In single photon emission computed tomography (SPECT), pinhole and cone-beam collimators are used for small object imaging. It is accepted that a pinhole collimator should be used if the object is very small, and the cone-beam collimator should be used if the object is larger. This paper presents criteria to determine which collimation geometry is more advantageous in terms of spatial resolutio...

We begin by considering the process of image formation when a scene is viewed through a camera. The word camera has its origins in the Latin camera and the Greek kamara, both of which refer to a room or a chamber. In particular we will consider image formation through a pinhole camera. This is the dominant image formation model that is studied in computer vision. A pinhole camera is a box in wh...

A pinhole camera selects a two-dimensional set of rays from the four-dimensional light field. Pinhole cameras are a type of general linear camera, defined as planar 2D slices of the 4D light field. Cameras with finite apertures can be considered as the summation of a collection of pinhole cameras. In the limit they evaluate a two-dimensional integral of the four-dimensional light field. Hence a...

Depth images have been used to approximate scene geometry in a variety of interactive 3-D graphics applications. In previous work, images were constructed using orthographic or perspective projection which limits approximation quality to what is visible along a single view direction or from a single viewpoint. This paper shows that images constructed with non-pinhole cameras improve approximati...

Coleoid cephalopods have an elaborate camera eye whereas nautiloids have primitive pinhole eye without lens and cornea. The Nautilus pinhole eye provides a unique example to explore the module of lens formation and its evolutionary mechanism. Here, we conducted an RNA-seq study of developing eyes of Nautilus and pygmy squid. First, we found that evolutionary distances from the common ancestor t...

In photogrammetric applications, the measurements are conducted on images given by optical imaging systems (cameras). In order to ensure the demanded accuracy, those cameras have to be well calibrated geometrically. A new method for measuring glass lens distortion based on using distortion-free pinhole lens is proposed, where the measure of the distortion progress is derived by comparing two im...

Multi-beam confocal microscopy without any physical pinhole was demonstrated. As a key device, a custom CMOS image sensor realizing a focal-plane pinhole array effect by special pixel addressing and discarding of the unwanted photocarriers was developed. The axial resolution in the confocal mode measured by FWHM for a planar mirror was 8.9 μm, which showed that the confocality has been achieved...

We report a scheme for the detector system of confocal microscopes in which the pinhole and a large-area detector are substituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal passing through the pinhole. We demonstrate the imaging capability and the optical sectioning of the system. Subtractive-imaging confocal microscopy can be...