TWI393979B - Photograph system and photograph method thereof - Google Patents

Description

Shooting system and method

The invention relates to a photographing system and method.

In order to reflect the sense of movement of the photos taken, the photographer often uses Radial Blur techniques for shooting and post-processing photos. As shown in FIG. 1, the radial blurring technique can produce a softening blur effect caused by the zoom or rotation of the analog camera, thereby highlighting the portion of the photograph taken and enhancing the sense of motion of the photograph.

There are usually two methods for obtaining radial blurred photos: 1. Changing the focal length during exposure to cause radial blurring; 2. Radically blurring the photographs taken by the image processing software. However, the previous camera required the photographer to manually change the focal length to take a radial blur photo, which requires the photographer to properly match the exposure time and the focal length change time, which is quite difficult to operate. The use of post-processing methods to achieve radial blurring also requires the use of computers and related software, which is very inconvenient and not time-sensitive.

In view of this, it is necessary to provide a photographing system and method that can automatically capture a radial blur effect.

A photographing system includes a photographing device for photographing an image and a zoom controller connected to the photographing device. The photographing device is set with a minimum zoom time, a zoom speed, and a focal length variation range. The zoom controller comprises: a time calculation module, a time comparison module, a speed calculation module, a focal length comparison module and a zoom control module.

The time calculation module is configured to calculate the exposure time suitable for the current ambient brightness by substituting the sensitivity value set by the shooting, the aperture value, and the ambient brightness value sensed by the photographing device into the exposure amount parameter equation.

The time comparison module is configured to compare the exposure time to a minimum zoom time of the camera and three times the minimum zoom time to determine a zoom time during exposure.

The speed calculation module is configured to calculate a zoom speed of the photographing device during the exposure process according to the zoom time determined by the time comparison module and the focal length change value of the photographing device during the exposure process.

The focal length comparison module is configured to compare a difference between a current focal length of the imaging device and a focal length variation range end value of the imaging device with the focal length variation value to determine a zoom direction during exposure.

The zoom control module is configured to perform shooting according to the determined zoom speed and zoom direction to change the focal length of the photographing device during exposure.

A photographing method of a photographing system, wherein the photographing system is configured with a minimum zoom time, a focal length change value, and a focal length change range, the photographing method comprising the steps of: calculating an exposure time; and comparing whether the exposure time is greater than or equal to a minimum preset by the photographing device a zoom time; if the exposure time is greater than the preset minimum zoom time, compare whether the exposure time is greater than or equal to three times the minimum zoom time; if the exposure time is greater than three times the minimum zoom time, determine the exposure The zoom time in the process is one-third of the exposure time; the zoom speed during the exposure is calculated according to the determined zoom time and the focal length change value of the photographing device; Comparing whether the difference between the current focal length of the photographing device and the maximum value of the focal length variation range of the photographing device is greater than the calculated focal length change value.

If the focal length change value is smaller than a difference between a current focal length of the photographing device and a maximum value of the focal length change range, controlling a zoom direction during exposure is toward a focus increase direction; according to the determined zoom speed and zoom direction during the exposure process The focal length of the photographing device is changed to perform photographing.

Compared with the prior art, the photographing system and method provided by the present invention automatically match a reasonable exposure time and zoom time according to the set sensitization value and aperture value, so as to change the focal length position of the photographing device during shooting exposure to capture A photo of the radial blur effect, which reduces the difficulty of shooting with the exposure time and zoom time by manual operation, and avoids the inconvenience caused by post-image processing.

2‧‧‧Photography system

4‧‧‧Photographing device

40‧‧‧ Zoom mechanism

42‧‧‧ imaging lenses

44‧‧‧Image sensor

6‧‧‧ Zoom controller

60‧‧‧Time calculation module

62‧‧‧Time comparison module

64‧‧‧Speed calculation module

66‧‧‧focal length comparison module

68‧‧‧Zoom control module

Figure 1 is a photograph of a radial blur effect.

2 is a hardware structural diagram of a photographing system provided by the present invention.

3 is a flow chart of a photographing method provided by the present invention.

Referring to FIG. 2, the photographing system 2 provided by the present invention includes a photographing device 4 and a zoom controller 6 connected to the photographing device 4.

The imaging device 4 includes a zoom mechanism 40, an imaging lens 42 and an image sensor 44.

The image sensor 44 is configured to convert external light into a digital signal corresponding to the light intensity, which may be a charge coupled device image sensor (CCD) or a complementary metal oxide semiconductor image. Sensor (CMOS, Complementary Metal Oxide Semiconductor).

The zoom mechanism 40 uses a zoom motor as a power source to drive the imaging lens 42 to move along the optical axis of the photographing device 4 to change the imaging focal length of the photographing device 4. Imaging apparatus 4 has a focal length range of the set F ₁ ~ F _2, a F _1, F ₂ are the focal length of the photographing device 4 minimum value and a maximum value of the focal length of the zoom process. In actual use, the focal length variation range F ₁ ~ F ₂ (pull down these upper texts) is divided into several zoom segments, and the zoom motor drives the imaging lens 42 to complete a zoom segment. Is the length L of the zoom segment.

In order to capture a photograph with a radial blur of the imaging means 4 is set to change in focal length during exposure value △ F of the length of a zoom segment L. If the maximum zoom speed of the zoom motor is F _{v max} , the zoom time required to take a radial blur photo is defined as the minimum zoom time F _{t min} , then the minimum zoom time F _{t min} = L / F _{v max} .

The zoom controller 6 is used to control the zoom mechanism 40 to continuously change the focal length of the imaging lens 42 during exposure to form an image of the radial blur effect on the image sensor 44. The zoom controller 6 includes a time calculation module 60, a time comparison module 62, a speed calculation module 64, a focus comparison module 66, and a zoom control module 68.

The time calculation module 60 is configured to calculate the imaging parameters set before the photographing, such as the aperture value F , the sensitivity value S, and the ambient brightness value B _v sensed by the image sensor 44 into the exposure amount parameter equation. Exposure time T in the current external environment.

The exposure parameter equation: A _V + T _V = B _V + S _V is based on the correct exposure conditions, that is, the empirical equation established by the exposure of the image surface on the imaging surface equal to the exposure required for the correct exposure of the photosensitive surface, It is the theoretical basis of automatic exposure control that is common in the industry.

Where A _V = 2log ₂ ( F ), F- line aperture value; T _V = log ₂ (1/ T ), T- system exposure time; S _V = log ₂ (0.3 S ), S- system sensitivity value; B _V =log ₂ ( B /0.3 K ), B _v is the ambient brightness value, B is the ambient brightness, and the K is the empirical constant.

The time comparison module 62 is configured to compare the exposure time T with a minimum zoom time F _{t min of the} imaging device 4 and three times the minimum zoom time F _{t min} .

In general, the exposure time T needs to be at least equal to or less than the minimum zoom time F _{t min} to take a picture with a radial blur effect by changing the focal length during exposure. Otherwise, the exposure has ended when the photographing device 4 has not had time to finish the length L of one zoom segment, so that it is impossible to take a photograph with a radial blur effect. Therefore, the exposure time T is compared with the minimum zoom time F _{t min of the} photographing device 4. When the comparison result is that the exposure time T is less than the minimum zoom time F _{t min} , the time comparison module 62 issues an inability to take a radial blur photo command.

However, if a desired radial blur effect photo is desired, the exposure time T should be equal to three times the zoom time F _t . Therefore, the comparison module 62 also needs to calculate the calculated exposure time T and three times. The minimum zoom time F _{t min} is compared. When the comparison result is that the exposure time T is greater than or equal to the minimum zoom time F _{t min} and less than three times the minimum zoom time F _{t min} , the time comparison module 62 determines the zoom time F _t as the minimum zoom time F _{t Min} . When the exposure time T is greater than three times the minimum zoom time F _{t min} , the time comparison module 62 determines the zoom time F _t to be one-third of the exposure time T.

The speed calculation module 64 calculates the zoom speed F _v of the photographing device 4 during the exposure according to the zoom time F _t determined by the time comparison module 62 and the focal length change value Δ F of the photographing device 4 during the exposure process. .

According to the physical meaning of the zoom speed F _v , F _v = Δ F / F _t = L / F _t . When the exposure time T is greater than or equal to the minimum zoom time F _{t min} and less than three times the minimum zoom time F _{t min} , the zoom time F _t = F _{t min} , so the zoom speed F _v = L / F _t = L / F _{t min} = F _{v max} . When the exposure time is greater than three times the minimum zoom time F _{t min} , the zoom time F _t = 1/3 T , so the zoom speed F _v = L / F _t = 3 L / T .

The focal length comparison module 66 compares the difference between the current focal length F of the imaging device 4 and the focal length variation range F ₁ ~ F _{2 of the} imaging device 4 with the focal length variation value Δ F to determine the exposure process. Zoom direction.

The photographing device 4 is set with a focal length variation range F ₁ to F ₂ . During the shooting, the focal length F of the imaging device 4 is selected within the focal length variation range F ₁ ~ F ₂ . In general, the focus comparison module 66 defaults the zoom direction toward the focus increase direction. For example, when the current focal length F of the photographing device 4 is relatively close to the maximum focal length value F ₂ and the focal length change value Δ F is greater than or equal to the difference between the maximum focal length value F ₂ and the current focal length F , the focal length variation range There is not enough focal length adjustment space in F ₁ ~ F ₂ to allow the camera 4 to increase the focal length during the exposure process. In this case, the focus comparison module 66 determines the zoom direction to be toward the focus reduction direction.

It can be understood that the focal length comparison module 66 can also default the zoom direction toward the focal length reduction direction. And the zoom direction is determined to be toward the focus increase direction when the focal length change value Δ F is greater than or equal to the difference between the current focal length F and the minimum focal length F ₁ .

The zoom control module 68 changes the focal length of the imaging device 4 according to the zoom speed calculated by the speed calculation module 64 and the zoom direction determined by the focal length comparison module 66 to detect radial blur. Photo of the effect.

Please refer to FIG. 3 , which is a flow chart of a photographing method provided by the present invention.

In step S801, a photographing system 2 is provided, which includes a photographing device 4 and a zoom controller 6 connected to the photographing device 4.

The imaging device 4 includes a zoom mechanism 40, an imaging lens 42 and an image sensor 44. The zoom controller 6 includes a time calculation module 60, a time comparison module 62, a speed calculation module 64, a focus comparison module 66, and a zoom control module 68.

Step S802, the time calculating module 60 in accordance with a value B _v ambient brightness measured by the aperture of the set number F, and the photographing apparatus sensitivity value S 4 substituted into equation exposure parameters _{A V + T V = B V} + S _V calculated for the current exposure time T of the external environment, and the exposure time T is transmitted to the time comparison module 62.

In step S803, the time comparison module 62 compares the exposure time T calculated by the time calculation module 60 with the minimum zoom time F _{t min of the} imaging device 4.

In step S804, if the exposure time T is smaller than the minimum zoom time F _{t min} of the photographing device 4, it is explained that the photographing device 4 cannot complete the length L of the at least one zoom segment within the exposure time T. Therefore, the photographing device 4 cannot capture a photograph having a radial blur effect in the outer boundary environment corresponding to the exposure time T. At this time, the time comparison module 62 issues an instruction that the radial blur photo cannot be taken.

Step S805, if the exposure time T is greater than or equal to the minimum zoom time F _{t min of the} photographing device 4, the time comparison module 62 compares the exposure time T with three times the minimum zoom time F _{t min} .

Because when the exposure time T and the zoom time F _t satisfy the relationship: the photograph taken at T = 3 F _t has a better radial blur effect, so the exposure time T is compared with the minimum zoom time F _{t min} of three times To determine if the zoom time F _t can satisfy the condition: T = 3 F _t .

Step S806, if the exposure time T is less than three times the minimum zoom time F _{t min} , the time comparison module 62 determines the zoom time F _t during the exposure process as the minimum zoom time F _{t min} , and determines The zoom time F _{t is} transmitted to the speed calculation module 64.

Step S807, if the exposure time T is greater than or equal to three times the minimum zoom time F _{t min} , the time comparison module 62 determines the zoom time F _t during the exposure process to be one-third of the exposure time T , The determined zoom time F _{t is} transmitted to the speed calculation module 64.

In step S808, the speed calculation module 64 calculates the zoom of the photographing device 4 during the exposure according to the zoom time F _t determined by the time comparison module 62 and the focal length change value Δ F of the photographing device 4 during the exposure process. Speed F _v .

According to the physical meaning of the zoom speed F _v , F _v = Δ F / F _t = L / F _t . When the exposure time T is greater than or equal to the minimum zoom time F _{t min} and less than three times the minimum zoom time F _{t min} , the zoom time F _t = F _{t min} , so the zoom speed F _v = L / F _t = L / F _{t min} = F _{v max} . When the exposure time is greater than three times the minimum zoom time F _{t min} , the zoom time F _t = 1/3 T , so the zoom speed F _v = L / F _t = 3 L / T .

Step S809, the focal length comparison module 66 compares the difference between the current focal length F of the imaging device 4 and the maximum focal length value F ₂ of the focal length variation range F ₁ ~ F ₂ of the imaging device 4, that is, | F ₂ - F | The focal length change value Δ F is compared.

Step S810, if the focal length change value Δ F is greater than or equal to | F ₂ - F |, the focal length comparison module 66 determines the zoom direction during the exposure process toward the focus reduction direction, and determines the determined zoom direction. Transfer to the zoom control module 68.

Step 811, if the focal length change value Δ F is less than | F ₂ - F |, the focal length comparison module 66 determines the zoom direction during the exposure process toward the focus increase direction, and transmits the determined zoom direction. To the zoom control module 68.

In step S812, the zoom control module 68 changes the focal length F of the photographing device 4 during the exposure according to the zoom speed F _v calculated by the speed calculation module 64 and the zoom direction determined by the focus comparison module 66.

Compared with the prior art, the photographing system and method provided by the present invention automatically match a reasonable exposure time and zoom time according to the set sensitization value and aperture value, so as to change the focal length position of the photographing device during shooting exposure to capture A photo with a radial blur effect, which reduces the difficulty of shooting with manual operation and exposure time and zoom time, and avoids the inconvenience caused by post-image processing.

In the following, the embodiments are only used to illustrate the technical solutions of the present invention and are not intended to be limiting, and the present invention will be described in detail with reference to the preferred embodiments. Modifications or equivalents are made without departing from the spirit and scope of the invention.

2‧‧‧Photography system

4‧‧‧Photographing device

40‧‧‧ Zoom mechanism

42‧‧‧ imaging lenses

44‧‧‧Image sensor

6‧‧‧ Zoom controller

60‧‧‧Time calculation module

62‧‧‧Time comparison module

64‧‧‧Speed calculation module

66‧‧‧focal length comparison module

68‧‧‧Zoom control module

Claims (9)

A photographing system including a photographing device for photographing an image, the photographing device being set with a minimum zoom time, a zoom speed, and a focal length variation range, the improvement being that the photographing system further includes a zoom connected to the photographing device The controller includes: a time calculation module, configured to substitute the sensitivity value set before the shooting, the aperture value, and the ambient brightness value sensed by the photographing device into the exposure amount parameter equation to calculate the current ambient brightness. Exposure time; a time comparison module for comparing the exposure time with a minimum zoom time of the camera and three times the minimum zoom time to determine a zoom time during exposure; a speed calculation module for Calculating a zoom speed of the photographing device during the exposure process according to the zoom time determined by the time comparison module and the focal length change value of the photographing device during the exposure process; the focal length comparison module for using the current focal length of the photographing device and photographing The difference between the end values of the focal length variation range of the device is compared with the change in the focal length to determine the exposure Zoom direction of the process; zoom control module for changing the focal length of said imaging means for imaging in the exposure process according to the zoom speed and the zoom direction is determined. The photographing system of claim 1, wherein the time calculation module calculates an exposure time suitable for the current ambient brightness according to the exposure amount parameter equation: A _V + T _V = B _V + S _V , wherein A _V = 2log ₂ ( F ), F- line aperture value; T _V = log ₂ (1/ T ), T- system exposure time; S _V = log ₂ (0.3 S ), S- system sensitivity value; B _V = log ₂ ( B /0.3 K ), B _v is the external environment brightness value, B system external environment average brightness, K system empirical constant. The photographing system of claim 1, wherein the photographing device comprises a zoom mechanism, an imaging lens, and an image sensor. A photographing method of a photographing system, wherein the photographing system is configured with a minimum zoom time, a focal length change value, and a focal length change range, the photographing method comprising the steps of: calculating an exposure time; and comparing whether the exposure time is greater than or equal to a minimum preset by the photographing device a zoom time; if the exposure time is greater than the preset minimum zoom time, compare whether the exposure time is greater than or equal to three times the minimum zoom time; if the exposure time is greater than three times the minimum zoom time, determine the exposure The zoom time in the process is one-third of the exposure time; the zoom speed during the exposure is calculated according to the determined zoom time and the focal length change value of the photographing device; the current focal length of the photographing device and the focal length of the photographing device are changed to the largest range. Whether the difference value is greater than the calculated focal length change value; if the focal length change value is smaller than the difference between the current focal length of the photographing device and the maximum value of the focal length change range, controlling the zoom direction during the exposure to increase toward the focal length Direction; according to the determined zoom speed and zoom direction Changing the focal length of light during the photographing of the photographing apparatus. The photographing method of claim 4, wherein if the exposure time is less than the minimum zoom time, an instruction to shoot a radial blur effect is issued. The photographing method of claim 4, wherein if the exposure time is greater than or equal to three times the minimum zoom time, the zoom speed is equal to three times the focal length change value divided by the exposure time. The photographing method of claim 4, wherein the zoom controller zooms during exposure if the exposure time is greater than or equal to the minimum zoom time and less than three times the minimum zoom time The time is determined as the minimum zoom time, which is equal to the focus change value divided by the minimum zoom time. The photographing method of claim 4, wherein if the focal length change value is greater than or equal to a difference between a current focal length of the photographing device and a maximum value of the focal length variation range, controlling a zoom direction during exposure is oriented The focal length is reduced in direction. The shooting method according to claim 4, wherein the formula for calculating the exposure time is: A _V + T _V = B _V + S _V , wherein A _V = ₂ log ₂ ( F ), F-type aperture Value; T _V = log ₂ (1/ T ), T- system exposure time; S _V = log ₂ (0.3 S ), S- system sensitivity value; B _V = log ₂ ( B / 0.3 K ), B _v is outside Ambient brightness value, B system external environment average brightness, K system empirical constant.