 signal again.
S90 if above-mentioned control is non-increase signal with reading standard value in the PC50 signal, just reduces the bias value of a Y value again, and then reads control PC50 signal.
At this moment S100, needs to judge whether above-mentioned control is to reduce signal with reading bias value in the PC50 signal.
S110 is to reduce signal if read bias value in the PC50 signal in above-mentioned control, and above-mentioned chromacoder 30 just reduces by a standard value, reads control PC50 signal again.
S120 is non-minimizing signal if read bias value in above-mentioned control in the PC50 signal, just increases a standard value, will be worth now to be defined as standard value again.
S130 then, after above-mentioned chromacoder 30 increases the yield value of an above-mentioned Y value, reads control PC50 signal.
At this moment S140, need to judge whether read yield value in above-mentioned control in the PC50 signal is the increase signal.
S150 is non-increase signal if read yield value in above-mentioned control in the PC50 signal, and above-mentioned chromacoder 30 just increases a yield value, reads control PC50 signal again.
S160, and, if above-mentioned control is to increase signal with reading yield value in the PC50 signal, just reduce the slope value of a Y value again, read control PC50 signal again.
S170 need to judge whether read yield value in above-mentioned control in the PC50 signal is the minimizing signal.
S180, if reading yield value in above-mentioned control in the PC50 signal is non-minimizing signal, above-mentioned chromacoder 30 just reduces by a slope value, reads control PC50 signal again.
S190 is if reading yield value in the PC50 signal in above-mentioned control is to reduce signal, just increases the yield value of a Y value, more present yield value is defined as the maxgain value of Y.
Said sequence figure is a process, and till said process arrived the convergence of gain (gain) and standard (bias) value always repeatedly; To Pb, Pr is also suitable in a like fashion.
Those of ordinary skill in the art will be appreciated that, above embodiment is used for illustrating the present invention, and be not to be used as limitation of the invention, as long as in connotation scope of the present invention, all will drop in the scope of claims of the present invention variation, the modification of the above embodiment.