In this work, we propose analytical solution to non-frontal camera calibration in a generalized pupil-centric imaging framework. The decentering distortion is explicitly modelled as a sensor rotation with respect to the lens plane. The rotation parameters are then computed analytically along with other calibration parameters. The centre of radial distortion is then computationally obtained given the analytical solution.
Category: Computational Cameras
Pupil-Centric Imaging Model
In developing the new opto-geometric configurations, we have found that certain classical models and approaches cease to be adequate. For example, the long-established Gaussian model of image formation fails to adequately predict the acquired images, and the optical and geometric phenomena ignored in the traditional characterization of the most focused scene point make the traditional methods of focus analysis unacceptable.
Omnifocus Imaging
We discuss how to generate omnifocus images from a sequence of different focal setting images. We first show that the existing focus measures would encounter difficulty when detecting which frame is most focused for pixels in the regions between intensity edges and uniform areas. Then we propose a new focus measure that could be used to handle this problem.
Accessible Aperture for Computational Imaging
Many computational imaging applications involve manipulating the incoming light beam in the aperture and image planes. However, accessing the aperture, which conventionally stands inside the imaging lens, is still challenging. In this paper, we present an approach that allows access to the aperture plane and enables dynamic control of its transmissivity, position, and orientation.
Hemispherical Imaging Camera
We have developed a camera which is capable of acquiring very large field of view (FOV) images at high and uniform resolution, from a single viewpoint, at video rates. The FOV can range from being nearly hemispherical, to being nearly omni-directional, barring some small scene parts being obstructed by image sensors themselves.
An Omni-Directional Stereo Vision System Using Single Camera
We describe a new omnidirectional stereo imaging system that uses a concave lens and a convex mirror to produce a stereo pair of images on the sensor of a conventional camera. The light incident from a scene point is split and directed to the camera in two parts. One part reaches camera directly after reflection from the convex mirror and forms a single-viewpoint omnidirectional image.
Single Lens Depth Camera
A visual depth sensor composed of a single camera and a transparent plate rotating about the optical axis in front of the camera. Depth is estimated from the disparities of scene points observed in multiple images acquired viewing through the rotating the plate.
We propose a novel depth sensing imaging system composed of a single camera along with a parallel planar plate rotating about the optical axis of the camera.
Split Aperture Imaging
Standard imaging sensors have limited dynamic range and hence are sensitive to only a part of the illumination range present in a natural scene. The dynamic range can be improved by acquiring multiple images of the same scene under different exposure settings and then combining them. We have developed a multi-sensor camera design, called Split-Aperture Camera, to acquire registered, multiple images of a scene, at different exposure, from a single viewpoint, and at video-rate.
High-Resolution Double Pyramid Panoramic Cameras
Pyramid Cameras
To acquire panoramic video sequences, we have developed two types of Double-Mirror-Pyramid cameras that capture up to 360-degree fields of view at high-resolution. The first one, A Single View Double-Mirror-Pyramid Panoramic Camera, acquires a single sequence from one viewpoint, whereas the second, A Multiview Double-Mirror-Pyramid Panoramic Camera, provides multiple video sequences each taken from a different viewpoint, e.g.
Multi-View Double Mirror Pyramid Panoramic Cameras
Pyramid Cameras
To acquire panoramic video sequences, we have developed two types of Double-Mirror-Pyramid cameras that capture up to 360-degree fields of view at high-resolution. The first one, A Single View Double-Mirror-Pyramid Panoramic Camera, acquires a single sequence from one viewpoint, whereas the second, A Multiview Double-Mirror-Pyramid Panoramic Camera, provides multiple video sequences each taken from a different viewpoint, e.g.
Panoramic Imaging with Infinite Dynamic Range
Most imaging sensors have a limited dynamic range and hence can satisfactorily respond to only a part of illumination levels present in a scene. This is particularly disadvantageous for omnidirectional and panoramic cameras since larger fields of view have larger brightness ranges. We propose a simple modification to existing high resolution omnidirectional/panoramic cameras in which the process of increasing the dynamic range is coupled with the process of increasing the field of view.
Omnifocus Nonfrontal Imaging Camera
The concept of omnifocus nonfrontal imaging camera, OMNICAM or NICAM, initiated a new chapter in imaging and digital cameras. NICAM has introduced hitherto non-existent imaging capabilities, in addition to overcoming some problems with previous methods. NICAM is capable of acquiring seamless panoramic images and range estimates of wide scenes with all objects in focus, regardless of their locations.