BACKGROUND OF THE INVENTION

[0001] The present invention generally relates to processing of video images streamed to a display, and more specifically to processing of streamed video images of scenes exterior to a vehicle. In some embodiments the present invention pertains even more specifically to processing of video images obtained from a rearward facing camera in a vehicle that are streamed to a display serving as a replacement for, or a supplement to, a rearview mirror.

SUMMARY OF THE INVENTION

[0002] According to one aspect of the present invention, a rearview display system is provided for a vehicle equipped with: a rear camera for generating a rearward video stream of a scene to a rear of the vehicle, a right-side camera for generating a right-side video stream of a scene to a right side of the vehicle, and a left-side camera for generating a left-side video stream of a scene to a left side of the vehicle. The rearview display system comprises: a processing circuit for receiving the rearward video stream, the right-side video stream, the left-side video stream, and an active spotter signal, wherein the processing circuit generates a composite video stream in response to the active spotter signal, the processing circuit forming the composite video stream from: (a) the rearward video stream and the right-side video stream, (b) the rearward video stream and the left-side video stream, and (c) at least the rearward video stream; and a display for displaying the composite video stream. When the composite video stream is formed from the rearward video stream and the right-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper right corner of the composite video stream where the right-side video stream is superimposed over the rearward video stream. When the composite video stream is formed from the rearward video stream and the left-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper left corner of the composite video stream where the left-side video stream is superimposed over the rearward video stream. [0003] According to another aspect of the present invention, a rearview display system is provided for a vehicle equipped with: a rear camera for generating a rearward video stream of a scene to a rear of the vehicle, a right-side camera for generating a right-side video stream of a scene to a right side of the vehicle, and a left-side camera for generating a left-side video stream of a scene to a left side of the vehicle. The rearview display system comprises: a processing circuit for receiving the rearward video stream, the right-side video stream, and the left-side video stream, wherein the processing circuit generates a composite video stream, the processing circuit forming the composite video stream from one of: (a) the rearward video stream and the right-side video stream, (b) the rearward video stream and the left-side video stream, and (c) at least the rearward video stream; and a display for displaying the composite video stream. When the composite video stream is formed from the rearward video stream and the right-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper right corner of the composite video stream where the right-side video stream is superimposed over the rearward video stream. When the composite video stream is formed from the rearward video stream and the left-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper left corner of the composite video stream where the left-side video stream is superimposed over the rearward video stream.

[0004] According to another aspect of the present invention, a method is provided for displaying rearward images on a rearview display for a vehicle equipped with: a rear camera for generating a rearward video stream of a scene to a rear of the vehicle, a right- side camera for generating a right-side video stream of a scene to a right side of the vehicle, and a left-side camera for generating a left-side video stream of a scene to a left side of the vehicle. The method comprises: generating a composite video stream in response to an active spotter signal from: (a) the rearward video stream and the right- side video stream, (b) the rearward video stream and the left-side video stream, and (c) at least the rearward video stream; and displaying the composite video stream. When the composite video stream is formed from the rearward video stream and the right-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper right corner of the composite video stream where the right-side video stream is superimposed over the rearward video stream. When the composite video stream is formed from the rearward video stream and the left-side video stream, the rearward video stream extends across the whole composite video stream with the exception of an upper left corner of the composite video stream where the left-side video stream is superimposed over the rearward video stream.

[0005] These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In the drawings:

[0007] Fig. 1 is a block diagram of an imaging system according to an embodiment of the invention;

[0008] Fig. 2 is a pictorial representation of an example of a composite video stream that may be generated by the processing circuit shown in Fig. 1;

[0009] Fig. 3 is a flow chart showing the method steps performed by the processing circuit shown in Fig. 1;

[0010] Fig. 4A is a front and side perspective view of a rearview assembly incorporating the imaging system of Fig. 1; and

[0011] Fig. 4B is a front elevational view of the rearview assembly shown in Fig. 4A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] As required, detailed embodiments of the present invention are disclosed herein.

However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to a detailed design and some schematics may be exaggerated or minimized to show function overview. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0013] Fig. 1 shows an imaging system 10 according to a first embodiment. As shown, imaging system 10 includes a rear camera 25 for generating a rearward video stream 125 of a scene to a rear of the vehicle, a right-side camera 26R for generating a right-side video stream 130R of a scene to a right side of the vehicle, a left-side camera 26L for generating a left-side video stream 130L of a scene to a left side of the vehicle, and a display system 12, which includes a processing circuit 30 that receives the streamed video images and generates a composite video stream 120 (as discussed in detail below), and a display 32 that displays the composite video stream 120. The imaging system 10 may be provided in a vehicle that is equipped with a source of an active spotter signal 34 such as a turn signal generating a right turn signa l and a left turn signal. The processing circuit 30 may be configured to receive the active spotter signals.

[0014] The processing circuit 30 may be configured to show the composite image 120 as depicted in Fig. 2 when an active spotter signal is received that indicates that the left spotter should be shown, the composite image may ta ke on this appearance either in response to other triggering mechanisms or in response to a user input or user default selection. I n other words, the spotter view corresponding to the left video stream 130L in Fig. 2 may be generated and displayed on-demand. One such other triggering method could be active spotter signals from left and right blind spot detectors that detect when a vehicle is present in one of the left or right blind spots. If a vehicle is present in the left blind spot, the composite display could include a spotter view of the left blind spot. Likewise, if a vehicle is present in the right blind spot, the composite display could include a spotter view of the right blind spot.

[0015] The active spotter signal may also be a rear cross path signal, an object detection signal, and/or a speed signal. Thus, the active spotter signal is selected from at least one of a turn signal, a side blind zone signal, a rear cross path signal, an object detection signal, and a speed signal.

[0016] As described further below, the processing circuit 30 is configured to form the composite video stream 120 from : (a) the rearward video stream 125 and the right-side video stream 130R, (b) the rearward video stream 125 and the left-side video stream 130L, and (c) at least the rearward video stream 125. The composite video stream 120 may include video streams that are stitched together or video streams that are separately displayed in a side-by-side or overlapping fashion.

[0017] As shown in Fig. 2, when the composite video stream 120 is formed from the rearward video stream 125 and the left-side video stream 130L, the rearward video stream 125 extends across the whole composite video stream 120 with the exception of an upper left corner of the composite video stream 120 where the left-side video stream 130L is superimposed over the rearward video stream 125. Similarly, when the composite video stream 120 is formed from the rearward video stream 125 and the right-side video stream 130R, the rearward video stream 125 extends across the whole composite video stream 120 with the exception of an upper right corner of the composite video stream 120 where the right-side video stream 130R is superimposed over the rearward video stream 125. The composite video stream 120 may thus selectively provide an appearance similar to a spotter mirror typically found on an outside mirror assembly so as to provide a better view of blind spots to the sides of the vehicle.

[0018] The spotter view may be processed to appear as though the video stream is from a wide angle view or fish-eye view camera, or the right-side camera 26R and left-side camera 26L may be equipped with a wide angle view or fish-eye view lens.

[0019] As shown in Fig. 2, a demarcation line 132 may be provided in the composite video stream 120 to demark the boundaries of the two video streams 130L and 125.

[0020] To further ensure that the spotter view does not significantly obstruct the rearward video stream 125, the spotter view is restricted to an upper corner of the composite video stream 120. In this case, the upper corner in which the spotter view is located may be confined above a horizontal center line of the rearward video stream and has a width less than a third of the width of the rearward video stream 125.

[0021] To further ensure that the view of the rearward scene is not obstructed, a convergence point 134 of the rearward video stream 125 may be moved from the center of the composite video stream 120 towards a side opposite the spotter view as shown in Fig. 2. This tends to shift the field of view to the direction in which a turn is being signaled while enabling the spotter view to be placed in an area of the rearward scene where there would likely not be a vehicle present.

[0022] Fig. 3 is a flowchart showing the method steps performed by the processing circuit 30. In step 100, the processing circuit 30 receives the rearward video stream 125, the right-side video stream 130R, and left-side video stream 130L from rear camera 25, right-side camera 26R, and left-side camera 26L, respectively. Then, in step 102, the processing circuit 30 determines if the active spotter signal 34 is received and whether the active spotter signal indicates that the right or left spotter should be shown. For example, if the active spotter signal is a turn signal, the processing circuit 30 determines whether the left or right turn signal is activated. If the active spotter signal is not received (or if the active spotter signal does not indicate that either the right or left spotter should be shown), the processing circuit 30 generates the composite video image 120 from at least the rearward video stream 125 (step 104). The processing circuit 30 then supplies this composite image 120 to the display 32 for display thereon (step 110). Steps 100, 102, 104, and 110 are repeated until such time that an active spotter signal is received.

[0023] If the processing circuit 30 determines in step 102 that an active spotter signal is received and that the active spotter signal indicates that the right spotter should be shown, the processing circuit 30 generates the composite video stream 120 from the rearward video stream 125 and the right-side video stream 130R where the rearward video stream 125 extends across the whole composite video stream 120 with the exception of an upper right corner of the composite video stream 120 where the right- side video stream 130R is superimposed over the rearward video stream 125 (step 106). The processing circuit 30 then supplies this composite image 120 to the display 32 for display thereon (step 110). Steps 100, 102, 106, and 110 are repeated until such time that the active spotter signal is no longer received or that the left spotter should be shown.

[0024] If the processing circuit 30 determines in step 102 that an active spotter signal is received and that the active spotter signal indicates that the left spotter should be shown, the processing circuit 30 generates the composite video stream 120 from the rearward video stream 125 and the left-side video stream 130L where the rearward video stream 125 extends across the whole composite video stream 120 with the exception of an upper left corner of the composite video stream 120 where the left-side video stream 130L is superimposed over the rearward video stream 125 (step 108). The processing circuit 30 then supplies this composite image 120 to the display 32 for display thereon (step 110). Steps 100, 102, 108, and 110 are repeated until such time that the active spotter signal is no longer received or that the right spotter should be shown.

[0025] The processing circuit 30 may form the composite video stream 120 from the rearward video stream 125, the right-side video stream 130R, and the left-side video stream 130L when no active spotter signal is received or if one is received that does not indicate that the right or left spotter should be shown. In this case, the composite video stream 120 may be formed by seamlessly stitching the video streams together to appear as one contiguous video stream representing a field of view that is larger than the field of view represented by any one of the separate video streams. This same stitched composite video stream may be used to generate the composite video stream when an active spotter signal is received such that the right-side video stream 130R or the left-side video stream 130L is superimposed thereon.

[0026] Fig. 4A is a front and side perspective view of a rearview assembly 50 incorporating the imaging system 10 of Fig. 1, and Fig. 4B is a front elevational view of the rearview assembly 50. The rearview assembly 50 includes a housing 54 and a transparent or semi-transparent element 52 extending across an opening in the housing 54. The display 32 is provided behind the transparent or semi-transparent element 52 so as to project the displayed composite image therethrough when the display 32 is active. The display 32 may be activated in response to a toggle switch 56.

[0027] The transparent or semi-transparent element 52 may be a partially reflective, partially transmissive mirror element or a switchable reflective element. Examples of a switchable reflective element are disclosed in commonly-assigned U.S. Patent Nos. 9,254,789, 9,637,054, and 9,834,146, the entire disclosures of which are hereby incorporated herein by reference. Examples of partially reflective, partially transmissive mirror elements positioned in front of a display are disclosed in in commonly-assigned US 2015/0266427 Al, the entire disclosure of which is incorporated herein by reference.

[0028] It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.