CN102905077A - Image vignetting brightness regulating method and device - Google Patents

Abstract

The invention relates to an image vignetting brightness regulating method and an image vignetting brightness regulating device. The method comprises the following steps of: S100) acquiring a two-dimensional image, and dividing a vignetting area on the two-dimensional image; S200) regulating the brightness of the vignetting area; and S300) outputting an image of which the brightness is regulated. By the method and the device, in the process of shooting by utilizing an image shooting device, the brightness of the image vignetting can be automatically regulated, so that the brightness of a whole image is maintained consistently after regulation, and the comfort level of image watching is improved; and the method and the device are implemented by modifying the conventional majority photographic devices, and the universality is high.

Description

The dark angular brightness control method of a kind of image and device

Technical field

The present invention relates to image processing field, more particularly, relate to a kind of method and device that the image of taking is carried out dark angular brightness adjusting.

Background technology

In image capturing device, such as camera, video camera etc., because the imaging characteristic of camera lens, the imaging effect on four corners is than the central area, its brightness is darker, forms shadow.The existence meeting of these shadows causes larger impact to the comfort level of vision.

To the elimination at this dark angle, it is by the shooting light path being redesigned the luminance shortage of compensation edge that a kind of method is arranged.Yet the cost of this method is higher, needs the elements such as redesign camera lens, and also is difficult to transform for existing apparatus for making a video recording.

Therefore, be badly in need of now the higher scheme of low, the pervasive degree of a kind of implementation cost valency, to overcome in the existing shooting process shadow phenomenon of corner.

Summary of the invention

The object of the invention is to, for existing image capture method and device, have the defective of shadow in the corner of imaging, a kind of method and apparatus that the corner shadow is eliminated is provided.

Solution of the above problems of the present invention is: provide a kind of image dark angular brightness control method, may further comprise the steps:

S100) obtain two dimensional image, and two dimensional image is divided dark angular zone;

S200) brightness of the dark angular zone of adjustment;

S300) image after output brightness is adjusted.

The dark angular brightness control method of image of the present invention wherein also comprises the step that two dimensional image is divided dark angular zone:

S110) obtain width W and the height H of two dimensional image;

S120) the dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r=1/2 * min{W of waist, H}.

The dark angular brightness control method of image of the present invention, wherein S200 specifically comprises:

S210) select a dark angular zone, and calculate R, G, the B component of each pixel in this dark angular zone;

S220) calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

S230) each R ', G ', B ' after output is adjusted, wherein:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

The dark angular brightness control method of image of the present invention, among the step S220, rateR, rateG, rateB are as follows:

$\mathrm{rateR}=1+(\frac{\mathrm{Rave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateG}=1+(\frac{\mathrm{Gave}}{\mathrm{PGave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateB}=1+(\frac{\mathrm{Bave}}{\mathrm{PBave}}-1)\·{(r-d)}^2/r^2;$

Wherein, r represents that the waist of dark angular zone is long, and d represents the distance on the summit, right angle of the dark angular zone of selected pixel distance;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image, is preferably 100 pixels;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area, and the foursquare length of side is 5 to 20 pixels, and second area is positioned at four drift angles of two dimensional image, is preferably 10 pixels;

RateR represents the adjustment coefficient of any point R component in the dark angular zone;

RateG represents the adjustment coefficient of any point G component in the dark angular zone;

RateB represents the adjustment coefficient of any point B component in the dark angular zone.

The present invention also provides a kind of image dark angular brightness adjusting device, comprising:

Dark angle acquisition module is used for obtaining two dimensional image, and two dimensional image is divided dark angular zone;

Dark angular brightness adjusting module is used for adjusting the brightness of dark angular zone;

Image output module is used for the image after output brightness is adjusted;

Dark angle acquisition module, dark angular brightness adjusting module, image output module link to each other successively.

The dark angular brightness adjusting device of image of the present invention, wherein acquisition module process that two dimensional image is divided dark angular zone in dark angle is:

Obtain width W and the height H of two dimensional image;

The dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r=1/2 * min{W of waist, H}.

The dark angular brightness adjusting device of image of the present invention, dark angular brightness adjusting module also comprises:

The component computing module is for R, the G, the B component that calculate each pixel in the dark angular zone;

Adjust coefficient module, calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

Each R ', G ', the B ' of image output module output are:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

The dark angular brightness adjusting device of image of the present invention, the adjustment coefficient module is calculated rateR, rateG, rateB is as follows:

$\mathrm{rateR}=1+(\frac{\mathrm{Rave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateG}=1+(\frac{\mathrm{Gave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateB}=1+(\frac{\mathrm{Bave}}{\mathrm{PBave}}-1)\·{(r-d)}^2/r^2;$

Wherein, r represents that the waist of dark angular zone is long, and d represents the distance on the summit, right angle of the dark angular zone of selected pixel distance;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image, is preferably 100 pixels;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area,, the foursquare length of side is 5 to 20 pixels, second area is positioned at four drift angles of two dimensional image, is preferably 10 pixels;

RateR represents the adjustment coefficient of any point R component in the dark angular zone;

RateG represents the adjustment coefficient of any point G component in the dark angular zone;

RateB represents the adjustment coefficient of any point B component in the dark angular zone.

Implement the dark angular brightness control method of image of the present invention and device, in the process of utilizing image capturing device to take, can automatically adjust the brightness at the dark angle of image, so that the brightness preservation of view picture figure is consistent after adjusting, improve the comfort level of image-watching; And the present invention is by realizing existing most of camera head transformations, and pervasive degree is high.

Description of drawings

The present invention will be described below in conjunction with accompanying drawing, wherein:

Fig. 1 is the flow chart of the dark angular brightness control method of image of the present invention;

Fig. 2 is the schematic diagram that the present invention selects the shadow zone;

Fig. 3 is the first schematic diagram of preferred embodiment of the dark angular brightness control method of image of the present invention;

Fig. 4 is the building-block of logic of the dark angular brightness adjusting device of image of the present invention;

Fig. 5 is the building-block of logic of dark angular brightness adjusting module.

Embodiment

The present invention is described in detail below in conjunction with the drawings and specific embodiments.

Be illustrated in figure 1 as the flow chart of the dark angular brightness control method of image of the present invention, in the present invention, the method for obtaining dark angular zone is as follows:

S100) obtain two dimensional image, and two dimensional image is divided dark angular zone; For the two dimensional image that obtains, be converted into the data format by each pixel of RGB numeric representation;

Divide dark angular zone for two dimensional image, need to carry out following step:

S110) obtain width W and the height H of two dimensional image;

S120) the dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r of waist is among W and the H, than half of fractional value, i.e. r=1/2 * min{W, H}.Form 4 dark angular zones as shown in Figure 2.

Need to prove that the dark angular zone that constructs isosceles triangle is based on the preferred selection that Luminance Distribution characteristic that existing apparatus for making a video recording obtains image has been done: it is darker in the brightness of the position of four drift angles that general apparatus for making a video recording obtains image, and it distributes and approximately becomes the distribution of isosceles right triangle.

Certainly the concrete image that obtains for different equipment, also can obtain the image difference according to it chooses flexibly, for example, select the mid point on each limit of two dimensional image, connect adjacent mid point, form the dark angular zone of 4 right-angled triangles, or be select inscribe in two dimensional image just round or oval as the central area, remaining is as dark angular zone.

After choosing dark angular zone, carry out step S200:

S200) brightness of the dark angular zone of adjustment; The specific implementation of regulating the brightness of dark angular zone is to regulate the RGB numerical value of each pixel in the dark angular zone; Concrete comprises:

S210) select a dark angular zone, and calculate R, G, the B component of each pixel in this dark angular zone;

S220) calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

S230) each R ', G ', B ' after output is adjusted, wherein:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

The dark angular brightness control method of image of the present invention, among the step S220, rateR, rateG, rateB are as follows:

$\mathrm{rateR}=1+(\frac{\mathrm{Rave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateG}=1+(\frac{\mathrm{Gave}}{\mathrm{PGave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateB}=1+(\frac{\mathrm{Bave}}{\mathrm{PBave}}-1)\·{(r-d)}^2/r^2;$

Wherein, r represents that the waist of dark angular zone is long, and d represents the distance on the summit, right angle of the dark angular zone of selected pixel distance;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image, is preferably 100 pixels;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area, and the foursquare length of side is 5 to 20 pixels, and second area is positioned at four drift angles of two dimensional image, is preferably 10 pixels;

RateR represents the adjustment coefficient of any point R component in the dark angular zone;

RateG represents the adjustment coefficient of any point G component in the dark angular zone;

RateB represents the adjustment coefficient of any point B component in the dark angular zone.

Above computational methods are the corresponding computational methods of the dark angular zone of isosceles right triangle, when selecting the dark angular zone of other shapes, need the account form of accommodation r.

S300) image after output brightness is adjusted.The new two dimensional image that the image of output forms for the RGB after adjusting.

As shown in Figure 3, be the dark angular brightness control method of the image of the present invention schematic diagram of preferred embodiment first; In the present embodiment, the dark angular zone of division and is introduced two parameter: K as shown in Figure 2, is used for representing dark angle; Pi is used for representing the pixel in the dark angle.For example, the dark angle 1 in the upper left corner in the K=1 presentation graphs 2, pi=1 represents first pixel in the dark angular zone.

At first initialization K and pi so that K=1 namely begins processing from first dark angle, and select pi=1, first pixel.

The RGB that calculates pi pixel adjusts coefficient, is specially:

$\mathrm{rateR}=1+(\frac{\mathrm{Rave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateG}=1+(\frac{\mathrm{Gave}}{\mathrm{PGave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateB}=1+(\frac{\mathrm{Bave}}{\mathrm{PBave}}-1)\·{(r-d)}^2/r^2;$

According to adjusting coefficient, export new RGB numerical value:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

After handling this pixel, judge whether pixel is the last pixel at current dark angle, if not then get new pi value, new pi value adds 1 for currency; And new pixel is carried out RGB process; Until handle all pixels of current dark angular zone.

After this judge whether current dark angular zone is the last dark angle, if not, then gets new K value, and new K value adds 1 for currency; And the RGB that new dark angular zone carries out whole pixels processed; Until all dark angular zones are finished dealing with.

Fig. 4 is the building-block of logic of the dark angular brightness adjusting device of image of the present invention, corresponding realization dark angular brightness method of adjustment of the present invention.This device comprises:

Dark angle acquisition module 100 is used for obtaining two dimensional image, and two dimensional image is divided dark angular zone;

Dark angular brightness adjusting module 200 is used for adjusting the brightness of dark angular zone;

Image output module 300 is used for the image after output brightness is adjusted;

Dark angle acquisition module 100, dark angular brightness adjusting module 200, image output module 300 link to each other successively.

At dark angle acquisition module 100, when two dimensional image is divided dark angular zone, take following mode of operation:

Obtain width W and the height H of two dimensional image;

The dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r=1/2 * min{W of waist, H}.The final dark angular zone that obtains as shown in Figure 2.

After dark angle acquisition module 100 is divided good dark angular zone, the data of the dark angular zone of correspondence are sent to dark angular brightness adjusting module 200, adjust the brightness of dark angular zone; Dark angular brightness adjusting module 200 also comprises:

Component computing module 210 is for R, the G, the B component that calculate each pixel in the dark angular zone;

Adjust coefficient module 220, calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

Each R ', G ', the B ' of image output module 300 outputs are:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

The computational process of wherein adjusting coefficient rateR, rateG, rateB is as follows:

$\mathrm{rateR}=1+(\frac{\mathrm{Rave}}{\mathrm{PRave}}-1)\·{(r-d)}^2/r^2,$

$\text{rateG=1+}(\frac{\mathrm{Gave}}{\mathrm{PGave}}-1)\·{(r-d)}^2/r^2,$

$\mathrm{rateB}=1+(\frac{\mathrm{Bave}}{\mathrm{PBave}}-1)\·{(r-d)}^2/r^2;$

Wherein:

R represents the right angle length of side of dark angular zone;

D represents that any point is to the distance on summit, right angle in the dark angular zone;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image, is preferably 100 pixels;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area, and the foursquare length of side is 5 to 20 pixels, and second area is positioned at four drift angles of two dimensional image, is preferably 10 pixels;

RateR represents the adjustment coefficient of any point R component in the dark angular zone;

RateG represents the adjustment coefficient of any point G component in the dark angular zone;

RateB represents the adjustment coefficient of any point B component in the dark angular zone.

Image output module 300 is replaced original legacy data with new R, G, the B numerical value of dark angular zone, and in original image, the view data combination of zone line (namely not carrying out the part of brightness adjustment) generates new two dimensional image.

It below only is the specific embodiment of the invention, can not limit scope of the present invention with this, the equalization that those skilled in the art in the art do according to this creation changes, and the change known of those skilled in that art, all should still belong to the scope that the present invention is contained.

Claims (10)

1. the dark angular brightness control method of image is characterized in that, may further comprise the steps:

S100) obtain two dimensional image, and two dimensional image is divided dark angular zone;

S200) brightness of the dark angular zone of adjustment;

S300) image after output brightness is adjusted.

2. the dark angular brightness control method of image according to claim 1 is characterized in that, the step of two dimensional image being divided dark angular zone also comprises:

S110) obtain width W and the height H of two dimensional image;

S120) the dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r=1/2 * min{W of waist, H}.

3. the dark angular brightness control method of image according to claim 1 is characterized in that, described S200 comprises:

S210) select a dark angular zone, and calculate R, G, the B component of each pixel in this dark angular zone;

S220) calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

S230) each R ', G ', B ' after output is adjusted, wherein:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

4. the dark angular brightness control method of image according to claim 3 is characterized in that, among the described step S220, rateR, rateG, rateB are as follows:

rateR=1+(Rave/PRave-1)(r-d) ²/r ²;

rateG=1+(Gave/PGave-1)(r-d) ²/r ²;

rateB=1+(Bave/PBave-1)(r-d) ²/r ²;

Wherein, r represents that the waist of dark angular zone is long, and d represents the distance on the summit, right angle of the dark angular zone of selected pixel distance;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area, and the foursquare length of side is 5 to 20 pixels, and second area is positioned at four drift angles of two dimensional image;

RateR represents the adjustment coefficient of pixel R component in the dark angular zone;

RateR represents the adjustment coefficient of pixel G component in the dark angular zone;

RateB represents the adjustment coefficient of pixel B component in the dark angular zone.

5. the dark angular brightness control method of image according to claim 4 is characterized in that, the length of side of described first area is that the length of side of 100 pixels, described second area is 10 pixels.

6. the dark angular brightness adjusting device of image is characterized in that, comprising:

Dark angle acquisition module (100) is used for obtaining two dimensional image, and two dimensional image is divided dark angular zone;

Dark angular brightness adjusting module (200) is used for adjusting the brightness of dark angular zone;

Image output module (300) is used for the image after output brightness is adjusted;

Dark angle acquisition module (100), dark angular brightness adjusting module (200), image output module (300) link to each other successively.

7. the dark angular brightness adjusting device of image according to claim 6 is characterized in that, the process that described dark angle acquisition module (200) is divided dark angular zone to two dimensional image is:

Obtain width W and the height H of two dimensional image;

The dark angular zone of structure isosceles triangle, the summit, right angle of isosceles triangle is the summit of two dimensional image, the waist length direction of isosceles triangle is width and the short transverse of two dimensional image, the long r=1/2 * min{W of waist, H}.

8. the dark angular brightness adjusting device of image according to claim 6 is characterized in that, described dark angular brightness adjusting module (200) also comprises:

Component computing module (210) is for R, the G, the B component that calculate each pixel in the dark angular zone;

Adjust coefficient module (220), calculate R, G, the adjustment coefficient rateR of B component, rateG, the rateB of each pixel;

Each R ', G ', the B ' of described image output module (300) output are:

R’=R×rateR；

G’=G×rateG；

B’=B×rateR。

9. the dark angular brightness adjusting device of image according to claim 8 is characterized in that, adjustment coefficient module (220) is calculated rateR, rateG, rateB is as follows:

rateR=1+(Rave/PRave-1)(r-d) ²/r ²;

rateG=1+(Gave/PGave-1)(r-d) ²/r ²;

rateB=1+(Bave/PBave-1)(r-d) ²/r ²;

Wherein, r represents that the waist of dark angular zone is long, and d represents the distance on the summit, right angle of the dark angular zone of selected pixel distance;

Rave, Gave, Bave are the mean value of two dimensional image first area R, G, B component, and the first area is square area, and the foursquare length of side is 80 to 120 pixels, and the first area is positioned at the center of two dimensional image;

PRave, PGave, PBave are the mean value of two dimensional image second area R, G, B component, and second area is four identical square area, and the foursquare length of side is 5 to 20 pixels, and second area is positioned at four drift angles of two dimensional image;

RateR represents the adjustment coefficient of pixel R component in the dark angular zone;

RateR represents the adjustment coefficient of pixel G component in the dark angular zone;

RateB represents the adjustment coefficient of pixel B component in the dark angular zone.

10. the dark angular brightness adjusting device of image according to claim 9 is characterized in that, the length of side of described first area is that the length of side of 100 pixels, described second area is 10 pixels.

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