Unlock instant, AI-driven research and patent intelligence for your innovation.

Color calibration method of camera module

a camera module and color calibration technology, applied in the field of color calibration, can solve the problems of poor stability high maintenance cost of the standard lighting cabinet, and time-consuming process, and achieve high automation degree, high flexibility and adaptability, and high convenience in color changing

Active Publication Date: 2016-12-22
THOUSAND LIGHTS LIGHTING CHANGZHOU LTD
View PDF0 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0005]In order to solve the disadvantages of the traditional calibration method of a camera module, the present invention provides a color calibration method of a camera module, characterized by a high degree of automation, improved light source stability and great flexibility. The present invention adopts the technical scheme as follows:
[0011]6) processing the parameter values X1′ to Xn′ obtained through photographing of each camera module by means of the color calibration models established in the step 5), so as to obtain corresponding calibrated parameter values X1″ to Xn″, thereby accomplishing color calibration of the camera module.
[0019]According to the present invention, firstly multiple reference parameter values of each color sample in a color chart are set, or a photograph and a measurement are performed on a standard color chart or a user-defined color chart in a certain standard lighting environment, multiple reference parameter values, SPD (λ)×R (λ) and brightness of each color sample are obtained. Then the SPD (λ)×R (λ) and the brightness of each color sample are reproduced by using a spectral tunable lighting source. Then each reproduced color sample is photographed by using the camera under the same settings to obtain multiple reproduced parameter values of each color sample. The two groups of parameter values are compared and a color calibration model is established. Finally color calibration of each batch of camera modules is implemented without the helping of a color chart and standard lighting environment. The present invention has the characteristics of high automation degree, high flexibility and adaptability, and high convenience in color changing and color sample calibrating, and thus has an extremely high practical value.

Problems solved by technology

The traditional method has the following disadvantages: a standard lighting cabinet and a standard color chart are needed, the stability of the standard lighting cabinet is poor, the maintenance cost of the standard lighting cabinet is high, a considerably experienced operator is needed during the whole calibration process, the process is time-consuming, and color samples needed by a user cannot be customized for color calibration.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Color calibration method of camera module
  • Color calibration method of camera module
  • Color calibration method of camera module

Examples

Experimental program
Comparison scheme
Effect test

embodiment i

[0036]Taking the setting of RGB values, SPD (λ)×R (λ), brightness of each color sample and a Canon EOS 650D three-channel RGB camera as an example, the flowchart is as shown in FIG. 1, and the specific steps are as follows:

[0037]1) adopting a 24-color X-Rite ColorChecker Classic color chart as shown in FIG. 2;

[0038]2) adopting officially provided RGB values of each color sample in the standard color chart as reference parameter values; meanwhile, adopting the multiplication result of spectral power distribution SPD (λ) of standard daylight D65 defined by International Commission on illumination and officially provided spectral reflectance R (λ) of each color sample of the standard color chart as SPD (λ)×R (λ) (as shown in FIG. 3 and FIG. 4); setting the brightness of each color sample;

[0039]3) reproducing the SPD (λ)×R (λ) and the brightness of each color sample through a spectral tunable lighting source;

[0040]4) sequentially photographing the each reproduced SPD (λ)×R (λ) and brigh...

embodiment ii

[0043]Taking obtaining RGB values of each color sample of a Canon EOS 650D three-channel RGB camera through photographing and measurement and obtaining the SPD (λ)×R (λ) and the brightness of each color sample through measurement as an example, the flowchart is as shown in FIG. 9, and the specific steps are as follows:

[0044]1) adopting a 24-color X-Rite ColorChecker Classic standard color chart;

[0045]2) as shown in FIG. 10, laying the color chart in the standard lighting cabinet using 0 / 45 geometry with daylight D50, photographing the color chart through a Canon EOS 650D single-lens reflex camera (f-number 5.6, exposure time 1 / 60 and ISO100), and obtaining the preference RGB values of each color sample in the color chart after processing; meanwhile, directly measuring the SPD (λ) (the spectral power distribution of the standard lighting cabinet D50)×R (λ) (the spectral reflectance) and the brightness of the color sample with a spectroradiometer (as shown in FIG. 11), wherein the mea...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

According to the present invention, firstly multiple reference parameter values of each color sample in a color chart are set, or a photograph and a measurement are performed on a standard color chart or a user-defined color chart in a certain standard lighting environment, multiple reference parameter values, SPD (λ)×R (λ) and brightness of each color sample are obtained. Then the SPD (λ)×R (λ) and the brightness of each color sample are reproduced by using a spectral tunable lighting source. Then each reproduced color sample is photographed by using the camera under the same settings to obtain multiple reproduced parameter values of each color sample. The two groups of parameter values are compared and a color calibration model is established. Finally color calibration of each batch of camera modules is implemented without the helping of a color chart and standard lighting environment. The present invention has the characteristics of high automation degree, high flexibility and adaptability, and high convenience in color changing and color sample calibrating, and thus has an extremely high practical value.

Description

FIELD OF THE INVENTION[0001]The present invention belongs to the field of color calibration, and particularly relates to a color calibration method of a camera module.BACKGROUND OF THE INVENTION[0002]With the rapid development of mobile Internet, mobile devices have also been widely applied to all fields of people's lives, and as a camera module serves as a very important component of a mobile device, increasing attention is paid to the imaging quality of the camera module.[0003]The performance test of the camera module includes multiple test items including resolution ratio, white balance, gray scale and color, etc., where color calibration of the camera module is a very important item, and colors of images, such as sky blue, grass green and etc., can be accurately expressed only after color calibration.[0004]The traditional color calibration method of a camera module includes photographing a standard color chart under the standard lighting cabinet, analyzing the relation between i...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): G06T7/00G06T7/40H04N17/00
CPCG06T7/0018G06T2207/10024G06T7/408H04N17/002H04N23/84
Inventor LUO, MING RONNIERWANG, BINYU
Owner THOUSAND LIGHTS LIGHTING CHANGZHOU LTD