CN106791758B

CN106791758B - The judgment method and device of natural light mixing colour temperature in a kind of image

Info

Publication number: CN106791758B
Application number: CN201611117128.1A
Authority: CN
Inventors: 王廷鸟
Original assignee: Zhejiang Dahua Technology Co Ltd
Current assignee: Zhejiang Dahua Technology Co Ltd
Priority date: 2016-12-07
Filing date: 2016-12-07
Publication date: 2018-07-06
Anticipated expiration: 2036-12-07
Also published as: CN106791758A

Abstract

The present invention discloses the judgment method and device of natural light mixing colour temperature in a kind of image, the method includes：Multiple rectangular areas are divided an image into, determine the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；Corresponding each first coordinate points in each rectangular area are determined according to the parameter；First coordinate points are divided into the first cluster and the second cluster, according to the central point of each cluster, determine the first unit direction vector；When the first unit direction vector and the angle of the second unit direction vector pre-saved are less than the first given threshold, determining image to be corrected, there are natural light mixing colour temperatures.Since in embodiments of the present invention, the angle of the first unit direction vector and the second unit direction vector reflects the possibility degree that image mixes colour temperature for natural light, therefore, judge that image to be corrected is more accurate with the presence or absence of natural light mixing colour temperature.

Description

The judgment method and device of natural light mixing colour temperature in a kind of image

Technical field

The present invention relates to a kind of judgment methods of natural light mixing colour temperature in technical field of image processing more particularly to image And device.

Background technology

With the continuous development of image processing techniques, white balance correcting is also increasingly perfect, in the prior art, When treating correction image progress white balance correction, mostly using method for correcting automatic white balance, Fig. 1 is of the prior art automatic white Method for correcting balance, detailed process include：

S101：The reference white point of image to be corrected is acquired, and determines that reference white point-rendering refers to white area.

S102：It calculates image to be corrected and currently falls into reference white point quantity with reference to white area, if reference white point quantity Less than or equal to the first predetermined threshold value, S105 is carried out, otherwise, carries out S103.

S103：Judge that image to be corrected mixes colour temperature with the presence or absence of natural light, if carrying out S105, otherwise, carry out S104.

S104：White point quantity according to falling into reference to white area calculates white balance gains, and uses the white balance gains pair The image to be corrected carries out complementary color correction.

S105：Go out white balance gains, and school is treated to described using the white balance gains using preset algorithm policy calculation Positive image carries out complementary color correction.

This method by image to be corrected fall into reference to white area white point carry out dynamic birds of the same feather flock together, white point is divided into two clusters In class, when the white point number in two cluster classes meets preset condition, then judge image to be corrected there are natural light mix colour temperature, But the rule of natural light mixing colour temperature is not considered when being judged.For example, when having white road and green plants in image When, white and green are divided into two cluster classes by dynamically birdsing of the same feather flock together, through judging, the white point number in white and green cluster class expires Sufficient preset condition, then this method thinks image there are natural light mixing colour temperature, and calculates white balance increasing respectively with green to white Benefit, and not there are natural lights to mix colour temperature for the actual conditions images.It allows for mixing image with the presence or absence of natural light in this way Colour temperature error in judgement thereby reduces the accuracy of white balance correction.

Invention content

The embodiment of the present invention provides the judgment method and device of natural light mixing colour temperature in a kind of image, existing to solve The problem of judgement of natural light mixing colour temperature is inaccurate in technology image.

The method of the present invention includes a kind of judgment method of natural light mixing colour temperature in image, and this method includes：

For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to each The red R of rectangular area, green G, indigo plant B mean values determine the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；

The value that colour temperature evaluation parameter is mixed according to a pair of of natural light of each rectangular area determines in the coordinate system of structure Corresponding each first coordinate points in each rectangular area, wherein coordinate system are made with the pair of natural light mixing colour temperature evaluation parameter For horizontally and vertically；

The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to the center of each cluster Point determines the first unit direction vector, wherein the direction of the first unit direction vector is low colour temperature to high color temperature direction；

Whether the angle of the second unit direction vector for judging the first unit direction vector and pre-saving is less than setting First threshold, wherein, the second unit direction vector is to be predefined according to the target image that colour temperature is mixed there are natural light And preserve；

If so, image to be corrected is determined there are natural light mixing colour temperature, otherwise, it determines image to be corrected is not present Natural light mixes colour temperature.

Further, it is determined that the process of the second unit direction vector includes：

For the target image of natural light mixing colour temperature acquired in advance, the target image is drawn according to the rule of setting It is divided into multiple rectangular areas, according to R, G, B mean value of each rectangular area, determines a pair of of natural light mixing of each rectangular area The value of colour temperature evaluation parameter；

The value that colour temperature evaluation parameter is mixed according to a pair of of natural light of each rectangular area determines in the coordinate system of structure Corresponding each second coordinate points in each rectangular area, wherein coordinate system mix colour temperature evaluation parameter with the pair of natural light As horizontally and vertically；

According to coordinate of each second coordinate points in the coordinate system, the second unit direction vector is determined, wherein described The direction of second unit direction vector is low colour temperature to high color temperature direction.

Further, coordinate of each second coordinate points of the basis in the coordinate system, determines the second unit direction Vector includes：

The coordinate information of two coordinate points input by user is obtained, determines the direction vector of described two coordinate points, and will The corresponding unit vector of the direction vector is as the second unit direction vector；Or

According to least square method, the corresponding linear equation of the second coordinate points in the coordinate system is determined, according to the straight line Equation determines the corresponding second unit direction vector of the linear equation；Or

According to the method for principal component analysis, the covariance matrix of the point set of the second coordinate points composition is determined, according to institute The feature vector for stating covariance matrix determines the second unit direction vector.

Further, after the determining image to be corrected mixes colour temperature there are natural light, the method further includes：

White balance gains are determined according to natural light mixing colour temperature white balance algorithm and described image is corrected.

Further, it is described to determine that white balance gains include according to natural light mixing colour temperature white balance algorithm：

According to the first unit direction vector and the angle and setup parameter of the second unit direction vector, use is preset Algorithm determines the angle and the corresponding natural light mixing colour temperature parameter value of the setup parameter；

Colour temperature parameter value is mixed according to the natural light and determines that monochromatic warm white balance algorithm and natural light mixing colour temperature are put down in vain Corresponding first weight of method and the second weight are accounted, colour temperature white balance is mixed according to the monochromatic warm white balance algorithm and natural light Algorithm and corresponding first weight and the second weight, determine white balance gains.

Further, it is described that colour temperature parameter value is mixed according to the natural light, determine monochromatic warm white balance algorithm and nature Corresponding first weight of light mixing colour temperature white balance algorithm and the second weight include：

The natural light is mixed into colour temperature parameter value as the second weight, using 1 with the difference of second weight as first Weight.

Further, it is described according to the first unit direction vector and the folder of the second unit direction vector pre-saved Angle and setup parameter using preset algorithm, determine the angle and the corresponding natural light mixing colour temperature ginseng of the setup parameter Numerical value includes：

According to the first unit direction vector and the angle of the second unit direction vector pre-saved, the folder is calculated Angle and the product of parameter preset；The cosine value of the product is determined as the natural light and mixes colour temperature parameter value.

Further, described to determine that image to be corrected is not present after natural light mixing colour temperature, the method further includes：

White balance gains are determined according to monochromatic warm white balance algorithm and described image is corrected.

Further, the first unit direction vector of the judgement is with the angle of the second unit direction vector pre-saved No to be less than before the first threshold of setting, the method further includes：

The ambient light illumination of image is determined according to the camera of preservation shooting aperture time, gain parameter, aperture, when the environment When illumination is more than the second given threshold, continue subsequent step；Or

When the distance between central point for judging the first cluster and the second cluster is more than third given threshold, continue follow-up step Suddenly；Or

Judge the first cluster abscissa corresponding with the colour temperature that the abscissa of the central point of the second cluster is respectively positioned on natural light In the range of, and the first cluster ordinate range corresponding with the colour temperature that the ordinate of the central point of the second cluster is respectively positioned on natural light When interior, continue subsequent step.

Further, the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area includes：

Each G/R values of rectangular area and G/B values；Or

Each logarithm of G/R of rectangular area and the logarithm of G/B；Or

Each logarithm of R/G of rectangular area and the logarithm of B/G.

On the other hand, an embodiment of the present invention provides a kind of judgment means of natural light mixing colour temperature in image, the dresses Put including：

Described image for being directed to image to be corrected, is divided into multiple by the first determining module according to the rule of setting Rectangular area according to the red R of each rectangular area, green G, indigo plant B mean values, determines a pair of of natural light secondary colour of each rectangular area The value of warm evaluation parameter；

Second determining module, for mixing the value of colour temperature evaluation parameter according to a pair of of natural light of each rectangular area in structure Corresponding each first coordinate points in each rectangular area are determined in the coordinate system built, wherein coordinate system is mixed with the pair of natural light Colour temperature evaluation parameter is closed as horizontally and vertically；

Third determining module, for the first coordinate points in the coordinate system to be divided into the first cluster and the second cluster, According to the central point of each cluster, the first unit direction vector is determined, wherein the direction of the first unit direction vector is low Colour temperature is to high color temperature direction；

First judgment module, for the folder of the second unit direction vector for judging the first unit direction vector Yu pre-saving Whether angle is less than the first threshold of setting, wherein, the second unit direction vector is to mix colour temperature according to there are natural lights What target image was predefined and was preserved；

4th determining module if the judging result for the first judgment module is yes, determines that image to be corrected exists Natural light mixes colour temperature, if the judging result of the first judgment module is no, determines image to be corrected there is no natural lights to mix Close colour temperature.

Further, first determining module is additionally operable to for the target figure of natural light mixing colour temperature acquired in advance The target image is divided into multiple rectangular areas by picture according to the rule of setting, equal according to R, G, B of each rectangular area Value determines the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；

Second determining module is additionally operable to mix colour temperature evaluation parameter according to a pair of of natural light of each rectangular area Value determines corresponding each second coordinate points in each rectangular area in the coordinate system of structure, wherein coordinate system with the pair of Natural light mixing colour temperature evaluation parameter is as horizontally and vertically；

The third determining module is additionally operable to the coordinate in the coordinate system according to each second coordinate points, determines Two unit direction vectors, wherein the direction of the second unit direction vector is low colour temperature to high color temperature direction.

Further, the third determining module, specifically for obtaining the coordinate information of two coordinate points input by user, Determine the direction vector of described two coordinate points, and using the corresponding unit vector of the direction vector as the second unit side To vector；Or, according to least square method, the corresponding linear equation of the second coordinate points in the coordinate system is determined, according to described straight Line equation determines the corresponding second unit direction vector of the linear equation；Or, the method according to principal component analysis, determine institute The covariance matrix of the point set of the second coordinate points composition is stated, the second unit side is determined according to the feature vector of the covariance matrix To vector.

Further, described device further includes：

5th determining module after determining that image to be corrected mixes colour temperature there are natural light, is mixed according to natural light Colour temperature white balance algorithm is closed to determine white balance gains and be corrected described image.

Further, the 5th determining module, specifically for according to the first unit direction vector and the second unit The angle and setup parameter of direction vector using preset algorithm, determine the angle and the corresponding nature of the setup parameter Light mixes colour temperature parameter value；Colour temperature parameter value is mixed according to the natural light and determines monochromatic warm white balance algorithm and natural light mixing Corresponding first weight of colour temperature white balance algorithm and the second weight, according to the monochromatic warm white balance algorithm and natural light secondary colour Warm white balance algorithm and corresponding first weight and the second weight, determine white balance gains.

Further, the 5th determining module, specifically for the natural light is mixed colour temperature parameter value as second Weight, using 1 with the difference of second weight as the first weight.

Further, the 5th determining module, specifically for according to the first unit direction vector and pre-saving The second unit direction vector angle, calculate the product of the angle and parameter preset；The cosine value of the product is determined Colour temperature parameter value is mixed for the natural light.

Further, described device further includes：

5th determining module, after determining image to be corrected there is no natural light mixing colour temperature, according to monochromatic temperature White balance algorithm determines white balance gains and described image is corrected.

Further, described device further includes：

Second judgment module, for determining the ring of image according to the camera of preservation shooting aperture time, gain parameter, aperture Border illumination when the ambient light illumination is more than the second given threshold, continues subsequent step；Or judge the first cluster and the second cluster The distance between central point when being more than third given threshold, continue subsequent step；Or judge the first cluster and the second cluster The abscissa of central point is respectively positioned in the range of the corresponding abscissa of colour temperature of natural light, and the center of the first cluster and the second cluster When the ordinate of point is respectively positioned in the range of the corresponding ordinate of colour temperature of natural light, the first judgment module is triggered.

Further, first determining module, the G/R of each rectangular area specifically for determining each rectangular area Value and G/B values；Or, determine the logarithm of G/R of each rectangular area and the logarithm of G/B；Or, determine each rectangular area Each logarithm of R/G of rectangular area and the logarithm of B/G.

The embodiment of the present invention provides the judgment method and device of natural light mixing colour temperature in a kind of image, the method packet It includes：For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to each rectangle region The red R in domain, green G, indigo plant B mean values determine the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；According to each The value of a pair of of natural light mixing colour temperature evaluation parameter of rectangular area determines that each rectangular area corresponds in the coordinate system of structure Each first coordinate points, wherein coordinate system using the pair of natural light mix colour temperature evaluation parameter as horizontally and vertically；It will The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to the central point of each cluster, determine the One unit direction vector, wherein the direction of the first unit direction vector is low colour temperature to high color temperature direction；Judge that first is single Whether position direction vector and the angle of the second unit direction vector pre-saved are less than the first threshold of setting, wherein, it is described Second unit direction vector is to predefine and preserve according to the target image that colour temperature is mixed there are natural light；If so, really Fixed image to be corrected is there are natural light mixing colour temperature, otherwise, it determines there is no natural light mixing colour temperatures for image to be corrected.By In the second unit direction vector be directed to there are natural light mixing colour temperature target image to determine, therefore, when the first unit The angle of direction vector and the second unit direction vector is less than the first threshold of setting, illustrates the image to be corrected and the presence The target image of natural light mixing colour temperature is similar, and there is also natural lights to mix colour temperature, thereby may be ensured that image natural light mixes The accuracy that colour temperature judges, and further ensure the accuracy of follow-up white balance correction.

Description of the drawings

To describe the technical solutions in the embodiments of the present invention more clearly, make required in being described below to embodiment Attached drawing is briefly introduced, it should be apparent that, the accompanying drawings in the following description is only some embodiments of the present invention, for this For the those of ordinary skill in field, without creative efforts, other are can also be obtained according to these attached drawings Attached drawing.

Fig. 1 is a kind of realizing auto kine bias function process schematic that the prior art provides；

Fig. 2 is the deterministic process schematic diagram that natural light mixes colour temperature in a kind of image that the embodiment of the present invention 1 provides；

Fig. 3 is that the image that the embodiment of the present invention 1 provides divides rectangular area schematic diagram；

Fig. 4 is the corresponding coordinate system schematic diagram of target image that the embodiment of the present invention 2 provides；

Fig. 5 is the deterministic process schematic diagram that natural light mixes colour temperature in a kind of image that the embodiment of the present invention 4 provides；

Fig. 6 is the judgment means structure diagram that natural light mixes colour temperature in a kind of image provided in an embodiment of the present invention.

Specific embodiment

It is more accurate in order to judge image natural light mixing colour temperature, and further make the accurate of follow-up white balance correction Property improve, an embodiment of the present invention provides in a kind of image natural light mixing colour temperature judgment method and device.

The present invention will be describe below in further detail with reference to the accompanying drawings, it is clear that described embodiment is only this Invention part of the embodiment, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art exist The all other embodiment obtained under the premise of creative work is not made, shall fall within the protection scope of the present invention.

Embodiment 1：

Fig. 2 mixes the deterministic process schematic diagram of colour temperature, the mistake for natural light in a kind of image provided in an embodiment of the present invention Journey includes the following steps：

S201：For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to The red R of each rectangular area, green G, indigo plant B mean values determine a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area Value.

The judgment method of natural light mixing colour temperature is applied to electronic equipment in a kind of image provided in an embodiment of the present invention.Institute It states electronic equipment and includes PC, smart television, camera and mobile phone etc..

Image to be corrected is divided into multiple rectangular areas by the electronic equipment according to the rule of setting, to be corrected Image when being divided, can the long of image be subjected to n deciles, m deciles be carried out to the wide of image, wherein the m and n is identical Or it is different, multiple rectangular areas are obtained after division.As shown in figure 3, the length and width to image carry out 6 deciles respectively, i.e., image is drawn It is divided into 36 rectangular areas.According to the red R of each pixel in each rectangular area, green G, indigo plant B values, each rectangle region is determined R, G, B mean value in domain, so determine each rectangular area a pair of of natural light mixing colour temperature evaluation parameter value, it is the pair of from The value of right light mixing colour temperature evaluation parameter can be G/R, G/B value of each rectangular area or each rectangular area The logarithm of G/R, the logarithm of G/B can also be the logarithm of the R/G of each rectangular area, the logarithm of B/G.

S202：The value of colour temperature evaluation parameter is mixed in the coordinate system of structure according to a pair of of natural light of each rectangular area Determine corresponding each first coordinate points in each rectangular area, wherein coordinate system is with the pair of natural light mixing colour temperature evaluation ginseng Number is as horizontally and vertically.

The value of the pair of natural light mixing colour temperature evaluation parameter can be G/R, G/B value of each rectangular area, also may be used Be each rectangular area G/R logarithm, the logarithm of G/B, can also be the R/G of each rectangular area logarithm, A pair of natural light is mixed colour temperature evaluation parameter as horizontally and vertically, builds coordinate system, determine each by the logarithm of B/G Corresponding each first coordinate points in rectangular area.

Such as G/R, G/B value that the value of a pair of natural light mixing colour temperature evaluation parameter is each rectangular area, structure Horizontal axis of the coordinate system using G/R as coordinate system, using G/B as the longitudinal axis of coordinate system.Therefore for each rectangular area, the rectangle G/R, G/B value in region, it is believed that be the abscissa and ordinate of the rectangular area, therefore the rectangular area is identified to the seat In mark system, it is believed that be abscissa be its G/R value, ordinate is the coordinate points of its G/B value.

Such as the value of a pair of natural light mixing colour temperature evaluation parameter can also be the logarithm of the G/R of each rectangular area Value, the logarithm of G/B, the horizontal axis of the coordinate system of structure using the logarithm of G/R as coordinate system, using the logarithm of G/B as seat Mark the longitudinal axis of system.A pair of natural light mixing colour temperature evaluation parameter value can also be each rectangular area R/G logarithm, The logarithm of B/G, the horizontal axis of the coordinate system of structure using the logarithm of R/G as coordinate system, using the logarithm of B/G as coordinate system The longitudinal axis.

S203：The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to each cluster Central point, the first unit direction vector is determined, wherein the direction of the first unit direction vector is low colour temperature to high color temperature Direction.

The value of colour temperature evaluation parameter is mixed according to a pair of of natural light of each rectangular area, it is determined that each square in coordinate system After corresponding first coordinate points in shape region, clustering algorithm may be used, the first coordinate points in coordinate system are clustered, specifically In cluster, the first coordinate points in the coordinate system are divided into the first cluster and the second cluster.Wherein in coordinate system The first coordinate points when being clustered, general clustering method, such as kmeans algorithms, K mean algorithms etc. may be used.

The first coordinate points in the coordinate system can be divided by K mean algorithms in embodiments of the present invention One cluster and the second cluster.It is divided into after two clusters and mean shift process may be used determines the first cluster and second poly- respectively The central point of class.

Colour temperature is higher, more inclined blue cast, and B values are bigger；Colour temperature is lower, more inclined red color tone, and R values are bigger.It specifically determines low The process in colour temperature to high color temperature direction belongs to the prior art, in embodiments of the present invention to the process without repeating.

Specifically using clustering algorithm, by the first coordinate points in coordinate system be divided into the first cluster and the second cluster and It determines that the process of the central point of the first cluster and the second cluster belongs to the prior art using mean shift process, implements in the present invention To the process without repeating in example.

S204：Judge whether the first unit direction vector is less than with the angle of the second unit direction vector pre-saved to set Fixed first threshold, wherein, the second unit direction vector is advance according to the target image that colour temperature is mixed there are natural light It determines and preserves, if it is, carrying out S205, otherwise, carry out S206.

In embodiments of the present invention according to there are natural light mixing colour temperature target image, generation the second unit direction to Amount.Because for there are natural light mixing colour temperature target image, when by it according to the regular partition set as multiple rectangle regions During domain, the value of a pair of of natural light mixing colour temperature evaluation parameter of each of which rectangular area is distributed approximate one directly in a coordinate system Line, therefore the low colour temperature of this line correspondences can be determined to the unit vector in high color temperature direction according to this feature, by the unit Vector is used as the second unit direction vector.

S205：Determining image to be corrected, there are natural light mixing colour temperatures.

S206：Determining image to be corrected, there is no natural light mixing colour temperatures.

After the first unit direction vector is determined, according to the first unit direction vector and the folder of the second unit direction vector Angle, you can judge that image to be corrected mixes colour temperature with the presence or absence of natural light, when the angle is less than the first given threshold, say The value of a pair of of natural light mixing colour temperature evaluation parameter of rectangular area after bright image division also complies with natural light mixing colour temperature The distribution characteristics of image, it is thus determined that image to be corrected there are natural light mix colour temperature, when the angle is set not less than first When determining threshold value, determining image to be corrected, there is no natural light mixing colour temperatures.Wherein first given threshold can be 3 degree, 5 degree Etc. smaller numerical value.

Due in embodiments of the present invention, being judged according to the angle of the first unit direction vector and the second unit direction vector Image to be corrected with the presence or absence of natural light mix colour temperature, the second unit direction vector be directed to there are natural light mix colour temperature Target image predefine and preserve, therefore, when the angle of the first unit direction vector and the second unit direction vector is small In the first threshold of setting, illustrate that the image to be corrected is similar with the target image there are natural light mixing colour temperature, also deposit Colour temperature is mixed in natural light, thereby may be ensured that the accuracy that image natural light mixing colour temperature judges, and further ensure The accuracy of follow-up white balance correction.

Embodiment 2：

On the basis of above-described embodiment, in order to mix the target image of colour temperature according to the natural light acquired in advance, accurately Determine the second unit direction vector, improve the accuracy that subsequently judges, in embodiments of the present invention, determine second unit The process of direction vector includes：

Electronic equipment acquires the target image of width natural light mixing colour temperature in advance, has blue sky, sun in the target image Target image is divided into multiple rectangular areas by the information such as light, shade according to the rule of setting.It is more target image is divided into During a rectangular area, various ways may be used, as long as the dividing mode phase with the rectangular area of the image in above-described embodiment With.Such as when being divided to target image, can the long of image be subjected to n deciles, m etc. is carried out to the wide of image Point, wherein the m and n are identical or different, multiple rectangular areas are obtained after division, specific dividing mode is with reference to Fig. 3.According to every The red R of each pixel in a rectangular area, green G, indigo plant B values determine R, G, B mean value of each rectangular area, and then determine every The value of a pair of of natural light mixing colour temperature evaluation parameter of a rectangular area.

The value of the pair of natural light mixing colour temperature evaluation parameter can be G/R, G/B value of each rectangular area, also may be used Be each rectangular area G/R logarithm, the logarithm of G/B, can also be the R/G of each rectangular area logarithm, The logarithm of B/G.

For G/R, G/B value by the value of the pair of natural light mixing colour temperature evaluation parameter for each rectangular area, really After G/R, G/B value for having determined each rectangular area, determine that G/R, G/B value of each rectangular area are corresponding in coordinate system is built Each second coordinate points, specifically in a coordinate system for there are each second that the target image of natural light mixing colour temperature determines Coordinate points are referring to Fig. 4.

As can be seen from FIG. 4, there are the target images of natural light mixing colour temperature, after being divided into multiple rectangular areas, root According to G/R, G/B value of each rectangular area, corresponding second coordinate points in each rectangular area are determined in the coordinate system of structure Afterwards, the distribution of the second coordinate points is approximate straight line in the coordinate system, therefore the second unit can be determined according to the straight line Direction vector, wherein the direction of the second unit direction vector is low colour temperature to high color temperature direction.

The value for specifically determining a pair of of mixing colour temperature evaluation parameter of each rectangular area and the method for building coordinate system with Method in the embodiment of the present invention 1 is identical, is no longer repeated in embodiments of the present invention.

In embodiments of the present invention, the second unit direction vector can be determined by different methods, according to each second Coordinate of the coordinate points in the coordinate system determines that the second unit direction vector includes：

The second coordinate points in a coordinate system are similar to straight line, and user can choose two coordinates on the straight line Point or user input the coordinate of two coordinate points, after electronic equipment determines the coordinate of two coordinate points, and then can determine The low colour temperature of described two coordinate points and is made the corresponding unit vector of the direction vector to the direction vector in high color temperature direction For the second unit direction vector.

Such as two coordinate points that electronic equipment determines are A (gr1, gb1) and B (gr2, gb2), then can determine A, B The corresponding direction vector of two coordinate points is C=B-A, and wherein direction is low colour temperature to high color temperature direction, and it is single to be then obtained second Position direction vector e=C/ | C |

It can also be coordinate of the electronic equipment according to each second coordinate points in the coordinate system, pass through least square Method determines the corresponding linear equation gb=k*gr+b of the second coordinate points in the coordinate system, wherein, pass through least square fitting The process of linear equation belongs to the prior art, in embodiments of the present invention to the realization process without repeating.It is straight when determining After line equation, any two coordinate points for meeting the linear equation are determined, and then can determine the low color of described two coordinate points Temperature arrive high color temperature direction direction vector, and using the corresponding unit vector of the direction vector as the second unit direction to Amount.

, by the method for principal component analysis, described can also be determined according to each second coordinate points in the coordinate system The covariance matrix of the point set of two coordinate points composition, and asks for the feature vector of the covariance matrix, according to the feature to Amount, and then determine the second unit direction vector, wherein the direction of the second unit direction vector is low colour temperature to high color temperature side To.Wherein determine that the process of covariance matrix belongs to the prior art by the method for principal component analysis, in embodiments of the present invention To the process without repeating.

Embodiment 3：

For the white balance correction to image of realization, on the basis of the various embodiments described above, in embodiments of the present invention, After determining that image to be corrected mixes colour temperature there are natural light, the method further includes：

The natural light mixing colour temperature white balance algorithm can be gray world algorithm, specifically, being calculated using gray world Method determines that the process of white balance gains belongs to the prior art, and according to white balance gains, to image, corrected process is also existing There is technology, in embodiments of the present invention to the process without repeating.

It is described in embodiments of the present invention that colour temperature white balance is mixed according to natural light in order to make white balance correction more accurate Algorithm determines that white balance gains include：

The direction of the first unit direction vector and the second unit direction vector be all by low colour temperature to high color temperature direction, According to the parameter that the angle and electronic equipment of the first unit direction vector and the second unit direction vector are set, use is preset Algorithm determines the angle and the corresponding natural light mixing colour temperature parameter value of the setup parameter.Wherein, preset algorithm can be with For the angle according to the first unit direction vector and the second unit direction vector, multiplying for the angle and parameter preset is calculated Product；The cosine value of the product is determined as the natural light and mixes colour temperature parameter value.

Specifically, the angle of the first unit direction vector and the second unit direction vector is α, setup parameter k, according to institute The angle α of the second unit direction vector and the product of parameter preset k stated the first unit direction vector and pre-saved；By institute The cosine value for stating product is determined as the natural light mixing colour temperature parameter value, i.e., described natural light mixing colour temperature parameter value is cos (kα)。

In the present embodiment, monochromatic warm white balance algorithm can be dynamic threshold algorithm, and natural light mixes colour temperature white balance Algorithm can be gray world algorithm.

After being determined that natural light mixes colour temperature parameter value, can colour temperature parameter value be mixed according to the natural light and determine monochrome Second weight of the first weight and natural light the mixing colour temperature white balance algorithm of warm white balance algorithm, the natural light is mixed Color temperature parameters value is as the second weight, and using 1 with the difference of second weight as the first weight, i.e. dynamic threshold algorithm is corresponding First weight is 1-cos (k α), and corresponding second weight of gray world algorithm is cos (k α).Certainly in determining monochrome Wen Baiping When accounting method and corresponding first weight of natural light mixing colour temperature white balance algorithm and the second weight, its other party can also be used Method, if can ensure the second weight and first weight and the second weight and ratio be equal to the natural light secondary colour Warm parameter value.

After the first weight and the second weight is determined, colour temperature is mixed by monochromatic warm white balance algorithm and natural light and is put down in vain It accounts method and its corresponding first weight and the second weight calculation goes out the final white balance gains of image to be corrected, algorithm Shown in equation below：

RGain=(1-cos (k α)) * RGain1+cos (k α) * RGain2；

BGain=(1-cos (k α)) * BGain1+cos (k α) * BGain2；

Wherein, RGain1, BGain1 are the R calculated according to monochromatic warm white balance algorithm, the white balance gains of B, RGain2, BGain2 are to mix the R that calculates of colour temperature white balance algorithm according to natural light, the white balance gains of B, RGain, BGain is the final white balance gains of the image to be corrected calculated.

Image is corrected according to the final white balance gains of the image to be corrected calculated, specifically, according to white To image, corrected process belongs to the prior art to balancing gain, in embodiments of the present invention to the process without repeating.

In embodiments of the present invention, when carrying out white balance correction to image to be corrected, only to the R in image, B component It is corrected, keeps G components constant, so that the brightness after image progress white balance correction to be corrected is kept not Become.

Due to according to monochromatic warm white balance algorithm and mixing colour temperature white balance algorithm and its corresponding first weight and second Weight calculation goes out final white balance gains so as to carry out white balance school to there are the images to be corrected of natural light mixing colour temperature Timing can mix colour temperature degree according to the natural light of image to be corrected, which is corrected, thereby may be ensured that white The accuracy of balance correction.

For the white balance correction to image of realization, on the basis of the various embodiments described above, in embodiments of the present invention, After determining image to be corrected there is no natural light mixing colour temperature, the method further includes：

The monochromatic warm white balance algorithm can be dynamic threshold algorithm, specifically, using dynamic threshold algorithm, determine white The process of balancing gain belongs to the prior art, and according to white balance gains, to image, corrected process is also the prior art, To the process without repeating in the embodiment of the present invention.

Embodiment 4：

On the basis of embodiment 1, judge in image with the presence or absence of the standard of natural light mixing colour temperature to further improve Whether true property, the angle of the second unit direction vector for judging the first unit direction vector and pre-saving are less than the first of setting Threshold value, wherein, the second unit direction vector is to predefine and protect according to the target image that colour temperature is mixed there are natural light Before depositing, the method further includes：

The ambient light illumination of image is judged according to the camera of preservation shooting aperture time, gain parameter, aperture, works as ambient light illumination During more than the second given threshold, continue subsequent step；Or

In embodiments of the present invention, since the illumination where natural light secondary colour thermal field scape is all bigger, electronic equipment root The ambient light illumination of image is judged according to camera shooting aperture time, gain parameter, the aperture of preservation, when ambient light illumination is set more than second When determining threshold value, then it is assumed that image to be corrected there is a possibility that natural light mixing colour temperature is big, at this point, continuing subsequent step, i.e., Whether the angle of the second unit direction vector for judging the first unit direction vector and pre-saving is less than the first threshold set.

Since in natural light secondary colour thermal field scape, colour temperature differs greatly, and is divided by the first coordinate points in coordinate system First cluster and the second cluster, according to the central point of each cluster, if two central points are nearer, it is easy to because in one of them The minute movement of heart point so that the first unit direction vector changes a lot, therefore is also just likely to be such that the first unit Direction vector and the angle α of the second unit direction vector pre-saved have greatly changed, and stability is poor.Therefore, exist Whether the angle of the second unit direction vector for judging the first unit direction vector and pre-saving is less than the first threshold set Before, judge whether the distance of the central point of two clusters is more than third given threshold, if greater than then judging the first unit side Whether it is less than the first threshold of setting to vector and the angle of the second unit direction vector pre-saved.

In order to avoid a certain color in image is mistakenly considered a kind of natural light of colour temperature, saved in electronic equipment certainly The reference color temperature of right light mixes the value of colour temperature evaluation parameter according to a pair of of natural light of determining rectangular area and builds coordinate system Method determines the corresponding abscissa range of reference color temperature of natural light and ordinate range, if it is determined that the first cluster and second The abscissa of the central point of cluster is in the range of the corresponding abscissa of colour temperature of natural light, the first cluster and the second cluster When the ordinate of central point is in the range of the corresponding ordinate of colour temperature of natural light, then it is assumed that image to be corrected exists certainly The possibility of right light mixing colour temperature is big, at this point, continuing subsequently to judge the first unit direction vector and the second unit pre-saved The step of whether angle of direction vector is less than the first threshold of setting.

Whether it is less than setting in the angle of the second unit direction vector for judging the first unit direction vector and pre-saving First threshold before any of the above-described method may be used judged or above two or three kinds of combination can also be used Judged, using above-mentioned three kinds of methods with reference to as shown in Figure 5 come the process that is judged.

Fig. 5 mixes the deterministic process schematic diagram of colour temperature, the mistake for natural light in a kind of image provided in an embodiment of the present invention Journey includes the following steps：

S501：For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to The red R of each rectangular area, green G, indigo plant B mean values determine a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area Value.

S502：The value of colour temperature evaluation parameter is mixed in the coordinate system of structure according to a pair of of natural light of each rectangular area Determine corresponding each first coordinate points in each rectangular area, wherein coordinate system is with the pair of natural light mixing colour temperature evaluation ginseng Number is as horizontally and vertically.

S503：The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to each cluster Density center, the first unit direction vector is determined, wherein the direction of the first unit direction vector is low colour temperature to high color Warm direction.

S504：The ambient light illumination of image is judged according to the camera of preservation shooting aperture time, gain parameter, aperture, works as ring When border illumination is more than the second given threshold, step S505 is carried out, otherwise, carries out step S509.

S505：When the distance between center for judging the first cluster and the second cluster is more than third given threshold, walked Otherwise rapid S506, carries out step S509.

S506：Judge the first cluster horizontal seat corresponding with the colour temperature that the abscissa of the central point of the second cluster is in natural light In the range of mark, the first cluster ordinate model corresponding with the colour temperature that the ordinate of the central point of the second cluster is in natural light is judged When enclosing interior, step S507 is carried out, otherwise, carry out step S509.

S507：Judge whether the first unit direction vector is less than with the angle of the second unit direction vector pre-saved to set Fixed first threshold, wherein, the second unit direction vector is advance according to the target image that colour temperature is mixed there are natural light It determines and preserves, if it is, carrying out S508, otherwise, carry out S509.

S508：Determining image to be corrected, there are natural light mixing colour temperatures.

S509：Determining image to be corrected, there is no natural light mixing colour temperatures.

Fig. 6 is the judgment means structure diagram that natural light mixes colour temperature in a kind of image provided in an embodiment of the present invention, Applied to electronic equipment, which includes：

Described image for being directed to image to be corrected, is divided into more by the first determining module 61 according to the rule of setting A rectangular area according to the red R of each rectangular area, green G, indigo plant B mean values, determines a pair of of natural light mixing of each rectangular area The value of colour temperature evaluation parameter；

Second determining module 62, the value for mixing colour temperature evaluation parameter according to a pair of of natural light of each rectangular area exist Corresponding each first coordinate points in each rectangular area are determined in the coordinate system of structure, wherein coordinate system is with the pair of natural light Colour temperature evaluation parameter is mixed as horizontally and vertically；

Third determining module 63 is gathered for the first coordinate points in the coordinate system to be divided into the first cluster and second Class according to the central point of each cluster, determines the first unit direction vector, wherein the direction of the first unit direction vector is Low colour temperature is to high color temperature direction；

First judgment module 64, for judging the first unit direction vector and the second unit direction vector for pre-saving Whether angle is less than the first threshold of setting, wherein, the second unit direction vector is to mix colour temperature according to there are natural lights Target image predefine and preserve；

4th determining module 65 if being yes for being used for the judging result of the first judgment module, determines figure to be corrected Colour temperature is mixed as there are natural lights, if the judging result of the first judgment module is no, determines that image to be corrected is not present certainly Right light mixing colour temperature.

First determining module 61 is additionally operable to for the target image of natural light mixing colour temperature acquired in advance, according to The target image is divided into multiple rectangular areas by the rule of setting, according to R, G, B mean value of each rectangular area, is determined every The value of a pair of of natural light mixing colour temperature evaluation parameter of a rectangular area；

Second determining module 62 is additionally operable to mix colour temperature evaluation parameter according to a pair of of natural light of each rectangular area Value determine corresponding each second coordinate points in each rectangular area in the coordinate system of structure, wherein coordinate system with described one To natural light mixing colour temperature evaluation parameter as horizontally and vertically；

The third determining module 63 is additionally operable to the coordinate in the coordinate system according to each second coordinate points, determines Second unit direction vector, wherein the direction of the second unit direction vector is low colour temperature to high color temperature direction.

The third determining module 63 specifically for obtaining the coordinate information of two coordinate points input by user, determines institute State the direction vector of two coordinate points, and using the corresponding unit vector of the direction vector as the second unit direction to Amount；Or according to least square method, the corresponding linear equation of the second coordinate points in the coordinate system is determined, according to the straight line side Journey determines the corresponding second unit direction vector of the linear equation；Or the method according to principal component analysis, determine described second Coordinate points composition point set covariance matrix, according to the feature vector of the covariance matrix determine the second unit direction to Amount.

Described device further includes：

5th determining module 66, after determining that image to be corrected mixes colour temperature there are natural light, according to natural light Mixing colour temperature white balance algorithm determines white balance gains and described image is corrected.

5th determining module 66, specifically for according to the first unit direction vector and the second unit direction vector Angle and setup parameter, using preset algorithm, determine the angle and the corresponding natural light secondary colour of the setup parameter Warm parameter value；Colour temperature parameter value is mixed according to the natural light and determines that monochromatic warm white balance algorithm and natural light mixing colour temperature are put down in vain Corresponding first weight of method and the second weight are accounted, colour temperature white balance is mixed according to the monochromatic warm white balance algorithm and natural light Algorithm and corresponding first weight and the second weight, determine white balance gains.

5th determining module 66, specifically for the natural light is mixed colour temperature parameter value as the second weight, by 1 Difference with second weight is as the first weight.

5th determining module 66, specifically for according to the first unit direction vector and the second list pre-saved The angle of position direction vector calculates the product of the angle and parameter preset；By the cosine value of the product be determined as it is described from Right light mixing colour temperature parameter value.

Described device further includes：

5th determining module 66, after determining image to be corrected there is no natural light mixing colour temperature, according to monochrome Warm white balance algorithm determines white balance gains and described image is corrected.

Described device further includes：

Second judgment module 67 determines image for shooting aperture time, gain parameter, aperture according to the camera of preservation Ambient light illumination when the ambient light illumination is more than the second given threshold, continues subsequent step；Or judge that the first cluster and second is gathered When the distance between central point of class is more than third given threshold, continue subsequent step；Or judge the first cluster and the second cluster The abscissa of central point be respectively positioned in the range of the corresponding abscissa of colour temperature of natural light, and in the first cluster and the second cluster When the ordinate of heart point is respectively positioned in the range of the corresponding ordinate of colour temperature of natural light, the first judgment module 64 is triggered.

First determining module 61, the G/R values and G/B of each rectangular area specifically for determining each rectangular area Value；Or, determine the logarithm of G/R of each rectangular area and the logarithm of G/B；Or, determine each square of each rectangular area The logarithm of the R/G in shape region and the logarithm of B/G.

The embodiment of the present invention provides the judgment method and device of natural light mixing colour temperature in a kind of image, the method packet It includes：For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to each rectangle region The red R in domain, green G, indigo plant B mean values determine the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；According to each The value of a pair of of natural light mixing colour temperature evaluation parameter of rectangular area determines that each rectangular area corresponds in the coordinate system of structure Each first coordinate points, wherein coordinate system using the pair of natural light mix colour temperature evaluation parameter as horizontally and vertically；It will The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to the central point of each cluster, determine the One unit direction vector, wherein the direction of the first unit direction vector is low colour temperature to high color temperature direction；Judge that first is single Whether position direction vector and the angle of the second unit direction vector pre-saved are less than the first threshold of setting, wherein, it is described Second unit direction vector is to predefine and preserve according to the target image that colour temperature is mixed there are natural light；If so, really Fixed image to be corrected is there are natural light mixing colour temperature, otherwise, it determines there is no natural light mixing colour temperatures for image to be corrected.By It is to be directed to predefine and preserve there are the target image of natural light mixing colour temperature in the second unit direction vector, therefore, When first threshold of the angle of the first unit direction vector and the second unit direction vector less than setting, illustrate the figure to be corrected The target image that picture mixes colour temperature with this there are natural light is similar, and there is also natural lights to mix colour temperature, thereby may be ensured that image The accuracy that natural light mixing colour temperature judges, and further ensure the accuracy of follow-up white balance correction.

The present invention be with reference to according to the method for the embodiment of the present invention, the flow of equipment (system) and computer program product Figure and/or block diagram describe.It should be understood that it can be realized by computer program instructions every first-class in flowchart and/or the block diagram The combination of flow and/or box in journey and/or box and flowchart and/or the block diagram.These computer programs can be provided The processor of all-purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices is instructed to produce A raw machine so that the instruction performed by computer or the processor of other programmable data processing devices is generated for real The device of function specified in present one flow of flow chart or one box of multiple flows and/or block diagram or multiple boxes.

These computer program instructions, which may also be stored in, can guide computer or other programmable data processing devices with spy Determine in the computer-readable memory that mode works so that the instruction generation being stored in the computer-readable memory includes referring to Enable the manufacture of device, the command device realize in one flow of flow chart or multiple flows and/or one box of block diagram or The function of being specified in multiple boxes.

These computer program instructions can be also loaded into computer or other programmable data processing devices so that counted Series of operation steps are performed on calculation machine or other programmable devices to generate computer implemented processing, so as in computer or The instruction offer performed on other programmable devices is used to implement in one flow of flow chart or multiple flows and/or block diagram one The step of function of being specified in a box or multiple boxes.

Although preferred embodiments of the present invention have been described, but those skilled in the art once know basic creation Property concept, then additional changes and modifications may be made to these embodiments.So appended claims be intended to be construed to include it is excellent It selects embodiment and falls into all change and modification of the scope of the invention.

Obviously, various changes and modifications can be made to the invention without departing from essence of the invention by those skilled in the art God and range.In this way, if these modifications and changes of the present invention belongs to the range of the claims in the present invention and its equivalent technologies Within, then the present invention is also intended to include these modifications and variations.

Claims

1. a kind of judgment method of natural light mixing colour temperature in image, which is characterized in that the method includes：

For image to be corrected, described image is divided into multiple rectangular areas according to the rule of setting, according to each rectangle The red R in region, green G, indigo plant B mean values determine the value of a pair of of natural light mixing colour temperature evaluation parameter of each rectangular area；

The value that colour temperature evaluation parameter is mixed according to a pair of of natural light of each rectangular area determines each in the coordinate system of structure Corresponding each first coordinate points in rectangular area, wherein coordinate system mix colour temperature evaluation parameter as horizontal stroke using the pair of natural light Axis and the longitudinal axis；

The first coordinate points in the coordinate system are divided into the first cluster and the second cluster, according to the central point of each cluster, The first unit direction vector is determined, wherein the direction of the first unit direction vector is low colour temperature to high color temperature direction；

Whether the angle of the second unit direction vector for judging the first unit direction vector and pre-saving is less than the first of setting Threshold value, wherein, the second unit direction vector is to predefine and protect according to the target image that colour temperature is mixed there are natural light It deposits；

If so, image to be corrected is determined there are natural light mixing colour temperature, otherwise, it determines nature is not present in image to be corrected Light mixes colour temperature；

Determine that the process of the second unit direction vector includes：

For the target image of natural light mixing colour temperature acquired in advance, the target image is divided into according to the rule of setting Multiple rectangular areas according to R, G, B mean value of each rectangular area, determine a pair of of natural light mixing colour temperature of each rectangular area The value of evaluation parameter；

The value that colour temperature evaluation parameter is mixed according to a pair of of natural light of each rectangular area determines each in the coordinate system of structure Corresponding each second coordinate points in rectangular area, wherein coordinate system using the pair of natural light mix colour temperature evaluation parameter as Horizontally and vertically；

According to coordinate of each second coordinate points in the coordinate system, the second unit direction vector is determined, wherein described second The direction of unit direction vector is low colour temperature to high color temperature direction.

2. according to the method described in claim 1, it is characterized in that, each second coordinate points of the basis are in the coordinate system Coordinate, determine that the second unit direction vector includes：

The coordinate information of two coordinate points input by user is obtained, determines the direction vector of described two coordinate points, and by described in The corresponding unit vector of direction vector is as the second unit direction vector；Or

According to least square method, the corresponding linear equation of the second coordinate points in the coordinate system is determined, according to the linear equation, Determine the corresponding second unit direction vector of the linear equation；Or

According to the method for principal component analysis, the covariance matrix of the point set of the second coordinate points composition is determined, according to the association The feature vector of variance matrix determines the second unit direction vector.

3. according to the method described in claim 1, it is characterized in that, it is described determine image to be corrected there are natural light secondary colours After temperature, the method further includes：

4. according to the method described in claim 3, it is characterized in that, described determine according to natural light mixing colour temperature white balance algorithm White balance gains include：

According to the first unit direction vector and the angle and setup parameter of the second unit direction vector, using preset calculation Method determines the angle and the corresponding natural light mixing colour temperature parameter value of the setup parameter；

Colour temperature parameter value is mixed according to the natural light, determines that monochromatic warm white balance algorithm and natural light mixing colour temperature white balance are calculated Corresponding first weight of method and the second weight mix colour temperature white balance algorithm according to the monochromatic warm white balance algorithm and natural light And corresponding first weight and the second weight, determine white balance gains.

5. according to the method described in claim 4, it is characterized in that, described mix colour temperature parameter value according to the natural light, really Order colour temperature white balance algorithm and corresponding first weight of natural light mixing colour temperature white balance algorithm and the second weight include：

The natural light is mixed into colour temperature parameter value as the second weight, using 1 with the difference of second weight as the first weight.

It is 6. according to the method described in claim 4, it is characterized in that, described according to the first unit direction vector and advance guarantor The angle and setup parameter of the second unit direction vector deposited using preset algorithm, determine the angle and the setting ginseng The corresponding natural light mixing colour temperature parameter value of number includes：

According to the first unit direction vector and the angle of the second unit direction vector that pre-saves, calculate the angle with The product of parameter preset；The cosine value of the product is determined as the natural light and mixes colour temperature parameter value.

7. according to the method described in claim 1, it is characterized in that, it is described determine image to be corrected there is no natural light mixing After colour temperature, the method further includes：

8. according to the method described in claim 1, it is characterized in that, described judge the first unit direction vector and pre-save Whether the angle of the second unit direction vector is less than before the first threshold of setting, and the method further includes：

The ambient light illumination of image is determined according to the camera of preservation shooting aperture time, gain parameter, aperture, when the ambient light illumination During more than the second given threshold, continue subsequent step；Or

When the distance between central point for judging the first cluster and the second cluster is more than third given threshold, continue subsequent step； Or

Judge the first cluster abscissa range corresponding with the colour temperature that the abscissa of the central point of the second cluster is respectively positioned on natural light It is interior, and in the range of the first cluster ordinate corresponding with the colour temperature that the ordinate of the central point of the second cluster is respectively positioned on natural light When, continue subsequent step.

9. according to the method described in claim 1, it is characterized in that, a pair of of natural light mixing colour temperature of each rectangular area The value of evaluation parameter includes：

Each G/R values of rectangular area and G/B values；Or

Each logarithm of G/R of rectangular area and the logarithm of G/B；Or

Each logarithm of R/G of rectangular area and the logarithm of B/G.

10. the judgment means of natural light mixing colour temperature in a kind of image, which is characterized in that described device includes：

For being directed to image to be corrected, multiple rectangles are divided into according to the rule of setting by the first determining module for described image Region according to the red R of each rectangular area, green G, indigo plant B mean values, determines that a pair of of natural light mixing colour temperature of each rectangular area is commented The value of valency parameter；

Second determining module, for mixing the value of colour temperature evaluation parameter according to a pair of of natural light of each rectangular area in structure Corresponding each first coordinate points in each rectangular area are determined in coordinate system, wherein coordinate system is with the pair of natural light secondary colour Warm evaluation parameter is as horizontally and vertically；

Third determining module, for the first coordinate points in the coordinate system to be divided into the first cluster and the second cluster, according to The central point each clustered determines the first unit direction vector, wherein the direction of the first unit direction vector is low colour temperature To high color temperature direction；

First judgment module, for judging that the first unit direction vector is with the angle of the second unit direction vector pre-saved The no first threshold for being less than setting, wherein, the second unit direction vector is according to there are the targets that natural light mixes colour temperature What image was predefined and was preserved；

4th determining module if the judging result for the first judgment module is yes, determines that there are natures for image to be corrected Light mixes colour temperature, if the judging result of the first judgment module is no, determines that natural light secondary colour is not present in image to be corrected Temperature；

First determining module is additionally operable to for the target image of natural light mixing colour temperature acquired in advance, according to setting The target image is divided into multiple rectangular areas by rule, according to R, G, B mean value of each rectangular area, determines each rectangle The value of a pair of of natural light mixing colour temperature evaluation parameter in region；

Second determining module, the value for being additionally operable to mix colour temperature evaluation parameter according to a pair of of natural light of each rectangular area exist Determine corresponding each second coordinate points in each rectangular area in the coordinate system of structure, wherein coordinate system with the pair of nature Light mixing colour temperature evaluation parameter is as horizontally and vertically；

The third determining module is additionally operable to the coordinate in the coordinate system according to each second coordinate points, determines that second is single Position direction vector, wherein the direction of the second unit direction vector is low colour temperature to high color temperature direction.

11. device according to claim 10, which is characterized in that the third determining module, specifically for obtaining user The coordinate information of two coordinate points of input, determines the direction vector of described two coordinate points, and the direction vector is corresponded to Unit vector as the second unit direction vector；Or, according to least square method, determine the second coordinate in the coordinate system The corresponding linear equation of point, according to the linear equation, determines the corresponding second unit direction vector of the linear equation；Or, According to the method for principal component analysis, the covariance matrix of the point set of the second coordinate points composition is determined, according to the covariance The feature vector of matrix determines the second unit direction vector.

12. device according to claim 10, which is characterized in that described device further includes：

5th determining module, after determining that image to be corrected mixes colour temperature there are natural light, according to natural light secondary colour Warm white balance algorithm determines white balance gains and described image is corrected.

13. device according to claim 12, which is characterized in that the 5th determining module, specifically for according to The angle and setup parameter of first unit direction vector and the second unit direction vector using preset algorithm, determine the folder Angle and the corresponding natural light mixing colour temperature parameter value of the setup parameter；Colour temperature parameter value is mixed according to the natural light and determines list Colour temperature white balance algorithm and corresponding first weight of natural light mixing colour temperature white balance algorithm and the second weight, according to the monochrome Warm white balance algorithm and natural light mixing colour temperature white balance algorithm and corresponding first weight and the second weight, determine that white balance increases Benefit.

14. device according to claim 13, which is characterized in that the 5th determining module, it is described certainly specifically for general Right light mixing colour temperature parameter value is as the second weight, using 1 with the difference of second weight as the first weight.

15. device according to claim 13, which is characterized in that the 5th determining module, specifically for according to First unit direction vector and the angle of the second unit direction vector pre-saved calculate multiplying for the angle and parameter preset Product；The cosine value of the product is determined as the natural light and mixes colour temperature parameter value.

16. device according to claim 10, which is characterized in that described device further includes：

5th determining module, after determining image to be corrected there is no natural light mixing colour temperature, according to monochromatic Wen Baiping The method of accounting determines white balance gains and described image is corrected.

17. device according to claim 10, which is characterized in that described device further includes：

Second judgment module determines that the environment of image shines for shooting aperture time, gain parameter, aperture according to the camera of preservation Degree when the ambient light illumination is more than the second given threshold, continues subsequent step；Or judge in the first cluster and the second cluster When the distance between heart point is more than third given threshold, continue subsequent step；Or judge the center of the first cluster and the second cluster The abscissa of point is respectively positioned in the range of the corresponding abscissa of colour temperature of natural light, and the central point of the first cluster and the second cluster When ordinate is respectively positioned in the range of the corresponding ordinate of colour temperature of natural light, the first judgment module is triggered.

18. device according to claim 10, which is characterized in that first determining module, it is each specifically for determining The G/R values of each rectangular area of rectangular area and G/B values；Or, determine the logarithm and G/B of the G/R of each rectangular area Logarithm；Or, determine the logarithm of R/G of each rectangular area of each rectangular area and the logarithm of B/G.