CN104661008A - Processing method and device for improving colorful image quality under condition of low-light level - Google Patents

Abstract

The invention discloses a processing method and device for improving the quality of color images under low illumination. The method includes: periodically switching the infrared filter and the full-transmission spectral filter arranged in front of the image sensor, and collecting corresponding images in real time. The infrared filter image and the full light transmission image; obtain the image color information of the infrared filter image, and obtain the image brightness information of the full light transmission image; perform data fusion processing on the image brightness information and image color information, and output color image. The present invention periodically switches the infrared filter and the full-transmission spectral filter deployed in front of the image sensor, and obtains the brightness information and color information of the image under low-light conditions through sequentially collected images, and then combines the two in the Features under low-light conditions Synthesize a new color image, which can reduce the noise of the image under low-light conditions and increase the brightness of the image at the same time, so as to obtain better-quality color images under low-light conditions.

Description

Processing method and device for improving color image quality under low illumination conditions

technical field

The present invention relates to the technical field of image processing, in particular to a processing method and device for improving the quality of color images under low illumination.

Background technique

A digital camera generally includes: an optical lens, an image sensor, an image processing chip, an image transmission module, and an image display module. Among them, the optical lens controls the light entering the digital camera, and the image sensor converts the optical signal into an electrical signal. Then the image processing chip is used for processing, and finally the finally obtained signal is transmitted to the image display module through the image transmission module for display.

With the wide application of surveillance camera equipment, people have higher and higher requirements for image quality obtained under low-light conditions. However, in the natural environment, there are various wavelengths of light, and the wavelength range of light that can be recognized by the human eye is generally between 320nm-760nm, that is, visible light, while other light rays with a wavelength range of 320nm-760nm cannot be recognized by the human eye. See, such as infrared light and ultraviolet light. But the camera's image sensor CCD (Charge-coupled Device, charge-coupled device image sensor) or CMOS (Complementary Metal Oxide Semiconductor, complementary metal oxide semiconductor image sensor) can receive most of the wavelengths of light, which will cause it to be in the image data In addition to visible light, other kinds of light are added to the collection process. Therefore, in practical applications, there may be deviations in color between the image restored by the digital camera and the actual scene observed by the human eye. For example, when the image When a sensor is capable of receiving infrared light, its output image will be reddish in color.

In order to solve this color shift problem, the solution proposed in the prior art is to add a filter in front of the image sensor to filter out the corresponding waveband light, for example, add an infrared filter to filter the infrared waveband, so as to restore the The "true color" recognized by the human eye. However, the inventors of the present invention have found that the introduction of infrared filters will reduce the amount of incident light, especially in low-light environments, which will not only lead to low brightness of the output image, but also sharply increase the noise of the output image. The current general practice is to remove the infrared filter in a low-illumination environment and use a fully transparent spectral filter to increase the amount of light incident. However, for this technical solution, due to the use of a fully transparent spectral filter, the Invisible light in other bands such as infrared light makes the image sensor unable to display normal color images, and it can only output black and white images in the end.

Contents of the invention

In order to solve the problem of low brightness and high noise in the color image output by the camera under low-illuminance conditions in the prior art, or the problem that only black and white images can be obtained through a fully transparent spectral filter, the purpose of the embodiments of the present invention is to provide a A processing method and device for improving the quality of color images under low illumination.

In order to achieve the purpose of the present invention, the embodiment of the present invention adopts the following technical solutions to realize:

A processing method for improving the quality of color images under low illumination, comprising:

A. Periodically switch the infrared filter and the fully transparent spectral filter deployed in front of the image sensor, and collect the corresponding infrared filter image and fully transparent image in real time;

B. Obtain image color information of the infrared filter image, and obtain image brightness information of the fully transparent image;

C. Perform data fusion processing on the image brightness information and image color information to output a color image.

Preferably, the step of acquiring image color information of the infrared filtered image includes:

B10, converting the infrared filter image into image data in YCbCr format, wherein, the Y refers to the brightness component of the infrared filter image, Cb refers to the blue chroma component of the infrared filter image, and Cr refers to the red chroma component of the infrared filter image ;

B11. Obtain the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information.

Preferably, the step of acquiring image brightness information of the fully transparent image includes:

B20, using the following mathematical formula to obtain the brightness average value Y _avg of the fully light-transmitting image:

Y _avg = Y _sum /n;

Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image;

B21. Judging whether the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target brightness value, and the Y _thd is the preset fluctuation error value, if yes, go to step B24, otherwise, go to the next step;

B22. Use the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target :

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

B23. Control the exposure time of the shutter, the gain of the image sensor, and the rate of change of the aperture according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output full light transmission image, and then go to step B20;

B24. Obtain image brightness information of a fully light-transmitting image in which the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ].

Preferably, data fusion processing is performed on the image brightness information and image color information, and the step of outputting a color image includes:

C1. Identify the brightness information of the image as the brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr included in the image color information to synthesize a color image in YCbCr format.

Preferably, after performing all the steps, the processing method for improving the quality of color images under low illumination further includes:

D. Performing white balance correction processing on the color image.

A processing device for improving the quality of color images under low illumination, comprising:

The filter switching module is used to periodically switch the infrared filter and the full-transmission spectral filter deployed in front of the image sensor;

The image acquisition module is used to collect corresponding infrared filter images and full light transmission images in real time when the filter switching module periodically switches the infrared filter and the full light transmission filter;

A color information acquisition module, configured to acquire image color information of the infrared filtered image;

A brightness information acquisition module, configured to acquire image brightness information of the fully transparent image;

The data fusion processing module is used to perform data fusion processing on the image brightness information and image color information, and output a color image.

Preferably, the color information acquisition module includes:

The first conversion unit is used to convert the infrared filtered image into image data in YCbCr format, wherein the Y refers to the brightness component of the infrared filtered image, Cb refers to the blue chrominance component of the infrared filtered image, and Cr refers to the infrared filtered image. The red chroma component of

The color information acquiring unit is configured to acquire the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information.

Preferably, the brightness information acquisition module includes:

The first calculation unit is used to obtain the average brightness Y _avg of the fully transparent image by using the following mathematical formula:

Y _avg = Y _sum /n;

Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image;

A judging unit, configured to judge whether the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target brightness value, and the Said Ythd is a preset fluctuation error value, if yes, then send a color information acquisition command to the brightness information acquisition unit, otherwise control the second calculation unit to calculate the adjustment step size f _step ;

The second calculation unit is used to adopt the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target :

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

The adjustment unit is used to control the exposure time of the shutter, the gain of the image sensor, and the rate of change of the aperture according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output fully light-transmitting image, and then control the first calculation unit to perform the brightness average value Y Calculation of _avg ;

A brightness information acquisition unit, configured to acquire an image of a fully transparent image in which the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ] according to the color information acquisition command Brightness information.

Preferably, the data fusion processing module includes:

a receiving unit, configured to obtain the image brightness information and image color information;

The fusion processing unit is used to confirm the brightness information of the image as the brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr contained in the image color information to synthesize a color image in YCbCr format.

Preferably, the processing device for improving the quality of color images under low illumination further includes:

The white balance processing module is used to perform white balance correction processing on the color image.

The present invention periodically switches the infrared filter and the full-transmission spectral filter deployed in front of the image sensor, and obtains the brightness information and color information of the image under low-light conditions through sequentially collected images, and then combines the two in the Features under low-light conditions Synthesize a new color image, which can reduce the noise of the image under low-light conditions and increase the brightness of the image at the same time, so as to obtain better-quality color images under low-light conditions.

Description of drawings

FIG. 1 is a schematic flowchart of a processing method for improving the quality of a color image under low illumination provided by an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a processing device for improving the quality of a color image under low illumination provided by an embodiment of the present invention.

The realization of the purpose of the present invention, functional characteristics and excellent effects will be further described below in conjunction with specific embodiments and accompanying drawings.

Detailed ways

The technical scheme of the present invention will be described in further detail below in conjunction with the accompanying drawings and specific examples, so that those skilled in the art can better understand the present invention and implement it, but the examples given are not intended to limit the present invention .

Aiming at the problem of color shift or inability to obtain color images in the images obtained by digital cameras in low-illuminance environments in the prior art, in order to obtain high-quality color images in low-illuminance environments, the purpose of the present invention is to provide a low-light The processing method for improving the quality of color images under illumination, the core idea of the present invention is: by periodically switching the infrared filter and the full-transmission spectral filter deployed in front of the image sensor in turn, and according to the different filters The corresponding brightness information and color information are obtained from the black-and-white image and the color image obtained respectively, and then combined with the brightness information and color information collected twice before and after to obtain a composite color image. In some embodiments, the output color image can be further The image is processed by white balance correction, and the color image obtained by the above method has higher brightness and less noise, which can meet the requirements of the actual monitoring environment.

Specifically, as shown in FIG. 1 , a processing method for improving the quality of a color image under low illumination provided by an embodiment of the present invention includes the following steps:

S10. Periodically switch the infrared filter and the fully transparent spectral filter deployed in front of the image sensor, and collect corresponding infrared filter images and fully transparent images in real time;

S20. Acquire image color information of the infrared filter image, and acquire image brightness information of the fully transparent image;

S30. Perform data fusion processing on the image brightness information and image color information, and output a color image.

In this embodiment, in the step S10, the period can be set by those skilled in the art according to actual application requirements, for example, the period can be set as: 1 second for the infrared filter and the full transmission spectrum The filter is switched 25 times to collect 25 sets of infrared filter images and fully transparent images.

In the embodiment of the present invention, the final output color image is obtained by processing a group of infrared filter images and fully transparent images collected before and after, extracting the corresponding color information and brightness information, and then performing data fusion processing. For details, please refer to the following.

In this embodiment, the step of obtaining the image color information of the infrared filtered image includes:

S201. Convert the infrared filter image into image data in YCbCr format;

For infrared filter image conversion in RGB format, it can be converted into image data in YCbCr format according to the following conversion relationship:

Y=0.299R+0.587G+0.114B;

Cb=0.564(B-Y);

Cr=0.713(R-Y).

Wherein, said Y refers to the luminance component of the infrared filter image, Cb refers to the blue chroma component of the infrared filter image, Cr refers to the red chroma component of the infrared filter image, and R, G, and B refer to the infrared filter image of RGB format respectively. Red R component intensity value, green G component intensity value, blue B component intensity value.

S202. Obtain the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information.

In this embodiment, the step of acquiring image brightness information of the fully transparent image includes:

S203. Obtain the average brightness Y _avg of the fully light-transmitting image by using the following mathematical formula:

Y _avg = Y _sum /n;

Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image;

S204. Determine whether the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target brightness value, and the Y _thd is the preset fluctuation error value, if yes, go to step S207, otherwise, go to the next step;

S205. Adopt the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target , wherein the adjustment step size f _step is mainly used to adjust the shutter exposure time and image sensor gain , and the aperture change rate, so that the accuracy and speed of image brightness adjustment are controlled within an appropriate range:

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

S206. Control the shutter exposure time, image sensor gain, and aperture change rate according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output fully light-transmitting image. For example, the shutter exposure time exposure _time can be adjusted according to the following formula :

Exposure _time =(1+f _step )exposure _time ;

After that, go to step S203;

S207. Obtain image brightness information of a fully transparent image in which the brightness average value Y _avg is within a preset target brightness range [Y _target −Y _thd , Y _target +Y _thd ].

In this embodiment, data fusion processing is performed on the image brightness information and image color information, and the step of outputting a color image includes:

S301. Confirm the brightness information of the image as the brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr included in the image color information to synthesize a color image in YCbCr format.

In this embodiment, continuing to refer to FIG. 1, after all the steps are performed, the processing method for improving the quality of color images under low illumination further includes:

S40. Perform white balance correction processing on the color image.

In this embodiment, for the white balance correction process, it is possible to obtain data under ideal white balance under different color temperatures by performing tests in different low-light scenes, and then perform statistics and analysis based on these data to obtain R/G, The distribution of B/G under different color temperature conditions (for example, presented in the form of a distribution curve).

For example, divide a color image into multiple small block images, calculate the R/G and B/G values of each pixel in each small block image, and then find The corresponding area is obtained, among which, the area with the most small block images is used as the reference area to obtain the color gain values Rgain, Bgain, and Ggain corresponding to the R, G, and B channels, and then use the following formula to correct the color image according to these gain values R, G, and B channels of the corrected R, G, and B channels to obtain R _new , G _new , and B _new .

R _new = R _gain × R;

G _new =G _gain ×G;

B _new = B _gain × B.

As shown in Figure 2, a processing device for improving the quality of color images under low illumination provided by an embodiment of the present invention includes:

The filter switching module 10 is used to periodically switch the infrared filter and the fully transparent spectral filter deployed in front of the image sensor;

The image acquisition module 20 is used to collect corresponding infrared filtered images and fully transparent images in real time when the filter switching module periodically switches the infrared filter and the fully transparent spectral filter;

A color information acquisition module 30, configured to acquire image color information of the infrared filtered image;

A brightness information acquisition module 40, configured to acquire image brightness information of the fully transparent image;

The data fusion processing module 50 is configured to perform data fusion processing on the image brightness information and image color information, and output a color image.

In this embodiment, the color information acquisition module 30 includes:

The first conversion unit 301 is used to convert the infrared filtered image into image data in YCbCr format, wherein the Y refers to the brightness component of the infrared filtered image, Cb refers to the blue chrominance component of the infrared filtered image, and Cr refers to the infrared filtered image the red chrominance component of the image;

The color information acquiring unit 302 is configured to acquire the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information.

In this embodiment, the brightness information acquisition module 40 includes:

The first calculation unit 401 is used to obtain the average brightness Y _avg of the fully transparent image by using the following mathematical formula:

Y _avg = Y _sum /n;

Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image;

A judging unit 402, configured to judge whether the luminance average value Y _avg is within a preset target luminance range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target luminance value, The Y _thd is a preset fluctuation error value, if yes, send a color information acquisition command to the brightness information acquisition unit 405, otherwise control the second calculation unit 403 to calculate the adjustment step size f _step ;

The second calculation unit 403 is used to adopt the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target :

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$

The adjustment unit 404 is used to control the shutter exposure time, the image sensor gain, and the aperture change rate according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output fully light-transmitting image, and then control the first calculation unit 401 to perform brightness average Calculation of the value Y _avg ;

Brightness information acquiring unit 405, configured to acquire the total light-transmitting image whose brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ] according to the color information acquisition command Image brightness information.

In this embodiment, the data fusion processing module 50 includes:

a receiving unit 501, configured to acquire the image brightness information and image color information;

The fusion processing unit 502 is configured to confirm the image brightness information as a brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr contained in the image color information to synthesize a color image in YCbCr format.

In this embodiment, the processing device for improving the quality of color images under low illumination further includes:

The white balance processing module 60 is configured to perform white balance correction processing on the color image.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the description of the present invention and the contents of the accompanying drawings, or directly or indirectly used in other related All technical fields are equally included in the scope of patent protection of the present invention.

Claims (10)

1. A processing method for color image quality promotion under low illumination, characterized in that, comprising: A. Periodically switch the infrared filter and the fully transparent spectral filter deployed in front of the image sensor, and collect the corresponding infrared filter image and fully transparent image in real time; B. Obtain image color information of the infrared filter image, and obtain image brightness information of the fully transparent image; C. Perform data fusion processing on the image brightness information and image color information to output a color image. 2. The processing method of color image quality promotion under low illumination as claimed in claim 1, is characterized in that, the step of obtaining the image color information of described infrared filter image comprises: B10, converting the infrared filter image into image data in YCbCr format, wherein, the Y refers to the brightness component of the infrared filter image, Cb refers to the blue chroma component of the infrared filter image, and Cr refers to the red chroma component of the infrared filter image ; B11. Obtain the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information. 3. The processing method for improving the quality of color images under low illumination as claimed in claim 1 or 2, wherein the step of obtaining the image brightness information of the fully transparent image comprises: B20, using the following mathematical formula to obtain the brightness average value Y _avg of the fully light-transmitting image: Y _avg = Y _sum /n; Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image; B21. Judging whether the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target brightness value, and the Y _thd is the preset fluctuation error value, if yes, go to step B24, otherwise, go to the next step; B22. Use the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target : ${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$ B23. Control the exposure time of the shutter, the gain of the image sensor, and the rate of change of the aperture according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output full light transmission image, and then go to step B20; B24. Obtain image brightness information of a fully light-transmitting image in which the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ]. 4. The processing method of color image quality promotion under low illumination as claimed in claim 3, it is characterized in that, carry out data fusion processing to described image brightness information and image color information, the step of output color image comprises: C1. Identify the brightness information of the image as the brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr included in the image color information to synthesize a color image in YCbCr format. 5. The processing method of color image quality improvement under low illumination as claimed in claim 1, is characterized in that, after performing all steps, also comprises: D. Performing white balance correction processing on the color image. 6. A processing device for improving the quality of color images under low illumination, characterized in that it comprises: The filter switching module is used to periodically switch the infrared filter and the full-transmission spectral filter deployed in front of the image sensor; The image acquisition module is used to collect corresponding infrared filter images and full light transmission images in real time when the filter switching module periodically switches the infrared filter and the full light transmission filter; A color information acquisition module, configured to acquire image color information of the infrared filtered image; A brightness information acquisition module, configured to acquire image brightness information of the fully transparent image; The data fusion processing module is used to perform data fusion processing on the image brightness information and image color information, and output a color image. 7. The processing device for improving the quality of color images under low illumination as claimed in claim 6, wherein the color information acquisition module comprises: The first conversion unit is used to convert the infrared filtered image into image data in YCbCr format, wherein the Y refers to the brightness component of the infrared filtered image, Cb refers to the blue chrominance component of the infrared filtered image, and Cr refers to the infrared filtered image. The red chroma component of The color information acquiring unit is configured to acquire the blue chrominance component Cb and the red chrominance component Cr of the YCbCr format image data, and use them as image color information. 8. The processing device for improving the quality of color images under low illumination as claimed in claim 6 or 7, wherein the brightness information acquisition module comprises: The first calculation unit is used to obtain the average brightness Y _avg of the fully transparent image by using the following mathematical formula: Y _avg = Y _sum /n; Among them, Y _sum is the sum of the brightness values of all pixels in the fully transparent image, and n is the number of pixels in the fully transparent image; A judging unit, configured to judge whether the brightness average value Y _avg is within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ], wherein the Y _target is a preset target brightness value, and the Said Y _thd is a preset fluctuation error value, if yes, send a color information acquisition command to the brightness information acquisition unit, otherwise control the second calculation unit to calculate the adjustment step size f _step ; The second calculation unit is used to adopt the following mathematical formula, and set the adjustment step size f _step according to the difference between the current brightness average value Y _avg and the target brightness value Y _target : ${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; step</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; avg</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}{{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; Y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; arg</span>}\mathrm{<span\; class="notranslate">\; et</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ;</span>$ The adjustment unit is used to control the exposure time of the shutter, the gain of the image sensor, and the rate of change of the aperture according to the adjustment step f _step , so as to realize the adjustment of the brightness of the output fully light-transmitting image, and then control the first calculation unit to perform the brightness average value Y Calculation of _avg ; A brightness information acquisition unit, configured to acquire an image of a fully transparent image with the brightness average value Y _avg within a preset target brightness range [Y _target -Y _thd , Y _target +Y _thd ] according to the color information acquisition command Brightness information. 9. The processing device for improving the quality of color images under low illumination as claimed in claim 8, wherein the data fusion processing module comprises: a receiving unit, configured to obtain the image brightness information and image color information; The fusion processing unit is used to confirm the brightness information of the image as the brightness component Y, and combine the blue chrominance component Cb and the red chrominance component Cr contained in the image color information to synthesize a color image in YCbCr format. 10. The processing device for improving the quality of color images under low illumination as claimed in claim 6, further comprising: The white balance processing module is used to perform white balance correction processing on the color image.