TWI889057B - Image capturing device and image capturing method thereof - Google Patents

Abstract

An image capturing device and an image capturing method thereof are provided. The image capturing device includes a plurality of infrared light sources, an image capturer and a controller. The infrared light sources respectively have a plurality of light types. The image capturer is configured to capture image information. The controller is coupled to the infrared light sources and the image capturer. The controller turns on or turns off each of the infrared light sources according to light intensity information, wherein at least one of the infrared light sources is turned on during an image capturing operation.

Description

Image shooting device and image shooting method thereof

The present invention relates to an image capturing device and an image capturing method thereof, and in particular to an image capturing device and an image capturing method thereof applied to infrared light images.

In order to improve the safety of life, image capture devices with night vision functions are commonly used in life. In today's technology, the body illumination range of image capture devices with night vision functions (such as secret recorders) is usually limited to the center of the field of view. The purpose of this setting is to provide a longer illumination distance. However, in secret recorders with a wide viewing angle shooting function, the surrounding area of the image is often dark and without an image, and it is impossible to shoot the same field of view as in the daytime state. In addition, the infrared light sources commonly used in known secret recorders are all light sources with highly directional light shapes, so that in night mode, when the object being photographed is too close, it will cause excessive exposure of infrared lighting, making the captured image unreadable.

The present invention provides an image shooting device and an image shooting method thereof, which can effectively improve the quality of the captured image.

The image capturing device of the present invention includes a plurality of infrared light sources, an image capturer and a controller. The infrared light sources have different light types. The image capturer is used to capture image information. The controller is coupled to the infrared light sources and the image capturer. The controller turns on or off each infrared light source according to the light intensity information, wherein during the image capturing action, at least one of the infrared light sources is turned on.

The image capturing method of the present invention includes: providing a plurality of infrared light sources, wherein the infrared light sources have a plurality of different light types; providing an image capturer to capture image information; and providing a controller to turn on or off each infrared light source according to the light intensity information, wherein during the image capturing action, at least one of the infrared light sources is turned on.

Based on the above, the image capturing device of the present invention is provided with a plurality of infrared light sources having a plurality of different light shapes, and determines the number of infrared light sources to be turned on according to the light intensity information of the shooting scene. In this way, when shooting infrared images, infrared light sources of different light shapes can be activated according to the state of the shooting scene to perform adaptive fill-in light. Moreover, when the light intensity is too high, some infrared light sources can be turned off to prevent the possibility of overexposure, thereby improving the quality of the captured image.

Please refer to FIG. 1 , which shows a schematic diagram of an image capturing device according to an embodiment of the present invention. The image capturing device 100 may have a night vision function. The image capturing device 100 includes a plurality of infrared light sources 111, 112, an image capture device 120, and a controller 130. The infrared light sources 111, 112 may have a plurality of different light types, respectively. To further explain, the infrared light sources 111, 112 may have different light beam transmission ranges, respectively. For example, the infrared light source 111 may be an infrared light emitting diode (IR LED) with wide-angle light type illumination, and the infrared light source 112 may be an infrared light emitting diode with a high directional light type. Among them, the light beam transmission range of the infrared light source 111 may be larger than the light beam transmission range of the infrared light source 112.

The image capture device 120 can be an infrared camera with infrared image capturing capability. When the image capture device 120 performs an image capturing action, the infrared light sources 111 and 112 can be activated to provide the light required for the image capturing action. The image capture device 120 can perform a light intensity detection action of the shooting scene and thereby obtain light intensity information. On the other hand, the image capture device 120 can also set the exposure setting time during the image capturing action according to the detected light intensity information. Among them, when the shooting scene has relatively high light intensity information, the image capture device 120 can set a relatively low exposure setting time. When the captured scene has relatively low light intensity information, the image capture device 120 may set a relatively high exposure setting time.

In addition, the controller 130 is coupled to the infrared light sources 111, 112 and the image capture device 120. The controller 130 can receive the light intensity information obtained by the image capture device 120, and control the on or off state of the infrared light sources 111, 112 according to the light intensity information. In detail, when the image capture device 100 is to perform an image capture action, the controller 130 can first activate the infrared light source 111 and enable the infrared light source 111 to provide an illumination beam. Then, the controller 130 can receive the light intensity information and compare the light intensity information with a preset first threshold. When the light intensity information is not greater than the preset first threshold, the controller 130 can determine that the light intensity of the infrared light in the shooting scene is insufficient, and accordingly turn on the infrared light source 112. Here, based on the fact that the infrared light source 112 is a light source with a highly directional light type, it can effectively perform fill light operation on a specific area of the image shooting scene of the image capture device 120. In this way, the image capture device 120 can obtain a relatively high-definition shooting image.

In contrast, if the infrared light source 111 is turned on and the infrared light source 112 is turned off, when the controller 130 determines that the light intensity information is not greater than the preset first threshold, the infrared light source 111 can be maintained turned on and the infrared light source 112 can be turned off, and the image capture device 120 can capture images and generate image information.

On the other hand, if both the infrared light sources 111 and 112 are turned on, the controller can further compare the light intensity information obtained by the image capture device 120 with a preset second threshold, wherein the second threshold is greater than the first threshold. When the light intensity information is greater than the preset second threshold, the controller 130 can determine that the light intensity of the shooting scene at this time is too high, and if the image capture action is performed, overexposure may occur. Therefore, correspondingly, the controller 130 can turn off the infrared light source 112, maintain the infrared light source 111 turned on, and then make the image capture device 120 perform the image capture action.

Please refer to FIG. 1, FIG. 2A and FIG. 2B for the following. FIG. 2A and FIG. 2B are schematic diagrams showing different implementations of the image capturing action of the image capturing device of the embodiment of the present invention. In FIG. 2A, in the night vision mode, when performing the image capturing action of the wide-range vision and close-up shooting scene, the controller 130 can activate the infrared light source 111 and turn off the infrared light source 112. The infrared light source 111 provides a wide-angle light type illumination beam, so that the image capturer 120 can obtain clear image information 210.

In FIG. 2B , in the night vision mode, when performing an image capture operation of a relatively long-distance shooting scene, the controller 130 can activate both the infrared light sources 111 and 112. In addition to providing a wide-angle infrared illumination beam through the infrared light source 111, the infrared light source 112 provides a high-directional infrared illumination beam to supplement the infrared illumination brightness required for the relatively long-distance object, so that the image capture device 120 can obtain clear image information 220.

Please refer to FIG. 1 again. In other embodiments of the present invention, the image capturing device 100 may have three or more infrared light sources. Under such conditions, the controller 130 may pre-set multiple thresholds corresponding to the number of infrared light sources. By comparing the light intensity information with the multiple thresholds, the range of the infrared light intensity in the shooting scene is determined, and the number of infrared light sources to be turned on is determined. It is worth mentioning that regardless of the size of the light intensity information, the infrared light source 111 is always turned on during the image capturing action.

Incidentally, the controller 130 may be built into the image capture device 120 or disposed outside the image capture device 120. In addition, the controller 130 may be a processor with computing capabilities. Alternatively, the controller 130 may be designed using a hardware description language (HDL) or any other digital circuit design method known to those skilled in the art, and implemented as a hardware circuit using a field programmable gate array (FPGA), a complex programmable logic device (CPLD), or an application-specific integrated circuit (ASIC).

Please refer to FIG. 3, which is a flow chart of the image capturing method of the image capturing device of the embodiment of the present invention. In step S310, the night mode of the image capturing device can be activated. In step S320, the infrared light (IR) light source 1 is turned on. Then, in step S330, the image capturing device can perform a light intensity detection operation of the shooting scene and thereby obtain light intensity information. In step S340, the image capturing device can determine whether the light intensity of the shooting scene is too low based on the light intensity information, and when the image capturing device determines that the light intensity of the shooting scene is too low, step S350 is executed to turn on the IR light source 2 while maintaining the IR light source 1 turned on. In step S340, the image capturing device can determine whether the light intensity of the shooting scene is too low based on whether the light intensity information is not greater than a preset threshold. In addition, the IR light source 1 and the IR light source 2 can have different light types.

In step S360, the image capture device can continuously detect the light intensity of the shooting scene and obtain dynamically changing light intensity information. In step S370, if the image capture device determines that the light intensity of the shooting scene is too high, the IR light source 2 can be turned off in step S380 while maintaining the IR light source 1 turned on. In step S370, the image capture device can determine whether the light intensity of the shooting scene is too high based on whether the light intensity information is greater than another preset threshold. The preset threshold in step S340 can be less than the other threshold in step S370.

It is worth mentioning that the above thresholds can be set by the designer according to the minimum exposure intensity required by the image capture device and the maximum exposure intensity that can be accepted. Among them, a relatively low threshold is used to ensure that the image capture device can perform image capture operations at infrared light intensities above the minimum exposure intensity. A relatively high threshold is used to ensure that the image capture device does not produce overexposure when performing image capture operations.

Please refer to Figure 4 below, which shows a flow chart of another implementation of the image capture method of the image capture device of the embodiment of the present invention. Among them, in step S410, the night mode of the image capture device can be activated. In step S420, the infrared (IR) light source 1 is turned on. Then, in step S430, the image capture device can perform an image information capture action. In step S440, the image capture device can perform an automatic exposure action. In step S450, the image capture device can detect the light intensity information of the shooting scene and determine whether the light intensity information is greater than the threshold A. If the image capturing device determines in step S450 that the light intensity information is not greater than the threshold value A, step S451 may be executed. Conversely, if the image capturing device determines in step S450 that the light intensity information is greater than the threshold value A, step S460 may be executed.

In step S451, the image capture device can further determine whether the exposure setting time at this time is the maximum value. If the exposure setting time of the image capture device at this time is the maximum value, step S452 can be executed to determine whether the IR light source 2 has been turned on. If the IR light source 2 has been turned on, the image capture device can capture the image information of the night mode through step S470. Conversely, if in step S452, the image capture device determines that the IR light source 2 is not turned on, the image capture device can execute step S453 to turn on the IR light source 2 and return to step S440.

Please note that the image capture device can adjust the exposure setting time according to the current light intensity of the shooting scene. When the light intensity is relatively low, the image capture device can adjust the exposure setting time higher to increase the exposure when the image is captured. Conversely, when the light intensity is relatively high, the image capture device can adjust the exposure setting time lower to increase the exposure when the image is captured.

In contrast, if the exposure setting time of the image capturing device is not the maximum value in step S451, the process returns to step S440.

In step S460, the image capture device can determine whether overexposure is likely to occur by determining whether the light intensity of the scene being captured is too high. If in step S460, the image capture device determines that overexposure will not occur, step S470 can be executed to capture image information in night mode. Conversely, if in step S460, the image capture device determines that overexposure will occur, step S461 can be executed.

In step S461, the image capturing device may further determine whether the exposure setting time at this time is the minimum value. If the determination result is yes, the IR light source 2 may be turned off. Conversely, if the determination result of step S461 is no, the process may return to step S440.

Please refer to FIG. 5 below, which is a flow chart of an image capturing method according to another embodiment of the present invention. In step S510, a plurality of infrared light sources are provided, wherein the infrared light sources have different light types. In step S520, an image capturer is provided to capture image information. In step S530, a controller is provided to turn on or off each infrared light source according to the light intensity information, wherein during the image capturing operation, at least one of the infrared light sources is turned on.

The implementation details of the above steps S510-S530 have been described in detail in the aforementioned implementation and implementation method, and will not be elaborated here.

In summary, the image capturing device of the present invention controls the infrared light source to be turned on according to the light intensity of the shooting scene. Thus, the image capturing device can dynamically adjust the on or off state of infrared light sources with different light shapes according to the actual conditions of the shooting scene, which can effectively improve the quality of the captured image.

100: Image capture device 111, 112: Infrared light source 120: Image capture device 130: Controller S310~S370, S410~S470, S510~S530: Steps

FIG. 1 is a schematic diagram of an image capturing device of an embodiment of the present invention. FIG. 2A and FIG. 2B are schematic diagrams of different implementations of the image capturing action of the image capturing device of the embodiment of the present invention, respectively. FIG. 3 is a flow chart of the image capturing method of the image capturing device of the embodiment of the present invention. FIG. 4 is a flow chart of another implementation of the image capturing method of the image capturing device of the embodiment of the present invention. FIG. 5 is a flow chart of the image capturing method of another embodiment of the present invention.

100: Image capture device 111, 112: Infrared light source 120: Image capture device 130: Controller

Claims (10)

An image capturing device includes: A plurality of infrared light sources, each having a plurality of different light types; An image capturer, for capturing image information; and A controller, coupled to the infrared light sources and the image capturer, the controller turns on or off each infrared light source according to light intensity information, wherein during the image capturing action, at least one of the infrared light sources is turned on, wherein the light beam transmission ranges of the infrared light sources are different, wherein the infrared light sources include a first infrared light source and a second infrared light source, the light beam transmission range of the first infrared light source is greater than the light beam transmission range of the second infrared light source. An image capture device as described in claim 1, wherein the image capture device is used to sense the light intensity information, and the controller is used to: turn on the first infrared light source; and turn on the second infrared light source according to the light intensity information. The image capture device as described in claim 2, wherein the controller is further used to: When the light intensity information is less than a first threshold, turn on the second infrared light source. The image capture device as described in claim 3, wherein the controller is further used to: When the light intensity information is not less than the first threshold, determine whether the light intensity information is greater than a second threshold; and When the light intensity information is not greater than the second threshold, enable the image capturer to capture the image information, wherein the first threshold is less than the second threshold. The image capture device as described in claim 4, wherein the controller is further used to: When the light intensity information is greater than the second threshold value, turn off the second infrared light source. A method for image capture includes: providing a plurality of infrared light sources, wherein the infrared light sources have different light types; providing an image capturer to capture image information; and providing a controller to turn on or off each of the infrared light sources according to light intensity information, wherein at least one of the infrared light sources is turned on during the image capture operation, wherein the light beam transmission ranges of the infrared light sources are different, wherein the infrared light sources include a first infrared light source and a second infrared light source, and the light beam transmission range of the first infrared light source is greater than the light beam transmission range of the second infrared light source. The image capturing method as described in claim 6 further comprises: Turning on the first infrared light source; and Turning on the second infrared light source according to the light intensity information. The image capturing method as described in claim 7, wherein the step of turning on the second infrared light source according to the light intensity information and the exposure setting time includes: When the light intensity information is less than a first threshold, turning on the second infrared light source. The image capturing method as described in claim 8 further includes: When the light intensity information is not less than the first threshold, determining whether the light intensity information is greater than a second threshold; and When the light intensity information is not greater than the second threshold, causing the image capturer to capture the image information, wherein the first threshold is less than the second threshold. The image capturing method as described in claim 9 further includes: When the light intensity information is greater than the second threshold, turning off the second infrared light source.

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