TDCI (Time Domain Continuous Imaging) is a system for image capture and representation in which scene appearance is modeled as a set of continuous waveforms recording the changes in incident light at each pixel over time. Several of the advantages of TDCI are related to the ability to set exposure parameters after-the-fact, rather than at the time of capture. These exposure parameters can be far more complicated than are physically realizable in a conventional camera, or reasonable to design without the ability to repeatedly expose the same scene. Previous TDCI experiments have performed relatively traditional integration; this work explores a pair of related exposure behavior enabled by TDCI - the non-uniform integration of incident light into an image along the axes of both the time and space. This paper details a proof-of-concept implementation which ingests video frames and re-exposes images from the resulting sampled light with user-specified spatially and temporally nonuniform gain.
A multicamera, array camera, cluster camera, or "supercamera" incorporates two or more component cameras in a single system that functions as a camera with superior performance or special capabilities. Many camera arrays have been built by many organizations, yet creating an effective multicamera has not become significantly easier. This paper attempts to provide some useful insights toward simplifying the design, construction, and use of multicameras. Nine multicameras our group built for diverse purposes between 1999 and 2017 are described in some detail, including four built during Summer 2017 using some of the proposed simplifications.
Time domain continuous imaging (TDCI) models scene appearance as a set of continuous waveforms, each recording how the value of an individual pixel changes over time. When a set of timestamped still images is converted into a TDCI stream, pixel value change records are created based on when the pixel value becomes more different from the previous value than the value error model classifies as noise. Virtual exposures may then be rendered from the TDCI stream data for arbitrary time intervals by integrating the area under the pixel value waveforms. Using conventional cameras, multispectral and high dynamic range imaging both involve combining multiple exposures; the needed variations in exposure and/or spectral filtering generally skew the time periods represented by the component exposures or compromise capture quality in other ways. This paper describes a simple approach in which converting the image data to a TDCI representation is used to support generation of a higher-quality fusion of the separate captures.
Time Domain Continuous Imaging (TDCI) is a new model for photography that allows exposure timing to be freely manipulated after capture. This is done by creating, and operating on, a continuous waveform representation of how the value of each pixel changes over time. However, at this writing, there are no sensors that directly implement TDCI capture. The FourSee multi-camera prototype enables temporally-skewed exposures to be captured using the four component cameras and then later post-processed to create a TDCI representation, but the postprocessing is awkward and requires upload of image data to a separate computer. In contrast, this paper reports on a method whereby a single, conventional, Canon PowerShot camera can be used as a stand-alone TDCI platform. The camera programming is enhanced by custom code which is loaded into the camera using the Canon Hack Development Kit (CHDK). Thus, using code that should be portable to most camera models supported by CHDK, an inexpensive Canon PowerShot camera is able to internally capture and manipulate TDCI streams in the new .tik (Temporal Image Kontainer) file format.