CN118540582A - Gain correction method for image stabilization function and electronic device - Google Patents

Abstract

The present disclosure relates to an electronic device and a gain correction method for image stabilization function thereof. The method comprises the following steps. The image stabilization function is enabled. The first image is generated by the image capturing device with a first gain and a first degree of blur of the first image is acquired. A second image is generated by the image capturing device using the second gain, and a second degree of blurring of the second image is acquired. A reference blur level corresponding to the second gain is determined based on the second blur level. A correction gain for the image stabilization function is determined based on a linear relationship established between a first degree of blurring corresponding to the first gain and a reference degree of blurring corresponding to the second gain. Therefore, good image stabilizing effect can be ensured, and the correction efficiency of the gain can be greatly improved.

Description

Gain correction method for image stabilization function and electronic device

Technical Field

The present invention relates to an electronic device, and more particularly, to a gain correction method for image stabilization and an electronic device using the same.

Background

With the advancement of technology, electronic devices with image acquisition function have been used in modern life. If the electronic device shoots a picture in a vibration state or a shake state, image quality is poor due to the possibility of image sticking in the acquired image. Accordingly, in order to improve the above-described problems, an image stabilizing function (also referred to as an anti-shake function or a hand shake function) has been developed to improve image quality.

At present, the image stabilization function needs to apply gyroscope gain to compensate the vibration of the electronic equipment so as to achieve the image stabilization function. Typically, the camera module manufacturer will provide a predetermined gyroscope gain. However, due to assembly tolerances, mechanical stresses, or component characteristic differences, the preset gyroscope gains provided by camera module manufacturers are not optimal values for the assembled electronic device to provide optimal image stabilization. Therefore, the gyroscope gain generally needs to be corrected again before the assembled electronic device leaves the factory. In the conventional calibration process, a global searching mode is mostly used to find out the optimal gyroscope gain. However, the conventional calibration method needs to test for a plurality of different gyroscope gains (e.g. 10 gyroscope gains or more) one by one, so as to search out the optimal gyroscope gain according to the curve formed by the image capturing results of the different gyroscope gains. In this case, the conventional correction procedure is significantly time consuming and inefficient in order to correct the gain applicable to the individual electronic device.

Disclosure of Invention

The present application provides a gain correction method of an image stabilization function for an electronic apparatus including an image capturing device, the gain correction method including the following steps. The image stabilization function is enabled. The first image is generated by the image capturing device with a first gain and a first degree of blur of the first image is acquired. A second image is generated by the image capturing device using the second gain, and a second degree of blurring of the second image is acquired. A reference blur level corresponding to the second gain is determined based on the second blur level. A correction gain for the image stabilization function is determined based on a linear relationship established between a first degree of blurring corresponding to the first gain and a reference degree of blurring corresponding to the second gain.

The present disclosure further provides an electronic device including an image capturing apparatus and a processor. The processor is coupled to the image capture device. The processor is used for executing the following steps. The image stabilization function is enabled. The first image is generated by the image capturing device with a first gain and a first degree of blur of the first image is acquired. A second image is generated by the image capturing device using the second gain, and a second degree of blurring of the second image is acquired. A reference blur level corresponding to the second gain is determined based on the second blur level. A correction gain for the image stabilization function is determined based on a linear relationship established between a first degree of blurring corresponding to the first gain and a reference degree of blurring corresponding to the second gain.

Based on the above, in the embodiment of the present invention, in the case of enabling the image stabilization function, the first image may be generated based on the first gain, and the second image may be generated based on the second gain. The first and second blur levels may be generated according to the first and second images, respectively. The reference degree of blurring may be determined based on the second degree of blurring. Thus, a linear relationship between the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain can be used to determine the correction gain. Therefore, the image stabilizing effect is good, and the correction efficiency of the gain can be greatly improved.

Drawings

Fig. 1 is a schematic diagram of a gain correction system of an image stabilization function shown in accordance with an embodiment of the present invention;

FIG. 2 is a schematic diagram of an electronic device shown in accordance with an embodiment of the present invention;

Fig. 3 is a flowchart of a gain correction method of the image stabilization function shown in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating the calculation of the degree of blurring according to an embodiment of the present invention;

FIG. 5 is a schematic diagram illustrating a gyroscope gain versus pixel offset, according to an embodiment of the invention;

Fig. 6 is a schematic diagram of an optical image stabilization system according to an embodiment of the present invention.

Description of the reference numerals

10, A gain correction system;

100, an electronic device;

P1, a vibrating table;

T1, test patterns;

110 an image capturing device;

111, lens;

112 an image sensing assembly;

113, a driving device;

114, a position sensor;

120, a processor;

130, a sensor;

40, a first image;

B1, left boundary;

B2, right boundary;

Δs, pixel offset;

A, B, C, B': points;

S301 to S305.

Detailed Description

Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Referring to fig. 1, the gain correction system 10 with image stabilization function may include an electronic device 100, a vibration table P1, and a test pattern T1.

The electronic device 100 may be, for example, a smart phone, a digital camera, a tablet computer, a game machine, an electronic wearable device, or a photographic device, or the like, and the type of the electronic device 100 is not limited thereto. It should be noted that the electronic device 100 has an image Stabilization (Image Stabilization) function, which may be an optical image Stabilization (Optical Image Stabilization, OIS) function or an electronic image Stabilization (ELECTRIC IMAGE Stabilization, EIS) function.

The electronic device 100 is disposed on the vibration table P1. The vibration table P1 may be a tool table capable of vibrating, and is used to fix the electronic device 100. The vibration table P1 can control the electronic device 100 to vibrate at a specific vibration frequency and a specific vibration angle. For example, if the hand shake state is to be simulated, the vibration frequency of the vibration table P1 may be set to 6Hz. In some embodiments, the test pattern T1 may be presented on a drawing or other material carrier. In some embodiments, the test pattern T1 may be composed of one or more vertical black lines and/or horizontal black lines, but the present invention is not limited thereto. From another point of view, the test pattern T1 may be a drawing, a physical object, or a light projection pattern, to which the present invention is not limited. The electronic device 100 on the vibration table P1 is adapted to take an image toward the test pattern T1 to correct a gain for the image stabilizing function according to the taken image of the test pattern T1.

Referring to fig. 2, the electronic apparatus 100 may include an image capturing device 110, a processor 120, and a sensor 130.

The image capturing device 110 is used to capture images or movies and may include a lens 111, an image sensing component 112, and other components. The lens 111 may include an optical lens for optical path control. The image sensing component 112 is used to provide an image sensing function. The image sensing device 112 may include a photosensitive device such as a charge coupled device (Charge Coupled Device, CCD), a complementary metal oxide semiconductor (Complementary Metal-Oxide Semiconductor, CMOS) device, or other device, as the invention is not limited in this respect. The lens 111 can collect imaging light on the image sensor 112 for obtaining an image. In some embodiments, when the electronic apparatus 100 has OIS function, the image capturing device 110 further includes components related to the OIS function, such as a driving device for controlling movement of the lens 111, and so on.

The processor 120 is coupled to the image capturing device 110 and the sensor 130, such as a central processing unit (central processing unit, CPU), an application processor (application processor, AP), or other general purpose or special purpose microprocessor (microprocessor), digital signal processor (DIGITAL SIGNAL processor, DSP), image signal processor (IMAGE SIGNAL processor, ISP), graphics processor (graphics processing unit, GPU), or other similar device, integrated circuit, or combination thereof. In some embodiments, the processor 120 may execute instructions or program code in a memory to implement the steps of the gain correction method according to the embodiments of the present invention. The memory may include volatile memory circuitry and non-volatile memory circuitry.

The sensor 130 may be an inertial sensor for sensing vibration and motion of the electronic device 100. The sensor 130 may include an accelerometer or gyroscope, etc. For example, the sensor 130 may be used to sense an angular velocity generated by vibration of the electronic device 100. The rotation angle and the rotation direction of the electronic device 100 can be calculated by integrating or other mathematical operations on the angular velocity or the linear acceleration sensed by the sensor 130. Thus, the processor 120 may perform image stabilization functions, such as adjusting the position of the lens 111, adjusting other photographing parameters (e.g., shutter or ISO values, etc.), or adjusting photographed images using software algorithms, etc., based on sensed data output by the sensor 130.

Fig. 3 is a flowchart of a gain correction method of an image stabilization function according to an embodiment of the present invention. Referring to fig. 3, the method of the present embodiment may be performed by the electronic device 100 of fig. 1 and 2, and details of each step of fig. 3 are described below with reference to the components shown in fig. 1 and 2.

In step S301, the processor 120 enables the image stabilization function. The image stabilization function includes an OIS function, an EIS function, or a combination thereof.

In step S302, the processor 120 generates a first image by using the first gain through the image capturing device 110, and obtains a first blur degree of the first image. Next, in step S303, the processor 120 generates a second image by using the second gain through the image capturing device 110, and acquires a second blur degree of the second image.

In detail, in case that the image capturing apparatus 110 is in a vibration state and the image stabilizing function is enabled, the processor 120 sequentially generates the first image and the second image by the image capturing apparatus 110 using the first gain and the second gain, respectively. In detail, in the case of activating the image stabilization function, the first gain and the second gain can be used to adjust the sensing data output by the sensor 130, respectively. In some embodiments, the first gain comprises a first gyroscope gain (Gyro gain) and the second gain comprises a second gyroscope gain. That is, the first gain and the second gain may also be referred to as angular velocity gains. In some embodiments, the angular velocity gain may be used to zoom in or out on the angular velocity output by the sensor 130, so that the processor 130 may perform the image stabilization function according to the angular velocity adjusted by the angular velocity gain.

In some embodiments, the processor 120 may determine the first gain and the second gain according to a predetermined gain. The predetermined gain is between the first gain and the second gain. The predetermined gain may be recorded in a memory device of the electronic device 100. For example, the predetermined gain may be a predetermined value pre-recorded in a memory circuit of the image capturing apparatus 110 by a manufacturer of the image capturing apparatus 110.

In some embodiments, the processor 120 may add a first positive number to the predetermined gain to obtain a first gain, and subtract a second positive number to the predetermined gain to obtain a second gain. In some embodiments, the processor 120 may subtract a first positive number from the predetermined gain to obtain a first gain, and add a second positive number to the predetermined gain to obtain a second gain. It should be noted that the first positive number may be different or the same as the second positive number.

Further, the processor 120 calculates a first degree of blurring of the first image and a second degree of blurring of the second image, respectively. The processor 120 may obtain the first blur degree and the second blur degree according to imaging states of the test pattern T1 in the first image and the second image, respectively. In some embodiments, the processor 120 may obtain the first degree of blurring based on an imaging size (e.g., line width, circular diameter, rectangular side length, etc.) of the test pattern T1 in the first image, and obtain the second degree of blurring based on an imaging size of the test pattern T1 in the second image. It is known that the lower the blurring degree of the photographed image is, the better the representative image stabilizing effect is.

In some embodiments, the first degree of blurring includes a first pixel offset and the second degree of blurring includes a second pixel offset. In detail, the processor 120 can obtain the first pixel offset according to the degree of the contour displacement of the test pattern T1 in the first image, and obtain the second pixel offset according to the degree of the contour displacement of the test pattern T1 in the second image.

For example, please refer to fig. 4, which illustrates an example in which the test image T1 includes a vertical black line, but the present invention is not limited thereto. In the case where the image capturing apparatus 110 is in a vibration state and the image stabilizing function is enabled, the processor 120 photographs the first image 40 with the first gain value through the image capturing apparatus 110. In response to the vibration of the image capturing apparatus 110, the imaging of the test image T1 in the first image 40 occurs with the gray patch Z1. The processor 120 may calculate the distance between the left boundary B1 and the right boundary B2 of the gray block Z1 to obtain a first pixel offset Δs (units: pixels). In addition, the processor 120 can also calculate the second pixel offset based on the second image in the same manner.

Next, in step S304, the processor 120 determines a reference blur level corresponding to the second gain according to the second blur level. It should be noted that the first blur degree and the second blur degree calculated by the processor 120 may both be values greater than 0. In some embodiments, the reference degree of blurring may be a negative number, and the absolute value of the reference degree of blurring is equal to the second degree of blurring. For example, if the second degree of blurring is "10", the reference degree of blurring may be "-10". Or in some embodiments, the reference degree of blurring is a negative number, and the difference between the absolute value of the reference degree of blurring and the second degree of blurring is less than a tolerance value. In some embodiments, the first gain may be greater than the second gain. Or in other embodiments the second gain may be greater than the first gain.

In step S305, the processor 120 determines a correction gain for the image stabilization function according to a linear relationship between the first blur level corresponding to the first gain and the reference blur level corresponding to the second gain. Specifically, the gain for the image stabilization function may have a linear relationship with the degree of blurring of the captured image within a certain numerical range. Based on this feature, the processor 120 may estimate the correction gain corresponding to the minimum blur level (e.g., 0) based on the online between the first blur level corresponding to the first gain and the reference blur level corresponding to the second gain.

In some embodiments, the processor 120 may generate a linear function based on a first degree of blurring corresponding to a first gain and a reference degree of blurring corresponding to a second gain. The slope of this linear function may be positive or negative. Then, the processor 120 acquires the correction gain of the image stabilization function based on the intersection of the linear function and the constant function. In some embodiments, the constant of the constant function is 0. That is, the processor 120 may obtain the correction gain based on an intersection between a line between the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain and an axis (e.g., X-axis).

In some embodiments, the processor 120 may record the correction gain to a memory device. The memory device is, for example, an electrically erasable and rewritable read only memory (EEPROM) connected to an Image Signal Processor (ISP), but the present invention is not limited thereto. That is, after the gain correction for the image stabilization function is completed, the processor 120 may perform the image stabilization function according to the correction gain in the storage device to compensate for the vibration of the electronic device 100 to generate a clear image.

It should be noted that, the above embodiment is described by taking the example that the processor 120 executes the steps of fig. 3 as an example, but each step of fig. 3 may be implemented as a plurality of program codes or circuits, which is not limited by the present invention.

In addition, in order to make the concept of the present invention easier to understand, the following description will be aided with fig. 5. However, fig. 5 is only an example for illustrating the present invention, and is not intended to limit the present invention. It should be noted that, fig. 5 is an example in which the first gain, the second gain, and the correction gain are respectively a gyroscope gain, and the blur degree is a pixel offset. Fig. 5 is a schematic diagram showing a correspondence relationship between a gyroscope gain and a pixel offset according to an embodiment of the invention.

It should be noted that, if the conventional calibration process is performed, a plurality of pixel offsets are measured or calculated for a plurality of gyroscope gains one by one to obtain a plurality of points (e.g., points a, B, C and other points not marked with symbols) as shown in fig. 5. From these points, it is known that the gyroscope gain value for the image stabilization function has a linear relationship of positive correlation and a linear relationship of negative correlation with the pixel shift amount of the captured image within a specific numerical range. Based on this feature, the processor 120 may obtain the corrected gyroscope gain according to the following description.

In the case where the image capturing apparatus 110 is in a vibration state and the image stabilizing function is enabled, the processor 120 captures a first image with the first gyro gain "G1" through the image capturing apparatus 110, and acquires the first pixel shift amount "S1" corresponding to the first gyro gain "G1". That is, the processor 120 may obtain the point a with the coordinate position (G1, S1).

Further, in the case where the image capturing apparatus 110 is in a vibration state and the image stabilizing function is enabled, the processor 120 captures a first image with the second gyro gain "G2" through the image capturing apparatus 110, and acquires the second pixel shift amount "S2" corresponding to the second gyro gain "G2". That is, the processor 120 may obtain the point B with the coordinate position (G2, S2). Thereafter, the processor 120 may obtain a reference pixel offset "-S2" from the second pixel offset "S2" to obtain a reference pixel offset "-S2" corresponding to the second gyroscope gain "G2". That is, the processor 120 may obtain a point B' that is symmetrical to the X-axis. The coordinate position of the point B' is (G2, -S2). Processor 120 may then obtain corrected gyroscope gain "Gc" based on the intersection of line L1 between point a and point B' with the X-axis.

It should be noted that fig. 5 is an example of the second gain (i.e., the second gyroscope gain "G2") being greater than the first gain (i.e., the first gyroscope gain "G2"). However, in other embodiments, the second gain may be smaller than the first gain, which is also within the scope of the present invention. Those skilled in the art should be able to derive the implementation manner that the second gain is smaller than the first gain by themselves after referring to the above description, and thus the description is omitted herein.

Therefore, compared with the conventional global searching method, a large amount of gyroscope gains are required to search out the optimal gyroscope gains, and the number of gyroscope gains to be tested in the embodiment of the invention is greatly reduced, so that the time required for the gain correction process of the image stabilizing function is greatly reduced.

In some embodiments, the correction gain may be used for OIS functionality. In another embodiment, the correction gain may be used for EIS functions. The correction gain may be used in conjunction with the sensed value output by the sensor 130 to determine the amplitude of the vibration of the image capture device 110. Accordingly, the processor 120 may perform OIS function or EIS function according to the vibration amplitude of the image capturing apparatus 110 to generate a clear image.

Referring to fig. 6, the driving device 113 is connected to the lens 111 to move the lens 111 according to the control signal received from the processor 120. The change in the position of the lens 111 can be detected by the position sensor 114 accordingly. In some embodiments, the position sensor 114 may be implemented by one or more hall assemblies (HALL ELEMENT). By controlling the driving device 113 to adjust the position of the lens 111 in different axial directions, the image captured by the image capturing apparatus 110 can be maintained stable in various movement states such as hand shake, head shake, vehicle vibration, and the like. In this way, OIS functions may be implemented through cooperation of the processor 120, the sensor 130, and the driving device 113. The driving means 113 is, for example, a voice coil motor or a Micro Electro-mechanical system (Micro Electro-MECHANICAL SYSTEMS, MEMS) or the like.

In more detail, the memory device 140 may record the correction gain generated according to the foregoing embodiments. The sensor 130 may output the sensed data to the processor 120, and the processor 120 may adjust the sensed data using the correction gain. Then, the processor 120 can calculate the compensation movement amount of the lens 111 in different axial directions according to the adjusted sensing data. Then, the processor 120 may control the driving device 113 to adjust the lens 111 to be at different axial positions according to the compensation movement amount, so as to implement vibration compensation, thereby improving the image blur due to vibration.

In summary, in the embodiment of the invention, when the image stabilization function is enabled, the correction gain can be determined by using the image blur level corresponding to the first gain and the image blur level corresponding to the second gain. Therefore, not only can the correction gain be utilized to obtain good image stabilization effect, but also the image quality is improved. In addition, the operation steps of gain correction of the image stabilizing function can be greatly simplified, so that the efficiency of gain correction is greatly improved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (16)

1. A gain correction method for an image stabilization function for an electronic apparatus including an image capturing device, the method comprising:

enabling an image stabilization function;

generating a first image by the image capturing device with a first gain, and acquiring a first degree of blurring of the first image;

generating a second image by the image capturing device with a second gain, and acquiring a second degree of blurring of the second image;

determining a reference ambiguity corresponding to the second gain according to the second ambiguity; and

A correction gain for the image stabilization function is determined from a linear relationship established between the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain.

2. The method according to claim 1, wherein the reference blur level is a negative number, and an absolute value of the reference blur level is equal to the second blur level.

3. The gain correction method for an image stabilization function according to claim 1, characterized in that the method further comprises:

Determining the first gain and the second gain according to a preset gain, wherein the preset gain is between the first gain and the second gain.

4. The gain correction method of an image stabilization function according to claim 1, wherein the step of determining the correction gain of the image stabilization function from the linear relationship established by the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain includes:

generating a linear function from the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain; and

And acquiring the correction gain of the image stabilizing function according to the intersection point of the linear function and a constant function.

5. The gain correction method for an image stabilization function according to claim 4, wherein a constant of the constant function is 0.

6. The gain correction method for an image stabilization function according to claim 1, characterized in that the method further comprises:

And recording the correction gain in a storage device.

7. The gain correction method of an image stabilization function according to claim 1, wherein the image stabilization function includes an optical image stabilization function or an electronic image stabilization function.

8. The method of gain correction for an image stabilization function according to claim 1, wherein the first degree of blurring comprises a first pixel offset and the second degree of blurring comprises a second pixel offset.

9. An electronic device, comprising:

An image capturing device; and

A processor coupled to the image capture device and configured to:

enabling an image stabilization function;

generating a first image by the image capturing device with a first gain, and acquiring a first degree of blurring of the first image;

generating a second image by the image capturing device with a second gain, and acquiring a second degree of blurring of the second image;

determining a reference ambiguity corresponding to the second gain according to the second ambiguity; and

A correction gain for the image stabilization function is determined from a linear relationship established between the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain.

10. The electronic device of claim 9, wherein the reference blur level is a negative number and an absolute value of the reference blur level is equal to the second blur level.

11. The electronic device of claim 9, wherein the processor is further configured to:

Determining the first gain and the second gain according to a preset gain, wherein the preset gain is between the first gain and the second gain.

12. The electronic device of claim 9, wherein the processor is further configured to:

generating a linear function from the first degree of blurring corresponding to the first gain and the reference degree of blurring corresponding to the second gain; and

And acquiring the correction gain of the image stabilizing function according to the intersection point of the linear function and a constant function.

13. The electronic device of claim 12, wherein the constant function has a constant of 0.

14. The electronic device of claim 9, wherein the processor is further configured to:

And recording the correction gain in a storage device.

15. The electronic device of claim 9, wherein the image stabilization function comprises an optical image stabilization function or an electronic image stabilization function.

16. The electronic device of claim 9, wherein the first degree of blurring comprises a first pixel offset and the second degree of blurring comprises a second pixel offset.