Method of operating a leaky integrator, leaky integrator and apparatus comprising a leaky integrator

Abstract

Embodiments of the present disclosure relate to a method of operating a leaky integrator, a leaky integrator and an apparatus comprising a leaky integrator. The present disclosure relates to receiving an input signal; generating an output signal by integrating a leaky signal over an integration time, wherein the leaky signal is obtained based on a damping signal, a leakage factor and the input signal; and providing the output signal.

Description

Technical Field

[0001] This disclosure relates to a method of operating a leakage integrator, a leakage integrator, and an apparatus including a leakage integrator. Background Technology

[0002] Some devices (e.g., mobile phones, tablets, laptops, desktop computers, video game consoles, smart card readers, cameras, televisions, vehicles, etc.) may be equipped with one or more optical sensors to capture images of a scene. These devices may be equipped with one or more functions (e.g., white balance control, exposure control, tone mapping control, etc.) to adjust the characteristics of the final image rendered on the display (e.g., brightness, dynamic range, contrast, etc.).

[0003] When the scene includes lights that flash periodically at a frequency of about 1 Hz (such as a car's indicator lights) or lights that periodically enter and exit at a frequency of about 1 Hz (such as a tunnel with overhead lighting), there can be problems using existing functions. Indeed, for such scenes, signals that control one or more functions based on images captured by optical sensors can oscillate at a frequency of about 1 Hz, thus generating visible artifacts in the final image rendered on the display.

[0004] Some devices are equipped with one or more leakage integrators to filter signals controlling one or more functions and to prevent abrupt changes. However, conventional leakage integrators only partially attenuate visible artifacts in the final image rendered on the display, and are therefore not entirely satisfactory. Summary of the Invention

[0005] According to one aspect, a method for operating a leakage integrator is provided, the method comprising: receiving an input signal; generating an output signal by integrating the leakage signal over an integration time, wherein the leakage signal is obtained based on a damping signal, a leakage factor, and the input signal; and providing the output signal.

[0006] The leakage signal can be obtained by multiplying the damping signal, the leakage factor, and the difference between the input signal and the output signal.

[0007] The leakage factor can be fixed within the integral time.

[0008] The damping signal can be varied within the integral time.

[0009] The damping signal can be designed to vary based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations.

[0010] The damping signal can be designed to dampen the leakage signal more effectively when there are periodic oscillations in the input signal, compared to the case where there are non-periodic oscillations in the input signal.

[0011] The damping signal can be designed to provide greater damping for leakage signals when high-frequency periodic oscillations exist in the input signal, compared to when low-frequency periodic oscillations exist in the input signal. That is, the higher the frequency of the periodic oscillation, the greater the damping of the leakage signal, and vice versa. Conversely, the lower the frequency of the periodic oscillation, the less damping of the leakage signal, and vice versa.

[0012] The damping signal can be designed to vary between 0 and 1.

[0013] The offset of the damping signal can vary based on the presence of periodic oscillations in the input signal and / or the duty cycle of the periodic oscillations.

[0014] When the input signal includes periodic oscillations, the damping signal can vary between 0 and 0+Δ1, where Δ1 is less than 1; and when the input signal includes non-periodic oscillations, the damping signal can vary between 1-Δ2 and 1, where Δ2 is greater than 0.

[0015] The closer the duty cycle of a periodic oscillation is to 50%, the lower Δ1 will be, and therefore the greater the damping of the input signal may be. The further the duty cycle of a periodic oscillation is from 50%, the greater Δ1 will be, and therefore the smaller the damping of the input signal may be.

[0016] The amplitude of the damping signal can vary based on the frequency of the periodic oscillations present in the input signal.

[0017] The higher the frequency of the periodic oscillation, the lower Δ1, and therefore the greater the damping of the input signal. Conversely, the lower the frequency of the periodic oscillation, the larger Δ1, and therefore the smaller the damping of the input signal.

[0018] The method may include: generating an upper difference signal by integrating the difference signal within an integration time when the difference signal is positive; generating a lower difference signal by integrating the difference signal within an integration time when the difference signal is negative; and generating a damping signal based on the upper and lower difference signals.

[0019] The damping signal is generated based on the upper and lower difference signals, which can be based on:

[0020]

[0021] Where “D” is the damping signal, “UpperDiff” is the upper difference signal, and “LowerDiff” is the lower difference signal.

[0022] The output signal can be designed as a control function, such as exposure control, white balance control, or tone mapping control.

[0023] Damped signals, differential signals, upper differential signals, and / or lower differential signals can be generated on a per-frame or per N-frame basis, where N is greater than 1.

[0024] According to one aspect, a leakage integrator is provided, comprising: means for receiving an input signal; means for generating an output signal by integrating the leakage signal over an integration time, wherein the leakage signal is obtained based on a damping signal, a leakage factor, and the input signal; and means for providing the output signal.

[0025] The leakage signal can be obtained by multiplying the damping signal, the leakage factor, and the difference between the input signal and the output signal.

[0026] The leakage factor can be fixed within the integral time.

[0027] The damping signal can be varied within the integral time.

[0028] The damping signal can be designed to vary based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations.

[0029] The damping signal can be designed to dampen the leakage signal more effectively when there are periodic oscillations in the input signal, compared to the case where there are non-periodic oscillations in the input signal.

[0030] The damping signal can be designed to provide greater damping for leakage signals when high-frequency periodic oscillations exist in the input signal, compared to when low-frequency periodic oscillations exist in the input signal. That is, the higher the frequency of the periodic oscillation, the greater the damping of the leakage signal, and vice versa. Conversely, the lower the frequency of the periodic oscillation, the less damping of the leakage signal, and vice versa.

[0031] The damping signal can be designed to vary between 0 and 1.

[0032] The offset of the damping signal can vary based on the presence of periodic oscillations in the input signal and / or the duty cycle of the periodic oscillations.

[0033] When the input signal includes periodic oscillations, the damping signal can vary between 0 and 0+Δ1, where Δ1 is less than 1; and when the input signal includes non-periodic oscillations, the damping signal can vary between 1-Δ2 and 1, where Δ2 is greater than 0.

[0034] The closer the duty cycle of a periodic oscillation is to 50%, the lower Δ1 will be, and therefore the greater the damping of the input signal may be. The further the duty cycle of a periodic oscillation is from 50%, the greater Δ1 will be, and therefore the smaller the damping of the input signal may be.

[0035] The amplitude of the damping signal can vary based on the frequency of the periodic oscillations present in the input signal.

[0036] The higher the frequency of the periodic oscillation, the lower Δ1, and therefore the greater the damping of the input signal. Conversely, the lower the frequency of the periodic oscillation, the larger Δ1, and therefore the smaller the damping of the input signal.

[0037] The leakage integrator may include: generating an upper difference signal by integrating the difference signal within an integration time when the difference signal is positive; generating a lower difference signal by integrating the difference signal within an integration time when the difference signal is negative; and generating a damping signal based on the upper and lower difference signals.

[0038] The damping signal is generated based on the upper and lower difference signals, which can be based on:

[0039]

[0040] Where “D” is the damping signal, “UpperDiff” is the upper difference signal, and “LowerDiff” is the lower difference signal.

[0041] The output signal can be designed as a control function, such as exposure control, white balance control, or tone mapping control.

[0042] Damped signals, differential signals, upper differential signals, and / or lower differential signals can be generated on a per-frame or per N-frame basis, where N is greater than 1.

[0043] According to one aspect, a leakage integrator is provided, the leakage integrator including at least one processor and at least one memory, the at least one memory including computer code for one or more programs, the at least one memory and the computer code being configured to utilize the at least one processor to cause the leakage integrator to at least: receive an input signal; generate an output signal by integrating the leakage signal over an integration time, wherein the leakage signal is obtained based on a damping signal, a leakage factor and the input signal; and provide the output signal.

[0044] The leakage signal can be obtained by multiplying the damping signal, the leakage factor, and the difference between the input signal and the output signal.

[0045] The leakage factor can be fixed within the integral time.

[0046] The damping signal can be varied within the integral time.

[0047] The damping signal can be designed to vary based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations.

[0048] The damping signal can be designed to dampen the leakage signal more effectively when there are periodic oscillations in the input signal, compared to the case where there are non-periodic oscillations in the input signal.

[0049] The damping signal can be designed to provide greater damping for leakage signals when high-frequency periodic oscillations exist in the input signal, compared to when low-frequency periodic oscillations exist in the input signal. That is, the higher the frequency of the periodic oscillation, the greater the damping of the leakage signal, and vice versa. Conversely, the lower the frequency of the periodic oscillation, the less damping of the leakage signal, and vice versa.

[0050] The damping signal can be designed to vary between 0 and 1.

[0051] The offset of the damping signal can vary based on the presence of periodic oscillations in the input signal and / or the duty cycle of the periodic oscillations.

[0052] When the input signal includes periodic oscillations, the damping signal can vary between 0 and 0+Δ1, where Δ1 is less than 1; and when the input signal includes non-periodic oscillations, the damping signal can vary between 1-Δ2 and 1, where Δ2 is greater than 0.

[0053] The closer the duty cycle of a periodic oscillation is to 50%, the lower Δ1 will be, and therefore the greater the damping of the input signal may be. The further the duty cycle of a periodic oscillation is from 50%, the greater Δ1 will be, and therefore the smaller the damping of the input signal may be.

[0054] The amplitude of the damping signal can vary based on the frequency of the periodic oscillations present in the input signal.

[0055] The higher the frequency of the periodic oscillation, the lower Δ1, and therefore the greater the damping of the input signal. Conversely, the lower the frequency of the periodic oscillation, the larger Δ1, and therefore the smaller the damping of the input signal.

[0056] At least one memory and computer code can be configured to utilize at least one processor to enable the leakage integrator to at least: generate an upper difference signal by integrating the difference signal within an integration time when the difference signal is positive; generate a lower difference signal by integrating the difference signal within an integration time when the difference signal is negative; and generate a damping signal based on the upper and lower difference signals.

[0057] The damping signal is generated based on the upper and lower difference signals, which can be based on:

[0058]

[0059] Where “D” is the damping signal, “UpperDiff” is the upper difference signal, and “LowerDiff” is the lower difference signal.

[0060] The output signal can be designed as a control function, such as exposure control, white balance control, or tone mapping control.

[0061] Damped signals, differential signals, upper differential signals, and / or lower differential signals can be generated on a per-frame or per N-frame basis, where N is greater than 1.

[0062] According to one aspect, an apparatus is provided, comprising: an optical sensor; and any of the above leakage integrators.

[0063] Devices may include mobile phones, tablets, desktop computers, laptops, video game consoles, video doors, smartwatches, vehicles, etc.

[0064] According to one aspect, a computer program is provided, the computer program including computer-executable code, configured, when the computer-executable code is run on at least one processor, to: receive an input signal; generate an output signal by integrating a leakage signal over an integral time, wherein the leakage signal is obtained based on a damping signal, a leakage factor, and the input signal; and provide the output signal.

[0065] The leakage signal can be obtained by multiplying the damping signal, the leakage factor, and the difference between the input signal and the output signal.

[0066] The leakage factor can be fixed within the integral time.

[0067] The damping signal can be varied within the integral time.

[0068] The damping signal can be designed to vary based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations.

[0069] The damping signal can be designed to dampen the leakage signal more effectively when there are periodic oscillations in the input signal, compared to the case where there are non-periodic oscillations in the input signal.

[0070] The damping signal can be designed to provide greater damping for leakage signals when high-frequency periodic oscillations exist in the input signal, compared to when low-frequency periodic oscillations exist in the input signal. That is, the higher the frequency of the periodic oscillation, the greater the damping of the leakage signal, and vice versa. Conversely, the lower the frequency of the periodic oscillation, the less damping of the leakage signal, and vice versa.

[0071] The damping signal can be designed to vary between 0 and 1.

[0072] The offset of the damping signal can vary based on the presence of periodic oscillations in the input signal and / or the duty cycle of the periodic oscillations.

[0073] When the input signal includes periodic oscillations, the damping signal can vary between 0 and 0+Δ1, where Δ1 is less than 1; and when the input signal includes non-periodic oscillations, the damping signal can vary between 1-Δ2 and 1, where Δ2 is greater than 0.

[0074] The closer the duty cycle of a periodic oscillation is to 50%, the lower Δ1 will be, and therefore the greater the damping of the input signal may be. The further the duty cycle of a periodic oscillation is from 50%, the greater Δ1 will be, and therefore the smaller the damping of the input signal may be.

[0075] The amplitude of the damping signal can vary based on the frequency of the periodic oscillations present in the input signal.

[0076] The higher the frequency of the periodic oscillation, the lower Δ1, and therefore the greater the damping of the input signal. Conversely, the lower the frequency of the periodic oscillation, the larger Δ1, and therefore the smaller the damping of the input signal.

[0077] The computer program includes computer-executable code, which, when executed on at least one processor, can be configured to: generate an upper difference signal by integrating the difference signal within an integration time when the difference signal is positive; generate a lower difference signal by integrating the difference signal within an integration time when the difference signal is negative; and generate a damping signal based on the upper and lower difference signals.

[0078] The damping signal is generated based on the upper and lower difference signals, which can be based on:

[0079]

[0080] Where “D” is the damping signal, “UpperDiff” is the upper difference signal, and “LowerDiff” is the lower difference signal.

[0081] The output signal can be designed as a control function, such as exposure control, white balance control, or tone mapping control.

[0082] Damped signals, differential signals, upper differential signals, and / or lower differential signals can be generated on a per-frame or per N-frame basis, where N is greater than 1.

[0083] According to one aspect, a computer-readable medium is provided, comprising program instructions stored thereon for performing at least one of the above methods.

[0084] According to one aspect, a non-transitory computer-readable medium is provided, comprising program instructions stored thereon for performing at least one of the above methods.

[0085] According to one aspect, a non-volatile physical memory medium is provided, comprising program instructions stored thereon for performing at least one of the above methods.

[0086] Many different aspects have been described above. It should be understood that other aspects can be provided through a combination of any two or more of the above aspects.

[0087] Various other aspects are also described in the following detailed description and the appended claims. Attached Figure Description

[0088] Now, refer to the attached diagram only as an example, where:

[0089] Figure 1 A schematic diagram of an apparatus including a leakage integrator is shown, which is configured to filter the signal controlling the exposure control function.

[0090] Figure 2 A schematic diagram of a device including a leakage integrator is shown, which is configured to filter the signal controlling the white balance control function.

[0091] Figure 3 A schematic diagram of an apparatus including a leakage integrator is shown, which is configured to filter the signal controlling the tone mapping control function.

[0092] Figure 4 A schematic diagram of a leakage integrator is shown, where the leakage signal is based on a leakage factor and the difference between the input and output signals.

[0093] Figure 5 This illustrates that when the input signal includes non-periodic oscillations, the... Figure 4 A schematic diagram of the input and output signals provided by the leakage integrator.

[0094] Figure 6 This illustrates the effect of the input signal including a periodic oscillation with a 50% duty cycle. Figure 4A schematic diagram of the input and output signals provided by the leakage integrator;

[0095] Figure 7 A schematic diagram of a leakage integrator is shown, where the leakage signal is based on a damping signal, a leakage factor, and the difference between the input and output signals.

[0096] Figure 8 This illustrates that when the input signal includes non-periodic oscillations, the... Figure 7 A schematic diagram of the input and output signals provided by the leakage integrator.

[0097] Figure 9 This illustrates the effect of the input signal including a periodic oscillation with a 50% duty cycle. Figure 7 A schematic diagram of the input and output signals provided by the leakage integrator;

[0098] Figure 10 The operation is shown Figure 7 A schematic diagram of the leakage integrator method; and

[0099] Figure 11 A schematic diagram is shown of a non-volatile memory medium for storing instructions, which allow the processor to execute these instructions when they are executed by the processor. Figure 10 One or more steps of a method. Detailed Implementation

[0100] Figure 1 A schematic diagram of device 110 is shown. Device 110 may include mobile phones, tablet computers, desktop computers, laptop computers, video game consoles, video gates, smartwatches, vehicles, etc.

[0101] The device 110 may include an optical sensor 112 (e.g., a digital camera) configured to capture images of a scene. Each image may include one or more channels (such as a red channel, a green channel, and a blue channel). Each image may be characterized by one or more characteristics (such as brightness, dynamic range, contrast, resolution, or other characteristics). Each characteristic may be adjusted by one or more parameters of the optical sensor 112 (such as exposure parameters, shutter speed parameters, channel gain parameters, channel curve parameters, or other parameters).

[0102] The device 110 may include an image signal processor (ISP) 114, which is configured to process scene images captured by the optical sensor 112.

[0103] The device 110 may include a display 116 configured to render scene images captured by the optical sensor 112.

[0104] Device 110 may include memory 118 configured to store scene images captured by optical sensor 112. Additionally or alternatively, memory 118 may be configured to store instructions that, when executed by image signal processor 114, allow image signal processor 114 to perform some or all of the steps of the methods described below. Memory 118 may include any suitable means for storing information, such as instructions and / or data (to be processed or already processed). These means may be, for example, random access memory (RAM) and / or read-only memory (ROM) or any suitable variations thereof.

[0105] The image signal processor 114 may include a statistical determination function 120, primary leakage integrators 122a to 122i, an exposure control function 124, a secondary leakage integrator 126, and a compiled exposure function 127.

[0106] The statistical determination function 120 can be configured to receive images captured by the optical sensor 112 and, based on these images, determine statistics about one or more characteristics of the images or statistics about the optical sensor parameters. Statistics can be determined on a per-image basis or on a per-N image basis, where N is greater than 1. Statistics may include minimum, average, maximum, or other statistics of the image characteristics or optical sensor parameters. Statistics can be provided per channel. For example, the minimum, average, and maximum values ​​of the red channel can be determined. The minimum, average, and maximum values ​​of the green channel can be determined. The minimum, average, and maximum values ​​of the blue channel can be determined.

[0107] The statistical determination function 120 can be configured to provide statistics to the primary leakage integrators 122a to 122i. For example, the minimum values ​​of the red, green, and blue channels can be provided to the primary leakage integrators 122a to 122c, respectively. The average values ​​of the red, green, and blue channels can be provided to the primary leakage integrators 122d to 122f, respectively. The maximum values ​​of the red, green, and blue channels can be provided to the primary leakage integrators 122g to 122i, respectively.

[0108] Primary leakage integrators 122a to 122i can be configured to filter statistical data to avoid sudden / abrupt changes. Primary leakage integrators 122a to 122i can be configured to provide filtered statistics to exposure control function 124. (See reference...) Figure 4 and Figure 7 The possible implementations of the primary leakage integrators 122a to 122i are described in more detail.

[0109] Exposure control function 124 can be configured to determine subsequent aperture parameters for capturing subsequent scene images by the optical sensor based on filtered statistics received from primary leakage integrators 122a to 122i and current aperture parameters received from optical sensor 122 used by the optical sensor to capture the current scene image (i.e., from which statistics are derived). Exposure control function 124 can be configured to provide the subsequent aperture parameters to secondary leakage integrator 126.

[0110] Secondary leakage integrator 126 can be configured to filter subsequent aperture parameters to further avoid sudden / abrupt changes. Secondary leakage integrator 126 can be configured to provide filtered aperture parameters to a compiled exposure function 127. The compiled exposure function 127 can translate desired aperture parameters (e.g., filtered subsequent aperture parameters) into specific settings usable for the optical sensor 112. (See reference...) Figure 4 and Figure 7 A more detailed description of a possible implementation of the secondary leakage integrator 126 is provided.

[0111] It should be understood that the statistical determination function 120, the primary leakage integrators 122a to 122i, the exposure control function 124, the secondary leakage integrator 126, and the compiled exposure function 127 are not necessarily all parts of the image signal processor 114. In some embodiments, some or all of the primary leakage integrators 122a to 122i, the exposure control function 124, the secondary leakage integrator 126, and the compiled exposure function 127 may be part of the optical sensor 112, or may be external to both the optical sensor 112 and the image signal processor 114.

[0112] It should also be understood that the statistical determination function 120, the primary leakage integrators 122a to 122i, the exposure control function 124, the secondary leakage integrator 126, and the compiled exposure function 127 can be implemented in software, but not necessarily in software. The statistical determination function 120, the primary leakage integrators 122a to 122i, the exposure control function 124, the secondary leakage integrator 126, and the compiled exposure function 127 can each be implemented in hardware, software, or a combination of electronic hardware and software running on a suitable processor.

[0113] In operation, control of the exposure parameters of the optical sensor 112 allows the images captured by the optical sensor 112 to be adapted to the dynamic range of the scene. The optical sensor 112 can use its respective exposure parameters to capture multiple images of the same scene. Multiple images can be merged to form a high dynamic range (HDR) image. A trade-off is made between capturing the full dynamics of the scene (e.g., the brightest parts of the scene) without cropping and simultaneously maintaining good signal-to-noise ratio (SNR) performance in the dark areas of the scene.

[0114] Images captured by optical sensor 112 are transmitted to image signal processor 114. Statistics of the images are determined. These statistics may change rapidly with changes in lighting sources (e.g., from sunlight to shadow, from tunnel lighting to sunlight) or other scene characteristics. Selecting exposure parameters for each image may involve continuous trade-offs, but rapid changes from one exposure parameter to another are never visually satisfactory. Therefore, the statistics are smoothed by primary leakage integrators 122a to 122i. The smoothed statistics are then used to determine the exposure parameters for the gradually changing next image to accommodate the changing scene characteristics. The exposure parameters can then be further smoothed by secondary leakage integrator 126.

[0115] Figure 2 A schematic diagram of device 210 is shown. Device 210 may include mobile phones, tablet computers, desktop computers, laptop computers, video game consoles, video gates, smartwatches, vehicles, etc.

[0116] The device 210 may include an optical sensor 212 (e.g., a digital camera) configured to capture images of a scene. Each image may include one or more channels (such as a red channel, a green channel, and a blue channel). Each image may be characterized by one or more characteristics (such as brightness, dynamic range, contrast, resolution, or other characteristics). Each characteristic can be adjusted by regulating one or more parameters of the optical sensor 212 (such as exposure parameters, shutter speed parameters, channel gain parameters, channel curve parameters, or other parameters).

[0117] The device 210 may include an image signal processor (ISP) 214, which is configured to process scene images captured by the optical sensor 212.

[0118] The device 210 may include a display 216 configured to render a scene image captured by an optical sensor 212 and processed by an image signal processor 214.

[0119] Device 210 may include memory 218 configured to store scene images captured by optical sensor 212 and processed by image signal processor 214. Additionally or alternatively, memory 218 may be configured to store instructions that, when executed by image signal processor 214, allow image signal processor 214 to perform some or all of the steps of the methods described below. Memory 218 may include any suitable means for storing information, such as instructions and / or data (to be processed or already processed). These means may be, for example, random access memory (RAM) and / or read-only memory (ROM) or any suitable variations thereof.

[0120] The image signal processor 214 may include a statistical determination function 220, a gain determination function 222, a leakage integrator 224a to 222c, and a white balance control function 226.

[0121] The statistical determination function 220 can be configured to receive images captured by the optical sensor 212 and determine statistics based on them. Statistics can be determined on a per-image basis or on a per N-image basis, where N is greater than 1. Statistics can include energy or total intensity. Statistics can be provided per channel. For example, energy or total intensity can be determined for the red channel. Energy or total intensity can be determined for the green channel. Energy or total intensity can be determined for the blue channel.

[0122] The statistical determination function 220 can be configured to provide statistics to the gain determination function 222.

[0123] The gain determination function 222 can be configured to determine the gain based on statistics. For example, the red gain can be determined based on the energy or total intensity of the red channel. The green gain can be determined based on the energy or total intensity of the green channel. The blue gain can be determined based on the energy or total intensity of the blue channel.

[0124] The gain determination function 222 can be configured to provide gain to leakage integrators 224a to 224c. For example, red gain can be provided to leakage integrator 224a. Green gain can be provided to leakage integrator 224b. Blue gain can be provided to leakage integrator 224c.

[0125] Leakage integrators 224a to 224c can be configured to filter the gain to avoid sudden / abrupt changes. Leakage integrators 224a to 224c can also be configured to provide filtered gain to the white balance control function 226. (Refer to...) Figure 4 and Figure 7 The possible implementations of leakage integrators 224a to 224c are described in more detail.

[0126] White balance control function 226 can be configured to apply filtered gain to the image captured by optical sensor 212 to form a white balance image. For example, filtered red gain can be applied to the red channel of the image captured by optical sensor 212. Filtered green gain can be applied to the green channel of the image captured by optical sensor 212. Filtered blue gain can be applied to the blue channel of the image captured by optical sensor 212.

[0127] White balance control function 226 can be configured to provide a white balance image to display 216 and / or memory 218.

[0128] It should be understood that the statistical determination function 220, the gain determination function 222, the leakage integrators 224a to 224c, and the white balance control function 226 are not necessarily all parts of the image signal processor 214. In some embodiments, some or all of the statistical determination function 220, the gain determination function 222, the leakage integrators 224a to 224c, and the white balance control function 226 may be part of the optical sensor 212. For example, in an implementation, the white balance control function 226 may be part of the optical sensor 212. Some or all of the statistical determination function 220, the gain determination function 222, the leakage integrators 224a to 224c, and the white balance control function 226 may also be external to both the image signal processor 214 and the optical sensor 212.

[0129] It should also be understood that the statistical determination function 220, the gain determination function 222, the leakage integrators 224a to 224c, and the white balance control function 226 can be implemented in software, but are not necessarily required to be implemented in software. The statistical determination function 220, the gain determination function 222, the leakage integrators 224a to 224c, and the white balance control function 226 can be implemented in software, hardware, or a combination of electronic hardware and software running on a suitable processor.

[0130] In operation, white balance control function 226 can be executed to adapt to changes in the lighting source. The lighting source may include sunlight, tungsten lamps, fluorescent lamps, or other lighting sources. Each lighting source may have an associated spectral content that results in a color cast in the image captured by optical sensor 212.

[0131] The image captured by optical sensor 212 is transmitted to image signal processor 214. Statistics are determined. These statistics may change rapidly with changes in the lighting source (e.g., from sunlight to shadow, from tunnel lighting to sunlight) or other scene characteristics. White balance can be achieved by applying red, green, and blue gains to the red, green, or blue channels at image signal processor 214 or at optical sensor 212. Rapid changes from one set of gains to another in the red, green, and blue channels may not be visually satisfactory. Therefore, the red, green, and blue gains can be filtered by leakage integrators 224a to 224c.

[0132] Figure 3 A schematic diagram of device 310 is shown. Device 310 may include mobile phones, tablet computers, desktop computers, laptop computers, video game consoles, video gates, smartwatches, vehicles, etc.

[0133] The device 310 may include an optical sensor 312 (e.g., a digital camera) configured to capture scene images. Each image may include one or more channels (such as red, green, and blue channels). Each image may be characterized by one or more characteristics (such as brightness, dynamic range, contrast, resolution, or other characteristics). Each characteristic may be adjusted by adjusting one or more parameters of the optical sensor 312 (such as exposure parameters, shutter speed parameters, channel gain parameters, channel curve parameters, or other parameters).

[0134] The device 310 may include an image signal processor (ISP) 314 configured to process scene images captured by the optical sensor 312.

[0135] The device 310 may include a display 316 configured to render a scene image captured by an optical sensor 312 and processed by an image signal processor 314.

[0136] Device 310 may include memory 318 configured to store scene images captured by optical sensor 312 and processed by image signal processor 314. Additionally or alternatively, memory 318 may be configured to store instructions that, when executed by image signal processor 314, allow image signal processor 314 to perform some or all of the steps of the methods described below. Memory 318 may include random access memory (RAM) and / or read-only memory (ROM).

[0137] The image signal processor 314 may include a statistical determination function 320, a leakage integrator 322a to 322i, a tone mapping curve determination function 324, and a tone mapping control function 326.

[0138] The statistical determination function 320 can be configured to receive images captured by the optical sensor 312 and determine statistics based on them. Statistics can be determined on a per-image basis or on a per N-image basis, where N is greater than 1. Statistics can include minimum, average, maximum, or other statistics. Statistics can be provided per channel. For example, minimum, average, and maximum values ​​can be determined for the red channel. Minimum, average, and maximum values ​​can be determined for the green channel. Minimum, average, and maximum values ​​can be determined for the blue channel.

[0139] The statistical determination function 320 can be configured to provide statistics to leakage integrators 322a to 322i. For example, the minimum values ​​of the red, green, and blue channels can be provided to leakage integrators 322a to 322c, respectively. The average values ​​of the red, green, and blue channels can be provided to primary leakage integrators 322d to 322f, respectively. The maximum values ​​of the red, green, and blue channels can be provided to primary leakage integrators 322g to 322i, respectively.

[0140] Leakage integrators 322a to 322i can be configured to filter statistics to avoid sudden / abrupt changes. Leakage integrators 322a to 322i can also be configured to provide filtered statistics to tone mapping control function 324. (See reference...) Figure 4 and Figure 7 The possible implementations of leakage integrators 322a to 322i are described in more detail.

[0141] The tone mapping curve determination function 324 can be configured to determine one or more tone mapping curves based on filtered statistics and provide the tone mapping curves to the tone mapping control function 326. For example, a red tone mapping curve, a green tone mapping curve, and a blue tone mapping curve can be determined.

[0142] The tone mapping control function 326 can be configured to apply tone mapping curves to the image captured by the optical sensor 312 to form a dynamic compressed representation captured from the optical sensor that preserves the visual impact of the perceived scene. For example, a red tone mapping curve can be applied to the red channel of the image captured by the optical sensor 312. A green tone mapping curve can be applied to the green channel of the image captured by the optical sensor 312. A blue tone mapping curve can be applied to the blue channel of the image captured by the optical sensor 312.

[0143] The tone mapping control function 326 can be configured to provide a tone-mapped image to the display 316 and / or the memory 318.

[0144] It should be understood that the statistical determination function 320, leakage integrators 322a to 322i, tone mapping curve determination function 324, and tone mapping control function 326 are not necessarily all parts of the image signal processor 314. In some embodiments, some or all of the statistical determination function 320, leakage integrators 322a to 322i, tone mapping curve determination function 324, and tone mapping control function 326 may be part of the optical sensor 312. For example, in an implementation, tone mapping control function 326 may be part of the optical sensor 312. In some embodiments, some or all of the statistical determination function 320, leakage integrators 322a to 322i, tone mapping curve determination function 324, and tone mapping control function 326 may be external to both the image signal processor 314 and the optical sensor 312.

[0145] It should also be understood that the statistical determination function 320, the leakage integrators 322a to 322i, the tone mapping curve determination function 324, and the tone mapping control function 326 can be implemented in software, but are not necessarily required to be implemented in software. The statistical determination function 320, the leakage integrators 322a to 322i, the tone mapping curve determination function 324, and the tone mapping control function 326 can each be implemented in hardware, software, or a combination of software and hardware.

[0146] In operation, tone mapping control function 326 can be executed to achieve an optimal trade-off between the quality of the rendered image and the dynamic range of the image captured by optical sensor 312. The image captured by optical sensor 312 is transmitted to image signal processor 314. Statistics are determined. These statistics may undergo rapid changes with changes in lighting sources (e.g., from sunlight to shadows, from tunnel lighting to sunlight) or other scene characteristics. Tone mapping can be achieved by applying red, green, and blue tone mapping curves at image signal processor 314 or at optical sensor 312 to the red, green, or blue channel. Rapid changes from one set of tone mapping curves to another are visually unsatisfactory. Therefore, statistics can be filtered by leakage integrators 322a to 322i to generate smooth changes from one set of tone mapping curves to another.

[0147] Figure 4 An implementation of a leakage integrator 400 is shown, where the output signal is determined by integrating the leakage signal over the integration time. The leakage integrator can be defined by the following equation:

[0148] (Equation 1)

[0149] Where “y” is the output signal, “y(n)” precedes “y(n+1)”, and “L” is the leakage signal. It should be understood that y(0) can be set to a predetermined value, such as “0”. The integration time is the period during which the signal is measured. In the example form, where L(n) is the leakage signal at time n, and y(n) is the output signal at time n, then the first output signal at time (n+1) is y(n+1), indicating that the integration period is the time interval between y(n) and y(n+1). However, different time intervals can also be used to measure the signal. For example, the first output signal could be at (n+2), (n+3), etc., while both the leakage signal and the output signal could still be at time n, such as L(n) and y(n).

[0150] Leakage signals can be determined based on a leakage factor and the difference between the input and output signals. The leakage factor can be fixed and may be in the range of "0" and "1". More specifically, a leakage signal can be determined by multiplying the leakage factor by the difference between the input and output signals. A leakage signal can be defined by the following equation:

[0151] (Equation 2)

[0152] (Equation 3)

[0153] Where "L" represents the leakage signal, α "x" is the leakage factor, "diff" is the difference signal, "x" is the input signal, and "y" is the output signal.

[0154] As a result, the leakage integrator 400 can be defined by the following equation:

[0155] (Equation 4)

[0156] Where "y" is the output signal, α “x” is the leakage factor and “x” is the input signal.

[0157] The leakage integrator 400 forms a low-pass filter. Even if the input signal changes suddenly or drastically, the output signal still adjusts according to the leakage factor. α "Change gradually or smoothly."

[0158] It should be understood that variations can be provided to the leakage integrator 400. For example, the leakage signal can be determined by multiplying the leakage factor by the input signal, rather than by the difference between the input and output signals. The leakage signal can then be defined by the following equation:

[0159] (Equation 5)

[0160] Where “L” is the leakage signal and “x” is the input signal.

[0161] As a result, the leakage integrator can be defined by the following equation:

[0162] (Equation 6)

[0163] Where "y" is the output signal, α “x” is the leakage factor and “x” is the input signal.

[0164] It should be understood that Figure 4 The leakage integrator 400 can be implemented in software, hardware, or a combination of both.

[0165] Figure 5 This shows that when the input signal 502 is... Figure 4 A schematic diagram of the input signal 502 and the output signal 504 when the leakage integrator 400 is filtering.

[0166] Output signal 504 can control functions such as exposure control, white balance control, or tone mapping control. (See reference...) Figures 1 to 3 The input signal discussed can be statistics (e.g., minimum, average, maximum, energy, total intensity), gain (red gain, green gain, blue gain), or exposure.

[0167] from Figure 5 As can be seen, the input signal 502 includes non-periodic / infrequent oscillations. The output signal 504 is more gradual / smooth than the input signal 502, and therefore, when the final image is rendered on the display, there may be no artifacts visible to the viewer, because the output signal 504 changes rapidly but infrequently over a long period of time (approximately 10 seconds).

[0168] Figure 6 This shows when the input signal 602 is... Figure 4 A schematic diagram of input signal 602 and output signal 604 during the filtering of the leakage integrator 400.

[0169] As can be seen, the input signal 602 includes periodic oscillations. For example, the periodic oscillation has a duty cycle of 50% and a frequency of 1Hz. Such periodic oscillations are typically the result of lights flashing periodically in a scene (e.g., a car's indicator light) or lights periodically entering or leaving a scene (e.g., a tunnel with overhead lighting). The output signal 604 is smoother / flatter than the input signal 602, but when the final image is rendered on a monitor, there may still be no artifacts visible to the viewer because the output signal 604 changes rapidly and frequently over a short period of time (approximately 1 second).

[0170] Figure 4 The drawback of the leakage integrator 400 is that it consistently dampens leakage signals regardless of whether the input signal includes periodic oscillations, the duty cycle of the periodic oscillations, or the frequency of the periodic oscillations. As a result, the leakage integrator 400 is not suitable for partially suppressing artifacts on the final image rendered on the display, which are typically caused by lights periodically blinking in the scene (e.g., car indicator lights) or lights periodically entering and leaving the scene (e.g., a tunnel with overhead lighting).

[0171] One or more examples below provide a leakage integrator that selectively dampens a leakage signal based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations. As a result, the leakage integrator can more effectively suppress time-varying artifacts on the final image rendered on the display.

[0172] Figure 7 An implementation of a leakage integrator 700 is shown, wherein the output signal is determined by integrating the leakage signal over the integration time. The leakage integrator can be defined by the following equation:

[0173] (Equation 7)

[0174] Where “y” is the output signal and “L” is the leakage signal. It should be understood that y(0) can be set to a predetermined value, such as “0”.

[0175] The leakage signal can be determined based on the damping signal, the leakage factor, and the difference signal between the input and output signals. The leakage factor can be fixed. The leakage factor can be in the range of "0" and "1". More specifically, the leakage signal can be determined by multiplying the damping signal, the leakage factor, and the difference signal between the input and output signals. The leakage signal can be defined by the following equation:

[0176] (Equation 8)

[0177] (Equation 9)

[0178] Where "L" is the leakage signal and "D" is the damping signal. α "x" is the leakage factor, "diff" is the difference signal, "x" is the input signal, and "y" is the output signal.

[0179] As a result, the leakage integrator 700 can be defined by the following equation:

[0180] (Equation 10)

[0181] Where "y" is the output signal and "D" is the damping signal. α “x” is the leakage factor and “x” is the input signal.

[0182] The damping signal can be designed to vary based on the presence of periodic oscillations in the input signal, the duty cycle of the periodic oscillations, and / or the frequency of the periodic oscillations.

[0183] The damping signal can be designed to dampen the leakage signal more effectively when there are periodic oscillations in the input signal, compared to the case where there are non-periodic oscillations in the input signal.

[0184] Compared to the case where the input signal contains periodic oscillations with a duty cycle far from 50%, the damping signal provides greater damping for the leakage signal when the input signal contains periodic oscillations with a duty cycle close to 50%. In some embodiments, the closer the duty cycle of the periodic oscillation is to 50%, the greater the damping of the leakage signal. The further the duty cycle of the periodic oscillation is from 50%, the smaller the damping of the leakage signal.

[0185] The damping signal can be designed to provide greater damping for leakage signals when high-frequency periodic oscillations exist in the input signal, compared to the case where low-frequency periodic oscillations exist. That is, the higher the frequency of the periodic oscillation, the greater the damping of the leakage signal, and vice versa. The lower the frequency of the periodic oscillation, the less the damping of the leakage signal, and vice versa. There may exist frequency ranges within which damping is required and outside which damping is not needed.

[0186] In implementation, the damping signal can be determined based on the upper and lower difference signals. The damping signal can be defined by the following equation:

[0187] (Equation 11)

[0188] Where “D” is the damping signal, “UpperDiff” is the upper difference signal, and “LowerDiff” is the lower difference signal.

[0189] It should be understood that the damping signal can be obtained using other suitable equations.

[0190] When the difference signal is positive, the upper difference signal can be determined by performing leakage integration on the difference signal between the input and output signals over the integration time. The upper difference signal can be defined by the following equation:

[0191] (Equation 12)

[0192] (Equation 13)

[0193] Where "Upperdiff" is the upper limit difference signal, "β" is the leakage factor, "Diff" is the difference signal, "x" is the input signal, and "y" is the output signal. The leakage factor can be fixed. The leakage factor can be in the range between 0 and 1.

[0194] When the difference signal is negative, the lower difference signal can be determined by performing leakage integration on the difference signal between the input and output signals over the integration time. The lower difference signal can be defined by the following equation:

[0195] (Equation 14)

[0196] (Equation 15)

[0197] Where "Lowerdiff" is the lower difference signal, "β" is the leakage factor, "Diff" is the difference signal, "x" is the input signal, and "y" is the output signal. The leakage factor can be fixed. The leakage factor can be in the range between 0 and 1.

[0198] In the above implementation, the damping signal is designed to vary between 0 and 1.

[0199] The imbalance (e.g., offset) of the damping signal varies based on the presence of periodic oscillations in the input signal. The imbalance (e.g., offset) of the damping signal can be smaller when periodic oscillations are present in the input signal compared to when aperiodic oscillations are present. That is, the damping signal provides greater damping of the leakage signal when periodic oscillations are present compared to when aperiodic oscillations are present.

[0200] When the input signal includes periodic oscillations, the damping signal can vary between 0 and 0+Δ1, while when the input signal includes non-periodic oscillations, the damping signal can vary between 1-Δ2 and 1, where Δ1 is less than 1 and Δ2 is greater than 0.

[0201] When the input signal includes a periodic oscillation with a duty cycle close to 50%, the damping signal can be between 0 and 0+Δ. 1close The damping signal can vary between 0 and 0+Δ when the input signal includes periodic oscillations with a duty cycle far exceeding 50%. 1far The variation between, where Δ 1close Less than Δ 1far .

[0202] The amplitude of the damping signal can vary based on the frequency of the periodic oscillations in the input signal. The higher the frequency of the periodic oscillations, the smaller the amplitude of the damping signal. Conversely, the lower the frequency of the periodic oscillations, the larger the amplitude of the damping signal.

[0203] For example, when the input signal includes periodic oscillations with high frequency, the damping signal can be between 0 and 0+Δ. 1high_frequency The damping signal varies between 0 and 0+Δ, and when the input signal includes periodic oscillations with low frequency, the damping signal can vary between 0 and 0+Δ. 1low_frequency The variation between, where Δ 1high_frequency Less than Δ 1low_frequency .

[0204] In this way, the leak integrator 700 can more effectively suppress artifacts on the final image rendered on the display, such as artifacts typically generated by lights flashing periodically in a scene (e.g., car indicator lights) or lights periodically entering and leaving a scene (e.g., a tunnel with overhead lighting).

[0205] It should be understood that alternative implementations can be provided. For example, the leakage signal can be determined by multiplying the leakage factor by the input signal, rather than by the difference signal between the input and output signals. The leakage signal can then be defined by the following equation:

[0206] (Equation 16)

[0207] Where “L” is the leakage signal and “D” is the damping signal.

[0208] As a result, the leakage integrator can be defined by the following equation:

[0209] (Equation 17)

[0210] Where "y" is the output signal, α “x” is the leakage factor and “x” is the input signal. It should be understood that y(0) can be set to a predetermined value, such as “0”.

[0211] It should also be understood that, as Figure 4 Leakage integrator 400, Figure 7The leakage integrator 700 can be implemented in software, hardware, or a combination of both.

[0212] Figure 8 This shows when the input signal 802 is... Figure 7 A schematic diagram of the input signal 802 and the output signal 804 when the leakage integrator 700 is filtering.

[0213] As can be seen, the input signal 802 includes non-periodic oscillations. The output signal 804 is smoother than the input signal, and when the final image is rendered on the display, there may be no artifacts visible to the viewer because the output signal 804 adapts quickly but infrequently over a long period of time (approximately 10 seconds).

[0214] Figure 9 This shows that when the input signal 902 is... Figure 7 A schematic diagram of input signal 902 and output signal 904 during the filtering of the leakage integrator 700.

[0215] As can be seen, the input signal 902 includes a periodic oscillation with a 50% duty cycle. This periodic oscillation is typically a result of lights periodically flashing in a scene (e.g., a car's indicator lights) or lights periodically entering and leaving a scene (e.g., a tunnel with overhead lighting). When the final image is rendered on the monitor, the output signal 904 has no artifacts visible to the viewer. Figure 4 The output signal 604 of the leakage integrator 400 filter changes frequently within a short period of time (approximately 1 second).

[0216] Figure 10 The operation is shown Figure 7 The method of leakage integrator 700.

[0217] In step 1002, the leakage integrator 700 can receive the input signal.

[0218] In step 1004, when the difference signal is positive (e.g., equations 12 and 13), the leakage integrator 700 can generate an upper difference signal by performing leakage integration on the difference signal between the input signal and the output signal.

[0219] In step 1006, when the difference signal is negative (e.g., equations 14 and 15), the leakage integrator 700 can generate a lower difference signal by performing leakage integration on the difference signal between the input signal and the output signal.

[0220] In step 1008, the leakage integrator 700 can generate a damping signal based on the upper difference signal and the lower difference signal (e.g., Equation 10).

[0221] In step 1010, the leakage integrator 700 can generate an output signal by integrating the leakage signal over an integration time, wherein the leakage signal is obtained by multiplying the damping signal, the leakage factor, and the difference signal between the input signal and the output signal (e.g., Equation 9).

[0222] As described above, steps 1002 to 1012 can be repeated on a per-image basis or on a per N-image basis.

[0223] Figure 11 A schematic diagram is shown of non-volatile memory media 1100a (e.g., a computer disk (CD) or digital multifunction disk (DVD)) and 1100b (e.g., a Universal Serial Bus (USB) memory stick) storing instructions and / or parameters 1102, when the instructions and / or parameters 1102 are processed by a processor (such as...) Figures 1 to 3 When the image signal processors 114, 214 or 314 are executed, they allow the processor to perform one or more steps of the above method.

[0224] Various embodiments with different variations have been described above. It should be noted that those skilled in the art can combine various elements of these various embodiments and variations.

[0225] Such changes, modifications, and improvements are intended to be part of this disclosure and are intended to fall within the scope of the claims. Accordingly, the foregoing description is by way of example only and is not intended to be limiting.

[0226] The various embodiments described above can be combined to provide further embodiments. These and other changes can be made to the embodiments based on the detailed description above. Generally, the terminology used in the appended claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full scope of equivalents enjoyed by these claims. Accordingly, the claims are not limited to this disclosure.

Claims

1. A method for operating a leakage integrator, comprising: Receive the input signal at the leakage integrator; A first output signal is generated at the leakage integrator by integrating the leakage signal over the integration time, wherein the leakage signal is obtained based on a damping signal, a leakage factor, and a difference signal between the input signal and the output signal; and Provide the first output signal, The damping signal is determined by a plurality of actions, the plurality of actions including: When the difference signal is positive, an upper difference signal is generated by integrating the difference signal within the integration time. When the difference signal is negative, a next difference signal is generated by integrating the difference signal within the integration time; and The damping signal is generated based on the upper and lower difference signals, and The generation of the damping signal based on the upper difference signal and the lower difference signal is based on: Wherein "D" is the damping signal, "UpperDiff" is the upper difference signal, and "LowerDiff" is the lower difference signal.

2. The method of claim 1, wherein the integration of the leakage signal comprises: Multiply the damping signal, the leakage factor, and the input signal by the difference signal between the second output signal of the leakage integrator, which precedes the first output signal.

3. The method of claim 1, wherein the leakage factor is fixed during the integral time.

4. The method of claim 1, wherein the damping signal is variable during the integral time.

5. The method of claim 4, wherein the damping signal varies based on one or more of whether the input signal includes a periodic oscillation, the duty cycle of the periodic oscillation, and the frequency of the periodic oscillation.

6. The method of claim 4, wherein the damping signal varies between 0 and 1.

7. The method of claim 5, wherein when the input signal includes a periodic oscillation, the damping signal varies between 0 and 0+Δ1, where Δ1 is less than 1; and When the input signal includes non-periodic oscillations, the damping signal varies between 1-Δ2 and 1, where Δ2 is greater than 0.

8. The method of claim 6, wherein the amplitude of the damping signal varies based on the frequency of the periodic oscillations included in the input signal.

9. The method of claim 1, wherein the first output signal is provided to control a function for controlling an optical sensor, the function including an exposure control function, a white balance control function, or a tone mapping control function.

10. A system including a leakage integrator, comprising: An optical sensor is configured to acquire images; A statistical determination unit is configured to generate statistical signals based on the image; The leakage integrator is configured to generate a first filtered statistical signal by integrating the leakage signal based on the damping signal, the leakage factor, and the statistical signal over an integration time. as well as The control unit is configured to control the parameters of the optical sensor based on the first filtered statistical signal. The integration of the leakage signal includes: multiplying the damping signal, the leakage factor, and the statistical signal by the difference signal between the second filtered statistical signal of the leakage integrator, which precedes the first filtered statistical signal, and... The amplitude of the damping signal is determined based on the frequency of the periodic oscillations included in the statistical signal. The damping signal is determined by a plurality of actions, the plurality of actions including: When the difference signal is positive, an upper difference signal is generated by integrating the difference signal within the integration time. When the difference signal is negative, a next difference signal is generated by integrating the difference signal within the integration time; and The damping signal is generated based on the upper and lower difference signals, and The generation of the damping signal based on the upper difference signal and the lower difference signal is based on: Wherein "D" is the damping signal, "UpperDiff" is the upper difference signal, and "LowerDiff" is the lower difference signal.

11. The system of claim 10, wherein the damping signal is determined based on one or more of the following: whether the statistical signal comprises a periodic oscillation or an aperiodic oscillation, the duty cycle of the periodic oscillation, and the frequency of the periodic oscillation.

12. The system of claim 11, wherein when the statistical signal includes periodic oscillations, the damping signal is in the range between 0 and 0+Δ1, where Δ1 is less than 1; and Wherein, when the statistical signal includes aperiodic oscillations, the damping signal is in the range between 1-Δ2 and 1, where Δ2 is greater than 0.

13. The system of claim 10, wherein the offset of the damping signal is determined based on one or more of whether the statistical signal includes a periodic oscillation and the duty cycle of the periodic oscillation.

14. An integrated circuit, comprising: The first circuit operates to generate a first signal based on at least one of the characteristics of the image and parameters when the optical sensor acquires the image; as well as A low-pass filter circuit operates to filter the first signal by integrating the leakage signal based on the damping signal, the leakage factor, and the first signal over an integral time. The damping signal is determined based on one or more of the following: whether the first signal includes a periodic oscillation or an aperiodic oscillation, the duty cycle of the periodic oscillation, and the frequency of the periodic oscillation. The leakage signal is obtained based on the damping signal, the leakage factor, and the difference between the first signal and the output signal. The damping signal is determined by a plurality of actions, the plurality of actions including: When the difference signal is positive, an upper difference signal is generated by integrating the difference signal within the integration time. When the difference signal is negative, a next difference signal is generated by integrating the difference signal within the integration time; and The damping signal is generated based on the upper and lower difference signals, and The generation of the damping signal based on the upper difference signal and the lower difference signal is based on: Wherein "D" is the damping signal, "UpperDiff" is the upper difference signal, and "LowerDiff" is the lower difference signal.

15. The integrated circuit of claim 14, wherein the integration of the leakage signal comprises: Multiply the difference between the damping signal, the leakage factor, and the first signal and the second output signal of the low-pass filter circuit that precedes the first output signal.

16. The integrated circuit of claim 14, wherein the leakage factor is fixed during the time period of the integration of the leakage signal.

17. The integrated circuit of claim 14, wherein the damping signal is variable over the time period of the integration of the leakage signal.

18. The integrated circuit of claim 14, wherein the damping signal varies between 0 and 1.

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