Electronic device having dynamically controlled flashlight for image capturing and related control method

Abstract

A control method of an electronic device with an image capture function is provided. The control method includes the following steps: detecting a distance between the electronic device and at least one subject in a scene to be captured to generate a distance detection result; and utilizing a controller for referring to the distance detection result to determine whether to turn on or turn off a flashlight of the electronic device to capture the scene.

What is claimed is: 
     
         1 . A control method of an electronic device with an image capture function, comprising:
 obtaining a plurality of images associated with a scene, wherein the plurality of images includes a left eye preview image and a right eye preview image that constitute a stereoscopic image;   detecting a distance between the electronic device and at least one subject in the scene based on the plurality of images;   generating a distance detection result based on the detected distance; and   determining, via a controller, whether to turn on or turn off a flashlight of the electronic device to capture the scene based on the distance detection result.   
     
     
         2 . The control method of  claim 1 , further comprising:
 determining a brightness value associated with an environmental brightness of the scene based on at least one of the plurality of images.   
     
     
         3 . The control method of  claim 1 , wherein determining whether to turn on or turn off the flashlight comprises:
 checking if a capture trigger event occurs; and   when it is detected that the capture trigger event occurs, referring to the distance detection result to turn on or turn off the flashlight to capture the scene.   
     
     
         4 . The control method of  claim 1 , wherein detecting the distance between the electronic device and the at least one subject in the scene based on the plurality of images comprises:
 calculating disparity information and/or depth information of at least a part of the plurality of images to determine the distance.   
     
     
         5 . The control method of  claim 4 , wherein said at least a part of the plurality of images comprises a region-of-interest (ROI) of the plurality of images. 
     
     
         6 . The control method of  claim 1 , wherein when at least a part of the plurality of images comprises a human face, detecting the distance between the electronic device and the at least one subject in the scene based on the plurality of images comprises:
 performing face detection to generate a face detection result, and using the face detection result to determine the distance.   
     
     
         7 . The control method of  claim 1 , wherein determining whether to turn on or turn off the flashlight comprises:
 determining whether the distance is within a predetermined range according to the distance detection result.   
     
     
         8 . The control method of  claim 7 , wherein when it is determined that the distance is within the predetermined range, determining, via the controller, to turn on the flashlight, and when it is determined that the distance is beyond the predetermined range, determining, via the controller, to turn off the flashlight. 
     
     
         9 . The control method of  claim 7 , wherein the predetermined range is determined according to at least one of flashlight illumination ability, an aperture size, lens parameters and optical sensitivity of the electronic device. 
     
     
         10 . The control method of  claim 1 , further comprising adjusting light intensity of the flashlight after determining to turn on the flashlight. 
     
     
         11 . A control method of an electronic device with an image capture function, comprising:
 obtaining a plurality of images associated with a scene, wherein the plurality of images includes a pair of images generated by dividing incident light based on phase detection;   detecting a distance between the electronic device and at least one subject in the scene based on the plurality of images;   generating a distance detection result based on the detected distance; and   determining, via a controller, whether to turn on or turn off a flashlight of the electronic device to capture the scene based on the distance detection result.   
     
     
         12 . The control method of  claim 11 , wherein determining whether to turn on or turn off the flashlight comprises:
 checking if a capture trigger event occurs; and   when it is detected that the capture trigger event occurs, referring to the distance detection result to turn on or turn off the flashlight to capture the scene.   
     
     
         13 . The control method of  claim 11 , wherein detecting the distance between the electronic device and the at least one subject in the scene based on the plurality of images comprises:
 calculating disparity information and/or depth information of at least a part of the plurality of images to determine the distance.   
     
     
         14 . The control method of  claim 11 , wherein determining whether to turn on or turn off the flashlight comprises:
 determining whether the distance is within a predetermined range according to the distance detection result.   
     
     
         15 . The control method of  claim 14 , wherein when it is determined that the distance is within the predetermined range, determining, via the controller, to turn on the flashlight, and when it is determined that the distance is beyond the predetermined range, determining, via the controller, to turn off the flashlight. 
     
     
         16 . The control method of  claim 14 , wherein the predetermined range is determined according to at least one of flashlight illumination ability, an aperture size, lens parameters and optical sensitivity of the electronic device. 
     
     
         17 . The control method of  claim 11 , further comprising adjusting light intensity of the flashlight after determining to turn on the flashlight. 
     
     
         18 . An electronic device, comprising:
 a flashlight configured to illuminate a scene to be captured;   an image capturing system configured to:
 obtain a plurality of images associated with a scene, wherein the plurality of images includes a left eye preview image and a right eye preview image that constitute a stereoscopic image, or a pair of images generated by dividing incident light based on phase detection; 
 detect a distance between the electronic device and at least one subject in the scene based on the plurality of images; and 
 generate a distance detection result based on the detected distance; and 
   a controller, coupled to the flashlight and the image capturing system, the controller is configured to determine whether to turn on or turn off the flashlight to capture the scene based on the distance detection result.   
     
     
         19 . The electronic device of  claim 18 , wherein an image capturing module in the image capturing module is a stereo camera. 
     
     
         20 . The electronic device of  claim 18 , wherein an image capturing module in the image capturing module is a camera having color pixel and phase detection pixel on image sensor.