Patent Publication Number: US-11643016-B2

Title: Rearview camera field of view with alternative tailgate positions

Description:
RELATED APPLICATIONS 
     This application claims the priority benefit of U.S. Provisional Patent Application No. 63/139,641, filed Jan. 20, 2021, entitled “REARVIEW CAMERA FIELD OF VIEW WITH ALTERNATIVE TAILGATE POSITIONS,” the entire contents of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to systems and methods for rear-view camera systems for a vehicle. 
     SUMMARY 
     In various implementations, systems and methods described herein provide camera systems with multiple cameras positioned with at least partially overlapping fields of view. In some implementations, the camera system includes a first camera mounted on a tailgate of a pick-up truck such that the field of view of the first camera relative to the vehicle changes from a first field of view when the tailgate is closed to a second field of view when the tailgate is opened. The system also includes a second camera mounted on the pickup truck with a rearward-facing field of view. For example, in some implementations, the second camera is mounted on a cabin of the pickup truck and the tailgate of the pickup truck partially obstructs the field of view of the second camera when the tailgate is closed. The system also includes a tailgate position sensor. An electronic controller determines a position of the tailgate sensor based on the output of the tailgate position sensor and identifies a portion of the field of view of the second camera that is obstructed by the tailgate based on the determined position of the tailgate. The electronic controller is further configured to fuse image data from the first camera and image data from the second camera to produce an output image by replacing the portion of the image data from the second camera that is obstructed by the tailgate with corresponding image data from the first camera causing the tailgate to appear at least partially transparent in the output image. In some implementations, the system is further configured to display the output image on a user display positioned within the cabin of the pickup truck (e.g., in response to determining that the pickup truck is being operated in reverse). 
     In some implementations, the tailgate sensor is a device or combination of devices configured to determine whether the tailgate is in a closed/“up” position or an open/“down” position. In some implementations, the tailgate sensor may include a contact sensor, a proximity sensor, and/or a camera (e.g., the second camera mounted on the pickup truck with the field of view that is partially obstructed by the tailgate). 
     In some implementations, the second field of view of the first camera partially includes a portion of the field of view of the second camera that is obstructed by a bottom surface of a bed of the pickup truck and, in response to determining that the tailgate is in the opened position, the electronic controller is configured to fuse the image data from the first camera and the image data from the second camera to cause at least a portion of the bottom surface of the bed of the pickup truck to appear at least partially transparent in the output image. 
     In some implementations, the camera system further includes a third camera mounted on a side mirror of the vehicle with a field of view that includes a portion of the field of view of the second camera that is obstructed by a first side wall of the pickup truck bed. The electronic controller is configured to generate the output image by fusing image data from the second camera and the third camera to cause at least a portion of the first side wall of the pickup truck bed to appear at least partially transparent in the output image. In some implementations, the camera system also includes a fourth camera mounted on a second side mirror of the vehicle opposite the third camera and the electronic controller is configured to generate the output image by fusing image data from the second camera and the fourth camera to cause at least a portion of a second side wall of the pickup truck bed to appear at least partially transparent in the output image. 
     In some implementations, the camera system is further configured to determine when the field of view of the second camera is partially obstructed by a load in the bed of the pickup truck and to fuse image data to plurality of cameras to cause the load to appear at least partially transparent in the output image. In some implementations, the electronic controller is configured to cause the load to appear transparent by replacing at least a portion of the image data from the second camera that is obstructed by the load with corresponding image data from another camera of the camera system that is not obstructed by the load. For example, in some implementations, when the electronic controlled determines, based on the output of the tailgate position sensor, that the tailgate is in a closed position and determines, based on an output of a load sensor, that a load is positioned within the bed of the pickup truck, the electronic controller replaces the portion of the image data from the second camera that is obstructed by the load with corresponding image data from the first camera. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an elevation view of a pickup truck equipped with a rearward-facing camera system according to one embodiment and the fields of view of the cameras in the camera system when the tailgate of the pickup truck is in a closed position. 
         FIG.  2    is an elevation view of the pickup truck of  FIG.  1    and the fields of view of the cameras when the tailgate of the pickup truck is in an open position. 
         FIG.  3    is a partially transparent schematic view of the tailgate and components of the system mounted thereon in the example of  FIG.  1   . 
         FIG.  4 A  is an elevation view of the pickup truck of  FIG.  1    with an alternative configuration of a tailgate camera and the field of view of the tailgate camera when the tailgate is in the closed position. 
         FIG.  4 B  is an elevation view of the pickup truck of  FIG.  1    with the alternative configuration of the tailgate camera of  FIG.  4 A  and the field of view of the tailgate camera when the tailgate is in the open position. 
         FIG.  5    is an elevation view of the pickup truck of  FIG.  1    configured to include a side mirror camera and showing the field of view of the side mirror camera. 
         FIG.  6    is a block diagram of a control system for the camera system illustrated in the examples of  FIGS.  1  through  5   . 
         FIG.  7    is a flowchart of a method of operating the camera system using the control system of  FIG.  6    to produce an output image. 
         FIGS.  8 A and  8 B  are a first example of image data captured by a rear-facing cabin-mounted camera and the output image displayed by the camera system when the tailgate of the pickup truck is in a closed position. 
         FIGS.  9 A and  9 B  are a second example of image data captured by the rear-facing cabin-mounted camera and the output image displayed by the camera system when the tailgate of the pickup truck is in an open position. 
         FIGS.  10 A and  10 B  are a third example of image data captured by the rear-facing cabin-mounted camera and the output image displayed by the camera system when a load positioned within the bed of the pickup truck partially obstructs the field of view of the rear-facing cabin-mounted camera. 
         FIGS.  11 A and  11 B  are a fourth example of image data captured by the rear-facing cabin-mounted camera and the output image displayed by the camera system when the tailgate is in the open position. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. 
       FIGS.  1  and  2    illustrate an example of a pickup truck  101  equipped with a rearward-facing camera system. The camera system in the example of  FIG.  1    includes a first camera  103  (referred to herein as a “tailgate camera”) mounted on a rear-lift door (i.e., a tailgate  105 ) of the pickup truck  101 , a tailgate position sensor  107 , and a second camera  109  (referred to herein as a “cabin camera”) mounted on the cabin of the pickup truck. 
     The tailgate position sensor  107  is configured to detect a position of the tailgate  105  and to output a signal indicative of the current position of the tailgate  105 . In the example of  FIGS.  1  and  2   , the tailgate position sensor  107  is mounted to the tailgate  105  and a corresponding second sensor component  107 ′ is mounted to a sidewall of the pickup truck. The second sensor component is positioned such that, when the tailgate  105  is in the closed positioned (as illustrated in  FIG.  1   ), the tailgate position sensor  107  &amp; the second sensor component  107 ′ are closely positioned relative to each other and, conversely, when the tailgate  105  is in the open position (as illustrated in  FIG.  2   ), the tailgate position sensor  107  is moved away from the second sensor component  107 ′. Accordingly, the tailgate position sensor  107  is configured to detect whether the second sensor component  107 ′ is positioned within a detectable distance from the tailgate position sensor  107 , to generate a first output signal in response to determining that the second sensor component  107 ′ is positioned within the detectable distance, and to generate a different second output signal in response to determining that the second sensor component  107 ′ is not positioned within the detectable distance. Accordingly, in this example, the tailgate position sensor  107  may include, for example, a contact sensor or a proximity sensor. 
     In various different implementations, the tailgate position sensor may be mounted on the tailgate  105 , the sidewall of the pickup truck bed, or both. In some implementations, the tailgate position sensor  107  may include a latch sensor configured to detect when a tailgate latching mechanism is engaged (e.g., coupling the tailgate  105  to the side wall of the pickup truck in the closed position). Furthermore, in some implementations, the tailgate position sensor  107  may be configured to utilize other types of sensors including, for example, non-contact sensing technologies such as radar or lidar. Alternatively, in some implementations, a camera (e.g., the cabin camera  109 ) may be configured to provide the functionality of the tailgate position sensor  107  by capturing image data including all or part of the tailgate  105  and then applying image processing techniques to determine a position of the tailgate  105  based on the captured image data. 
     As illustrated in  FIGS.  1  and  2   , because the tailgate camera  103  is mounted on the tailgate  105  of the pickup truck  101 , the field of view of the tailgate camera  103  changes when the position of the tailgate  105  is altered. As shown in  FIG.  1   , when the tailgate  105  is in the closed position, the field of view of the tailgate camera  103  (i.e., the first field of view) includes a lower field of view  111  including an area directly behind the tailgate  105  and an upper field of view  113  including an area above the tailgate  105 . As shown in  FIG.  2   , when the tailgate  105  is in the open position, the field of view of the tailgate camera  103  (i.e., the second field of view) is similarly altered such that the upper field of view  113  generally includes an area behind the pickup truck  101  while the lower field of view  111  is generally downward facing and includes an area below the tailgate  105 . 
     As illustrated in  FIGS.  1  and  2   , because the cabin camera  109  is mounted to a fixed location on the pickup truck  101 , the field of view  115  of the cabin camera  109  remains stationary regardless of the position of the tailgate  105 . The field of view  115  of the cabin camera  109  in this example extends behind the cabin of the pickup truck  101  and includes at least a portion of the interior of the bed of the pickup truck  101  and an area behind the pickup truck  101 . The field of view  115  of the cabin camera  109  at least partially overlaps with the field of view  111 ,  113  of the tailgate camera  103  and, as illustrated in the example of  FIGS.  1  and  2   , the field of view of the cabin camera  109  is at least partially obstructed by the tailgate  105  when the tailgate  105  is in the open position ( FIG.  2   ) and when the tailgate  105  is in the closed position ( FIG.  1   )—although, the extent to which the field of view  115  is obstructed is decreased when the tailgate  105  is in the open position. 
     In the example of  FIGS.  1  and  2    (and as illustrated in further detail in  FIG.  3   ), the tailgate camera  103  includes an image sensing component  121  (e.g., a CCD array) positioned with a central imaging axis  123  oriented at an oblique angle α (e.g., 45°) relative to the outer surface of the tailgate  105 . In other implementations, the orientation angle of the central imaging axis  123  may be configured differently. For example,  FIGS.  4 A and  4 B  illustrates an implementation in which the central imaging axis  123  of the tailgate camera  103  is oriented at 90° relative to the outer surface of the tailgate  105 . Accordingly, when the tailgate  105  is in the closed position, the field of view of the tailgate camera  103  (i.e., the first field of view) includes an area directly behind the tailgate  105  (as shown in  FIG.  4 A ) and, when the tailgate  105  is in the open position, the field of view of the tailgate camera  103  (i.e., the second field of view) include an area directly below the open tailgate  105  (as shown in  FIG.  4 B ). 
     Returning to  FIG.  3   , in some implementations, the tailgate camera  103  (and/or other cameras in the camera system) may include a fish-eye or other type of wide-angle lens to obtain image data from a large field of view in the vertical direction. In some such implementations, the field of view of the camera is approximately 120° (e.g., a conical imaging field extending 60° relative to the central axis  123 . 
     Image data captured by the tailgate camera  103  and other cameras (not shown in  FIG.  3   ) is transmitted (e.g., through a wired or wireless communication mechanism) to an electronic controller  131 . The electronic controller  131  is configured to process the captured image data from the multiple different cameras and to produce a single output image (as discussed in further detail below) that is then transmitted to and displayed on a display screen  133 . In some implementations, the display screen  133  is positioned within the cabin of the pickup truck  101  and is viewable by the driver of the pickup truck  101 . In some implementations, the electronic controller  131  is configured to display the rearward facing output image on the display screen  133  in response to determining that the pickup truck is being operated in reverse. Alternatively or additionally, in some implementations, the electronic controller  131  is configured to display the rearward facing output image on the display screen  133  in response to a user input received through a dashboard-mounted instrument of the pickup truck  101  (e.g., through a touch-screen display screen  133 ). 
     In some implementations, the camera system of the pickup truck  101  may include other cameras mounted in other positions in addition to or instead of the tailgate camera  103  and/or the cabin camera  109 . For example,  FIG.  5    illustrates a configuration where a side mirror camera  135  is mounted on the passenger-side rearview mirror of the pickup truck  101  with a rearward facing field of view  137 . In some implementations, the camera system of the pickup truck  101  includes the tailgate camera  103 , and one or more side mirror cameras  135 . For example, the system may include a side mirror camera  135  mounted to the passenger side rear view mirror as illustrated in  FIG.  5    and also another side mirror camera  135  mounted to the driver side rear view mirror on the opposite side of the pickup truck  101 . 
       FIG.  6    illustrates an example of a control system for the camera system of the pickup truck  101  illustrated in  FIGS.  1  through  5   . The system includes the electronic controller  131  which includes an electronic processor  601  and a non-transitory computer-readable memory  603 . The memory  603  stores data and computer-executable instructions that are accessed and executed by the electronic processor  601  to provide the functionality of the controller  131  including, for example, the functionality described herein. The controller  131  is communicatively coupled (e.g., by wired or wireless communication mechanism) to and receives captured image data from the tailgate camera  103 , the cabin camera  109 , the right side mirror camera  135 , and a left side mirror camera  605 . As noted above and as described in further detail below, the electronic processor  131  is configured to receive the image data captured by one or more cameras and to generate an output image, which is then transmitted to and displayed on a graphical display screen  133  (e.g., a user display screen  133  in the cabin of the pickup truck  101 ). 
     The controller  131  is also communicatively coupled to various other sensors. For example, based on the output received from the tailgate position sensor  107 , the electronic controller  131  is configured to determine whether the tailgate  105  is currently in an open position (as shown in  FIG.  2   ) or a closed position (as shown in  FIG.  1   ). Additionally, in some implementations, the controller  131  is also communicatively coupled to a load sensor  607  configured to determine whether a load is currently positioned within the bed of the pickup truck  101  that might obstruct the field of view  115  of the cabin camera  109 . In some implementations, the load sensor  607  is configured to sense a weight of the bed of the pickup truck and to generate an output signal indicative of the sensed weight (e.g., an output signal indicative of the measured weight of the contents of the bed or a binary signal indicating when the weight measured by the load sensor exceeds a threshold). However, in other implementations, the electronic controller  131  may be configured to accomplish the functionality of the load sensor  607  with other sensing mechanism. For example, instead of measuring a weight of the bed of the pickup truck (and any contents thereof), the system may instead be configured to include lidar, radar, or image processing technologies to detect the presence of objects in the bed of the pickup truck and to determine what, if any, portion of the field of view  115  of the cabin camera  109  might be obstructed by the contents of the bed of the pickup truck. 
     As described in the examples above, the cabin camera  109  has a rearward-facing field of view  115 . Rearward-facing image data, such as the image data captured by the cabin camera  109 , might be displayed to the operator of the pickup truck  101 , for example, to assist the driver when operating the pickup truck  101  in reverse. However, the field of view  115  of the cabin camera  109  is partially obstructed by other parts of the pickup truck  101  includes, for example, the tailgate  105 , the bottom surface of the bed of the pickup truck, and the sidewalls of the bed of the pickup truck. This field of view  115  might also be further obstructed by objects positioned within the bed of the pickup truck  101 . However, the other cameras  103 ,  135 ,  605  are positioned with fields of view that at least partially overlap with the field of view  115  of the cabin camera  109  in obstructed portions of the field of view  115  of the cabin camera  109 . Accordingly, as described in further detail in the examples below, the electronic controller  115  is configured to generate an output image by replacing portions of the image data from the cabin camera  109  that is determined to be obstructed with corresponding unobstructed image data from one of the other cameras mounted on the pickup truck  101 . For example, image data that is obstructed by the tailgate  105  is replaced with corresponding image data captured by the tailgate camera  103 —in this manner, the tailgate  105  of the pickup truck  101  may appear as though it were transparent in the output image generated by the electronic controller  131  and displayed on the graphical display screen  133 . Similarly, in some implementations, for example, image data that is obstructed by the sidewalls of the bed of the pickup truck may be replaced with corresponding image data captured by the side mirror cameras  135 ,  605 ; image data that is obstructed by the bottom surface of the bed of the pickup truck  101  may be replaced with corresponding image data captured by the tailgate camera  103  and/or the side mirror cameras  135 ,  605 ; and image data that is obstructed by one or more objects within the bed of the pickup truck may be replaced with corresponding image data captured by the tailgate camera  103  and/or the side mirror cameras  135 ,  605 . 
       FIG.  7    illustrates one example of a method for generating an output image by fusing data from multiple different cameras to remove obstructions in the field of view of the cabin camera  109  and to replace the obstructed image data with unobstructed image data captured by another camera. The electronic controller  131  receives image data from the cabin camera  109  (step  701 ) and receives image data from the tailgate camera  103  (step  703 ). The electronic controller  131  also receives the output of the tailgate position sensor  107  (step  705 ) and determines, based on the output of the tailgate position sensor  107 , whether the tailgate  105  is currently in closed/“up” position or the open/“down” position (step  707 ). 
     The orientation of the tailgate camera  103  relative to the cabin camera  109  is known based on the determined position of the tailgate  105 . Accordingly, once the position of the tailgate is determined, perspective mapping techniques can be used to identify a group of pixels in the image data captured by the tailgate camera  103  that correspond to the portion of the image data captured by the cabin camera  109  that is obstructed by the tailgate and to map the pixels from the image data captured by the tailgate camera  103  to the image data captured by the cabin camera  109  to correct for the difference in perspective between the two cameras. 
     Therefore, when the electronic controller  131  determines that the tailgate is in the closed/“up” position (step  707 ), a first perspective mapping is applied to the tailgate image data (i.e., the image data captured by the tailgate camera  103 ) (step  709 ) and the perspective mapped tailgate image data is overlaid onto a first defined section of the cabin camera image data (i.e., the portion of the image data captured by the cabin camera  109  that is obstructed by the closed tailgate  105 ) (step  711 ). Conversely, when the electronic controller  131  determines that the tailgate is in the open/“down” position (step  707 ), a different second perspective mapping is applied to the tailgate image data (step  713 ) and the perspective mapped tailgate image data is overlaid onto a second defined section of the cabin camera image data (i.e., the portion of the image data captured by the cabin camera  109  that is obstructed by the open tailgate  105 ) (step  715 ). 
     As discussed above, in some implementations, the electronic controller  131  is further configured to determine whether the field of view  115  of the cabin camera is obstructed by one or more objects are positioned in the bed of the pickup truck. In some such implementations, the electronic controller  131  receives the output of a load sensor  607  (step  717 ) and, based on the received load sensor output, determines whether a load is currently positioned in the bed of the pickup truck (step  719 ). If a load is detected in the bed, then the perspective mapping and image data overlaying described above (in steps  709 / 711  and  713 / 715 ) is applied to an extended area corresponding to the load in the bed of the pickup truck (step  723 ). The output image generated as a composite of image data from the multiple different cameras is then displayed to the driver of the pickup truck  101  on the graphical display screen  133  (step  721 ). 
       FIGS.  8 A through  11 B  illustrate specific examples of the image mapping techniques performed by the electronic processor (such as described in  FIG.  7   ).  FIG.  8 A  shows a first example of an image captured by the cabin camera  109 . In this example, the bottom  801  and the interior surface of the sidewalls  802  of the pickup truck bed are visible in the image data captured by the cabin camera  109 . A tree  803  is located behind the pickup truck  101  and is partially obstructed by the tailgate  105  in the image data captured by the cabin camera  109 . Because the system can be calibrated to know the position and size of the tailgate  105  relative to the cabin camera  109 , the electronic controller  131  can be configured to know in advance what portion of the image data captured by the cabin camera  109  will be obstructed by the tailgate  105  when the tailgate  105  is in the closed/“up” position and which portion of the image data captured by the cabin camera  109  will be obstructed by the tailgate  105  when the tailgate  105  is in the open/“down” position. In the example of  FIG.  8 A , the electronic controller  131  determines, based on the output of the tailgate position sensor  107 , that the tailgate  105  is in the closed/“up” position and, therefore, is able to determine that a predefined portion  805  of the image data captured by the cabin camera  109  is obstructed by the tailgate  105 . Accordingly, the electronic controller  131  applies the perspective mapping techniques (see, e.g., step  709  in  FIG.  7   ) and overlays image data from the tailgate camera  103  in the portion  805  of the image data captured by the cabin camera  109 . As a result, in the output image generated by the controller  131 , as shown in  FIG.  8 B , the tailgate  105  appears transparent and more of the tree  803  is visible in the output image than in the original image captured by the cabin camera  109 . 
       FIGS.  9 A and  9 B  illustrate a similar example where the tailgate  805  is in the open/“down” position. As shown in  FIG.  9 A , although the open tailgate  105  obstructs less of the field of view of the cabin camera  109  than the closed tailgate  105  (shown in  FIG.  8 A ), the open tailgate  105  still obstructs part of the field of view. Similar to the example described above in reference to  FIGS.  8 A and  8 B , the electronic controller  131  is calibrated to know the position and size of the tailgate relative to the cabin camera  109  and, therefore, the electronic controller  131  can be calibrated and/or programmed to know in advance what portion of the image data captured by the cabin camera  109  will be obstructed by the tailgate  105  when the tailgate  105  is in the open/“down” position. In the example of  FIG.  9 A , the electronic controller  131  determines, based on the output of the tailgate position sensor  107 , that the tailgate  105  is in the open/“down” position and, therefore, is able to determine that a second predefined portion  905  of the image data captured by the cabin camera  109  is obstructed by the tailgate  105 . Accordingly, the electronic controller  131  applies the second perspective mapping (see, e.g., step  713 ) to the image data captured by the tailgate camera  103  and overlays the perspective-mapped image data from the tailgate camera  103  in the portion  905  of the image data captured by the cabin camera  109 . As a result, in the output image generated by the controller  131 , as shown in  FIG.  9 B , the tailgate  105  appears transparent and more of the tree  803  is visible in the output image than in the original image captured by the cabin capture  109 . 
       FIGS.  10 A and  10 B  illustrate yet another example in which the field of view of the cabin camera  109  is partially obstructed by a load  1003  positioned within the bed of the pickup truck. As shown in  FIG.  10 A , the load  1003  obstructs even more of the field of view of the cabin camera  109  than the tailgate  105  in the examples of  FIGS.  8 A through  9 B . Similar to the examples described above, the electronic controller  131  is configured to apply perspective mapping to unobstructed image data captured by another camera (e.g., image data captured by the tailgate camera  103 ) and to overlay the perspective mapped image data onto an area  1005  of the image data captured by the cabin camera  109  that is obstructed by the load  1003  so that the load  1003  appears transparent in the output image, as shown in  FIG.  10 B . 
     In some implementations, the electronic controller  131  may be configured to determine or approximate the actual size and position of the load  1003  based, for example, on data from a radar system, a lidar system, or the image data captured by the cabin camera  109  in order to dynamically determine the portion  1005  of the image data from the cabin camera  109  that is actually obstructed by the load  1003 . In other implementations, the electronic controller  131  may instead be configured to use the same predefined portion  1005  regardless of the actual size/position of the load  1003 . 
     In some situations and implementations, the image data obstructed by the load  1003  may exceed the image data that can be replaced by perspective mapping and overlays using image data captured by other cameras. For example, if the height of the load  1003  extends above the field of view of the tailgate camera  103 , then image data from the tailgate camera  103  cannot be used to replace all of the image data captured by the cabin camera  109  that is obstructed by the load  1003 . This may occur particularly when the tailgate  105  is in the open/“down” position as the position of the tailgate  105  will alter the field of view of the tailgate camera  103  (as illustrated above in  FIGS.  1  and  2   ). Accordingly, in some implementations, the electronic controller  131  may be configured to apply perspective mapping and image data overlay to remove a load  1003  from the output image only when the load  1003  is detected in the bed of the pickup truck and the tailgate  105  is in the closed/“up” position. In other implementations the electronic controller  131  is instead configured to replace whatever obstructed image data that it can based on the size of the load  1003  and the relative position of the various cameras. Accordingly, in some such implementations, the entire load  1003  may appear transparent in the output image in some situations while, in other situations, part of the load  1003  may still appear visible in the output image. 
     Finally, in some implementations, the electronic controller  131  may be configured to use perspective mapping and image data overlay to “remove” or to render at least partially transparent additional components of the pickup truck other than the tailgate  105  and/or the load  1003 . For example, as discussed above and as illustrated in the example of  FIGS.  11 A and  11 B , the image data captured by the cabin camera  109  is partially obstructed by the sidewalls  803  of and the bottom surface  801  of the bed of the pickup truck. However, in some implementations, the side mirror cameras  135 ,  605  may be positioned and configured to capture image data of the same areas that are obstructed by the sidewalls  803  in the image data captured by the cabin camera  109 . Accordingly, in some implementations, the electronic controller  131  may be configured to apply perspective mapping to the image data captured by the side mirror cameras  135 ,  605  and to overlay the perspective mapped image data onto the image data captured by the cabin camera  109  to replace the portion of the image data that is obstructed by the sidewalls  802  so that the sidewalls  802  appear at least partially transparent in the output image. 
     Similarly, in some implementations, the field of view of the tailgate camera  103  extends to include areas that are obstructed by the bottom surface  801  of the bed in the image data captured by the cabin camera  109  even when the tailgate  105  is in the closed/“up” position. And, when the tailgate  105  is moved to the open/“down” position, even more of the area obstructed by the bottom surface  801  of the bed in the image data captured by the cabin camera  109  is included in the field of view of the tailgate camera  103 . Accordingly, in some implementations, the electronic controller  131  may be configured to determine the position of the the tailgate  105  and, based on the determined position of the tailgate, determine which portion of the bottom surface  801  of the bed in the image data captured by the cabin camera  109  can be replaced with perspective mapped image data from the tailgate camera  103 . 
     As shown in the example of  FIG.  11 A , when the tailgate  105  is in the closed/“up” position, the electronic controller  131  is configured to replace the image data in area  805  of the image data captured by the cabin camera  109  with perspective mapped image data from the tailgate camera  103  and to also replace the image data in area  1101  of the image data captured by the cabin camera  109  with additional perspective mapped image data from the tailgate camera  103  so that the tailgate  105  and part of the bottom surface  801  of the bed appear transparent (or partially transparent) in the output image. Similarly, as shown in the example of  FIG.  11 B , when the tailgate  105  is in the open/“down” position, the electronic controller  131  is again configured to replace the image data in area  905  of the image data captured by the cabin camera  109  with perspective mapped image data from the tailgate camera  103  and to also replace image data in area  1103  of the image data captured by the cabin camera  109  with additional perspective mapped image data from the tailgate camera  103  so that the tailgate  105  and part of the bottom surface  801  of the bed appear transparent (or partially transparent) in the output image. 
     As discussed above, the field of view of the tailgate camera  103  is altered when the position of the tailgate  105  is changed and the field of view of the tailgate camera  103  includes a greater portion of the area obstructed by the bottom surface  801  of the bed in the image data captured by the cabin camera  109  when the tailgate  105  is in the open/“down” position. Accordingly, in some implementations, the electronic controller  131  may be configured to adjust the portions of the obstructed image data that are rendered transparent (or partially transparent) in the output image based on the current position of the tailgate  105 . For example, as illustrated in  FIGS.  11 A and  11 B , the size of the area  1103  of the bottom surface  801  that is rendered transparent in the output image when the tailgate  105  is in the open/“down” position (as shown in  FIG.  11 B ) is greater than the size of the area  1101  of the bottom surface  801  that is rendered transparent in the output image when the tailgate  105  is in the closed/“up” position (as shown in  FIG.  11 A ). As a result, objects may be visible in the output image generated when the tailgate  105  is in the open/“down” position that might not be visible in the output image generated when the tailgate  105  is in the closed/“up” position. For example, in  FIG.  11 A , the rear wheels  1105  of the pickup truck and a rock  1107  are visible in the output image when the tailgate  105  is in the open/“down” position, but are not visible in the output image when the tailgate  105  is in the closed/“up” position. 
     Thus, the invention provides, among other things, a camera system including a plurality of cameras mounted on a vehicle and configured to fuse image data captured from the different cameras to generate &amp; display an output image in which portions of the vehicle and/or loads carried by the vehicle are rendered transparent or partially transparent. Various features and advantages of the invention are set forth in the following claims.