CN101067926A

CN101067926A - Method for smoothing knee in process of multi-segment Gamma curve correction

Info

Publication number: CN101067926A
Application number: CN 200710200806
Authority: CN
Inventors: 江友才; 张俊喜; 苏容强
Original assignee: Sichuan Changhong Electric Co Ltd
Current assignee: Sichuan Changhong Electric Co Ltd
Priority date: 2007-06-12
Filing date: 2007-06-12
Publication date: 2007-11-07
Anticipated expiration: 2027-06-12
Also published as: CN100583232C

Abstract

This invention relates to a method for smoothing inflexions in the process of calibration of multi-section Gamma curve including: taking multiple points on Gamma curve as the calibration points, selecting three continuous calibration points: k, k+1, k+2 to connect k with k+2 in line and judge positions of k+1 and the line: connecting k with k+1 in protrusion at the upper part, connecting k with k+1 in concave line at the lower part and connecting k + 1 on line to connect all calibration points accordingly, which smoothes inflexions in the calibration process of multiple sections of Gamma curves.

Description

The method of smoothing knee in the process of multi-segment Gamma curve correction

Technical field

The present invention relates to the Gamma curvature correction technology of video display apparatus, particularly the method for smoothing knee in the process of multi-segment Gamma curve correction.

Background technology

Can occur the image of input and the image of actual output in video display apparatus such as display, televisor has deviation in brightness, and Gamma curvature correction technology is exactly the method for this demonstration deviation of correcting image.Generally speaking, when the Gamma of Gamma curve curve coefficients greater than 1 the time, the high light of image partly is compressed and shadow partly is expanded, when the Gamma of Gamma curve curve coefficients less than 1 the time, the high light of image partly is expanded and shadow partly is compressed, and Gamma curvature correction technology generally is used for expanding smoothly the details of shadow part.

In order to reach more satisfactory display effect, employing is divided into multistage with a Gamma curve, each section has different Gamma curve coefficients, in the trimming process of Gamma curve " salient point " or " concave point " such flex point can appear so, make video display apparatus when display image, the GTG luminance transition is inhomogeneous, thereby causes the image color transition to be discord poor image quality.

Summary of the invention

Technical matters to be solved by this invention is, the image color transition that the flex point that occurs in the trimming process at multistage Gamma curve can cause video display apparatus to show is discord, the shortcoming of poor image quality provides the method for smoothing knee in a kind of process of multi-segment Gamma curve correction.

The technical scheme that the present invention solve the technical problem employing is that the method for smoothing knee comprises the following steps: in the process of multi-segment Gamma curve correction

A, on the Gamma curve, get a plurality of as check point;

B, choose adjacent 3 check point: k, k+1, k+2, straight line connects check point k and check point k+2;

The position of c, judgement check point k+1 and straight line is if check point k+1 above straight line, then enters steps d; If check point k+1 below straight line, then enters step e; If check point k+1 on straight line, then enters step f;

D, convex line connect check point k and check point k+1, and the point on the convex line is all between check point k and check point k+1;

E, concave connect check point k and check point k+1, and the point on the concave is all between check point k and check point k+1;

F, straight line connect check point k and check point k+1;

G, according to above-mentioned steps, connect each check point successively.

The invention has the beneficial effects as follows, the flex point that level and smooth process of multi-segment Gamma curve correction occurs, realized the smooth connection of the Gamma curve of the different Gamma curve coefficients of multistage, make the brightness even transition of video display apparatus, guarantee the image color transition harmony that video display apparatus shows, increased stereovision, real colour and the sharpness of display image.

Below in conjunction with embodiment and accompanying drawing, the invention will be further described.

Description of drawings

Fig. 1 is the Gamma curve map.

Fig. 2 adjusts the check point process flow diagram.

Fig. 3 connects the check point process flow diagram.

Fig. 4 is a check point smooth connection synoptic diagram.

Embodiment

The method of smoothing knee in the process of multi-segment Gamma curve correction of the present invention is applied in the Gamma curvature correction process of panel TV set, and this Gamma curve is combined by the Gamma curve of the different Gamma curve coefficients of multistage.At first the optical signalling acquired signal is measured, and the data that analyzed by industrial computer and color analyzer obtain the value of Gamma, obtain a most basic Gamma curve table, and the Gamma curve table can be 64 grades, 256 grades, 1024 grades etc.;

Then, again the Gamma curve being made smoothing knee handles:

On the Gamma curve, get a plurality of as check point; Corresponding check point of each GTG of the Gamma ash exponent number of Gamma curve, referring to Fig. 1, the 0th GTG is that check point 0, the 1 GTG is a check point 1 ... the k GTG is check point k; In order to make the better effects if of smoothing knee, further adjust each check point, the flow process of adjusting check point is referring to Fig. 2:

1. initialization check point k is the 0th check point;

2. choose adjacent 4 check point: k, k+1, k+2, k+3;

3. the difference that obtains the Gamma value of the Gamma value of check point k+1 and check point k is Δ G; The difference of the Gamma value of check point k+2 and the Gamma value of check point k+1 is Δ G1; The difference of the Gamma value of check point k+13 and the Gamma value of check point k+2 is Δ G2:

4. judge whether Δ G1＞[(Δ G+ Δ G2)/2], if then enter step 5.; Otherwise enter step 6.;

5. adjust check point k+1, k+2, make [(Δ G+ Δ G2)/2]＞Δ G1 after the adjustment;

6. judge whether all check points adjusted to finish that then enter the process that connects each check point if adjust to finish, the flow process that connects check point is participated in Fig. 3; Otherwise enter step 7.;

7. k adds 1 (shifting to the adjacent next check point of check point k), returns step 2.;

Connect adjusted each check point successively:

(1) initialization check point k is the 0th check point;

(2) choose adjacent 3 check point: k, k+1, k+2, straight line connects check point k and check point k+2;

(3) position of judgement check point k+1 and straight line is if check point k+1 above straight line, then enters step (4); If check point k+1 below straight line, then enters step (5); If check point k+1 on straight line, then enters step (6);

(4) check point k+1 is above straight line, and shown in Fig. 4 A, then convex line connects check point k and check point k+1, and the point on the convex line is all between check point k and check point k+1, shown in Fig. 4 B:

(5) check point k+1 is below straight line, and shown in Fig. 4 C, then concave connects check point k and check point k+1, and the point on the concave is all between check point k and check point k+1, shown in Fig. 4 D:

(6) check point k+1 is on straight line, and shown in Fig. 4 E, then straight line connects check point k and check point k+1, shown in Fig. 4 F:

(7) judge whether smoothly to finish, if then finish; Otherwise enter step (8);

(8) k adds 1 (shifting to the adjacent next check point of check point k), returns step (2).

Embodiment

Measure by the optical signalling acquired signal, the data that analyzed by industrial computer and color analyzer obtain the Gamma value of multistage Gamma curve, obtain a most basic Gamma table, 256 grades of GTGs of Gamma table employing, as shown in Figure 1.Gamma is shown described Gamma curve do the smoothing knee processing, comprise the following steps:

At first, get 256 points as check point on the Gamma curve, corresponding check point of each GTG of Gamma ash exponent number: the k GTG is check point k, and wherein k is an integer, and k ∈ [0,256], as shown in Figure 1;

Secondly, adjust 256 check points successively according to process flow diagram shown in Figure 2:

At last, connect adjusted 256 check points successively, thereby obtain the Gamma curve of smooth connection according to process flow diagram shown in Figure 3.

Claims

1. the method for smoothing knee in the process of multi-segment Gamma curve correction is characterized in that, comprises the following steps:

A, on the Gamma curve, get a plurality of as check point;

F, straight line connect check point k and check point k+1;

G, according to above-mentioned steps, connect each check point successively.

2. the method for smoothing knee is characterized in that in the process of multi-segment Gamma curve correction as claimed in claim 1, among the described step a, and corresponding check point of each GTG of the Gamma of Gamma curve ash exponent number.

3. the method for smoothing knee is characterized in that in the process of multi-segment Gamma curve correction as claimed in claim 1 or 2, among the described step a, adjusts each check point as follows:

A1, choose adjacent 4 check point: k, k+1, k+2, k+3; The difference of the Gamma value of check point k and the Gamma value of check point k+1 is Δ G, and the difference of the Gamma value of check point k+1 and the Gamma value of check point k+2 is Δ G1, and the difference of the Gamma value of check point k+2 and the Gamma value of check point k+3 is Δ G2;

A2, judge whether Δ G1＞[(Δ G+ Δ G2)/2], if then enter step a3; Otherwise enter step a4;

A3, adjustment check point k+1, k+2 make [(Δ G+ Δ G2)/2]＞Δ G1;

A4, according to above-mentioned steps, adjust each check point successively.