Method and apparatus for expanded dynamic range imaging
AssigneeBroadcom Corporation
InventorsNoam Sorek, Ilia Vitsnudel, Ron Fridental
Life of this patent
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Abstract
A method and apparatus for enabling wide intensity range in digital imaging using a small amount of memory beyond the memory required for storing the relevant image. The methods and apparatus disclose exposing few-line segments within an image using two different exposure times before continuing with other segments of the image. In alternative configurations, sensors are sampled such that neighboring sensors having the same colors are sampled after being exposed for different durations.
Claims21
A method for capturing an at least one image of a scene by a capturing device comprising a sensor made up of multiple sensor cells, the at least one image comprising a number of pixels, the scene having areas with substantially varying intensity levels, the method comprising:
- connecting a memory unit to the capturing device to serve as a temporary storage for dynamically expanding an exposure range of the captured at least one image;
- storing in the memory unit first intensity values received from a multiplicity of first light-sensitive sensor cells under a first exposure time;
- receiving second intensity values received from a multiplicity of second light-sensitive sensor cells under a second exposure time being longer than the first exposure time;
- interpolating one of the second intensity values from a intensity value of a neighboring first light-sensitive sensor of the same color in response to the one of the second intensity values being saturated;
- integrating the first intensity values stored in the memory unit and the second intensity value into combined values;
- assigning values associated with the combined values to pixels forming a part of the at least one image,
- sending each part of the at least one Image formed by the assigned pixel values to a destination adapted to receive the at least one image;
- and
- wherein the memory unit has storage size large enough to meet the requirements to provide dynamic expansion of the exposure range of a whole image and of at most a number of values which is about ten percent of a total number of the multiple sensor cells in the sensor.
An image signal processor for capturing an at least one image of a scene, the at least one image comprising a number of pixels, the scene having areas with substantially varying intensity levels, the image signal processor comprising:
- a sensor comprising an array of light-sensitive sensor cells, at least one first light:
- sensitive sensor cell providing a first value related to a long exposure time and at least one second light-sensitive sensor cell providing a second value related to a short exposure time;
- a memory unit connected to the sensor, serving as a temporary storage for dynamically expanding the exposure range of the captured at least one image;
- and adapted to store the first value or the second value, the memory unit capable of storing a number of values substantially smaller than a total number of the light-sensitive sensor cells in the sensor;
- and
- a processing unit for integrating the first value and the second value, and wherein the memory unit has storage size large enough to meet the requirements to provide dynamic expansion of the exposure range of a whole image and of at most a number of values which is about ten percent of total number of the array of light-sensitive sensor cells in the sensor, wherein the processing unit is configured to overlap a plurality of samplings of the long exposure time and the short exposure time.
Dependencies are inferred from the claim text.