Dual aperture zoom camera with video support and switching / non-switching dynamic control
A dual-aperture zoom digital camera operable in both still and video modes. The camera includes Wide and Tele imaging sections with respective lens/sensor combinations and image signal processors and a camera controller operatively coupled to the Wide and Tele imaging sections. The Wide and Tele imaging sections provide respective image data. The controller is configured to output, in a zoom-in operation between a lower zoom factor (ZF) value and a higher ZF value, a zoom video output image that includes only Wide image data or only Tele image data, depending on whether a no-switching criterion is fulfilled or not.
1. A zoom digital camera comprising:
a) a Wide imaging section that includes a fixed focal length Wide lens with a Wide field of view (FOV) and a Wide sensor, the Wide imaging section operative to provide Wide image data of an object or scene;
b) a Tele imaging section that includes a fixed focal length Tele lens with a Tele FOV that is narrower than the Wide FOV and a Tele sensor, the Tele imaging section operative to provide Tele image data of the object or scene; and
c) a camera controller operatively coupled to the Wide and Tele imaging sections and configured to evaluate if a no-switching criterion is fulfilled or not fulfilled, wherein if the no-switching criterion is fulfilled in a zoom-in operation between a lower zoom factor (ZF) value and a higher ZF value at a zoom factor (ZF) higher than an up-transfer ZF, the camera controller is further configured to output a zoom video output image that includes only Wide image data, and wherein if the no-switching criterion is not fulfilled, the camera controller is further configured to output a zoom video output image that includes only transformed, digitally zoomed Tele image data.
2. The camera of claim 1 , wherein the no-switching criterion includes a shift between the Wide and Tele images calculated by global registration, the shift being greater than a first threshold.
3. The camera of claim 1 , wherein the no-switching criterion includes a disparity range calculated by global registration, the disparity range being greater than a second threshold.
4. The camera of claim 1 ; wherein the no-switching criterion includes an effective resolution of the Tele image being lower than an effective resolution of the Wide image.
5. The camera of claim 1 , wherein the no-switching criterion includes a number of corresponding features in the Wide and Tele images being smaller than a third threshold.
6. The camera of claim 1 , wherein the no-switching criterion includes a majority of objects imaged in an overlap area of the Wide and Tele images being calculated to be closer to the camera than a first threshold distance.
7. The camera of claim 1 , wherein the no-switching criterion includes some objects imaged in an overlap area of the Wide and Tele images being calculated to be closer than a second threshold distance while other objects imaged in the overlap area of the Wide and Tele images being calculated to be farther than a third distance threshold.
8. The camera of claim 1 , wherein the camera controller includes a user control module for receiving user inputs and a sensor control module for configuring each sensor to acquire the Wide and Tele image data based on the user inputs.
9. The camera of claim 8 , wherein the user inputs include a zoom factor, a camera mode and a region of interest.
10. The camera of claim 1 , wherein the Tele lens includes a ratio of total track length (TTL)/effective focal length (EFL) smaller than 1.
11. The camera of claim 1 , wherein the camera controller is further configured to combine in still mode, at a predefined range of ZF values, at least some of the Wide and Tele image data to provide a fused output image of the object or scene from a particular point of view.
12. A method for obtaining zoom images of an object or scene using a digital camera, comprising the steps of:
a) providing in the digital camera a Wide imaging section having a Wide lens with a Wide field of view (FOV) and a Wide sensor, a Tele imaging section having a Tele lens with a Tele FOV that is narrower than the Wide FOV and a Tele sensor, and a camera controller operatively coupled to the Wide and Tele imaging sections; and
b) configuring the camera controller to evaluate if a no-switching criterion is fulfilled or not fulfilled, and, if the no-switching criterion is fulfilled, configuring the camera controller to output at a zoom factor (ZF) higher than an up-transfer ZF a zoom video output image that includes only Wide image data in a zoom-in operation between a lower ZF value and a higher ZF value, or if the no-switching criterion is not fulfilled, configuring the camera controller to output a zoom video output image that includes only transformed, digitally zoomed Tele image data.
13. The method of claim 12 , wherein the no-switching criterion includes a shift between the Wide and Tele images calculated by global registration, the shift being greater than a first threshold.
14. The method of claim 12 , wherein the no-switching criterion includes a disparity range calculated by global registration, the disparity range being greater than a second threshold.
15. The method of claim 12 , wherein the no-switching criterion includes an effective resolution of the Tele image being lower than an effective resolution of the Wide image.
16. The method of claim 12 , wherein the no-switching criterion includes a number of corresponding features in the Wide and Tele images being smaller than a third threshold.
17. The method of claim 12 , wherein the no-switching criterion includes a majority of objects imaged in an overlap area of the Wide and Tele images being calculated to be closer to the camera than a first threshold distance.
18. The method of claim 12 , wherein the no-switching criterion includes some objects imaged in an overlap area of the Wide and Tele images being calculated to be closer than a second threshold distance while other objects imaged in the overlap area of the Wide and Tele images being calculated to be farther than a third threshold distance.
19. The method of claim 12 , further comprising the step of configuring the camera controller to combine in still mode, at a predefined range of ZF values, at least some of the Wide and Tele image data to provide a fused output image of the object or scene from a particular point of view.
20. The method of claim 12 , wherein the step of configuring the camera controller to combine in still mode, at a predefined range of ZF values, at least some of the Wide and Tele image data to provide a fused output image includes configuring the camera controller to combine Wide and Tele image data only in focused areas.