Camera exposure method of dual-camera endoscope and dual-camera endoscope system

Abstract

The invention provides a double-camera endoscope camera exposure method and a double-camera endoscope system. The method comprises the following steps: acquiring a current white light camera exposure parameter and a current brightness parameter of a white light imaging system; based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, converting the current white light camera exposure parameter into a current equivalent exposure parameter corresponding to a specified brightness parameter; obtaining a current fluorescent camera exposure parameter corresponding to the current equivalent exposure parameter based on a mapping relationship between a preset equivalent exposure parameter and a fluorescent camera exposure parameter; and controlling the exposure of a fluorescence imaging system based on the current fluorescence camera exposure parameter. According to the invention, under the condition of a fixed distance, even if different light source gears and image brightness gears are adopted, the image brightness of the fluorescence imaging system is kept unchanged.

Description

Technical Field

[0001] The present application relates to the field of medical device technology, and in particular to a dual-camera endoscope camera exposure method and a dual-camera endoscope system. Background Art

[0002] A dual-camera endoscope is provided with both a white light imaging system and a fluorescence imaging system. In the prior art, in order to realize automatic exposure of the fluorescence imaging system and improve the imaging quality of the fluorescence imaging system, the exposure parameters of the fluorescence imaging system are adjusted according to the exposure parameters of the white light imaging system. This adjustment method requires pre-calibration of the relationship between the exposure parameters of the white light imaging system and the exposure parameters of the fluorescence imaging system. During the calibration process, the light source position and the image brightness position of the white light imaging system do not change. Therefore, the adjustment method calibrates the relationship between the exposure parameters of the white light imaging system and the exposure parameters of the fluorescence imaging system under the condition of fixed light source position and image brightness position.

[0003] The relationship between the exposure parameters of the fluorescence imaging system and the exposure parameters of the white light imaging system is one-to-one. When the distance between the endoscope and the imaging target remains unchanged, if the light source position of the white light imaging system changes, the exposure parameters of the white light imaging system will also change, which will cause the exposure parameters of the associated fluorescence imaging system to change. However, in fact, since the distance remains unchanged, in order to ensure that the brightness of the fluorescence image remains unchanged, the exposure parameters of the fluorescence imaging system should not change. In addition, when the image brightness position of the white light imaging system changes, the exposure of the white light imaging system will also change, causing the exposure of the associated fluorescence imaging system to change. However, at this time, the distance remains unchanged, and in order to ensure that the brightness of the fluorescence image remains unchanged, the exposure of the fluorescence imaging system should not change.

[0004] Therefore, in the actual automatic exposure process, since the target image brightness and light source position of the white light imaging system are both user-adjustable, when the actual target image brightness and light source position change, the correspondence between the exposure parameters of the white light imaging system and the exposure parameters of the fluorescent imaging system that are pre-calibrated while keeping the target image brightness and light source position unchanged is no longer applicable, that is, the existing adjustment method is no longer applicable. Summary of the invention

[0005] In response to the problems in the prior art, the purpose of the present application is to provide a dual-camera endoscope camera exposure method and a dual-camera endoscope system, which can achieve the goal of maintaining the image brightness of the fluorescence imaging system unchanged even when different light source gears and image brightness gears are used under fixed distance conditions.

[0006] The present application embodiment provides a dual-camera endoscope camera exposure method, comprising:

[0007] Obtain the current white light camera exposure parameters and current brightness parameters of the white light imaging system;

[0008] Based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, the current white light camera exposure parameter is converted into a current equivalent exposure parameter corresponding to the specified brightness parameter;

[0009] Based on a mapping relationship between a preset equivalent exposure parameter and a fluorescence camera exposure parameter, obtaining a current fluorescence camera exposure parameter corresponding to the current equivalent exposure parameter;

[0010] The exposure of the fluorescence imaging system is controlled based on the current fluorescence camera exposure parameters.

[0011] In some embodiments, the brightness parameter includes at least one of a light source level and an image brightness level of a white light imaging system.

[0012] In some embodiments, based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, converting the current white light camera exposure parameter into a current equivalent exposure parameter corresponding to the specified brightness parameter includes the following steps:

[0013] Based on a preset mapping relationship between brightness parameters and exposure parameter conversion coefficients, a current exposure parameter conversion coefficient corresponding to the current brightness parameter is obtained, and the exposure parameter conversion coefficient corresponding to each brightness parameter is used to convert the exposure parameter of each brightness parameter into an equivalent exposure parameter under the specified brightness parameter;

[0014] According to the current white light camera exposure parameter and the current exposure parameter conversion coefficient, a current equivalent exposure parameter corresponding to the current white light camera exposure parameter is calculated.

[0015] In some embodiments, before obtaining the current exposure parameter conversion coefficient corresponding to the current brightness parameter based on the preset mapping relationship between the brightness parameter and the exposure parameter conversion coefficient, the following steps are also included:

[0016] While keeping the distance between the endoscope and the object unchanged, respectively obtain the exposure parameters when shooting under various non-specified brightness parameters and the exposure parameters when shooting under the specified brightness parameters, and calculate the exposure parameter conversion coefficient corresponding to each non-specified brightness parameter;

[0017] A mapping relationship between the brightness parameter and the exposure parameter conversion coefficient is established according to each non-specified brightness parameter and the corresponding exposure parameter conversion coefficient.

[0018] In some embodiments, the current brightness parameter includes a current light source position and a current image brightness position of a white light imaging system; the step of obtaining a current exposure parameter conversion coefficient corresponding to the current brightness parameter based on a preset mapping relationship between the brightness parameter and the exposure parameter conversion coefficient comprises the following steps:

[0019] Based on a preset mapping relationship between a light source position and a first exposure parameter conversion coefficient, obtaining a current first exposure parameter conversion coefficient corresponding to the current light source position;

[0020] Based on a preset mapping relationship between the image brightness level and the second exposure parameter conversion coefficient, a current second exposure parameter conversion coefficient corresponding to the current image brightness level is acquired.

[0021] In some embodiments, calculating the current equivalent exposure parameter corresponding to the current white light camera exposure parameter according to the current white light camera exposure parameter and the current exposure parameter conversion coefficient comprises the following steps:

[0022] The current white light camera exposure parameter is multiplied by the current first exposure parameter conversion coefficient and the current second exposure parameter conversion coefficient to obtain the current equivalent exposure parameter.

[0023] In some embodiments, before acquiring the current fluorescence camera exposure parameter corresponding to the current equivalent exposure parameter based on the mapping relationship between the preset equivalent exposure parameter and the fluorescence camera exposure parameter, the following steps are also included:

[0024] Keep the white light imaging system under the specified brightness parameters and calibrate the mapping relationship between the equivalent exposure parameters and the fluorescence camera exposure parameters.

[0025] In some embodiments, the mapping relationship between the calibration equivalent exposure parameters and the fluorescence camera exposure parameters includes the following steps:

[0026] Keeping the white light imaging system under the specified brightness parameters, adjusting the distance between the imaging target and the endoscope, collecting multiple sets of calibration data, each set of calibration data including the white light camera exposure parameters and the fluorescence camera exposure parameters corresponding to the same distance, and taking the white light camera exposure parameters in each set of calibration data as equivalent exposure parameters;

[0027] A mapping relationship between the equivalent exposure parameters and the exposure parameters of the fluorescent camera is established based on the multiple groups of calibration data.

[0028] In some embodiments, in each set of the calibration data, the fluorescence camera exposure parameters are fluorescence camera exposure parameters manually adjusted by a user.

[0029] The present application also provides a dual-camera endoscope system, including a white light imaging system, a fluorescence imaging system and an exposure controller, wherein the exposure controller is used to implement the dual-camera endoscope camera exposure method.

[0030] The dual-camera endoscope exposure method and dual-camera endoscope system provided by the present application have the following advantages:

[0031] By adopting the dual-camera endoscope camera exposure method of the present application, a mapping relationship between equivalent exposure parameters and fluorescent camera exposure parameters is pre-established. When obtaining the current white light camera exposure parameters, the current brightness parameters of the white light imaging system are also obtained. The current brightness parameters are brightness factors that affect the white light exposure parameters. According to the current brightness parameters, the current white light camera exposure parameters are converted into current equivalent exposure parameters corresponding to the specified brightness parameters, eliminating the influence of the adjusted brightness parameters on the white light camera exposure parameters. Then, based on the current equivalent exposure parameters instead of the current white light camera exposure parameters, the current fluorescent camera exposure parameters are obtained, and the exposure of the fluorescent imaging system is controlled. Therefore, the present application eliminates the influence of the adjusted brightness parameters on the white light camera exposure parameters. When the distance between the endoscope and the imaging target remains unchanged, regardless of whether the brightness parameters of the white light imaging system change, the exposure parameters of the fluorescent imaging system will not change, and the image brightness of the fluorescent imaging system remains fixed, thereby improving the imaging brightness stability of the fluorescent imaging system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0033] Figure 1 is a flow chart of a dual-camera endoscope camera exposure method according to an embodiment of the present application;

[0034] Figure 2 is a structural block diagram of a dual-camera endoscope system according to an embodiment of the present application;

[0035] Figure 3 This is a flowchart of converting current white light camera exposure parameters into current equivalent exposure parameters corresponding to specified brightness parameters according to an embodiment of the present application. DETAILED DESCRIPTION

[0036] The example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as being limited to the embodiments set forth herein; on the contrary, these embodiments are provided so that the present application will be comprehensive and complete, and the concept of the example embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. "Or" and "or" in the specification may both mean "and" or "or". Although the terms "upper", "lower", "between", etc. may be used in this specification to describe different exemplary features and elements of the present application, these terms are used herein only for convenience, such as according to the directions of the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional direction of the structure to fall within the scope of the present application. Although "first" or "second" etc. are used in this specification to represent certain features, they are only used to represent the function, and are not used as a limitation on the number and importance of specific features.

[0037] like Figure 1 As shown, the present application provides a dual-camera endoscope camera exposure method. Figure 2 As shown, the present application also provides a dual-camera endoscope system, including a white light imaging system M100, a fluorescence imaging system M200 and an exposure controller M300, wherein the exposure controller M300 is used to implement the dual-camera endoscope camera exposure method. The white light imaging system M100 includes a white light camera and a light source, and the fluorescence imaging system M200 includes at least a fluorescence camera.

[0038] like Figure 1 As shown, the dual-camera endoscope camera exposure method includes the following steps:

[0039] S100: Acquire current white light camera exposure parameters and current brightness parameters of the white light imaging system;

[0040] In this embodiment, the exposure amount E is defined as the product of the exposure time T and the exposure gain G, that is, it satisfies the following formula (1):

[0041] E=T*G (1)

[0042] The white light camera exposure parameters include the white light camera exposure amount E_white, that is, the white light camera exposure amount E_white is equal to the product of the white light camera exposure time T_white and the exposure gain G_white;

[0043] In this embodiment, the brightness parameter includes at least one of a light source position and an image brightness position of a white light imaging system, which is a brightness factor affecting the white light exposure parameter. In an endoscope system in which both the light source position and the image brightness position are adjustable, the brightness parameter may include both the light source position and the image brightness position. In an endoscope system in which only the light source position is adjustable, the brightness parameter may include only the light source position. In an endoscope system in which only the image brightness position is adjustable, the brightness parameter may include only the image brightness position.

[0044] S200: Based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, convert the current white light camera exposure parameter into a current equivalent exposure parameter corresponding to the specified brightness parameter;

[0045] S300: acquiring a current fluorescent camera exposure parameter corresponding to the current equivalent exposure parameter based on a mapping relationship between a preset equivalent exposure parameter and a fluorescent camera exposure parameter;

[0046] In this embodiment, the fluorescence camera exposure parameter includes the fluorescence camera exposure amount E_ying, and the fluorescence camera exposure amount E_ying is equal to the product of the fluorescence camera exposure time T_ying and the exposure gain G_ying;

[0047] S400: Controlling the exposure of a fluorescence imaging system based on the current fluorescence camera exposure parameter.

[0048] By adopting the dual-camera endoscope camera exposure method of the present application, a mapping relationship between equivalent exposure parameters and fluorescence camera exposure parameters is pre-established. When the current white light camera exposure parameters are obtained through step S100, the current brightness parameters of the white light imaging system are also obtained. The current brightness parameters are brightness factors that affect the white light exposure parameters, such as the light source position and / or the image brightness position. Step S200 converts the current white light camera exposure parameters into current equivalent exposure parameters corresponding to the specified brightness parameters according to the current brightness parameters, thereby eliminating the influence of adjusting the brightness parameters on the white light camera exposure parameters. Then, step S300 is used to obtain the current fluorescence camera exposure parameters based on the current equivalent exposure parameters rather than the current white light camera exposure parameters, and the exposure of the fluorescence imaging system is controlled through step S400.

[0049] Therefore, the present application eliminates the influence of adjusting the brightness parameter on the exposure parameter of the white light camera. When the distance between the endoscope and the imaging target remains unchanged, regardless of whether the brightness parameter of the white light imaging system changes, the exposure parameter of the fluorescence imaging system will not change, and the image brightness of the fluorescence imaging system remains fixed, thereby improving the imaging brightness stability of the fluorescence imaging system. The exposure controller of the dual-camera endoscope system is used to implement the dual-camera endoscope camera exposure method. Therefore, the dual-camera endoscope system can achieve the technical effect of the dual-camera endoscope camera exposure method, which will not be described in detail here.

[0050] In this embodiment, before the step S300: obtaining the current fluorescence camera exposure parameter corresponding to the current equivalent exposure parameter based on the mapping relationship between the preset equivalent exposure parameter and the fluorescence camera exposure parameter, the following steps are also included:

[0051] The mapping relationship between the equivalent exposure parameter and the fluorescence camera exposure parameter is calibrated while keeping the white light imaging system under the specified brightness parameter. Therefore, the mapping relationship between the equivalent exposure parameter and the fluorescence camera exposure parameter is pre-established while keeping the brightness parameter of the white light imaging system as the specified brightness parameter. No matter how much the brightness parameter of the white light imaging system is set to in actual application, after converting it to the equivalent exposure parameter corresponding to the specified brightness parameter, the corresponding fluorescence camera exposure parameter can be obtained, and the brightness stability of the fluorescence camera imaging can be maintained.

[0052] The following takes the brightness parameters including the light source position and the image brightness position as an example to specifically illustrate the specific implementation of the dual-camera endoscope camera exposure method.

[0053] In this embodiment, the specified brightness parameters include a specified light source position and a specified image brightness position. The mapping relationship between the calibration equivalent exposure parameters and the fluorescence camera exposure parameters includes the following steps:

[0054] Keeping the white light imaging system at a specified light source position and a specified image brightness position, adjusting the distance between the imaging target and the endoscope, collecting multiple sets of calibration data, each set of calibration data including white light camera exposure parameters and fluorescent camera exposure parameters corresponding to the same distance, using the white light camera exposure parameters in each set of calibration data as equivalent exposure parameters, and in each set of the calibration data, the fluorescent camera exposure parameters are fluorescent camera exposure parameters manually adjusted by the user;

[0055] Based on the multiple sets of calibration data, a mapping relationship E_ying=f(E_white_e) between the equivalent exposure parameters and the fluorescence camera exposure parameters is established. Wherein, E_ying represents the fluorescence camera exposure parameters, and E_white_e represents the equivalent exposure parameters of the white light imaging system. f() represents the relationship between the fitted fluorescence camera exposure parameters and the equivalent exposure parameters. For example, E_white_e=K*E_ying+B, where parameters K and B can be calibrated through multiple sets of calibration data. After the calibration is completed, for the equivalent exposure parameters of a white light imaging system, the uniquely determined fluorescence camera exposure parameters can be obtained through the mapping relationship.

[0056] The brightness of the white light image of the white light imaging system is determined by three parameters: light source position, exposure time and exposure gain (i.e., it is jointly determined by the light source position and exposure amount). However, there is no light source position in the fluorescence imaging system, and the brightness of the fluorescence image is only controlled by the exposure time and exposure gain (i.e., it is determined solely by the exposure amount). In the existing method, the influence of the light source position and the image brightness position is not considered, and the mapping relationship between the white light camera exposure parameters and the fluorescence camera exposure parameters is directly calibrated E_ying=f1(E_white), where E_white represents the directly acquired white light camera exposure parameters. In actual applications, when the position of the endoscope and the imaging target does not change, when the light source position or the image brightness position of the white light imaging system changes, in order to maintain the stability of the white light image brightness, the automatic exposure algorithm of the white light imaging system will adjust the white light camera exposure from E_white_1 to E_white_2, but the image brightness of the white light imaging system does not change. If the exposure parameters of the fluorescence camera are directly obtained according to E_ying=f1(E_white), the exposure parameters of the fluorescence camera will change from E_ying_1=f1(E_white_1) to E_ying_2=f1(E_white_2), which will directly cause the brightness of the fluorescence image to change.

[0057] Since the imaging distance has not changed, the brightness of the fluorescent image of the fluorescent imaging system should not actually change. Therefore, the existing method of obtaining the exposure parameters of the fluorescent camera is no longer applicable to the case where the light source position and / or image brightness position of the white light imaging system are adjustable. In order to solve this defect in the prior art, the present application proposes an equivalent conversion method. When the distance between the endoscope and the imaging target remains unchanged, E_white_2 can be equivalently converted into an equivalent exposure parameter E_white_e under the light source position and image brightness position when calibrating the mapping relationship between the white light camera exposure parameters and the fluorescent camera exposure parameters, and then it can be substituted into the pre-calibrated mapping relationship E_ying=f(E_white_e), which can ensure that the calculated fluorescent camera exposure parameters are not affected by changes in the light source position and image brightness position.

[0058] like Figure 3 As shown, in this embodiment, the step S200: based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, converting the current white light camera exposure parameter into a current equivalent exposure parameter corresponding to the specified brightness parameter, includes the following steps:

[0059] S210: based on a preset mapping relationship between brightness parameters and exposure parameter conversion coefficients, obtaining a current exposure parameter conversion coefficient corresponding to the current brightness parameter, wherein the exposure parameter conversion coefficient corresponding to each brightness parameter is used to convert the exposure parameter of each brightness parameter into an equivalent exposure parameter under a specified brightness parameter;

[0060] In this embodiment, the brightness parameter includes a light source position degree and an image brightness position aim, the exposure parameter conversion coefficient includes a first exposure parameter conversion coefficient and a second exposure parameter conversion coefficient, and the mapping relationship between the brightness parameter and the exposure parameter conversion coefficient includes a mapping relationship between the light source position and the first exposure parameter conversion coefficient and a mapping relationship between the image brightness parameter and the second exposure parameter conversion coefficient;

[0061] S220: Calculating a current equivalent exposure parameter corresponding to the current white light camera exposure parameter according to the current white light camera exposure parameter and the current exposure parameter conversion coefficient;

[0062] In this embodiment, step S210 includes the following steps:

[0063] Based on a preset mapping relationship between a light source position and a first exposure parameter conversion coefficient, obtaining a current first exposure parameter conversion coefficient corresponding to the current light source position;

[0064] Based on a preset mapping relationship between the image brightness level and the second exposure parameter conversion coefficient, a current second exposure parameter conversion coefficient corresponding to the current image brightness level is acquired.

[0065] In this embodiment, in step S220, the current equivalent exposure parameter corresponding to the current white light camera exposure parameter is calculated according to the current white light camera exposure parameter, the current first exposure parameter conversion coefficient and the current second exposure parameter conversion coefficient. In one implementation, step S220 includes: multiplying the current white light camera exposure parameter with the current first exposure parameter conversion coefficient and the current second exposure parameter conversion coefficient to obtain the current equivalent exposure parameter.

[0066] In this embodiment, the step S210: before obtaining the current exposure parameter conversion coefficient corresponding to the current brightness parameter based on the preset mapping relationship between the brightness parameter and the exposure parameter conversion coefficient, further includes calibrating the mapping relationship between the brightness parameter and the exposure parameter conversion coefficient by using the following steps:

[0067] While keeping the distance between the endoscope and the object unchanged, respectively obtain the exposure parameters when shooting under various non-specified brightness parameters and the exposure parameters when shooting under the specified brightness parameters, and calculate the exposure parameter conversion coefficient corresponding to each non-specified brightness parameter;

[0068] A mapping relationship between the brightness parameter and the exposure parameter conversion coefficient is established according to each non-specified brightness parameter and the corresponding exposure parameter conversion coefficient.

[0069] In this embodiment, since the exposure parameter conversion coefficient includes a first exposure parameter conversion coefficient and a second exposure parameter conversion coefficient, it is necessary to calibrate the mapping relationship between the light source position and the first exposure parameter conversion coefficient and the mapping relationship between the image brightness position and the second exposure parameter conversion coefficient respectively. When calibrating a mapping relationship, other influencing factors need to be kept unchanged, that is, when calibrating the mapping relationship between the light source position and the first exposure parameter conversion coefficient, the distance between the endoscope and the object and the image brightness position must be kept unchanged; when calibrating the mapping relationship between the image brightness position and the second exposure parameter conversion coefficient, the distance between the endoscope and the object and the light source position must be kept unchanged.

[0070] Specifically, the mapping relationship between the calibrated light source position and the first exposure parameter conversion coefficient includes: while keeping the distance between the endoscope and the object unchanged and the image brightness position at the specified image brightness position, respectively obtaining the exposure parameters when shooting at each non-specified light source position and the exposure parameters when shooting at the specified light source position, and calculating the first exposure parameter conversion coefficient corresponding to each non-specified light source position; and establishing a mapping relationship between the light source position and the first exposure parameter conversion coefficient according to each non-specified light source position and the corresponding first exposure parameter conversion coefficient.

[0071] The mapping relationship between the calibrated image brightness level and the second exposure parameter conversion coefficient includes: while keeping the distance between the endoscope and the object unchanged and the light source level at the designated light source level, respectively obtaining the exposure parameters when shooting at each non-designated image brightness level and the exposure parameters when shooting at the designated image brightness level, and calculating the second exposure parameter conversion coefficient corresponding to each non-designated image brightness level; and establishing the mapping relationship between the image brightness level and the second exposure parameter conversion coefficient according to each non-designated image brightness level and the corresponding second exposure parameter conversion coefficient.

[0072] In this embodiment, the designated light source gear and the designated image brightness gear can be selected from the optional light source gear and the optional image brightness gear as needed. The following takes the setting of 15 optional light source gears, 15 optional image brightness gears, the designated light source gear is set to the highest gear, i.e., gear 15, and the designated image brightness gear is set to the highest gear, i.e., gear 15 as an example to specifically illustrate the calibration process of each mapping relationship. However, the present application is not limited to this, and the number of light source gears and image brightness gears in the endoscope system varies with the actual product. The designated light source gear and the designated image brightness gear can be selected as other gears, as long as the designated gear when calibrating the mapping relationship between the white light camera exposure parameters and the fluorescent camera exposure parameters is consistent with the designated gear of the conversion object when calculating the exposure parameter conversion coefficient. In the following description, the exposure time is represented by T, the exposure gain is represented by G, the exposure amount is represented by E, the light source gear is represented by Degree, and the image brightness gear is represented by aim.

[0073] In an exemplary implementation, the mapping relationship between the calibration light source position and the first exposure parameter conversion coefficient includes the following steps:

[0074] First, the light source gear degree is set to 15 gears, the image brightness gear is set to 15 gears, the exposure time of the white light imaging system at this time is recorded as T_max, and the exposure gain of the white light imaging system is recorded as G_max. At this time, the exposure of the white light camera is E_max = T_max*G_max;

[0075] While keeping the distance between the endoscope and the object unchanged and the image brightness level unchanged, the light source level Degree is sequentially set to different light source levels n (1≤n<15), and the exposure time of the white light imaging system at each light source level is obtained, which is recorded as T_15_n, and the exposure gain of the white light imaging system is recorded as G_15_n;

[0076] For the white light imaging system, since the distance between the endoscope and the object remains unchanged and the image brightness level remains unchanged, the following equation exists:

[0077] T_max*G_max*L_max=T_15_n*G_15_n*L_n (2)

[0078] Wherein, L_max represents the luminous flux when the light source gear is at gear 15 (the luminous flux depends only on the light source gear), which is equal to L_15, and L_n represents the luminous flux when the light source gear is at gear n.

[0079] By transforming formula (2), we can get the following three formulas:

[0080] T_max*G_max=T_15_n*G_15_n*α_n (2.1)

[0081]

[0082] Among them, α_n is the first exposure parameter conversion coefficient corresponding to the nth light source position. According to formula (2.3), the value of each α_n can be calculated. According to the numerical correspondence between α_n and n, a mapping relationship between the light source position and the first exposure parameter conversion coefficient as shown in Table 1 below can be established.

[0083] Table 1 Mapping relationship between light source position and first exposure parameter conversion coefficient

[0084] Degree 1 2 3 … n … 15 α α_1 α_2 α_3 … α_n … α_15

[0085] It can be seen from Table 1 that when the image brightness level is at level 15, under any light source level, its exposure (i.e., the product of exposure time and exposure gain) can be converted into an equivalent exposure under level 15, and the conversion coefficient α_n is the ratio of the luminous flux of the current light source level to the luminous flux of the 15th light source level. Under the condition that the image brightness level is at level 15, the current exposure parameter is multiplied by the first exposure parameter conversion coefficient α corresponding to the current light source level to obtain the equivalent exposure at this time.

[0086] In an exemplary implementation, the mapping relationship between the calibration image brightness level and the second exposure parameter conversion coefficient includes the following steps:

[0087] While keeping the distance between the endoscope and the object unchanged and the light source gear at 15 gears, the image brightness gear aim is set to different image brightness gears m (1≤m<15) in sequence, and the exposure time of the white light imaging system at each image brightness gear is obtained, which is recorded as T_m_15, and the exposure gain of the white light imaging system is recorded as G_m_15. The exposure amount corresponding to the m-th image brightness gear is calculated to be E_m_15=T_m_15*G_m_15; correspondingly, the exposure amount when the image brightness gear is 15 gears and the light source gear is 15 gears is E_max=T_max*G_max;

[0088] When the image brightness level of the white light imaging system changes, but the white light source level remains unchanged at level 15, the luminous flux of the light source does not change either. However, due to the change in the white light image brightness level, the exposure of the white light imaging system changes. For the brightness of the white light image, when the luminous flux of the light source does not change, the image brightness and the exposure are in direct proportion, and the image brightness represents the target brightness in the white light automatic exposure algorithm.

[0089] For the exposure value E_m_15 at the m-th image brightness level, the second exposure parameter conversion coefficient β_m corresponding to the m-th image brightness level can be calculated as:

[0090]

[0091] According to the above formula (3), the second exposure parameter conversion coefficient β_m corresponding to each image brightness level can be calculated. According to the second exposure parameter conversion coefficient corresponding to each image brightness level, a mapping relationship between the image brightness level and the second exposure parameter conversion coefficient as shown in Table 2 below can be established.

[0092] Table 2 Mapping relationship between image brightness level and second exposure parameter conversion coefficient

[0093] aim 1 2 3 … m … 15 β β_1 β_2 β_3 … β_m … β_15

[0094] That is, when the light source gear remains unchanged at 15 gears, for any image brightness gear, the obtained white light camera exposure parameter is multiplied by the second exposure parameter conversion coefficient to obtain an equivalent exposure parameter when the image brightness gear is 15 gears.

[0095] Based on this, in actual applications, the current light source gear is n, the current image brightness gear is m, and the current exposure parameter is E_m_n. After obtaining the first exposure parameter conversion coefficient α_n and the second exposure parameter conversion coefficient β_m according to step S210, step S220 is performed: calculate the equivalent exposure parameter E_white_e = E_m_n*α_n*β_m.

[0096] In an exemplary implementation, the mapping relationship between the calibration equivalent exposure parameters and the fluorescence camera exposure parameters includes the following steps:

[0097] The light source gear Degree is set to 15 gears, the image brightness gear aim is set to 15 gears, the exposure time of the white light imaging system is recorded as T_max, the exposure gain of the white light imaging system is recorded as G_max, and the exposure amount of the white light imaging system is E_max=T_max*G_max. Here, the exposure amount E_max when the light source gear is at the specified light source gear and the image brightness gear is at the specified image brightness gear is defined as the equivalent exposure parameter E_white_e of the white light imaging system.

[0098] Keeping the light source position and the image brightness position unchanged, adjust the distance between the imaging target and the endoscope, and collect a set of calibration data at each distance, each set of calibration data includes the white light camera exposure and the fluorescence camera exposure corresponding to the distance, and in each set of the calibration data, the fluorescence camera exposure is the fluorescence camera exposure manually adjusted by the user, that is, the user manually adjusts the exposure time and exposure gain of the fluorescence camera under each distance condition, and the product of the manually adjusted exposure time and exposure gain is the fluorescence camera exposure.

[0099] Thus, multiple sets of calibration data corresponding to multiple distances are obtained. In the calibration data, the exposure of the white light camera is used as the equivalent exposure parameter E_white_e, and the exposure of the fluorescence camera is used as the target fluorescence camera exposure parameter E_ying. Based on the multiple sets of calibration data, the mapping relationship between the equivalent exposure parameter and the fluorescence camera exposure parameter is fitted, E_ying=f(E_white_e). For example, the mapping relationship between the equivalent exposure parameter and the fluorescence camera exposure parameter is pre-constructed to satisfy the following formulas (4) and (5):

[0100] T_white_e*G_white_e=K*T_ying*G_ying+B (4)

[0101] E_white_e=K*E_ying+B (5)

[0102] Based on multiple sets of calibration data, the values ​​of K and B can be fitted, that is, a definite mapping relationship E_ying=f(E_white_e) is obtained.

[0103] Based on this, in practical applications, the implementation method of the dual-camera endoscope camera exposure method specifically includes: obtaining the current exposure parameter E_m_n, the current light source gear n and the current image brightness gear m of the white light imaging system through step S100, and then obtaining the first exposure parameter conversion coefficient α_n corresponding to the current light source gear n and the second exposure parameter conversion coefficient β_m corresponding to the current image brightness gear m through step S200, and using the following formula (6) to calculate the current equivalent exposure parameter E_white_e:

[0104] E_white_e=E_m_n*α_n*β_m (6)

[0105] Then, the current equivalent exposure parameter is substituted into the mapping relationship E_ying=f(E_white_e) to obtain the current fluorescence camera exposure parameter, and the exposure of the fluorescence camera is controlled based on the current fluorescence camera exposure parameter. In addition, the mapping relationship between the white light camera exposure parameter and the fluorescence camera exposure parameter eliminates the influence of different light source positions and image brightness positions, and realizes that when the distance between the endoscope and the imaging target is fixed, no matter how the light source position and the image brightness position change, the fluorescence image brightness of the fluorescence imaging system remains fixed, thereby improving the imaging brightness stability of the fluorescence imaging system.

[0106] The above content is a further detailed description of the present application in combination with specific preferred implementation methods, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, several simple deductions or substitutions can be made without departing from the concept of the present application, which should be deemed to fall within the scope of protection of the present application.

Claims

1. A dual-camera endoscope camera exposure method, characterized in that: include: Obtain the current white light camera exposure parameters and current brightness parameters of the white light imaging system; Based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, the current white light camera exposure parameter is converted into a current equivalent exposure parameter corresponding to the specified brightness parameter; Based on a mapping relationship between a preset equivalent exposure parameter and a fluorescence camera exposure parameter, obtaining a current fluorescence camera exposure parameter corresponding to the current equivalent exposure parameter; The exposure of the fluorescence imaging system is controlled based on the current fluorescence camera exposure parameters.

2. The dual-camera endoscope camera exposure method according to claim 1, characterized in that: The brightness parameter includes at least one of a light source position and an image brightness position of a white light imaging system.

3. The dual-camera endoscope camera exposure method according to claim 1, characterized in that: Based on a preset exposure parameter conversion algorithm, according to the current brightness parameter, the current white light camera exposure parameter is converted into a current equivalent exposure parameter corresponding to the specified brightness parameter, including the following steps: Based on a preset mapping relationship between brightness parameters and exposure parameter conversion coefficients, a current exposure parameter conversion coefficient corresponding to the current brightness parameter is obtained, and the exposure parameter conversion coefficient corresponding to each brightness parameter is used to convert the exposure parameter of each brightness parameter into an equivalent exposure parameter under the specified brightness parameter; According to the current white light camera exposure parameter and the current exposure parameter conversion coefficient, a current equivalent exposure parameter corresponding to the current white light camera exposure parameter is calculated.

4. The dual-camera endoscope exposure method according to claim 3, characterized in that: Before obtaining the current exposure parameter conversion coefficient corresponding to the current brightness parameter based on the preset mapping relationship between the brightness parameter and the exposure parameter conversion coefficient, the method further includes the following steps: While keeping the distance between the endoscope and the object unchanged, respectively obtain the exposure parameters when shooting under various non-specified brightness parameters and the exposure parameters when shooting under the specified brightness parameters, and calculate the exposure parameter conversion coefficient corresponding to each non-specified brightness parameter; A mapping relationship between the brightness parameter and the exposure parameter conversion coefficient is established according to each non-specified brightness parameter and the corresponding exposure parameter conversion coefficient.

5. The dual-camera endoscope camera exposure method according to claim 3, characterized in that: The current brightness parameter includes the current light source gear and the current image brightness gear of the white light imaging system; the step of obtaining the current exposure parameter conversion coefficient corresponding to the current brightness parameter based on the preset mapping relationship between the brightness parameter and the exposure parameter conversion coefficient includes the following steps: Based on a preset mapping relationship between a light source position and a first exposure parameter conversion coefficient, obtaining a current first exposure parameter conversion coefficient corresponding to the current light source position; Based on a preset mapping relationship between the image brightness level and the second exposure parameter conversion coefficient, a current second exposure parameter conversion coefficient corresponding to the current image brightness level is acquired.

6. The dual-camera endoscope exposure method according to claim 5, characterized in that: Calculating the current equivalent exposure parameter corresponding to the current white light camera exposure parameter according to the current white light camera exposure parameter and the current exposure parameter conversion coefficient comprises the following steps: The current white light camera exposure parameter is multiplied by the current first exposure parameter conversion coefficient and the current second exposure parameter conversion coefficient to obtain the current equivalent exposure parameter.

7. The dual-camera endoscope camera exposure method according to claim 1, characterized in that: Before obtaining the current fluorescence camera exposure parameter corresponding to the current equivalent exposure parameter based on the mapping relationship between the preset equivalent exposure parameter and the fluorescence camera exposure parameter, the method further includes the following steps: Keep the white light imaging system under the specified brightness parameters and calibrate the mapping relationship between the equivalent exposure parameters and the fluorescence camera exposure parameters.

8. The dual-camera endoscope exposure method according to claim 7, characterized in that: The mapping relationship between the calibration equivalent exposure parameters and the fluorescence camera exposure parameters includes the following steps: Keeping the white light imaging system under the specified brightness parameters, adjusting the distance between the imaging target and the endoscope, collecting multiple sets of calibration data, each set of calibration data including the white light camera exposure parameters and the fluorescence camera exposure parameters corresponding to the same distance, and taking the white light camera exposure parameters in each set of calibration data as equivalent exposure parameters; A mapping relationship between the equivalent exposure parameters and the exposure parameters of the fluorescent camera is established based on the multiple groups of calibration data.

9. The dual-camera endoscope exposure method according to claim 8, characterized in that: In each set of calibration data, the fluorescence camera exposure parameters are fluorescence camera exposure parameters manually adjusted by the user.

10. A dual-camera endoscope system, characterized in that: It comprises a white light imaging system, a fluorescent imaging system and an exposure controller, wherein the exposure controller is used to implement the dual-camera endoscope camera exposure method according to any one of claims 1 to 9.

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