CN106125480B

CN106125480B - Image color temperature adjusting method and device

Info

Publication number: CN106125480B
Application number: CN201610739354.7A
Authority: CN
Inventors: 郭大勃
Original assignee: Qingdao Hisense Laser Display Co Ltd
Current assignee: Qingdao Hisense Laser Display Co Ltd
Priority date: 2016-08-26
Filing date: 2016-08-26
Publication date: 2021-06-01
Anticipated expiration: 2036-08-26
Also published as: CN106125480A

Abstract

The invention provides a method and a device for adjusting color temperature of an image. The method comprises the following steps: obtaining the brightness ratio of a first primary color between at least two primary colors of light of a light path between the wavelength conversion device and the image processing device; and then adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the preset target color temperature, so that the image projected to the screen reaches the target color temperature. The brightness of the primary color light is adjusted according to the acquired brightness ratio of the first primary color light, so that the brightness ratio of the primary color light between at least two primary color lights reaches a second primary color brightness ratio in the preset target color temperature, and an image projected to a screen reaches the preset target color temperature corresponding to the second primary color brightness ratio, so that the purposes of effectively adjusting the color temperature and improving the display effect of the screen are achieved.

Description

Image color temperature adjusting method and device

Technical Field

The invention relates to a display technology, in particular to a method and a device for adjusting color temperature of an image.

Background

With the continuous improvement of scientific technology, laser projection display has better image quality expressive force such as high brightness and high color gamut and is widely applied compared with the traditional projection display, and the laser projection technology is a technology for displaying pictures in a laser projection screen by modulating a laser light source beam.

The laser is a basic light emitting device of a laser light source, laser display generally adopts laser emitted by the laser to excite a fluorescent powder wheel to generate light with other wavelengths so as to generate red, green and blue tricolor light required by display, and due to the influence of factors such as environment, temperature, self material attenuation and the like, the tricolor light intensity may be attenuated to different degrees. Once the light source is attenuated, the proportion of red, green and blue lights may be changed, which may cause the color temperature of the image to shift, and the displayed image may be color-cast.

In the prior art, a brightness sensor is added inside or outside a projector to acquire current brightness data, so that the driving current of a laser is adjusted according to the acquired current brightness data to achieve the purpose of adjusting the color temperature offset of an image.

Disclosure of Invention

The embodiment of the invention provides a method and a device for adjusting color temperature of an image, which aim to overcome the problem that the color temperature of the image cannot be effectively shifted because current brightness data cannot be accurately acquired in the prior art.

The invention provides a method for adjusting color temperature of an image, which is applied to a projection device and comprises the following steps:

acquiring the brightness ratio of first primary color light between at least two primary color lights of a light path between a wavelength conversion device and an image processing device;

and adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the preset target color temperature so as to enable the image projected to the screen to reach the target color temperature.

The second aspect of the present invention provides an apparatus for adjusting color temperature of an image, the apparatus being applied to a projection device, the apparatus comprising:

the acquisition module is used for acquiring the brightness ratio of first primary color light between at least two primary color lights of a light path between the wavelength conversion device and the image processing device;

and the adjusting module is used for adjusting the brightness of each primary color light according to the first primary color light brightness ratio and a second primary color light brightness ratio in a preset target color temperature so as to enable the image projected to the screen to reach the target color temperature.

In the embodiment, the first primary color light brightness ratio between at least two primary color lights of the light path between the wavelength conversion device and the image processing device is obtained; and then adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the preset target color temperature, so that the image projected to the screen reaches the target color temperature. The brightness of the primary color light is adjusted according to the acquired brightness ratio of the first primary color light, so that the brightness ratio of the primary color light between at least two primary color lights reaches a second primary color brightness ratio in the preset target color temperature, and an image projected to a screen reaches the preset target color temperature corresponding to the second primary color brightness ratio, so that the purposes of effectively adjusting the color temperature and improving the display effect of the screen are achieved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic diagram of a prior art laser projection system;

FIG. 2 is a schematic structural diagram of a wavelength conversion device;

FIG. 3 is a flowchart illustrating a method for adjusting color temperature of an image according to an embodiment of the present invention;

FIG. 4 is a schematic view of a light stick with a brightness sensor disposed around the light stick;

FIG. 5 is a schematic diagram of a luminance sensor disposed around the DMD;

fig. 6 is a schematic structural diagram of an image color temperature adjusting device according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention.

The network architecture and the service scenario described in the embodiment of the present invention are for more clearly illustrating the technical solution of the embodiment of the present invention, and do not constitute a limitation to the technical solution provided in the embodiment of the present invention, and it is known by those skilled in the art that, with the progress of technology and the appearance of new products, the technical solution provided in the embodiment of the present invention is also applicable to similar technical problems.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first," "second," and the like in the description, in the claims, and in the drawings described above, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover non-exclusive inclusions, such that a process, method, system, article, or apparatus that comprises a list of steps is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The term "at least one" as used herein means one or more.

Fig. 1 is a schematic structural diagram of a laser projection system in the prior art, and referring to fig. 1, the laser projection system includes a light emitting device, a wavelength conversion device, a beam shaping device, an image processing device, a projection lens, and a projection screen, a light beam emitted by the light emitting device reaches the wavelength conversion device, three primary lights are obtained by the wavelength conversion device, the beam shaping means is then an optical device or a set of optical devices for shaping the light of the primary colors passing through the wavelength conversion means into a beam suitable for the imaging device, the image processing device receives the three primary colors of light processed by the light beam shaping device and combines the characteristic values of each pixel in the image to be displayed, and processing the light beams corresponding to the three primary color lights, reflecting the processed light beams to the projection lens, projecting the received light beams to a projection screen by the projection lens, and presenting an image on the projection screen. Fig. 2 is a schematic structural diagram of the wavelength conversion device, and as shown in fig. 2, the wavelength conversion device is a rotating device capable of converting the primary light emitted by the light emitting device into other colors, such as red, yellow, blue, green, and the like, during rotation.

In the system shown in fig. 1, in the using process, the light emitting device may be affected by factors such as temperature, environmental cleanliness, air pressure, device parameters, etc., so that the tricolor light emitted by the light emitting device is attenuated, and once the tricolor light emitted by the light emitting device is attenuated, the proportion of the generated tricolor light may be changed variably, so that the color temperature of the image may be shifted, and the displayed image may be color-shifted.

In order to solve the above problems, the inventors found in the research that the brightness of each primary color light of the image projected onto the screen can be adjusted to reach the target color temperature by setting a plurality of brightness sensors to obtain the brightness ratio of the first primary color light between at least two primary color lights and combining the brightness ratio of the second primary color light in the preset target color temperature, and the brightness of each primary color light can be obtained more accurately in all directions by using a plurality of brightness sensors to obtain the brightness value of each primary color light, and the obtained brightness value of the primary color light is more accurate, that is, the brightness ratio of the first primary color light between at least two primary color lights is more accurate, so that the brightness ratio of the first primary color light between at least two adjusted primary color lights and the brightness ratio of the second primary color light in the preset target color temperature can reach the same purpose, the image projected to the screen reaches the preset target color temperature corresponding to the brightness ratio of the second primary color, so that the problem of color temperature deviation of the image is effectively solved, and the display effect of the screen is improved.

The technical solution of the present invention will be described in detail below with specific examples. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

Fig. 3 is a flowchart illustrating a method for adjusting color temperature of an image according to an embodiment of the present invention, where the method of the present embodiment is applied to a projection device, and as shown in fig. 3, the method of the present embodiment may include:

s101: acquiring the brightness ratio of first primary color light between at least two primary color lights of a light path between a wavelength conversion device and an image processing device;

s102: and adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the preset target color temperature so as to enable the image projected to the screen to reach the target color temperature.

Wherein obtaining a primary light luminance ratio between at least two primary lights of a light path between the wavelength conversion device and the image processing device comprises:

acquiring, by at least one brightness sensor, at least one first brightness data for each primary light of a light path between the wavelength conversion device and the image processing device; the first brightness data of each primary color light correspond to the brightness sensors one by one;

and acquiring the brightness ratio of the primary light between at least two primary lights according to at least one first brightness data of each primary light and the distance from each brightness sensor to the center of the light spot.

In order to ensure the accuracy of the primary light brightness data acquired by the brightness sensor, the brightness sensor can acquire the primary light brightness data for multiple times in the corresponding color segment, and then screen the primary light brightness data to eliminate the interference of errors.

Specifically, acquiring at least one first luminance data of each primary light of the optical path between the wavelength conversion device and the image processing device by at least one luminance sensor includes:

acquiring at least one set of second brightness data of each primary light through at least one brightness sensor; each brightness sensor collects a group of second brightness data of the primary light;

and eliminating data which do not belong to a preset brightness range in each group of second brightness data corresponding to each primary color light, and averaging the remaining second brightness data of each group to obtain at least one first brightness data of the primary color light.

In the scheme provided by the invention, the brightness value of each primary light can be obtained through the brightness sensor, and further the brightness ratio of the primary light between at least two primary lights can be obtained.

In this embodiment, a brightness sensor may be disposed at a position of the light beam shaping device or an image processing device [ Digital micro-mirror device (DMD)/Liquid Crystal On Silicon (LCOS)/Liquid Crystal Display (LCD) ].

Since the closer to the DMD the more reflective of the chromaticity uniformity of the real illumination on the DMD, a luminance sensor may be placed behind the color filter wheel, or light bar. Moreover, the luminance sensor cannot be placed directly into the light path, typically to the side of the light path. Or by the back of a curved mirror opposite the lens.

Since there is a case where the illumination of each primary light is not uniform in the illumination system, there is a possibility that the luminance ratio of the primary light obtained by the luminance sensor does not coincide with the luminance ratio of the primary light in the actual image, and therefore, in the present invention, the luminance ratio of the primary light can be obtained by using a plurality of luminance sensors.

For example: in the invention, brightness sensors can be respectively arranged in four directions of a light path propagation path or four directions of an imaging device and are used for collecting brightness data of primary light.

Fig. 4 is a schematic diagram showing that the brightness sensors are disposed around the light stick, and as shown in fig. 4, if the light beam propagation direction is the Z-axis direction, the peripheral sensors are respectively disposed in the X-axis direction and the Y-axis direction, at this time, each surface around the light stick in the figure may be respectively provided with one brightness sensor, or each surface around the light stick may be respectively provided with a plurality of brightness sensors, and the number of the disposed brightness sensors is not limited in the present invention.

Fig. 5 is a schematic diagram showing that the brightness sensor is disposed around the DMD, and as shown in fig. 5, in order to avoid the dark band phenomenon of the DMD (light beam spots do not fully illuminate the DMD surface), the size of the light spot irradiated on the DMD surface is generally larger than the actual size of the DMD, so that a sensor group may be disposed between the light spot and the gap of the DMD.

In this case, one brightness sensor may be disposed around the DMD in the light spot, or a plurality of brightness sensors may be disposed around the DMD, respectively.

For example: at least one group of second brightness data of each primary color light collected by the brightness sensor with the number of 1 in one periodComprises the following steps: second luminance data of red: r_1a、R_1b、R_1c、R_1d、R_1e… …, second luminance data of green: g_1a、G_1b、G_1c、G_1d、G_1e… …, second luminance data of blue: b is_1a、B_1b、B_1c、B_1d、B_1e… …, second luminance data of yellow: y is_1a、Y_1b、Y_1c、Y_1d、Y_1e……；

At least one group of second brightness data of each primary light collected by the brightness sensor with the number of 2 is as follows: second luminance data of red: r_2a、R_2b、R_2c、R_2d、R_2e… …, second luminance data of green: g_2a、G_2b、G_2c、G_2d、G_2e… …, second luminance data of blue: b is_2a、B_2b、B_2c、B_2d、B_2e… …, second luminance data of yellow: y is_2a、Y_2b、Y_2c、Y_2d、Y_2e……；

At least one group of second brightness data of each primary light collected by the brightness sensor with the number of 3 is as follows: second luminance data of red: r_3a、R_3b、R_3c、R_3d、R_3e… …, second luminance data of green: g_3a、G_3b、G_3c、G_3d、G_3e… …, second luminance data of blue: b is_3a、B_3b、B_3c、B_3d、B_3e… …, second luminance data of yellow: y is_3a、Y_3b、Y_3c、Y_3d、Y_3e……；

At least one group of second brightness data of each primary light collected by the brightness sensor with the number of 4 is as follows: second luminance data of red: r_4a、R_4b、R_4c、R_4d、R_4e… …, second luminance data of green: g_4a、G_4b、G_4c、G_4d、G_4e… …, second luminance data of blue: b is_4a、B_4b、B_4c、B_4d、B_4e… …, second luminance data of yellow: y is_4a、Y_4b、Y_4c、Y_4d、Y_4e……。

A brightness range can be preset according to the empirical value, and the brightness data which do not belong to the brightness range in the second brightness data of the primary lights collected by each brightness sensor are removed.

Suppose that: r in red second luminance data_1a、R_1b、R_1c、R_1dAnd R_1eAll data are within a preset brightness range; g in the second data of green_1a、G_1b、G_1c、G_1dAnd G_1eAll data are within a preset brightness range; b in the second data of blue_1a、B_1b、B_1c、B_1dAnd B_1eAll data are within a preset brightness range; y in the second data of yellow_1a、Y_1b、Y_1cAnd Y_1d、Y_1eAll data are within a preset brightness range;

then averaging the data which accord with the brightness range in the brightness data of each primary light collected by the brightness sensor with the number of 1 to obtain first brightness data of each primary light: r_1ag、G_1ag、B_1agAnd Y_1agAnd then:

similarly, averaging the data in accordance with the brightness range in the brightness data of each primary light collected by the brightness sensor with the number 2 to obtain first brightness data of each primary light, R_2ag、G_2ag、B_2agAnd Y_2ag,；

Similarly, averaging the data in accordance with the brightness range in the brightness data of each primary light collected by the brightness sensor with the number of 3 to obtain first brightness data of each primary light, R_3ag、G_3ag、B_3agAnd Y_3ag；

Similarly, averaging the data in accordance with the brightness range in the brightness data of each primary light collected by the brightness sensor with the number of 4 to obtain first brightness data of each primary light, R_4ag、G_4ag、B_4agAnd Y_4ag。

Further, obtaining the luminance ratio of the primary lights between the at least two primary lights according to the first luminance data of each primary light and the distance from each luminance sensor to the center of the light spot, includes:

determining a weight coefficient of data acquired by each brightness sensor according to the distance from each brightness sensor to the center of a light spot;

calculating to obtain third brightness data of each primary light according to at least one first brightness data of each primary light and the weight coefficient corresponding to each brightness sensor;

and acquiring the brightness proportion of the primary light through the third brightness data of each primary light.

The weight coefficient may be determined according to the distance between the position of the luminance sensor and the center of the light spot (the shape of the light spot is consistent with the shape of the image on the screen, and the position relationship between the luminance sensor and the center of the light spot is the position relationship relative to the center of the screen), if the position of the luminance sensor is farther from the center of the screen, the weight occupied by the luminance sensor will be lower (the distance from the center of the light spot reflects the actual luminance of the light spot, and the distance from the center of the light spot is closer, and the luminance data is generally larger, and the luminance data is closer to the actual luminance), and conversely, if the position of the luminance sensor is closer to the center of the screen, the weight occupied by the luminance.

Taking red as an example: the distance between the

brightness sensors

1, 2, 3 and 4 and the center of the screen is L respectively₁,L₂,L₃And L₄First, the following is obtained: l is_total＝L₁+L₂+L₃+L₄The weight coefficient occupied by the luminance sensor 1 is

The weight coefficient occupied by the luminance sensor 2 is

The weight coefficient occupied by the luminance sensor 3 is

The luminance sensor 4 occupies a weight coefficient of

Continuing with the above example, after the first luminance data for each primary color light is obtained, the first luminance data obtained for each numbered luminance sensor is matched to the weighting factor of that luminance sensor, and the third luminance data for each primary color light is obtained,

specifically, the third luminance data of each primary light is obtained according to the following formula:

the third luminance data of red is:

the third luminance data for green is:

the third luminance data for blue is:

the third luminance data for yellow is:

with the above-mentioned R_avg、G_avg、B_avgAnd Y_avgAnd the color temperature is used as the acquired original color temperature data of the image, and the brightness of the light source is adjusted accordingly.

Wherein, according to the brightness ratio of the primary color light and the brightness ratio of the second primary color light in the preset target color temperature, the brightness of each primary color light is adjusted to make the image projected to the screen reach the target color temperature, and the method comprises the following steps:

obtaining the lowest primary color light proportion according to the second primary color light brightness proportion and the first primary color light brightness proportion;

and reducing the brightness of the light sources of other primary lights according to the lowest primary light proportion so as to enable the image projected to the screen to reach the target color temperature.

Specifically, after the first primary color luminance ratio is obtained, the primary color luminance is adjusted according to a second primary color luminance ratio in the preset target color temperature to reach an expected color temperature value.

The color temperature adjusting method can adopt an equal ratio scaling method, for example, the ratio of the first primary color light is compared with the brightness ratio of the second primary color light, the lowest primary color light ratio is searched, and other color ratios are reduced in equal ratio; or the proportion of the lowest primary color light is reversely improved within the range of the maximum brightness value, and the function of color temperature adjustment can also be realized.

Specifically, in one implementation manner of the present invention, the step of reducing the brightness of the light sources of the other primary lights according to the lowest primary light proportion may be: and adjusting the driving current of the light sources of other primary color light according to the lowest primary color light proportion, thereby reducing the brightness of the light sources of other primary color light and achieving the purpose of adjusting the color temperature.

In another implementation manner of the present invention, the color of the image to be displayed may be adjusted according to the lowest primary color light ratio, that is, the color temperature may be adjusted by adjusting the gray scale value of the image to be displayed.

In the embodiment of the invention, the first primary color light brightness ratio between at least two primary color lights of the light path between the wavelength conversion device and the image processing device is obtained; and then adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the preset target color temperature, so that the image projected to the screen reaches the target color temperature. The brightness of the primary color light is adjusted according to the acquired brightness ratio of the first primary color light, so that the brightness ratio of the primary color light between at least two primary color lights reaches a second primary color brightness ratio in the preset target color temperature, and an image projected to a screen reaches the preset target color temperature corresponding to the second primary color brightness ratio, so that the purposes of effectively adjusting the color temperature and improving the display effect of the screen are achieved.

The solution of the invention is illustrated below by specific examples:

taking fig. 3 and 4 as an example, the

luminance sensors

1, 2, 3, 4 are respectively 4mm, 8mm and 4mm from the center of the screen, and then L is_rtotal＝24，

Then:

the weight coefficient occupied by the luminance sensor 1 is:

the weight coefficient occupied by the luminance sensor 2 is:

the weight coefficient occupied by the luminance sensor 3 is

The luminance sensor 4 occupies a weight coefficient of

The first luminance data of each primary light is:

red: r_1ag＝200，R_2ag＝100，R_3ag＝300，R_4ag＝200；

Green: g_1ag＝400，G_2ag＝200，G_3ag＝600，G_4ag＝400；

Blue color: b is_1ag＝300，B_2ag＝150，B_3ag＝450，B_4ag＝300；

Yellow: y is_1ag＝600，Y_2ag＝300，Y_3ag＝900，Y_4ag＝600；

Then:

the third data for red is:

the third data for green is:

the third data for blue is:

the third data for yellow is:

then the ratio of the luminance of the first primary color in the image information is obtained:

R_avg:G_avg:B_avg:Y_avg＝2:4:3:6；

and the pre-configured ratio of the brightness of the second primary color in the target color temperature is as follows:

R_t:G_t:B_t:Y_t＝2:5:3:6，

judging that the lowest primary color light proportion in the first primary color light brightness proportion is G, and the proportion is G_avg/G_tWhen the luminance of all the other primary color light sources is reduced to 4/5 of the original value, 4/5 is set, and white balance adjustment is performed.

However, 4/5, which reduces the light source luminance of all the other primary color lights to the original value, may be a method of adjusting the drive current value of the light source.

Fig. 6 is a schematic structural diagram of an adjusting apparatus for color temperature of an image according to an embodiment of the present invention, and as shown in fig. 6, the apparatus of the present embodiment is applied to a projection device, and the apparatus of the present embodiment may include:

the obtaining module 11 is configured to obtain a first primary color luminance ratio between at least two primary color lights of a light path between the wavelength conversion device and the image processing device;

and the adjusting module 12 is configured to adjust the brightness of each primary color light according to the first primary color light brightness ratio and a second primary color light brightness ratio in a preset target color temperature, so that the image projected onto the screen reaches the target color temperature.

Optionally, in terms of acquiring the luminance ratio of primary light between at least two primary colors of the optical path between the wavelength conversion device and the image processing device, the acquiring module 11 is configured to:

acquiring at least one first luminance data of each primary light of a light path between the wavelength conversion device and the image processing device through at least one luminance sensor; the first brightness data of each primary color light correspond to the brightness sensors one by one;

and acquiring the brightness ratio of the first primary color light between the at least two primary color lights according to at least one first brightness data of each primary color light and the distance from each brightness sensor to the center of the light spot.

Optionally, in the aspect of acquiring at least one first brightness data of each primary color light of the optical path between the wavelength conversion device and the image processing device by at least one brightness sensor, the acquiring module 11 is configured to:

acquiring at least one set of second brightness data of each primary light through the at least one brightness sensor; each brightness sensor collects a group of second brightness data of the primary light;

Optionally, in the aspect of obtaining the ratio of the brightness of the first primary color light between the at least two primary color lights according to the first brightness data of each primary color light and the distance from each brightness sensor to the center of the light spot, the obtaining module 11 is configured to:

and acquiring the brightness ratio of the first primary color light through the third brightness data of each primary color light.

Optionally, in the aspect that the brightness of each primary color light is adjusted according to the first primary color light brightness ratio and a second primary color light brightness ratio in a preset target color temperature, so that an image projected to a screen reaches the target color temperature, the adjusting module 12 is configured to:

and reducing the brightness of the light sources of other primary lights according to the lowest primary light proportion so as to enable the image projected to the screen to reach the preset target color temperature.

The apparatus of this embodiment may be used to implement the technical solution of the method embodiment shown in fig. 3, and the implementation principle and the technical effect are similar, which are not described herein again.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for adjusting color temperature of an image is applied to a projection device, and the method comprises the following steps:

adjusting the brightness of each primary color light according to the first primary color light brightness ratio and a second primary color light brightness ratio in a preset target color temperature so as to enable the image projected to the screen to reach the target color temperature;

the obtaining of the first primary color luminance ratio between at least two primary color lights of the optical path between the wavelength conversion device and the image processing device includes:

calculating to obtain third brightness data of each primary light according to at least one first brightness data of each primary light and the weight coefficient corresponding to each brightness sensor, wherein the first brightness data of each primary light correspond to the brightness sensors one by one;

2. The method of claim 1, wherein before determining the weighting factor for the data collected by each intensity sensor based on the distance of each intensity sensor from the center of the spot, the method further comprises:

acquiring at least one first luminance data of each primary light of a light path between the wavelength conversion device and the image processing device through at least one luminance sensor; wherein at least one of the brightness sensors is disposed around the light stick or around the imaging device.

3. The method of claim 2, wherein said obtaining at least one first luminance data for each primary light of the optical path between the wavelength conversion device and the image processing device by at least one luminance sensor comprises:

4. The method according to any one of claims 1 to 3, wherein adjusting the brightness of each primary color light according to the brightness ratio of the first primary color light and the brightness ratio of the second primary color light in the pre-configured target color temperature to make the image projected to the screen reach the target color temperature comprises:

and reducing the brightness of the light sources of other primary color lights according to the lowest primary color light proportion to adjust the first primary color light brightness proportion to the second primary color light brightness proportion, so that the image projected to the screen reaches the preset target color temperature corresponding to the second primary color light brightness proportion.

5. An apparatus for adjusting color temperature of an image, the apparatus being used in a projection device, the apparatus comprising:

the adjusting module is used for adjusting the brightness of each primary color light according to the first primary color light brightness ratio and a second primary color light brightness ratio in a preset target color temperature so as to enable the image projected to the screen to reach the target color temperature;

in the aspect of acquiring the ratio of luminance of the first primary color between at least two primary color lights of the optical path between the wavelength conversion device and the image processing device, the acquiring module is configured to:

6. The apparatus according to claim 5, wherein before the determining the weighting factor of the data collected by each luminance sensor according to the distance of each luminance sensor from the center of the light spot, the obtaining module is configured to:

7. The apparatus of claim 6, wherein in said acquiring at least one first luminance data for each primary light of the optical path between the wavelength conversion device and the image processing device by at least one luminance sensor, the acquiring module is configured to:

8. The apparatus according to any one of claims 5 to 7, wherein in the aspect of adjusting the brightness of each primary color light according to the first primary color light brightness ratio and a second primary color light brightness ratio in a pre-configured target color temperature to make the image projected to the screen reach the target color temperature, the adjusting module is configured to: