Described herein are methods and devices that employ a plurality of image sensors to capture a target image of a scene. As described, positioning at least one reflective or refractive surface near the plurality of image sensors enables the sensors to capture together an image of wider field of view and longer focal length than any sensor could capture individually by using the reflective or refractive surface to guide a portion of the image scene to each sensor. The different portions of the scene captured by the sensors may overlap, and may be aligned and cropped to generate the target image.

Multi-camera system using folded optics

An image capturing system and a method of autofocusing are disclosed such that, for example, when a folded optics configuration is used, a field corrector lens can be placed on the image sensor of the system and a plurality of lenses can be placed perpendicular to the image sensor. The plurality of lenses can be movable relative to the image sensor such that acceptable MTF curve performances can be obtained when the image capturing system is focused at reference distances.

Auto-focus in low-profile folded optics multi-camera system

Aspects relate to methods and systems for producing ultra-wide field of view images. In some embodiments, an image capture system for capturing wide field-of-view images comprises an aperture, a central camera positioned to receive light through the aperture, the center camera having an optical axis, a plurality of periphery cameras disposed beside the central camera and pointed towards a portion of the optical axis of the center camera, the plurality of cameras arranged around the center camera, and a plurality of extendible reflectors. The reflectors are configured to move from a first position to a second position and have a mirrored first surface that faces away from the optical axis of the center camera and a second black surface that faces towards the optical axis of the center camera, the plurality of periphery cameras arranged around the center camera.

Wide field of view array camera for hemispheric and spherical imaging

An image enhancement apparatus is provided. The image enhancement apparatus includes a global contrast curve generator, a local contrast curve generator and an image generator. The global contrast curve generator generates a global contrast curve for an input image according to a global histogram of the input image. The local contrast curve generator generates a local contrast curve for each image partition within the input image according to the global contrast curve and further a feature of the image partition. The image generator generates an output image by enhancing a contrast of each image partition according to the local contrast curve for the image partition and the input image, and merging the enhanced image partitions.

Image enhancement method and apparatuses utilizing the same

Aspects relate to an array camera exhibiting little or no parallax artifacts in captured images. For example, the planes of the central mirror surfaces of the array camera can be located at a midpoint along, and orthogonally to, a line between the corresponding camera location and the virtual camera location. Accordingly, the cones of all of the cameras in the array appear as if coming from the virtual camera location after folding by the mirrors. Each sensor in the array “sees” a portion of the image scene using a corresponding facet of the central mirror prism, and accordingly each individual sensor/mirror pair represents only a sub-aperture of the total array camera. The complete array camera has a synthetic aperture generated based on the sum of all individual aperture rays.

Multi-camera system using folded optics free from parallax artifacts

Methods for contrast enhancement of digital images are provided. A method of adaptive histogram equalization is provided that determines weighting factors for discriminating between sub-regions of a digital image to be more enhanced or less enhanced. Another method for content adaptive local histogram equalization is provided that uses a mapping function in which the dynamic range is not changed by the transformation. A third method for contrast enhancement is provided that includes dividing a digital image into a plurality of regions of pixels, and for each region in the plurality of regions, determining a threshold gray level for the region, generating a mapping curve for the region based on the threshold gray level, and applying the generated mapping curve to each pixel in the region to enhance contrast.

Methods and systems for contrast enhancement

The mixing of high-gain and low-gain outputs of a wide dynamic range image sensor uses relationship parameter estimation according to linear regression; and the mixed output is adaptively filtered for noise gap reduction.

Apparatus and method for processing images

A wide dynamic range image sensor method combines the response of high-gain sensing cells and low-gain sensing cells with better linearity than the prior art. A search is made in successive central regions within the response curve of the high-gain and low-gain cells to find a highest slope linear fit. This highest slope and the corresponding offset are used in mixing the high-gain and low-gain responses to achieve a wide dynamic range.

Emi Arai

Papers

Methods and systems for contrast enhancement

Apparatus and method for processing images

Method for mixing high-gain and low-gain signal for wide dynamic range image sensor