Method and apparatus for image stitching in camera monitoring system

Abstract

A method and apparatus for image stitching in a camera monitoring system. A method for a camera monitoring system (CMS) includes obtaining a first image from a first camera depicting a first area extending along a first side of a commercial vehicle; obtaining a second image from a second camera depicting a second area extending along a second side of the commercial vehicle opposite the first side; obtaining a third image from a third camera depicting a rear area behind the commercial vehicle; performing a perspective transformation on the first image, the second image, and the third image to obtain an updated image set such that each of the first image, the second image, and the third image is updated in the updated image set; and stitching the images of the updated image set together to form a combined image, where the third image is disposed between the first image and the second image, and where the first region, the second region, and the rear region are each depicted. A CMS is also disclosed.

Description

Technical Field

[0001] This disclosure relates to a camera monitoring system (CMS), and more specifically to a method and apparatus for providing image stitching in a CMS. Background Technology

[0002] In commercial vehicles, vehicle camera systems are used to enhance the driver's ability to see the vehicle's surroundings, either by replacing or supplementing the view from the side mirrors. Camera monitoring systems (CMS) utilize one or more cameras to provide the vehicle operator with an enhanced field of view. In some examples, side mirror replacement systems cover a larger field of view than conventional side mirrors, or include views that cannot be fully obtained via conventional side mirrors. When images are provided to vehicle occupants from multiple cameras, the driver may find it difficult to effectively analyze the images. Summary of the Invention

[0003] A method for a camera monitoring system (CMS) according to an exemplary embodiment of the present disclosure includes: acquiring a first image from a first camera depicting a first region extending along a first side of a commercial vehicle; acquiring a second image from a second camera depicting a second region extending along a second side of the commercial vehicle opposite to the first side; acquiring a third image from a third camera depicting a rear region behind the commercial vehicle; performing a perspective transformation on the first, second, and third images to obtain an updated image set, such that each of the first, second, and third images is updated in the updated image set; and stitching the images of the updated image set together to form a composite image, in which the third image is positioned between the first and second images, and in which the first region, the second region, and the rear region are each depicted.

[0004] In another embodiment of the foregoing embodiments, the field of view of the third camera overlaps with the field of view of the first camera and the field of view of the second camera.

[0005] In another embodiment of any of the foregoing embodiments, the third image includes a left portion extending along the left edge of the third image and a right portion extending along the right edge of the third image. The stitching is performed such that, in the combined image, the left portion of the third image is stitched to the middle portion of the first image, and the right portion of the third image is stitched to the middle portion of the second image.

[0006] In another embodiment of any of the foregoing embodiments, the first camera, the second camera, and the third camera have respective optical axes that intersect the ground plane at their respective optical angles. The optical angle of the third camera is less than 90° and greater than the respective optical angles of the first and second cameras.

[0007] In another embodiment of any of the foregoing embodiments, a first camera is mounted on the first side of the cab of the commercial vehicle, a second camera is mounted on the second side of the cab of the commercial vehicle, and a third camera is mounted on the trailer of the commercial vehicle.

[0008] In another embodiment of any of the foregoing embodiments, the first camera, the second camera, and the third camera each have their own focal length. The focal length of the third camera is less than the focal lengths of the first camera and the second camera.

[0009] In another embodiment of any of the foregoing embodiments, the method includes performing at least one of the following before performing perspective transformation: performing distortion correction on a first image from a first camera to reduce image distortion caused by the lens or sensor of the first camera, performing distortion correction on a second image from a second camera to reduce image distortion caused by the lens or sensor of the second camera, and performing distortion correction on a third image from a third camera to reduce image distortion caused by the lens or sensor of the third camera.

[0010] In another embodiment of any of the foregoing embodiments, the method includes cropping at least one of the first image, the second image, and the third image before stitching.

[0011] In another embodiment of any of the foregoing embodiments, stitching together the images of the updated image set to form a combined image includes: performing a first mapping from a first plurality of points of a third image in the updated image set to a first image in the updated image set; performing a second mapping from a second plurality of points of a third image in the updated image set to a second image in the updated image set; aligning the first image, the second image, and the third image in the updated image set based on the first mapping and the second mapping; and mixing the first image, the second image, and the third image in the updated image set to obtain a combined image.

[0012] In another embodiment of any of the foregoing embodiments, the method includes displaying a first image on a first electronic display in a commercial vehicle, displaying a second image on a second electronic display in a commercial vehicle, and displaying a combined image on a third electronic display in a commercial vehicle, the third electronic display being disposed between the first and second electronic displays.

[0013] A camera monitoring system (CMS) according to an example embodiment of the present disclosure includes a first camera, a second camera, and a third camera mounted at different locations on a commercial vehicle. The camera monitoring system also includes processing circuitry operatively connected to a memory and configured to: acquire a first image from the first camera depicting a first region extending along a first side of the commercial vehicle; acquire a second image from the second camera depicting a second region extending along a second side of the commercial vehicle opposite to the first side; acquire a third image from the third camera depicting a rear region behind the commercial vehicle; perform perspective transformation on the first, second, and third images to obtain an updated image set, such that each of the first, second, and third images is updated in the updated image set; and stitch the images of the updated image set together to form a composite image, in which the third image is positioned between the first and second images, and in which the first region, the second region, and the rear region are each depicted.

[0014] In another embodiment of the foregoing embodiments, the field of view of the third camera overlaps with the field of view of the first camera and the field of view of the second camera.

[0015] In another embodiment of any of the foregoing embodiments, the third image includes a left portion extending along the left edge of the third image and a right portion extending along the right edge of the third image. In the composite image, the left portion of the third image is stitched to the middle portion of the first image, and the right portion of the third image is stitched to the middle portion of the second image.

[0016] In another embodiment of any of the foregoing embodiments, the first camera, the second camera, and the third camera have respective optical axes that intersect the ground plane at their respective optical angles. The optical angle of the third camera is less than 90° and greater than the respective optical angles of the first and second cameras.

[0017] In another embodiment of any of the foregoing embodiments, the first and second cameras are mounted in the cab of the commercial vehicle, and the third camera is mounted in the trailer of the commercial vehicle.

[0018] In another embodiment of any of the foregoing embodiments, the first camera, the second camera, and the third camera have their own focal lengths, and the focal length of the third camera is less than the focal lengths of the first camera and the second camera.

[0019] In another embodiment of any of the foregoing embodiments, the processing circuitry is configured to perform at least one of the following before performing perspective transformation: performing distortion correction on a first image from a first camera to reduce image distortion caused by the lens or sensor of the first camera; performing distortion correction on a second image from a second camera to reduce image distortion caused by the lens or sensor of the second camera; and performing distortion correction on a third image from a third camera to reduce image distortion caused by the lens or sensor of the third camera.

[0020] In another embodiment of any of the foregoing embodiments, the processing circuitry is configured to crop at least one of the first image, the second image, and the third image before stitching.

[0021] In another embodiment of any of the foregoing embodiments, in order to stitch together images in the updated image set, the processing circuit is configured to perform a first mapping of a first plurality of points of the third image in the updated image set to the first image in the updated image set; perform a second mapping of a second plurality of points of the third image in the updated image set to the second image in the updated image set; and align the first image, the second image, and the third image in the updated image set based on the first mapping and the second mapping; and mix the first image, the second image, and the third image in the updated image set to obtain a combined image.

[0022] In another embodiment of any of the foregoing embodiments, the processing circuitry is configured to display a first image on a first electronic display in the commercial vehicle, a second image on a second electronic display in the commercial vehicle, and a combined image on a third electronic display in the commercial vehicle, the third electronic display being disposed between the first and second electronic displays.

[0023] The embodiments, examples, and alternatives described in the foregoing paragraphs, claims, or the following description and drawings, including any of their various aspects or corresponding features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments unless these features are incompatible. Attached Figure Description

[0024] This disclosure can be further understood by referring to the following detailed description when considered in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 It is a schematic front view of a commercial vehicle equipped with a Camera Monitoring System (CMS) for providing at least Category II and Category IV views.

[0026] Figure 2 yes Figure 1 A schematic bird's-eye view of commercial vehicles, where CMS provides views of Class II, IV, V, VI and VIII.

[0027] Figure 3 This is a schematic top view of the interior of an exemplary carriage.

[0028] Figure 4 yes Figure 3 A perspective view of the interior of the train carriage.

[0029] Figure 5 yes Figure 1 A schematic diagram of two associated optical angles of a commercial vehicle and a CMS camera.

[0030] Figure 6A These are sample images from the first CMS camera.

[0031] Figure 6B These are sample images from the second CMS camera.

[0032] Figure 6C These are sample images from the third CMS camera.

[0033] Figure 7A It is after perspective transformation. Figure 6A Examples of images.

[0034] Figure 7B It is after perspective transformation. Figure 6B Examples of images.

[0035] Figure 7C It is after perspective transformation. Figure 6C Examples of images.

[0036] Figure 8 yes Figures 7A-7C A combination of images.

[0037] Figure 9 This is a flowchart of an example method used in CMS. Detailed Implementation

[0038] A schematic diagram of commercial vehicle 10 is shown in Figures 1-4 As shown in the figure. Commercial vehicle 10 includes a vehicle cab or "tractor" 12 for towing trailer 14, wherein trailer 14 pivots relative to tractor 12 during turning. Although commercial vehicle 10 is depicted in this disclosure as a commercial vehicle with a single trailer, it should be understood that other commercial vehicle configurations (e.g., different types or numbers of trailers) may be used.

[0039] A pair of camera arms 16A-16B each includes a base fixed to, for example, a tractor unit 12. The pivoting arms are supported by the bases and can be hinged relative to the bases. At least one rear-facing camera 20A-20B is respectively arranged on or within the camera arms 16A-16B. The cameras 20A-20B are "rear-facing" because they face the rear of the commercial vehicle 10. The external cameras 20A-20B each provide an external field of view (FOV). EX1 FOV EX2 Each external field of view includes at least one of Class II and Class IV views. Figure 2 These are views legally permitted in the commercial trucking industry. Cameras 20A-20B are Camera Monitoring Systems (CMS) 15 (see...). Figure 3 Part of ).

[0040] like Figure 2 As shown, camera 20A provides a view of a first region 28A extending along a first side 27A of the commercial vehicle 10, and is included in both Class II and Class IV views of camera 20A. Furthermore, camera 20B provides a view of a second region 28B extending along a second side 27B of the commercial vehicle 10, and is included in both Class II and Class IV views of camera 20B.

[0041] A Category II view on a given side of commercial vehicle 10 is a subset of a Category IV view on the same side of commercial vehicle 10. Multiple cameras may also be used in each camera arm 16A-16B to provide these views if desired. For example, Category II (narrow) and Category IV (wide) views are defined in European R46 legislation, and the United States and other countries have similar driving visibility requirements for commercial trucks. Any reference to “class” views is not intended to be restrictive, but rather to serve as an example of the type of view provided to a display from a particular camera.

[0042] Each camera arm 16A-16B may also be provided with a housing that encloses electronics configured to provide various features of the CMS15, such as controllers. For example, the camera arms 16A-16B may be mounted in a roof-mounted position above the cab door (as shown), or on a bracket or station mounted on the door.

[0043] If video of Class V and / or Class VI views is also desired, camera housing 16C and camera 20C can be positioned at or near the front of the commercial vehicle 10 to provide those views. Figure 2 ).

[0044] The 20D reversing camera provides a 28C field of view (FOV) for the rear area of ​​commercial vehicles. EX3 Its relationship with the field of view (FOV) EX1 FOV EX2Overlapping. For example, a 20D reversing camera can be mounted on the top / center line of the trailer, at the level of the trailer bumper / cargo box, or at the top corner of the rear of the trailer. Therefore, in Figures 1-2 In the example, camera 20A is mounted on the first side 27A to the cab 12 of commercial vehicle 10, camera 20B is mounted on the second side 27B to the cab 12 of commercial vehicle 10, and camera 20D is mounted to the rear of the trailer 14 of commercial vehicle.

[0045] Alternatively, in addition to the trailer-mounted rear camera, a "fifth-wheel camera" 20E can be provided, which is mounted at the rear of the tractor unit 12 and provides a field of view (FOV). EX4 When the trailer 14 is disconnected from the cab 12, the field of view (FOV) is... EX4 Also related to the field of view (FOV) EX1 FOV EX2 Overlap. For example, the fifth wheel camera 20E can be mounted anywhere between the lateral plane of the fifth wheel fixture and the top / roof edge of the tractor.

[0046] Figure 3 This is a schematic top view of the interior 24 of an exemplary carriage, and Figure 4 This is a perspective view of the interior of the carriage (24). Now for reference. Figures 3-4 And continue to refer to Figures 1-2 The diagram illustrates electronic displays 18A-18E (which may be video displays, such as LCD displays) and cameras 20A-20E. The various electronic displays 18A-18E and cameras 20A-20E are part of CMS 15 and therefore function as CMS displays and CMS cameras. As used herein, "CMS camera" 20 is a camera configured to record images of the environment surrounding commercial vehicle 10, and "CMS display" 18 is an electronic display (e.g., LCD) configured to image feeds from those cameras.

[0047] CMS15 includes a CMS electronic control unit (ECU) 22, which acts as a controller and includes processing circuitry supporting the operation of CMS15. The CMS ECU 22 is operatively connected to any one or a combination of memory elements (which may include volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.)) and / or non-volatile memory elements (e.g., ROM, hard disk drive, magnetic tape, CD-ROM, etc.). The processing circuitry may include one or more microprocessors, microcontrollers, application-specific integrated circuits (ASICs), etc.

[0048] CMS displays 18A-18B are arranged on or near the A-pillars 19A-B on each of the driver's and passenger sides within the vehicle cab 12 to display Class II and Class IV views on the respective sides of the commercial vehicle 10, providing rearward-facing side views of the commercial vehicle 10 captured by external cameras 20A-20B.

[0049] As described above, if Class V and Class VI views are also desired, the camera housing 16C and camera 20C can be positioned at or near the front of the commercial vehicle 10 to provide those views. Figure 2 ).exist Figure 3 In the example, additional displays 18C-18E are provided. Display 18C, located at the top center near the windshield within the passenger compartment 24, can be used to display to the driver a Class V or Class VI view facing forward of the commercial vehicle 10, or a view from a reversing camera (from camera 20D or 20E). Display 18D is located in the center console area within the passenger compartment 24 and can be used as a backup display or for other purposes such as navigation, infotainment, etc. Display 18E can be, for example, part of an instrument cluster and can be used as a backup display.

[0050] If desired, camera arms 16A-16B may also include a conventional sight integrated therewith, but the CMS15 can be used to completely replace the sight. In another example, each side may include multiple camera arms, with each arm housing one or more cameras and / or sights.

[0051] As will be discussed in more detail below, CMS ECU 22 is configured to perform image stitching to combine views from CMS camera 20A (“first camera”), CMS camera 20B (“second camera”), and CMS camera 20D or 20E (“third camera”). Although the use of camera 20E is an option for the third camera, the embodiments discussed below will focus on camera 20D.

[0052] In the examples discussed below, cameras 20A, 20B, and 20D each have their own focal length, and the focal length of camera 20D is less than the focal lengths of CMS cameras 20A-20B, thus giving camera 20D a wider field of view than cameras 20A and 20B. In one or more embodiments, CMS cameras 20A-20B have the same focal length.

[0053] Figure 5This is a schematic diagram of a commercial vehicle 10 and two associated optical angles 52A and 52B, each less than 90°. As shown, CMS camera 20A has a first optical axis 50A, and CMS camera 20D has a second optical axis 50B. Optical angle 52A is formed between the intersection of the optical axis 50A of camera 20A and the ground plane G. Optical angle 52B is formed between the intersection of the optical axis 50B of CMS camera 20D and the ground plane G. Figure 5 As shown, optical angle 52A is smaller than optical angle 52B.

[0054] As discussed in more detail below, the CMS ECU 22 performs image stitching from images from cameras 20A, 20B, and 20D (or 20E) to produce a combined image that allows vehicle occupants to have a panoramic view of areas 28A-28C and effectively provides a perspective view of trailer 14.

[0055] Figure 6A An exemplary first image 60A from camera 20A depicts a region 28A extending along one side 27A of the commercial vehicle 10 before correction or perspective transformation.

[0056] Figure 6B The example second image 62A is from camera 20B, which depicts a region 28B extending along a side 27B opposite to side 27A of the commercial vehicle 10, which depicts the area behind the commercial vehicle.

[0057] Figure 6C This is an example third image 64A from a 20D camera, depicting region 28C before correction or perspective transformation. Although the 20D camera... Figure 5 It is depicted as being on top of the rear of trailer 14, but Figure 6C The images were taken with the camera 20D positioned at the lower rear of the trailer 14 (e.g., at or near the bottom of the rear of the trailer 14).

[0058] Figure 7A yes Figure 6A The first image 60A serves as an example of image 60B after a perspective transformation. As shown, the perspective transformation elongates the left side of image 60A and shortens the right side of image 60A.

[0059] Figure 7B yes Figure 6B The second image 62A serves as an example of image 62B after a perspective transformation. As shown, the perspective transformation stretches the right side of image 60A and shortens the left side of image 60A.

[0060] Figure 7C yes Figure 6C The third image, after perspective transformation, serves as an example of image 64B.

[0061] Figure 8 It was shown as Figures 7A-7C An exemplary composite image 68 is a stitched combination of images, wherein a third image 64A is disposed between a first image 60A and a second image 62A, and wherein a first region 28A, a second region 28B and a rear region 28C are each depicted to provide a panoramic view of regions 28A-28C.

[0062] Refer again Figure 6C and Figure 7C The third image 64A includes a left portion 66A along the left side of the third image 64A and a right portion 66B along the right side of the third image 64A. After perspective transformation, these are respectively adjusted to the lower left edge 70A and the lower right edge 70B of image 64B. Figure 8 In the example, image stitching is performed such that in the combined image 68, the left portion 66A of the third image 64A is stitched to the middle region 65A of the first image 60A, and the right portion 66B of the third image 64A is stitched to the middle region 65B of the second image 62A. As used herein, "middle region" refers to image data spaced at least 25% from each edge of the original images 60A, 62A. Using image 60A as an example, with image 60A having a width W1 and a length L1, the "middle region" is spaced at least 0.25 times W1 from the left and right sides of image 60A, and at least 0.25 times L1 from the top and bottom sides of image 60A. Using image 62A as an example, where image 62A has a width W2 and a length L2, the "middle region" is spaced at least 0.25 times W2 from the left and right sides of image 62A, and spaced at least 0.25 times L2 from the top and bottom sides of image 62A.

[0063] In one or more embodiments, prior to performing the perspective transformation in step 108, at least one of the following is performed: distortion correction is applied to a first image 60A from a first camera 20A to reduce image distortion caused by the lens or sensor of the first camera 20A; distortion correction is applied to a second image 62A from a second camera 20B to reduce image distortion caused by the lens or sensor of the second camera 20B; and distortion correction is applied to a third image 64A from a third camera 20D to reduce image distortion caused by the lens or sensor of the third camera 20D. In one or more embodiments, each of these distortion corrections is performed. However, it should be understood that these are non-limiting examples, and distortion correction of one or more of images 60A, 62A, and 64A may be omitted.

[0064] In one or more embodiments, before image stitching in step 110, at least one of the first image 60A, the second image 62A, and the third image 64A is cropped.

[0065] Figure 9 This is a flowchart of an example method 100 for CMS. A first image 60A is obtained from a first camera 20A, which depicts a first region 28A extending along a first side 27A of the commercial vehicle 10 (step 102).

[0066] A second image 62A is obtained from the second camera 20B, which depicts a second region 28B extending along the second side 27B of the commercial vehicle 10 opposite to the first side 27A (step 104).

[0067] A third image 64A is obtained from a third camera 20D (or possibly 20E), which depicts the rear region 28C behind the commercial vehicle 10, wherein the field of view (FOV) of the third camera is... EX3 Field of view (FOV) of the first camera 20A EX1 Field of view (FOV) of the second camera 20B EX2 Overlap (step 106).

[0068] Perform perspective transformation on the first image 60A, the second image 62A and the third image 64A to obtain an updated image set, such that each of the first image 60A, the second image 62A and the third image 64A is updated in the updated image set (step 108).

[0069] The updated images 60A, 62A, and 64A of the updated image set are stitched together to form a composite image 68, in which the third image 64A is placed between the first image 60A and the second image 62A, and the first region 28A, the second region 28B, and the rear region 28C are each depicted in the composite image 68 (step 110).

[0070] In one or more embodiments, step 110 of stitching includes: performing a first mapping of a first plurality of points of the third image 64 in the updated image set (e.g., along the lower left edge 70A of the updated third image 64B) to the first image 60 in the updated image set, and performing a second mapping of a second plurality of points of the third image in the updated image set (e.g., along the lower right edge 70B of the updated third image 64B) to the second image in the updated image set. Stitching includes aligning and blending the first image 60, the second image 62, and the third image 64 in the updated image set based on the first and second mappings to obtain a combined image.

[0071] As described above, the first camera 20A, the second camera 20B, and the third camera 20D have their respective optical axes intersecting the ground plane G at their respective optical angles, and in one or more embodiments, the optical angle of the third camera 20D is less than 90° and greater than the respective optical angles of the first camera 20A and the second camera 20B.

[0072] The combined image 68 is displayed on an electronic display in the commercial vehicle 10, such as display 18C, 18D, or 18E (each located between display 18A and 18B). Simultaneously, an image from camera 20A can continue to be displayed on display 18A, and an image from camera 20B can continue to be displayed on display 18B.

[0073] Although exemplary embodiments have been disclosed, those skilled in the art will recognize that certain modifications will fall within the scope of the claims. Therefore, the following claims should be examined to determine their true scope and content.

Claims

1. A method for a camera monitoring system (CMS), comprising: obtaining a first image from a first camera, the first image depicting a first area extending along a first side of a commercial vehicle; obtaining a second image from a second camera, the second image depicting a second area extending along a second side of the commercial vehicle opposite the first side; obtaining a third image from a third camera, the third image depicting a rear area behind the commercial vehicle; performing a perspective transformation on the first image, the second image, and the third image to obtain an updated set of images, such that each of the first image, the second image, and the third image is updated in the updated set of images; and stitching together images of the updated set of images to form a combined image in which the third image is disposed between the first image and the second image, and in which the first area, the second area, and the rear area are each depicted.

2. The method of claim 1, wherein a field of view of the third camera overlaps a field of view of the first camera and a field of view of the second camera.

3. The method of claim 1, wherein: the third image includes a left side portion extending along a left edge of the third image and a right side portion extending along a right edge of the third image; and the stitching is performed such that, in the combined image, the left side portion of the third image is stitched to a middle portion of the first image and the right side portion of the third image is stitched to a middle portion of the second image.

4. The method of claim 1, wherein: the first camera, the second camera, and the third camera have respective optical angles that intersect a ground plane; and the optical angle of the third camera is less than 90° and greater than the respective optical angles of the first camera and the second camera.

5. The method of claim 4, wherein: the first camera is mounted to a cab of the commercial vehicle on the first side; the second camera is mounted to the cab on the second side of the commercial vehicle; and the third camera is mounted to a trailer of the commercial vehicle.

6. The method of claim 1, wherein: the first camera, the second camera, and the third camera have respective focal lengths; and the focal length of the third camera is less than the respective focal lengths of the first camera and the second camera.

7. The method of claim 1, comprising, prior to the performing a perspective transformation, performing at least one of: distortion correction on the first image from the first camera to mitigate image distortion caused by a lens or a sensor of the first camera; distortion correction on the second image from the second camera to mitigate image distortion caused by a lens or a sensor of the second camera; and distortion correction on the third image from the third camera to mitigate image distortion caused by a lens or a sensor of the third camera. ​ 8. The method of claim 1, comprising, prior to the stitching together: cropping at least one of the first image, the second image, and the third image.

9. The method of claim 1, wherein the stitching together images of the updated set of images to form a combined image comprises: performing a first mapping of a first plurality of points of the third image in the updated set of images to the first image in the updated set of images; performing a second mapping of a second plurality of points of the third image in the updated set of images to the second image in the updated set of images; and based on the first mapping and the second mapping: aligning the first image, the second image, and the third image in the updated set of images; and blending the first image in the updated set of images, the second image in the updated set of images, and the third image in the updated set of images to obtain the combined image.

10. The method of claim 1, comprising: displaying the first image on a first electronic display in the commercial vehicle; displaying the second image on a second electronic display in the commercial vehicle; and displaying the combined image on a third electronic display in the commercial vehicle, the third electronic display disposed between the first electronic display and the second electronic display.

11. A camera monitoring system (CMS), comprising: a first camera, a second camera, and a third camera mounted to different locations of a commercial vehicle; and processing circuitry operably connected to a memory and configured to: obtain a first image from the first camera, the first image depicting a first area extending along a first side of the commercial vehicle; obtain a second image from the second camera, the second image depicting a second area extending along a second side of the commercial vehicle opposite the first side; obtain a third image from the third camera, the third image depicting a rear area behind the commercial vehicle; perform a perspective transformation on the first image, the second image, and the third image to obtain an updated set of images such that each of the first image, the second image, and the third image is updated in the updated set of images; and stitch together images of the updated set of images to form a combined image in which the third image is disposed between the first image and the second image and in which the first area, the second area, and the rear area are each depicted. a field of view of the third camera overlaps a field of view of the first camera and a field of view of the second camera.

13. The CMS of claim 11, wherein: the third image includes a left side portion extending along a left edge of the third image and a right side portion extending along a right edge of the third image; and 12. The CMS of claim 11, wherein, in the combined image, the left side portion of the third image is stitched to a middle portion of the first image and the right side portion of the third image is stitched to a middle portion of the second image. ​ ​ ​ 14. The CMS of claim 11, wherein: the first camera, the second camera, and the third camera have respective optical angles that intersect a ground plane; and the optical angle of the third camera is less than 90° and greater than the respective optical angles of the first camera and the second camera.

15. The CMS of claim 14, wherein: the first camera and the second camera are mounted to a cab of the commercial vehicle; and the third camera is mounted to a trailer of the commercial vehicle.

16. The CMS of claim 11, wherein: the first camera, the second camera, and the third camera have respective focal lengths; and the focal length of the third camera is less than the respective focal lengths of the first camera and the second camera.

17. The CMS of claim 11, wherein the processing circuitry is configured to, prior to performing the perspective transform: perform distortion correction on the first image from the first camera to mitigate image distortion caused by a lens or sensor of the first camera; perform distortion correction on the second image from the second camera to mitigate image distortion caused by a lens or sensor of the second camera; and perform distortion correction on the third image from the third camera to mitigate image distortion caused by a lens or sensor of the third camera.

18. The CMS of claim 11, wherein the processing circuitry is configured to, prior to the stitching: crop at least one of the first image, the second image, and the third image.

19. The CMS of claim 11, wherein to stitch the images of the updated set of images, the processing circuitry is configured to: perform a first mapping of a first plurality of points of the third image in the updated set of images to the first image in the updated set of images; perform a second mapping of a second plurality of points of the third image in the updated set of images to the second image in the updated set of images; and based on the first mapping and the second mapping: align the first image, the second image, and the third image in the updated set of images; and blend the first image, the second image, and the third image in the updated set of images to obtain the combined image. the processing circuitry is configured to: display the first image on a first electronic display in the commercial vehicle; 20. The CMS of claim 11, wherein, display the second image on a second electronic display in the commercial vehicle; and display the combined image on a third electronic display in the commercial vehicle, the third electronic display disposed between the first electronic display and the second electronic display. ​ ​ ​

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