Abstract:
Embodiments provide methods, apparatuses, and articles of manufacture for generating frames and changing lens positions based on the analysis of the frames. In one example, a controller coupled to a first camera and a second camera is to change a lens position of the first camera for a second frame based on the identification of a focal target in a frame generated by the second camera.

Description:
BACKGROUND 
     Imaging devices, such as cameras and video recorders, among others, are capable of various exposure settings. An exposure setting may impact the camera&#39;s ability to focus on various targets. For example, an image including an over exposed or under exposed region may prevent the imaging device from determining whether the over exposed or under exposed region includes detail that may be used to adjust the focus of the imaging device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of an apparatus in accordance with an example of the present disclosure; 
         FIG. 2  is an illustration of an apparatus in accordance with an example of the present disclosure; 
         FIGS. 3-6  are example frames having various exposure settings in accordance with the present disclosure; and 
         FIGS. 7-8  are example flow diagrams illustrating processes in accordance with the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In a well exposed frame there may be regions which are either over exposed or under exposed. These regions may or may not obscure items that can be used as focal targets. To determine if these poorly exposed regions of the well exposed frame include valid focal targets, the imaging device may generate a new frame with a different exposure. Once generated, the imaging device may determine whether focal targets are present. This determination, via the generation of another frame, is difficult to accomplish without disturbing various imaging device characteristics such as frame rates, media architecture, and video quality, which includes among other things video brightness and image noise. 
     In the present disclosure, methods, systems, apparatuses, and associated programming are disclosed that enable an imaging device having dual cameras to assess poorly exposed regions for focal targets without disturbing a frame rate, associated video quality, or media architecture of the imaging device. A poorly exposed region is defined as a region of a frame that is either over exposed or under exposed. Over exposed and under exposed regions are regions having an exposure that prevents the imaging device from distinguishing, identifying, and/or utilizing detail within that region as a focal target. A focal target is defined as any detail that may be utilized by the imaging device for the purpose of focusing. Whether a frame is over exposed, under exposed, or correctly exposed may be controlled by an exposure setting of the imaging device. 
     Referring to  FIG. 1 , an apparatus is illustrated in accordance with the present disclosure. The apparatus  100  includes a first camera  102 , a second camera  104 , and a controller  106  capable of executing instructions  108 . The instructions may be computer-readable instructions tangibly embodied on a computer-readable medium, which when executed by a processor or controller, enable a device to perform various operations. 
     The apparatus  100  may be an imaging device such as, but not limited to, a camera, a video camera, a smart phone, a tablet computer, a slate computer, a mobile phone, or any other device capable of generating video and/or still frames. A frame as discussed herein is defined as an image captured by an imaging device. Multiple frames may be iteratively output to form a video. Alternatively, a single frame may be output to form a still image, e.g., a picture. In forming a still image, an imaging device may output multiple frames to a display thereby enabling a user to determine when the still image should be generated. This may be referred to as a “live view” on various imaging devices. 
     The first camera  102  and the second camera  104  may be similar cameras disposed in different locations on apparatus  100 . While disposed in different regions, the first camera  102  and the second camera  104  may capture images of the same scene from their respective locations on the apparatus. The captured images may then be correlated to one another. The first camera  102  and the second camera  104  may be capable of recording video and still images and may have similar or different components, for example, sensors. The first camera  102  and the second camera  104  may both be disposed in a forward-facing manner or a rear-facing manner with respect to a display or user interface (UI) of the imaging device. 
     The controller  106  is coupled to the first camera  102  and the second camera  104 . The controller  106  may be an application specific integrated circuit (ASIC), a controller having a processor configured to process instructions, or a component including logic. The controller  106  may perform functions or processes other than those associated with this disclosure. Additionally, the controller  106  may include other components or be incorporated into other components without deviating from the scope of the disclosure. 
     In one example, the first camera  102  is to generate a first frame and a second frame. The two frames, when viewed together may create the perception of a video or live view. The second camera  104  is to generate an analysis frame. An analysis frame is defined as a frame generated for analysis purposes. The analysis frame may be discarded after use, or alternatively, stored within memory. The controller  106  is to change a lens position and/or an exposure setting of the first camera  102  between the first frame and the second frame based on whether a focal target is identified in the analysis frame. 
     For example, the controller  106  may focus the first camera  102  on an object and control its exposure based on that object. The exposure may result in a frame having a poorly exposed region. While generating the first frame with the first camera  102 , the controller  106  may generate an analysis frame with the second camera  104 . The analysis frame may have an exposure setting that is different than the first camera  102 . The exposure setting of the second camera  104  may correctly expose the poorly exposed region of the first frame, thereby allowing the controller  106  to analyze whether any focal targets are present within the poorly exposed region of the first frame. 
     In generating the analysis frame, the controller  106  may adjust the exposure setting of the second camera  104  resulting in the analysis frame having other under exposed regions or over exposed regions. However, the adjusted exposure setting may enable the controller  106  to determine whether a focal target exists within the poorly exposed region of the first frame. Based on the existence of a focal target, the controller may adjust a lens of the first camera  102  for the second frame. In addition to adjusting the lens of the first camera  102  for the second frame, the controller  106  may also adjust the exposure settings of the first camera  102  to better capture the details of the focal target. In various examples, the exposure adjustment may be minimal. The minimal adjustment may lighten or darken the poorly exposed regions, and conversely lighten or darken the correctly exposed regions. The controller  106  may attempt to achieve a balance between the two regions, or alternatively, may attempt merely to correctly expose the poorly exposed region. 
     The adjustment of the lens and/or exposure settings of the first camera  102  for the second frame may occur without altering a desired frame rate of the first camera  102 . The adjustment may be based on focal targets having a predetermined priority. For example, if a face is determined to be in the poorly exposed region, the controller  106  may determine that the correct focal target is the face and adjust the first camera  102  accordingly. Other focal targets may include objects, faces, smiles, and text, among others. 
     Referring to  FIG. 2 , an apparatus is illustrated in accordance with another example of the present disclosure. The apparatus includes a first camera  202  having a lens  212 , a second camera  204  having a lens  214 , and a controller  206 . The controller  206  is to control exposure settings  210 , among other settings, for the first camera  202  and the second camera  204 . The controller  206  is further to execute instructions  208 . Similar to  FIG. 1 , apparatus  200  may be an imaging device such as, but not limited to, a camera, a video camera, a smart phone, a tablet computer, a slate computer, a mobile phone, or any other device capable of generating video and/or still frames. The instructions may be computer-readable instructions tangibly embodied on a computer-readable medium, which when executed by a processor or controller, enable a device to perform various operations. 
     Lens  212  and lens  214  may be coupled, respectively, to the first camera  202  and the second camera  204 . The lenses  212  and  214  may be configured to focus on various objects disposed at varying distances from the apparatus  200 . The first camera  202  and the second camera  204  may operate in a similar manner to the first and second cameras of  FIG. 1 . Camera  202 , having lens  212 , and camera  204  having lens  214  may be similar or different. For example, camera  202  may incorporate a different or similar sensor in comparison to camera  204 , and likewise, lens  212  may be different or similar to lens  214 . 
     In one example, the controller  206  is to control the first camera to generate a first frame and a second frame. While generating the first frame with the first camera  202 , the controller  206  may control the second camera  204  to generate an analysis frame. The controller  206  may then change a lens position of the lens  212  of the first camera  202  between the first frame and the second frame based on a focal target identified in the analysis frame. The analysis frame may suitably expose a region of the first frame that was poorly exposed in the first frame. 
     To suitably expose a region of the first frame that was poorly exposed, the second camera  204  may alter its exposure setting  210  such that it is different than the first camera  202 . For example, if the exposure setting  210  of the first camera is such that the poorly exposed region is over exposed, thereby appearing predominately white in nature, the exposure setting  210  of the second camera may be set such that the analysis frame is under exposed, thereby bringing the poorly exposed region into a more accurate exposure. 
     In another example, the exposure setting  210  of the first camera may be such that the poorly exposed region is under exposed, thereby appearing predominately black or dark in nature. The exposure setting  210  of the second camera may be set such that the analysis frame is over exposed, thereby bringing the poorly exposed region into a more accurate exposure. In other words, the controller is to adjust an exposure setting  210  of the second camera  204  to enable the second camera  204  and the controller  206  to identify a focal target. 
     The controller  206  may execute the instructions  208  to adjust the various exposure settings  210  of the first camera  202  and the second camera  204 . In adjusting the exposure setting of the second camera  204 , the exposure setting  210  may be determined based on a setting that suitably exposes the poorly exposed region of the first frame generated by the first camera  202 . The suitable exposure setting for this region may result in other poorly exposed regions in the analysis frame. However, this exposure setting may enable the controller  206  to determine whether an appropriate focal target exists in the poorly exposed region. Based on the existence of a focal target, the controller  206  may adjust the lens  212  and/or exposure setting of the first camera  202  for the second frame. The alteration between the first frame and the second frame may be such that a predetermined frame rate is not altered or delayed. That is, generating the first frame and altering the lens position of the first camera  202  for the second frame may include generating the first frame and the second frame at a predetermined frame rate. 
     The controller  206  may determine whether an analysis frame should be generated by the second camera  204  in multiple ways. In one example, the controller  206  may determine an analysis frame is to be generated based on a histogram of the first frame generated by the first camera  202 . If the histogram includes an indication of either an over exposed region or an under exposed region, the controller  206  may generate an analysis frame with the second camera  204 . Alternatively, the controller  206  may receive a command to generate an analysis frame. The command may be in the form of a signal generated in response to a user identifying a poorly exposed frame on a display. For example, a user may tap on a poorly exposed area of the first frame displayed on a touch-sensitive display. In response to the tap, the controller  206  may control the second camera  204  to generate the analysis frame. Other manners of detecting over exposed and under exposed regions are contemplated. 
     Referring to  FIGS. 3-6 , various example frames are illustrated. The example frames may have been generated by an apparatus as described with reference to  FIG. 1  or  2 . As illustrated,  FIG. 3  illustrates a first frame generated by a first camera and  FIG. 4  illustrates a second frame generated by a second camera. The first and second frames having different exposures of the same scene. Likewise,  FIG. 5  illustrates a first frame generated by a first camera and  FIG. 6  illustrates a second frame generated by a second camera. The first and second frames of  FIGS. 5 and 6  having different exposures of the same scene. 
     Referring to  FIGS. 3 and 4 , a first frame  300  and an analysis frame  400  are illustrated, respectively. In  FIG. 3 , a frame  300  is illustrated having a focal target  304  in a region having a suitable exposure  302 . A suitable exposure is an exposure that enables a camera to identify detail associated with the focal target  304 . In other words, the suitable exposure associated with region  302  may vary so long as the focal target  304  may be identified. Given this exposure setting, the first frame may include a poorly exposed region, region  306 . The poorly exposed region  306 , as illustrated is over exposed. An over exposed region may result in the appearance of a merely white region. While delineated with a line separating the two regions  302  and  306 , no such line generally exists; rather, there may be a gradual change in exposure. 
     In response to receipt of frame  300 , or in other examples a user command, a controller may control a second camera to generate a second frame or an analysis frame such as the analysis frame  400  of  FIG. 4 . The controller may alter an exposure setting of the second camera such that it may analyze whether a focal target exists in the poorly exposed region  306  of frame  300 . In altering the exposure setting, the analysis frame may be predominantly under exposed as indicated by the cross-hatched lines in region  402 . The under exposed region may or may not reveal detail associated with the previous focal target  304 . However, the previously over exposed region  306  may now be suitably exposed such that the controller may determine whether a focal target exists. In  FIG. 4 , the suitably exposed region  406  includes a focal target  408 , namely a person. Consequently, in response to a determination that the focal target exits, the controller may alter a lens position and/or an exposure of the first camera and generate a second frame. This alteration of the first camera may result in a second frame focusing on the target  408 , which may occur without deviating from a predetermined frame rate. 
     Referring to  FIGS. 5 and 6  a first frame  500  and an analysis frame  600  are illustrated, respectively. In  FIG. 5 , a frame  500  is illustrated having a focal target  504  in a region having a suitable exposure  502 . The region  502  may have an exposure that enables a camera to determine detail associated with the focal target  504 . In other words, the exposure associated with region  502  may vary so long as the focal target  504  may be identified. Given this exposure setting, the first frame  500  may include a poorly exposed region, region  506 . The poorly exposed region  506 , as illustrated is under exposed. An under exposed region may result in the appearance of a merely black or dark region. While delineated with a line separating the two regions  502  and  506 , no such line generally exists; rather, there may be a gradual change in exposure. 
     In response to receipt of frame  500 , the controller may control a second camera to generate a second frame or an analysis frame  600 , as illustrated in  FIG. 6 . The controller may alter an exposure setting of the second camera such that it may analyze whether a focal target exists in the poorly exposed region  506  of frame  500 . In altering the exposure setting, the frame  600  may be predominantly over exposed. Such an over exposure may result in loss of detail of the original focal target  504 . In some examples, however, the over exposed region may or may not lose detail associated with the focal target  504 . In  FIG. 6 , the suitably exposed region  606  includes a focal target  608 , namely a person. Consequently, in response to a determination that the focal target exits, the controller may alter a lens position and/or an exposure setting of the first camera and generate a second frame. This alteration of the first camera may result in a second frame focusing on the target  608 . The second frame may be generated within a time period determined by a frame rate. 
     Referring to  FIGS. 7 and 8 , flow diagrams are illustrated in accordance with various examples of the present disclosures. The flow diagrams may depict processes that may be executed by devices, for examples those depicted in  FIGS. 1 and 2 . The flow diagrams may also illustrate instructions which may be embodied on a computer readable medium and which may be executable by a processor or controller to enable a device to perform the various operations. While illustrated in order, it should be understood that the various processes are not order dependent unless explicitly stated. 
     Referring now to  FIG. 7 , a process is illustrated in accordance with an example of the present disclosure. The method may begin at  700  and progress to  702  wherein an imaging device may generate a first frame with a first camera. The first camera may utilize an exposure setting that results in a poorly exposed region. The poorly exposed region may be over exposed or under exposed such that any detail within the region is unidentifiable by the imaging device. 
     At  704 , the imaging device may determine by a second camera whether the poorly exposed region includes a focal target. The determination of whether the poorly exposed region includes a focal target may occur simultaneously or sequentially with the generation of the first frame. If a focal target is determined to be within the poorly exposed region, the method may continue to  706 , where the controller of the imaging device may alter a lens focus position and/or an exposure setting of the first camera for a second frame. The lens alteration may be based on the determination that the poorly exposed region includes the focal target. After the alteration, the method may end at  708 . 
     Returning to  704 , if a focal target is not identified in the poorly exposed region of the first frame, the imaging device may generate another frame without altering the lens position of the first camera. The method may then end at  708 . In various examples, ending may include the continued monitoring of frames generated subsequent to the first and second frames. 
     Referring to  FIG. 8 , another example of a flow diagram is illustrated in accordance with the present disclosure. The method may begin at  800  and progress to  802  where an imaging device may generate a first frame with a first camera. The first camera may have an exposure setting that results in a poorly exposed region in the first frame. 
     At  804 , the imaging device may determine whether the poorly exposed region in the first frame is over exposed or under exposed. The determination may be based on an analysis of a data associated with the first frame, for example a histogram, or alternatively, may be determined in response to input from a user. 
     If it is determined that the poorly exposed region in the first frame is over exposed, the process may continue to  806  where the imaging device may generate an under exposed frame with the second camera. The under exposed frame may enable the imaging device, via a controller, to analyze the poorly exposed region of the first frame for focal targets at  808 . If a focal target is identified at  808 , the imaging device may alter the focus of the lens and/or an exposure of the first camera to focus on the focal target identified in the under exposed frame at  810 . Once adjusted, the imaging device may generate a second frame via the first camera, the second frame compensating for the first frame. The method may then end at  814 . 
     Returning to  808 , if no focal target is found in the under exposed frame, the camera may generate the second frame from the first camera without altering the focus of the first camera&#39;s lens and/or exposure. The method may then end at  814 . 
     Returning to  804 , if a determination is made that the poorly exposed region is under exposed, the method may continue to  812 . At  812 , the imaging device may generate an over exposed frame with the second camera. The over exposed frame may enable the imaging device, via a controller for example, to analyze the poorly exposed region of the first frame for focal targets at  808 . If a focal target is identified at  808 , the imaging device may alter the focus of the lens and/or an exposure setting of the first camera to focus on the focal target at  810 . Once focused, the imaging device may generate a second frame via the first camera. The method may end at  814 . 
     Returning to  808 , if no focal target is found in the under exposed frame, the camera may generate the second frame from the first camera without altering the focus and/or an exposure setting of the first. The method may then end at  814 . 
     Returning, again, to  804 , if the first frame generated by the first camera does not include a poorly exposed region, for example, neither an over exposed region or an under exposed region, the method may continue to  814  and end. Ending in various embodiments may include the generation and analysis of additional frames via the first camera the second camera. 
     Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments shown and described without departing from the scope of this disclosure. Those with skill in the art will readily appreciate that embodiments may be implemented in a wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that embodiments be limited only by the claims and the equivalents thereof.