CN103402102B - The method and apparatus of dual camera camera system and white balance adjusting thereof - Google Patents

Abstract

The invention discloses a dual-camera camera system and a method for adjusting white balance thereof, and relates to a camera system and a method for adjusting white balance thereof. The dual-camera camera system includes a main camera and a sub-camera. A sub-picture of a scene different from the main picture is obtained, and the white balance of the main picture is adjusted by using the white balance adjustment gain value obtained from the sub-picture. The white balance adjustment method of the present invention is to obtain a secondary picture through the secondary camera, obtain a gain value for white balance adjustment based on the secondary picture, and use this gain value to perform white balance adjustment on the main picture captured by the main camera. When using the main camera to shoot solid-color scenes, use the white area of the picture captured by the sub-camera as the reference area for white balance adjustment to adjust the white balance of the main camera, which can greatly reduce the chance of color cast when shooting solid-color scenes.

Description

Dual-camera camera system and method and device for adjusting white balance thereof

technical field

The invention relates to a dual-camera camera system and a method for adjusting white balance thereof. The method is completed by establishing a functional module framework and controlling a computer system by computer program instructions, and these computer program instructions are stored in a computer-readable storage medium.

Background technique

White balance is an index that describes the accuracy of red (R), green (G), and blue (B) three primary colors mixed to form white. The basic concept of white balance is that white can be restored to white under any light source. The color cast that occurs when shooting under a light source can be compensated by strengthening the corresponding complementary color, which is white balance adjustment. When the white balance is adjusted accurately, changing the color and brightness of the display screen will not affect the purity of white, that is, there will be no color cast.

In recent years, mobile phones have developed rapidly and their functions have become increasingly powerful. At present, most mobile phones have cameras and have the function of taking pictures. Along with the rise of 3G network, 4G network, video call becomes popular gradually, and for the convenience of video call, many mobile phones have been equipped with front camera, so these mobile phones just have rear camera and front camera two cameras. When using a mobile phone to take pictures, the usual method of white balance adjustment in the current mobile phone camera application is to identify the area with the highest brightness in the picture captured by the camera as a white area, and then use the R value, G value, and B value of this area to adjust the white balance. Calibrate the R value, G value and B value of other areas in the picture as a reference (the R value, G value and B value are all average values). This method has a common problem, using a single camera to shoot solid color scenes It is very easy to have a white balance error, resulting in a color cast in the entire picture. The reason for this problem is that when shooting a pure color scene, it is difficult to find or there is no white area in the whole screen, so the above-mentioned color cast will appear in other positions of the screen when the point in the screen is used as the reference point for white balance adjustment to calibrate other positions of the screen. question.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the present invention provides a dual-camera camera system and a white balance adjustment method thereof that can significantly reduce the probability of color cast when shooting solid-color scenes.

In order to achieve the above object, the technical solutions provided by the present invention are as follows.

The dual-camera camera system includes a main camera and a sub-camera. The main camera captures the main picture, and the sub-camera captures a sub-picture with a scene different from the main picture. The white balance of the main picture is adjusted using the white balance adjustment gain value obtained from the sub-picture.

Wherein, the shooting directions of the main camera and the secondary camera are opposite.

The methods for performing the above white balance adjustment include:

Step B． A gain value for white balance adjustment is obtained according to the secondary picture, and the white balance adjustment of the main picture is performed based on the gain value.

Among them, also include:

step a. Determine whether the scene captured by the main camera is a solid color scene, and if so, proceed to step B.

Wherein, in step A, the specific steps of judging whether the scene captured by the main camera is a solid color scene are: obtaining the R value, G value and B value of the point with the highest brightness in the main picture, and then calculating the R value, G value and The difference between two of the B values, if two of the absolute values of the three differences obtained are greater than the maximum set value and the other is less than the minimum set value, then it is judged that the shooting scene is a solid color scene, otherwise It is judged that this shooting scene is a non-solid color scene.

Wherein, the specific steps of obtaining the gain value for white balance adjustment according to the sub-picture in step B are: first divide the sub-picture into several regions of the same size and calculate the average brightness of each of the regions respectively, and then take Calculate its R value average value r, G value average value g and B value average value b in the area with the largest brightness average value, and finally draw the gain value of the white balance adjustment as R:B:G=(g/r): 1: (g/b).

The beneficial effects of the present invention are: when the main camera is used to shoot a solid-color scene, the auxiliary camera is used to adjust the white balance, because the scene aimed at by the auxiliary camera is different from the scene aimed at by the main camera, so in the picture obtained by the auxiliary camera The probability of white areas is very high. At this time, use the white area of the picture captured by the secondary camera as the reference area for white balance adjustment to adjust the white balance of the main camera, which can greatly reduce the probability of color cast when shooting solid color scenes.

detailed description

The present invention is described in detail below in conjunction with embodiment.

Now take a mobile phone with a front camera and a rear camera as an example to describe the dual camera camera system and the white balance adjustment method of the present invention. In the prior art, the conventional method of white balance adjustment when a mobile phone takes pictures is to set the brightest area in the picture to white by default, and then use this area as a reference area, and take its R, G, and B values as a reference to calibrate other areas. This method is no problem in most cases, but when encountering a pure color scene, that is, there are few or even no white areas in the entire screen, it is easy to adjust the white balance inaccurately by using this method, and it is easy to appear biased. color problem.

The basic idea of the present invention is to use another camera to capture pictures of scenes other than the solid-color scene when shooting a solid-color scene, and find out a white area therefrom as a reference area. Therefore, the technical solution provided by the present invention is a dual-camera camera system and a method for adjusting white balance applicable to the dual-camera camera system. For example, some mobile phones have two cameras, a front camera and a rear camera. The present invention is suitable for mobile phones or camera equipment. The mobile phone is taken as an example in this embodiment, and the principle of the camera system of other dual cameras is the same, so it will not be repeated here.

The dual-camera camera system of the present invention includes a main camera and an auxiliary camera. The camera used for taking pictures in the front camera and the rear camera of the mobile phone is the main camera, and the other camera used for auxiliary white balance adjustment is the auxiliary camera. The picture acquired by the camera is the main picture, and the picture acquired by the sub-camera is the sub-picture. Generally speaking, the key point of the white balance adjustment method of the present invention is that when necessary, the gain value of the white balance is obtained from the sub-picture and calculated as This gain value adjusts the white balance of the main picture. As shown in Figure 1, the method for adjusting the white balance of the dual-camera camera system in the present invention first opens the main camera to obtain the main picture, and the remaining steps are as follows:

step a. Judging whether the scene captured by the main camera is a solid color scene, if so, enter step B, otherwise enter step C, the method for judging whether the scene captured by the main camera is a solid color scene is specifically: obtain the R of the point with the highest brightness in the main picture. value, G value and B value, and then calculate the difference between any two of the R value, G value and B value, if two of the absolute values of the obtained three differences are greater than the maximum set value and If the other is less than the minimum set value, it is judged that the shooting scene is a solid color scene, otherwise it is judged that the shooting scene is a non-solid color scene;

Step B． Obtain the secondary picture through the secondary camera, obtain the gain value of white balance adjustment according to the secondary picture, and adjust the white balance of the main picture obtained by the main camera with this gain value, and obtain the gain value of white balance adjustment according to the secondary picture The specific method is as follows: first divide the secondary picture into several regions of the same size and calculate the average brightness of each region, and then calculate the average R value r, the average G value g and the average value g of the region with the largest average brightness value. The average value of B value b, and finally the gain value of the white balance adjustment is R:B:G=(g/r):1:(g/b), in the case where the shooting directions of the main camera and the secondary camera are opposite For example, for the front camera and rear camera of a mobile phone, when the main camera is aimed at the scene to be photographed, the auxiliary camera is often aimed at the face of the photographer, and the face is not a solid color, so the auxiliary images captured by the auxiliary camera include The probability of the white area is very high;

Step C． The gain value for white balance adjustment is obtained according to the main picture acquired by the main camera, and the white balance adjustment is performed on the main picture based on the gain value.

When shooting non-solid-color scenes, the sub-camera is not enabled; when shooting solid-color scenes, use the sub-picture captured by the sub-camera to assist in adjusting the white balance of the main picture captured by the main camera. In rare cases, the scenes captured by the main camera and the sub-camera The scenes shot are all solid-color scenes, so the white balance adjustment method of the present invention has no obvious effect, but this situation is easy to avoid in actual use. As mentioned above, the secondary camera is generally aimed at the face of the photographer. Therefore, the white balance adjustment method of the present invention often has a significant effect. Compared with the existing single camera white balance adjustment method, the white balance adjustment method of the dual camera camera system of the present invention can greatly reduce the color cast when shooting a pure color scene probability.

In the method for adjusting the white balance of the dual-camera camera system given in this paper, all or part of the steps can be completed by establishing a functional module framework and controlling the computer system by computer program instructions. These computer program instructions are stored on a computer readable storage medium.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention, although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand , the technical solution of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (8)

1. A dual-camera camera system, including a main camera and an auxiliary camera. The main camera obtains the main picture, which is characterized in that: when the scene captured by the main camera is a solid color scene, the auxiliary camera obtains a sub-picture whose scene is different from the main picture, and the main picture is replaced by the main picture. Use the white balance adjustment gain value obtained from the secondary screen to adjust the white balance. 2. The dual-camera camera system according to claim 1, wherein the shooting directions of the main camera and the secondary camera are opposite. 3. the white balance adjustment method that is used for the dual camera camera system described in claim 1, is characterized in that, comprises: Step A. Determine whether the scene captured by the main camera is a solid color scene, and if so, proceed to step B; Step B. Obtain a gain value for white balance adjustment according to the secondary picture, and use this gain value to adjust the white balance of the main picture. 4. The method for adjusting white balance according to claim 3, wherein in step A, the specific steps for judging whether the scene captured by the main camera is a solid color scene are: obtaining the R value of the point with the highest brightness in the main picture, G value and B value, then calculate the difference between any two of the R value, G value and B value, if two of the absolute values of the three differences obtained are greater than the maximum set value and the other If it is less than the minimum setting value, it is judged that the shooting scene is a solid color scene, otherwise it is judged that the shooting scene is a non-solid color scene. 5. The white balance adjustment method according to claim 3, characterized in that, the specific step of obtaining the gain value for white balance adjustment according to the sub-picture in step B is: first divide the sub-picture into several equal-sized and calculate the average brightness of each of the regions, and then take the region with the largest average brightness to calculate its R value average r, G value average g, and B value average b, and finally obtain the white balance adjustment The gain value of R:B:G=(g/r):1:(g/b). 6. The white balance adjusting device for the dual-camera camera system of claim 1, characterized in that, comprising: Device A. It judges whether the scene captured by the main camera is a solid color scene, and if so, then runs Device B; Device B. It obtains a gain value for white balance adjustment based on the secondary picture, and uses the gain value to perform white balance adjustment on the main picture captured by the main camera. 7. The white balance adjusting device according to claim 6, wherein the specific device for judging whether the scene captured by the main camera is a solid color scene in device A comprises: Device A1. It acquires the R value, G value and B value of the point with the highest brightness in the main picture; Device A2. The difference between any two of the R value, G value and B value obtained in the calculation device A1, if two of the absolute values of the obtained three differences are greater than the maximum set value and the other If it is less than the minimum setting value, it is judged that the shooting scene is a solid color scene, otherwise it is judged that the shooting scene is a non-solid color scene. 8. The white balance adjustment device according to claim 6, characterized in that, the specific device for obtaining the gain value of the white balance adjustment according to the secondary picture in the device B comprises: Device B1. It divides the secondary picture into several areas of the same size and calculates the average brightness of each of the areas; Device B2. It calculates its R value average value r, G value average value g, and B value average value b in the region where the brightness average value is the largest, and finally draws the gain value of the white balance adjustment as R: B: G=( g/r):1:(g/b).