Camera module multi-focal-section evaluation method and system

Abstract

In order to solve the problems of low evaluation efficiency and poor accuracy in the prior art, the invention provides a camera module multi-focal-length evaluation method and system, and the method comprises the steps: installing a camera module and aligning a test device, controlling the focal length of the camera module to be switched to different focal lengths, starting a self-adaptive light source adjustment system, and adjusting the focal lengths of the camera module to different focal lengths. A light source is automatically adjusted according to the change of ambient light, and a computer system captures images of all focal segments, analyzes image data to calculate analytic power and outputs a test report. According to the invention, through cooperative work of the components, rapid and accurate focusing and automatic evaluation under a multi-focal-section condition can be realized.

Description

A method and system for evaluating multi-focal length camera modules Technical Field

[0001] This invention relates to the field of cameras, and in particular to a method and system for evaluating multi-focal length camera modules. Background Technology

[0002] With the rapid development of smart devices and autonomous driving technology, the demand for camera modules in various applications is increasing, and the performance requirements are also constantly rising. Especially in multi-focal length testing, traditional testing methods typically require manually adjusting the focal length one by one to test the camera's near, medium, and far focal lengths. This method has several drawbacks: low efficiency: traditional testing methods require multiple adjustments to the focal length and testing equipment, making the testing process cumbersome and time-consuming, and making it difficult to test multiple focal lengths simultaneously, resulting in low efficiency.

[0003] Accuracy issues: Due to the reliance on manual operation, human error is easily introduced during the testing process, resulting in insufficient accuracy and stability of the test results.

[0004] Light interference: Changes in external light may interfere with test results, especially under different test conditions, making it difficult to maintain consistency in the evaluation results.

[0005] The need for rapid focusing: In multi-focal-length applications, cameras need to quickly adjust their focus at different distances to achieve clear imaging. Traditional methods cannot respond to this need quickly enough, affecting the practical performance of cameras.

[0006] Existing testing devices typically employ a single test chart and manual focus adjustment, which fails to effectively address the aforementioned issues. Therefore, the market urgently needs a fully automated device and method that can improve the efficiency and accuracy of multi-focal-length testing, while also adapting to changes in ambient light and providing rapid and precise focusing capabilities.

[0007] Chinese invention patent CN202311555006.0 proposes a camera evaluation method, apparatus, device, and storage medium. The method includes: identifying multiple cameras to be evaluated on a target device and acquiring evaluation images captured by each camera; performing imaging detection on each camera based on each evaluation image to obtain imaging detection results for each camera; and determining the camera evaluation result of the target device based on the imaging detection results of each camera. However, this invention cannot be applied to multi-focal length scenarios at once, resulting in low efficiency and the inability to perform imaging detection on multiple cameras with different focal lengths. Summary of the Invention

[0008] This invention primarily addresses the problems of low efficiency and poor accuracy in existing testing technologies by providing a multi-focal length testing method and system for camera modules.

[0009] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: a multi-focal length evaluation method for a camera module, characterized by comprising the following steps: S1, installing the camera module and aligning it with the testing device; S2, controlling the focal length of the camera module to switch to different focal lengths through a fully automatic focal length switching system; S3, activating an adaptive light source adjustment system to automatically adjust the light source according to changes in ambient light; S4, the computer system captures images of each focal length and analyzes the image data to calculate the resolution; S5, outputting a test report, the test report including a resolution curve and a data report.

[0010] As a preferred embodiment, step S1 specifically includes the following steps: S1.1, pushing the motor to make the resolution value of the near-view feature pattern in group 1 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 1 meets the threshold range, and recording the motor code1 value at this time in the memory; S1.2, pushing the motor to make the resolution value of the near-view feature pattern in group 2 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 3 meets the threshold range, and recording the motor code2 value at this time in the memory; S1.3, pushing the motor to make the resolution value of the near-view feature pattern in group 3 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 3 meets the threshold range, and recording the motor code3 value at this time in the memory.

[0011] As a preferred embodiment, step S3 specifically includes the following steps: S3.1, acquiring data from the light source sensor, adjusting the light source controller to initially adjust the light source illuminance and color temperature so that the sensor is stable within the threshold; S3.2, then acquiring the grayscale value of the same field of view through the camera, and determining whether it is within the threshold.

[0012] As a preferred option, in step S3.2, if the threshold is exceeded, the light source controller is fine-tuned so that the illuminance of the light source in the corresponding field of view meets the requirements.

[0013] As a preferred approach, in step S4, if the feature pattern is horizontal or vertical bars, the MTF method is used to calculate the analytical data at each ROI (Region of Interest).

[0014] As a preferred approach, in step S4, if the feature pattern is a rhombus, the SFR method is used to calculate the analytical data at each ROI (Region of Interest).

[0015] As a preferred embodiment, the system includes a host computer, a fully automatic focal length switching system in which the host computer controls the camera movement via communication software, an adaptive light source adjustment system in which the host computer adjusts the light source via a light source sensor, and a multi-layer test chart attached to the adaptive light source adjustment system. The adaptive light source adjustment system includes a light sensor and several adjustable light sources.

[0016] As a preferred embodiment, the multi-layer test chart includes several chart layers with charts, each chart having a feature pattern and a light-transmitting area.

[0017] As a preferred embodiment, the cards are separated by an optical insulating material.

[0018] As a preferred embodiment, the fully automatic focal length switching system includes a computer-controlled focal length switching device, which is equipped with a motor and an encoder.

[0019] Therefore, the advantages of this invention are: fully automated evaluation: This invention introduces a fully automatic focal length switching system, which, through computer control, allows the camera module to automatically switch to different focal lengths. This design reduces manual intervention and greatly improves evaluation efficiency and accuracy.

[0020] Multi-focal length simultaneous screen testing structure: This invention designs a multi-layer test chart, with each layer having different feature patterns, allowing the camera module to simultaneously capture images at multiple focal lengths. This structure not only improves testing efficiency but also avoids the hassle of repeatedly adjusting the focus.

[0021] Adaptive Light Source Adjustment System: By monitoring changes in ambient light in real time, the adaptive light source adjustment system of this invention can automatically adjust the intensity and color temperature of the light source to ensure the consistency and accuracy of test results and overcome the influence of changes in ambient light.

[0022] Fast and accurate focusing: This invention provides a method for rapid focusing in a terminal, automatically adjusting the focal length of the camera module based on the distance to the object. By using pre-recorded focal length parameters, the system can automatically select the most suitable focal length at different distances, achieving fast and accurate focusing under multi-focal length conditions. Attached Figure Description

[0023] Figure 1 is a flowchart of the present invention.

[0024] Figure 2 is a system structure diagram of the present invention.

[0025] Figure 3 is a schematic diagram of the device for calculating SFR based on the oblique knife-edge method of the present invention.

[0026] Figure 4 is a schematic diagram of the SFR camera imaging calculation based on the oblique knife-edge method of the present invention. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0028] Example 1: With the rapid development of smart devices and autonomous driving technology, the demand for camera modules in various applications is increasing, and the performance requirements are also constantly rising. Especially in multi-focal length evaluation, traditional testing methods typically require manually adjusting the focal length one by one to test the camera's near, medium, and far focal lengths. This method has several drawbacks: low efficiency: Traditional testing methods require multiple adjustments to the focal length and testing equipment, making the testing process cumbersome and time-consuming, and making it difficult to test multiple focal lengths simultaneously, resulting in low efficiency.

[0029] Accuracy issues: Due to the reliance on manual operation, human error is easily introduced during the testing process, resulting in insufficient accuracy and stability of the test results.

[0030] Light interference: Changes in external light may interfere with test results, especially under different test conditions, making it difficult to maintain consistency in the evaluation results.

[0031] The need for rapid focusing: In multi-focal-length applications, cameras need to quickly adjust their focus at different distances to achieve clear imaging. Traditional methods cannot respond to this need quickly enough, affecting the practical performance of cameras.

[0032] Existing testing devices typically employ a single test chart and manual focus adjustment, which fails to effectively address the aforementioned issues. Therefore, the market urgently needs a fully automated device and method that can improve the efficiency and accuracy of multi-focal-length testing, while also adapting to changes in ambient light and providing rapid and precise focusing capabilities.

[0033] To address the aforementioned issues, this invention provides a multi-focal-length evaluation method and system for camera modules, aiming to improve evaluation efficiency and accuracy, reduce human error, and maintain consistency of evaluation results under different environmental conditions, thus providing reliable technical support for the quality control and application of camera modules.

[0034] One of the methods for evaluating multi-focal length camera modules includes the following steps: S1, installing the camera module and aligning it with the testing device.

[0035] Step S1 specifically includes the following steps: S1.1, push the motor to make the resolution value of the near-field feature pattern in group 1 meet the threshold range, and at the same time, the resolution value of the far-field feature pattern in group 1 meets the threshold range, and record the motor code1 value at this time into the memory.

[0036] S1.2. Drive the motor to make the resolution value of the near-field feature pattern in group 2 meet the threshold range, and at the same time, the resolution value of the far-field feature pattern in group 3 meets the threshold range. Record the motor code2 value at this time into the memory.

[0037] S1.3. Drive the motor to make the resolution value of the near-field feature pattern in group 3 meet the threshold range, and at the same time, the resolution value of the far-field feature pattern in group 3 meets the threshold range. Record the motor code3 value at this time into the memory.

[0038] S2. The fully automatic focal length switching system controls the camera module to switch focal lengths to different focal lengths. This process mainly relies on the camera module's built-in automated control algorithm and hardware adjustment module. The automatic focal length switching system enables the camera module to respond quickly, allowing it to precisely switch to the specified focal length according to different shooting needs or scene changes. Specifically, the focal length adjustment mechanism in the camera module uses an electric adjustment device to achieve precise focal length adjustment, thus adapting to the shooting needs of different scenes such as distant views and close-ups. This fully automated design not only improves the system's intelligence level but also reduces the need for manual intervention, greatly enhancing the camera's efficiency and applicability.

[0039] S3. Activate the adaptive light source adjustment system to automatically adjust the light source according to changes in ambient light, ensuring the stability and consistency of shooting results. The adaptive light source adjustment system is a closed-loop control system based on real-time feedback of sensor data. Its main function is to dynamically adjust the brightness and color temperature of the light source by sensing changes in the brightness and color temperature of the external ambient light to meet the optimal requirements of the shooting environment.

[0040] Step S3 specifically includes the following steps: S3.1, acquiring data from the light source sensor. This data acquisition mainly includes illuminance (brightness) and color temperature information. The light source sensor transmits the acquired data to the light source controller. The light source controller adjusts the illuminance and color temperature of the light source initially to stabilize the sensor within the threshold. This initial adjustment is coarse, aiming to quickly approach the target value in order to lay the foundation for subsequent fine adjustments.

[0041] S3.2 Next, acquire grayscale values ​​within the same field of view using the camera and determine if they are within the threshold range. This step is crucial for verifying the effectiveness of the light source adjustment. Grayscale value is a quantitative representation of the brightness of an image. By analyzing whether the grayscale value is within the preset threshold range, it can be determined whether the current light source adjustment has achieved the desired effect. If the grayscale value exceeds the set threshold range, the system will identify areas requiring further optimization.

[0042] In step S3.2, if the threshold is exceeded, the light source controller is fine-tuned to ensure the illuminance of the light source within the corresponding field of view meets the requirements. This fine-tuning process more precisely adjusts the brightness and color temperature of the light source to ensure that the lighting conditions within the camera's field of view meet the expected goals. Specifically, the fine-tuning stage combines data from multiple sensor feedbacks and camera acquisitions, dynamically optimizing various parameters through an adaptive algorithm to make the lighting conditions of the shooting scene more uniform and the brightness and color temperature more harmonious. This design can significantly improve the quality of the captured image, especially under complex lighting conditions, effectively avoiding overexposure or underexposure and ensuring the stability of the shooting results.

[0043] S4. The computer system captures images at various focal lengths and analyzes the image data to calculate resolution. During execution, the computer system selects different calculation methods based on the characteristic pattern type of the test target, thereby ensuring more accurate resolution calculation results.

[0044] In step S4, if the feature pattern consists of horizontal and vertical bars, the MTF method is used to calculate the resolved data for each Region of Interest (ROI). The MTF method is a commonly used image quality assessment method that quantitatively describes the resolving power of a system by analyzing the relationship between image contrast and spatial frequency. In this case, the computer calculates specific resolved data for each ROI. The selection of the ROI is usually related to the design of the test target to ensure that the data reflects the performance characteristics of the optical system.

[0045] If the feature pattern is a rhombus, the SFR method is used to calculate the resolving data at each ROI (Region of Interest). The SFR method is another common image quality assessment technique, particularly suitable for analyzing image content with rhomboid features. Using this method, the system can more accurately calculate the resolving power data at each ROI.

[0046] Whether using the MTF or SFR method, the computer system performs a series of complex processes on the image data, including image preprocessing, edge detection, and spectral analysis, to ensure that the resolution calculation results are highly accurate and reliable.

[0047] S5. Output the test report, which includes a resolution curve and a data report. The test report is the final output of the entire testing process, containing the resolution curve and a detailed data report. The resolution curve is an intuitive graphical representation, typically used to show the resolving power of an optical system at different spatial frequencies. Through the resolution curve, users can clearly see the trend of the system's imaging performance changing with spatial frequency, thus determining whether the system's resolution meets expectations. The data report details the specific resolution data for each focal length and ROI in tabular or text format. This data provides important reference for optical system design optimization, performance evaluation, and quality control.

[0048] Another part is a multi-focal-length evaluation system for camera modules, including a host computer, a fully automatic focal-length switching system controlled by the host computer via communication software, an adaptive light source adjustment system adjusted by the host computer via a light sensor, and a multi-layer test chart attached to the adaptive light source adjustment system. The adaptive light source adjustment system includes a light sensor and several adjustable light sources. This system, through rigorous hardware and software design, aims to achieve efficient and accurate evaluation of the performance of camera modules at different focal lengths.

[0049] To ensure consistent test results under varying lighting conditions, this invention introduces an adaptive light source adjustment system equipped with multiple adjustable light sources. This system automatically adjusts the brightness and color temperature of the light sources according to changes in ambient light, ensuring consistent image quality. The system monitors changes in ambient light in real time and automatically adjusts the intensity and color temperature of the light sources. In this way, interference from ambient light can be eliminated, ensuring the accuracy and stability of image data. The light source system monitors changes in ambient light in real time via a photosensor and feeds this information back to the computer control system for adjustment.

[0050] The computer control system is the central component of this invention, responsible for coordinating the operation of each subsystem. The system first installs a camera module and aligns it with the testing device, then captures images at different focal lengths through an automated process. The computer system analyzes the acquired images, calculates the resolution at each focal length, and outputs test results including resolution curves and data reports.

[0051] The multi-layer test chart comprises several chart layers, each featuring characteristic patterns and light-transmitting areas. These characteristic patterns are designed to meet the evaluation requirements of camera modules at different focal lengths, assessing their resolution, image quality, and optical performance. Specifically, the characteristic patterns may include methods such as the knife-edge method, slit method, or modulation transfer function (MTF) feature maps used to calculate spatial frequency response (SFR) data. These designs accommodate the needs of various analytical algorithms, enabling the system to comprehensively evaluate the performance of different types of camera modules. The light-transmitting areas ensure that the light source is accurately projected onto the camera module through the chart, thereby facilitating efficient optical performance testing.

[0052] The multi-layer test chart is the core component of this system, with each layer featuring different feature patterns and light-transmitting areas. These patterns are designed to test the performance of camera modules at different focal lengths. The charts are separated by an optical isolation material to prevent signal interference between different focal lengths. This optical isolation material effectively blocks light signal interference between different focal lengths, ensuring a high degree of independence and accuracy in the test data for each focal length. The use of this optical isolation material not only accurately distinguishes the signals from each focal length but also prevents measurement errors caused by light interference. Furthermore, this isolation design reduces the interference of ambient light on the testing process, further improving the reliability of the evaluation. The feature patterns can be the oblique knife-edge method, slit method, or MTF feature map used to calculate SFR data, meeting the needs of various analytical algorithms.

[0053] Taking the oblique knife-edge method as an example, its feature pattern design can be used to calculate the spatial frequency response (SFR) data of the camera module, thereby analyzing the camera's resolution. The slit method, on the other hand, is more suitable for high-precision optical image quality testing, judging the imaging performance of the camera module by analyzing light intensity distribution and imaging characteristics. Modulation transfer function (MTF) feature maps are also a commonly used testing method, evaluating the imaging sharpness and detail reproduction capability of the camera module by analyzing the contrast variation with spatial frequency. The design of these feature patterns fully considers the performance differences of the camera module at different focal lengths, thus providing the most suitable testing scheme for each focal length.

[0054] The fully automatic focal length switching system includes a computer-controlled focal length switching device that automatically adjusts the camera's focal length according to testing requirements, enabling rapid switching. The focal length switching device is equipped with a motor and encoder; through motor drive and encoder feedback, it can precisely control the focal length changes of the camera module. The system automatically switches to different focal lengths by controlling the camera module's focal length via computer. It achieves automatic focal length switching through precise motor control. The system captures images at different focal lengths and adjusts the focal length according to a preset resolution threshold to achieve optimal imaging results. The focal length switching system is connected to a computer control system and can automatically select the appropriate focal length according to testing requirements.

[0055] The beneficial effects of this invention are as follows: Improved testing efficiency: The design of the multi-layer test chart and the introduction of the fully automatic focal length switching system enable the camera module to complete multi-focal length testing at one time, avoiding the tedious operation of manual adjustment and greatly improving testing efficiency.

[0056] Improving testing accuracy and consistency: Through a computer control system and automated processes, this invention eliminates human error, achieving highly accurate and consistent testing results. Simultaneously, the adaptive light source adjustment system ensures that changes in ambient light do not affect the test results.

[0057] Achieving fast and accurate focusing: The system can automatically adjust the camera module's focal length based on the distance to the object during terminal testing, according to preset focal length parameters. This automated, fast focusing mechanism ensures clear imaging at different distances, improving the practical application performance of the camera module.

[0058] Multiple parsing algorithms supported: The test card designed in this invention supports multiple parsing algorithms, including SFR and MTF feature maps, which are suitable for the evaluation needs of various camera modules.

[0059] Example 2: Figures 3 and 4 show preferred embodiments of the multi-focal length test structure: the feature pattern of the near-field position in group 1 is 1, and the feature pattern of the far-field position is 2.

[0060] The characteristic pattern in the foreground of Group 2 is 3, and the characteristic pattern in the background is 5.

[0061] The characteristic pattern in the foreground of group 3 is 4, and the characteristic pattern in the background is 6.

[0062] One to six feature patterns are placed within the field of view of the image. The field of view can be at position 0.3 or 0.6, so that the foreground and background in the same group are in the same field of view, ensuring resolution. At the same time, according to the need of "near objects appear larger and far objects appear smaller", the feature patterns are scaled proportionally according to the distance to keep the resolution benchmark consistent.

[0063] Figures 3 and 4 show three sets of near and far views, but in reality, more sets of near and far view features can be captured on the camera.

[0064] Steps: 1. Drive the motor so that the resolution values ​​of the near-field feature patterns MTF1 and SFR1 in group 1 meet the threshold range (MTF1_low~MTF1_high or SFR1_low~SFR1_high), and at the same time, the resolution values ​​of the far-field feature patterns MTF2 and SFR2 in group 1 meet the threshold range (MTF2_low~MTF2_high or SFR2_low~SFR2_high). Record the motor code1 value at this time in the memory.

[0065] 2. Drive the motor to make the resolution values ​​of the near-field feature patterns MTF3 and SFR3 in group 2 meet the threshold range (MTF3_low~MTF3_high or SFR3_low~SFR3_high), and at the same time, the resolution values ​​of the far-field feature patterns MTF5 and SFR5 in group 2 meet the threshold range (MTF5_low~MTF5_high or SFR5_low~SFR5_high). Record the motor code2 value at this time in the memory.

[0066] 3. Drive the motor to make the resolution values ​​of the near-field feature patterns in group 3, MTF4 and SFR4, meet the threshold range (MTF4_low~MTF4_high or SFR4_low~SFR4_high), and at the same time, the resolution values ​​of the far-field feature patterns in group 3, MTF6 and SFR6, meet the threshold range (MTF6_low~MTF6_high or SFR6_low~SFR6_high). Record the motor code3 value at this time in the memory.

[0067] Autofocus operation: During terminal testing, when the object distance is within the range of near and far distances in Group 1, the motor is pushed to code 1; when the object distance is within the range of near and far distances in Group 2, the motor is pushed to code 2; when the object distance is within the range of near and far distances in Group 3, the motor is pushed to code 3, achieving fast and accurate focusing.

[0068] During terminal testing, the multi-focal length fast focusing system of this invention can automatically adjust the focal length of the camera module according to the distance of the object, achieving fast and accurate focusing. The specific implementation is as follows: Focal length data storage: During multi-focal length testing, the system records the motor code values ​​corresponding to the feature pattern resolution values ​​of different groups (e.g., group 1, group 2, group 3) at near and far positions. These code values ​​represent the state of the camera module at a specific focal length.

[0069] Group 1 Focus: When the object is within the near and far distance range of Group 1 during terminal testing, the system will automatically adjust the motor to the code 1 value. This means that the camera module will set the focus to a suitable distance range for Group 1 to ensure clear imaging.

[0070] Group 2 Focus: When the object is within the range of near and far distances in Group 2, the system will automatically adjust the motor to the code2 value to ensure that the camera module achieves the best focusing effect within this range.

[0071] Group 3 Focus: Similarly, when the object is within the range of near and far distances in Group 3, the system will adjust the motor to the code 3 value to achieve precise focus.

[0072] This focusing mechanism achieves automated focusing at different distances by using pre-recorded focal length parameters. This not only improves focusing speed but also reduces errors caused by human intervention, ensuring focusing accuracy and consistency. The system can automatically select the most suitable focal length based on the distance to the object, achieving fast and accurate focusing under multiple focal length conditions.

[0073] The feature map is not limited to the oblique knife-edge method or slit method used to calculate SFR data, but can also be other analytical algorithms such as the MTF feature map of horizontal and vertical stripes.

[0074] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for evaluating multi-focal length camera modules, characterized in that, Includes the following steps: S1. Install the camera module and align it with the testing device; S2. Control the camera module to switch its focal length to different focal lengths using the fully automatic focal length switching system; S3. Activate the adaptive light source adjustment system to automatically adjust the light source according to changes in ambient light; S4. The computer system captures images at each focal length and analyzes the image data to calculate the resolution. S5. Output the test report, which includes the resolution curve and data report.

2. The multi-focal length evaluation method for a camera module according to claim 1, characterized in that, Step S1 specifically includes the following steps: S1.1, pushing the motor to make the resolution value of the near-view feature pattern in group 1 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 1 meets the threshold range, and recording the motor code1 value at this time in the memory; S1.2, pushing the motor to make the resolution value of the near-view feature pattern in group 2 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 3 meets the threshold range, and recording the motor code2 value at this time in the memory; S1.3, pushing the motor to make the resolution value of the near-view feature pattern in group 3 meet the threshold range, and at the same time, the resolution value of the far-view feature pattern in group 3 meets the threshold range, and recording the motor code3 value at this time in the memory.

3. The multi-focal length evaluation method for a camera module according to claim 1, characterized in that, Step S3 specifically includes the following steps: S3.1, acquiring data from the light source sensor, adjusting the light source controller to initially adjust the light source illuminance and color temperature so that the sensor is stable within the threshold; S3.2, then acquiring the grayscale value of the same field of view through the camera to determine whether it is within the threshold.

4. The multi-focal length evaluation method for a camera module according to claim 3, characterized in that, In step S3.2, if the threshold is exceeded, the light source controller is fine-tuned to ensure that the illuminance of the light source in the corresponding field of view meets the requirements.

5. The multi-focal length evaluation method for a camera module according to claim 1, characterized in that, In step S4, if the feature pattern is horizontal or vertical bars, the MTF method is used to calculate the analytical data at each ROI (Region of Interest).

6. A multi-focal length evaluation method for a camera module according to claim 1 or 5, characterized in that, In step S4, if the feature pattern is a rhombus, the SFR method is used to calculate the analytical data at each ROI (Region of Interest).

7. A multi-focal length evaluation system for camera modules, characterized in that, The system includes a host computer, a fully automatic focal length switching system that controls the camera movement via communication software, an adaptive light source adjustment system that adjusts the light source via a light source sensor, and a multi-layer test chart attached to the adaptive light source adjustment system. The adaptive light source adjustment system includes a light sensor and several adjustable light sources.

8. The multi-focal length evaluation system for a camera module according to claim 7, characterized in that, The multi-layer test chart includes several chart layers with charts, each chart having a feature pattern and a light-transmitting area.

9. A multi-focal length evaluation system for a camera module according to claim 8, characterized in that, The cards are separated by an optical insulating material.

10. A multi-focal length evaluation system for a camera module according to claim 7, characterized in that, The fully automatic focal length switching system includes a computer-controlled focal length switching device, which is equipped with a motor and an encoder.

Images