Close Focus with GPU
AssigneeMotorola Mobility LLC
InventorsDenis S Shchepetov, Eric F Aas
Life of this patent
Estimating the term…
Abstract
Disclosed are systems and methods for focusing a digital camera to capture a scene. It is first detected that a change in a scene requires the digital camera to be focused or refocused. The camera focus is automatically scanned from a closest settable distance to farther distances until a first closest object in the scene is detected. Once the first closest object in the scene is detected, the camera focus is set at the distance of the first closest object and a finer scan is executed. In an embodiment, a dynamic movement threshold is calculated and used to determine that the change in scene requires the digital camera to be focused or refocused.
Claims20
A method for auto focusing a digital camera on a scene, the method comprising:
- determining that a change in the scene requires that the digital camera be refocused;
- automatically setting a focus distance of the digital camera to a lowest available distance;
- dividing the scene into multiple sub-frames, incrementally increasing the focus distance at a first increment without user intervention and determining a focus value at each increment for each sub-frame and for the entire scene;
- automatically resetting the focus distance of the digital camera to a fine scan start point corresponding to a closest focus value peak in one or more sub-frames if the closest focus value peak for the one or more sub-frames is closer than a focus value peak for the entire scene, and otherwise setting the fine scan start point to the focus value peak for the entire scene;
- and
- executing a first final scan from the final scan start point at a second increment, the second increment being smaller than the first increment.
A method for auto focusing a digital camera on a scene, the method comprising:
- determining that a digital camera is to be focused;
- automatically scanning a focus of the digital camera at a first increment over a range of distances including a closest settable distance to determine a set of focus values for the scene as a whole and for each of a plurality of sub-frames;
- automatically setting a starting focus distance of the digital camera to a distance that is a closer of a focus value peak for the scene as a whole and a focus value peak for one or more of the plurality of sub-frames;
- and
- performing a first final scan of the focus of the digital camera at a second increment smaller than the first increment.
A system for focusing a digital camera on a scene, the system comprising:
- a differencer configured to difference a current frame of the scene and a prior frame of the scene to produce a frame difference;
- a jitter simulator configured to jitter the current frame of the scene to produce a jitter frame and to compare the jitter frame to the current frame of the scene to produce a jitter difference;
- a comparator configured to compare the frame difference and the jitter difference and to output a movement value based on the comparison, the movement value indicating whether focusing on the scene should occur;
- and
- a controller configured to focus the digital camera on a closest object in the scene by performing a first scan of a focus distance of the digital camera from near to far for the scene, and for multiple sub-frames of the scene, with coarse resolution to identify the distance to the closest object and then performing a second scan of the focus distance of the digital camera for the scene with a finer resolution about the distance to the closest object.
Dependencies are inferred from the claim text.