Integral imaging is a three-dimensional imaging technique that captures and reproduces a light field by using a two-dimensional array of microlenses (or lenslets), sometimes called a fly's-eye lens, normally without the aid of a larger overall objective or viewing lens. In capture mode, in which a film or detector is coupled to the microlens array, each microlens allows an image of the subject as seen from the viewpoint of that lens's location to be acquired. In reproduction mode, in which an object or source array is coupled to the microlens array, each microlens allows each observing eye to see only the area of the associated micro-image containing the portion of the subject that would have been visible through that space from that eye's location. The optical geometry can perhaps be visualized more easily by substituting pinholes for the microlenses, as has actually been done for some demonstrations and special applications.
A display using integral imaging is a type of light field display.
The result is a visual reproduction complete with all significant depth cues, including parallax in all directions, perspective that changes with the position and distance of the observer, and, if the lenses are small enough and the images of sufficient quality, the cue of accommodation — the adjustments of eye focus required to clearly see objects at different distances. Unlike the voxels in a true volumetric display, the image points perceived through the microlens array are virtual and have only a subjective location in space, allowing a scene of infinite depth to be displayed without resorting to an auxiliary large magnifying lens or mirror.
Integral imaging was partly inspired by barrier grid autostereograms and in turn partly inspired lenticular printing.
Inventor Gabriel Lippmann called the technique "photographie intégrale" (in French). It is usually translated literally as "integral photography", which suggests the integration of a whole image from parts of many small ones. However, a more usual meaning of the French word "intégrale" is "complete" or "unabridged", so that "complete photography" is another valid translation of Lippmann's perhaps deliberately ambiguous name for it.
On March 2, 1908 Nobel prize winning French physicist Gabriel Lippmann presented his ideas for "Photographie intégrale", based on insect eyes. He was probably also inspired by the barrier grid autostereograms of Frederic Ives and Eugène Estanave, representing Estanave at several presentations of Estanave's works at the French Academy of Sciences. Lippmann suggested to use a screen of tiny lenses. Spherical segments should be pressed into a sort of film with photographic emulsion on the other side. The screen would be placed inside a lightproof holder and on a tripod for stability. When exposed each tiny lens would function as a camera and record the surroundings from a slightly different angle than neighboring lenses. When developed and lit from behind the lenses should project the life-size image of the recorded subject in space. He could not yet present concrete results in March 1908, but by the end of 1908 he claimed to have exposed some Integral photography plates and to have seen the "resulting single, full-sized image". However, the technique remained experimental since no material or technique seemed to deliver the optical quality desired. At the time of his death in 1921 Lippmann reportedly had a system with only twelve lenses. [1]
Eugène Estanave performed further experiments with Lippmann's technique. He exhibited an integral photograph in 1925 and published about his findings in La Nature. In 1930 he had 432 lenses in a 6.5 x 9 cm plate with viewable results, but then abandoned the lenticular screen and continued his integral photography experiments with pinholes. [1]
Louis Lumière worked on integral photography and corresponded with Lippman about the technique. Lumière patented a system a few years after Lippmann's death, but never seems to have actually manufactured lenticular screens. [1]
Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed in many fields of science, manufacturing, and business, as well as its more direct uses for art, film and video production, recreational purposes, hobby, and mass communication.
A pinhole camera is a simple camera without a lens but with a tiny aperture —effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect. The size of the images depends on the distance between the object and the pinhole.
The Autochrome Lumière was an early color photography process patented in 1903 by the Lumière brothers in France and first marketed in 1907. Autochrome was an additive color "mosaic screen plate" process. It was the principal color photography process in use before the advent of subtractive color film in the mid-1930s.
Stereoscopy is a technique for creating or enhancing the illusion of depth in an image by means of stereopsis for binocular vision. The word stereoscopy derives from Greek στερεός (stereos) 'firm, solid', and σκοπέω (skopeō) 'to look, to see'. Any stereoscopic image is called a stereogram. Originally, stereogram referred to a pair of stereo images which could be viewed using a stereoscope.
Gabriel Lippmann conceived a two-step method to record and reproduce colours, variously known as direct photochromes, interference photochromes, Lippmann photochromes, Photography in natural colours by direct exposure in the camera or the Lippmann process of colour photography. Lippmann won the Nobel Prize in Physics for this work in 1908.
Color photography is photography that uses media capable of capturing and reproducing colors. By contrast, black-and-white or gray-monochrome photography records only a single channel of luminance (brightness) and uses media capable only of showing shades of gray.
An autostereogram is a two-dimensional (2D) image that can create the optical illusion of a three-dimensional (3D) scene. Autostereograms use only one image to accomplish the effect while normal stereograms require two. The 3D scene in an autostereogram is often unrecognizable until it is viewed properly, unlike typical stereograms. Viewing any kind of stereogram properly may cause the viewer to experience vergence-accommodation conflict.
Lenticular printing is a technology in which lenticular lenses are used to produce printed images with an illusion of depth, or the ability to change or move as they are viewed from different angles.
A 3D display is a display device capable of conveying depth to the viewer. Many 3D displays are stereoscopic displays, which produce a basic 3D effect by means of stereopsis, but can cause eye strain and visual fatigue. Newer 3D displays such as holographic and light field displays produce a more realistic 3D effect by combining stereopsis and accurate focal length for the displayed content. Newer 3D displays in this manner cause less visual fatigue than classical stereoscopic displays.
Jonas Ferdinand Gabriel Lippmann was a Franco-Luxembourgish physicist and inventor, and Nobel laureate in physics for his method of reproducing colours photographically based on the phenomenon of interference. His parents were French Jews.
A light field camera, also known as a plenoptic camera, is a camera that captures information about the light field emanating from a scene; that is, the intensity of light in a scene, and also the precise direction that the light rays are traveling in space. This contrasts with conventional cameras, which record only light intensity at various wavelengths.
A lenticular lens is an array of lenses, designed so that when viewed from slightly different angles, different parts of the image underneath are shown. The most common example is the lenses used in lenticular printing, where the technology is used to give an illusion of depth, or to make images that appear to change or move as the image is viewed from different angles.
Autostereoscopy is any method of displaying stereoscopic images without the use of special headgear, glasses, something that affects vision, or anything for eyes on the part of the viewer. Because headgear is not required, it is also called "glasses-free 3D" or "glassesless 3D". There are two broad approaches currently used to accommodate motion parallax and wider viewing angles: eye-tracking, and multiple views so that the display does not need to sense where the viewer's eyes are located. Examples of autostereoscopic displays technology include lenticular lens, parallax barrier, and may include Integral imaging, but notably do not include volumetric display or holographic displays.
The following outline is provided as an overview of and topical guide to photography:
PHSCologram is a registered trademark for barrier-strip and lenticular autostereograms made by Chicago-based art collective (Art)n laboratory.
A microlens is a small lens, generally with a diameter less than a millimetre (mm) and often as small as 10 micrometres (µm). The small sizes of the lenses means that a simple design can give good optical quality but sometimes unwanted effects arise due to optical diffraction at the small features. A typical microlens may be a single element with one plane surface and one spherical convex surface to refract the light. Because micro-lenses are so small, the substrate that supports them is usually thicker than the lens and this has to be taken into account in the design. More sophisticated lenses may use aspherical surfaces and others may use several layers of optical material to achieve their design performance.
A 3D stereo view is the viewing of objects through any stereo pattern.
A 3D display is multiscopic if it projects more than two images out into the world, unlike conventional 3D stereoscopy, which simulates a 3D scene by displaying only two different views of it, each visible to only one of the viewer's eyes. Multiscopic displays can represent the subject as viewed from a series of locations, and allow each image to be visible only from a range of eye locations narrower than the average human interocular distance of 63 mm. As a result, not only does each eye see a different image, but different pairs of images are seen from different viewing locations.
Barrier-grid animation or picket-fence animation is an animation effect created by moving a striped transparent overlay across an interlaced image. The barrier-grid technique originated in the late 1890s, overlapping with the development of parallax stereography (Relièphographie) for 3D autostereograms. The technique has also been used for color-changing pictures, but to a much lesser extent.
Lightfieldmicroscopy (LFM) is a scanning-free 3-dimensional (3D) microscopic imaging method based on the theory of light field. This technique allows sub-second (~10 Hz) large volumetric imaging with ~1 μm spatial resolution in the condition of weak scattering and semi-transparence, which has never been achieved by other methods. Just as in traditional light field rendering, there are two steps for LFM imaging: light field capture and processing. In most setups, a microlens array is used to capture the light field. As for processing, it can be based on two kinds of representations of light propagation: the ray optics picture and the wave optics picture. The Stanford University Computer Graphics Laboratory published their first prototype LFM in 2006 and has been working on the cutting edge since then.