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Topic: Cylindrical perspective

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	Cylindrical Map Projections
		Perspective projections to a cylinder are less important than perspective projections to a plane because they do not share the same special properties.
		Cylindrical stereographic projections are rarely used, although Gall's stereographic projection has been proposed as compromise projection having less distortion of distances than the cylindrical gnomonic projection and less distortion of shapes than the cylindrical orthographic projection.
		The cylindrical orthographic projection assumes that the light source is an infinite distance from the projection surface, resulting in parallel rays of light.
	www.fes.uwaterloo.ca /crs/geog165/cylproj.htm (1163 words)

	Mathematics and Art
		Leonardo distinguished two different types of perspective: artificial perspective which was the way that the painter projects onto a plane which itself may be seen foreshortened by an observer viewing at an angle; and natural perspective which reproduces faithfully the relative size of objects depending on their distance.
		Another contribution to perspective made by Dürer in his 1525 treatise was the description of a variety of mechanical aids which could be used to draw images in correct perspective.
		The phrase "linear perspective" was invented by Taylor in this work and he defined the vanishing point of a line, not parallel to the plane of the picture, as the point where a line through the eye parallel to the given line intersects the plane of the picture.
	www-groups.dcs.st-and.ac.uk /~history/HistTopics/Art.html (4272 words)

	Cartographic Projections
		Cylindrical projections are based upon the projection of the earth onto a cylinder that can be then unrolled into a plane.
		The principal characteristics of cylindrical projections are that (if the usual aspect is seen) all meridians and parallels are straight lines, with the meridians parallel and equally spaced, and the parallels also parallel and perpendicular to the meridians.
		This is the simplest cylindrical projection, and has the property that equal spaces on both meridians and parallels are to be found.
	www.research.ibm.com /dx/proceedings/cart/cart.htm (1671 words)

	Basic Photography Techniques - Perspective.
		In other words, perspective in the composition of a photograph is the way real three-dimensional objects are pictured in a photograph that has a two-dimensional plane.
		When you know the principles of perspective and skillfully apply them, the photographs you produce show a good rendition of the subject's form and shape, and the viewer is given the sensation of volume, space, depth, and distance.
		The other false perspective is produced by a fisheye lens in which all straight lines in the subject are imaged as curved lines toward the edges of the picture.
	photoinf.com /General/NAVY/Perspective.htm (1422 words)

	Azimuthal Map Projections -- 3DSoftware.com (Site not responding. Last check: 2007-10-28)
		While cylindrical and conic projections are related to cylinders and cones wrapped around the globe representing the Earth, the azimuthal projections are formed onto a plane which is usually tangent to the globe at either pole, the Equator, or any intermediate point.
		Although perspective cylindrical and conic projections are much less used than those which are not perspective, the perspective azimuthals are frequently used and have valuable properties.
		A true perspective in the spherical form, with the point of perspective on the surface of the sphere at a point exactly opposite the point of tangency for the plane, or opposite the center of the projection, even if the plane is secant.
	www.3dsoftware.com /Cartography/USGS/MapProjections/Azimuthal (909 words)

	Mars Exploration Rover Mission: Panoramas: Spirit
		This view is presented in a cylindrical projection with geometric seam correction.
		The 360-degree view is presented in a cylindrical projection with geometrical seam correction.
		The image is presented in a cylindrical projection with geometrical seam correction.
	marsrovers.jpl.nasa.gov /gallery/panoramas/spirit/2004.html (4760 words)

	Map Projections: Perspective Cylindrical Projections
		Like most cylindrical projections, it is quite acceptable for the tropics, but practically useless at polar regions, which are rather compressed, resulting in a map much broader than tall.
		Their patterns of shape distortion are similar and, like all cylindrical projections, independent of longitude: vertical scale is more affected the farther from the standard parallels (exaggerated between them and compressed in the outer portions).
		In the central cylindrical (also called centrographic cylindrical) projection, vertical scale increases very fast far from the map's centerline, even faster than in Mercator's projection; likewise, poles cannot be shown in the equatorial aspect.
	www.progonos.com /furuti/MapProj/Normal/ProjCyl/ProjCEA/projCEA.html (851 words)

	Vol. 3 Ch. 4
		Perspectives and grottoes are almost no longer in fashion anymore....As for perspectives they serve to hide gabled walls and walls at the end of a path which one cannot go beyond.
		Wulff (1907), termed this inverted perspective, related it to a tradition of bird’s eye views, which he claimed originated in old Byzantine art of the fourth century and explained it in terms of Lipps theory of empathy whereby the viewer supposedly imagined themself in the position of the persons represented.
		The next series returned to the earlier example a mosque in Somalia which was shown in total perspective on a sphere represented in axonometry, in total perspective of a cylindrical type, with an interior view, a simplified view, an anamorphic view and one in curved perspective.
	www.sumscorp.com /perspective/Vol3/ch4.htm (18075 words)

	Panoramic Resolution
		For a perspective image, this is the distance to the imaging plane at the center.
		For a cylindircal panorama, this is the cylindrical radius (at the equator).
		The formula for the perspective image assumes that a standard 35 mm camera is used, with a frame size of 36 mm x 24 mm.
	www.worldserver.com /turk/quicktimevr/panores.html (981 words)

	Mars Exploration Rover Mission: Panoramas: Opportunity
		This view is the left-eye member of a stereo pair presented in a cylindrical projection with geometric seam correction.
		This view is the right-eye member of a stereo pair presented in a cylindrical projection with geometric seam correction.
		This view is presented in a cylindrical projection with geometric and brightness seam correction.
	origin.mars5.jpl.nasa.gov /gallery/panoramas/opportunity/2005.html (3888 words)

	panoguide: Types of panoramic images
		A cylindrical panorama is intended to be viewed as if curved around the inside of a cylinder.
		Like cylindrical images, horizontal curves can be seen in the flat image, but unlike cylindrical images, the very top and bottom of the image will seem squashed.
		Note that spherical/equirectangular has an advantage over cylindrical from quite a small vertical field of view upwards, assuming the image is cropped to the visible vertical field of view (it is in most panoramic software).
	www.panoguide.com /howto/panoramas/types.jsp (653 words)

	Max Lyons Forums :: View topic - Hybrid Rectilinear & Cylindrical projections
		Perspective paintings, photographs, computer-graphic images, and motion pictures can yield a compelling sensation of the 3d layout of the depicted scene.
		I guess the reason the rectilinear and the cylindrical projections don't match at the vertical center lines of each is aproximately the equivalent of the differance between a Mercator and a geographic map.
		The rectilinear (the same as 'perspective') projection has the same vertical distortion at the center of perspective as the Mercator projection has uniformly and a cylindrical projection is the same as the geographic projection...
	www.tawbaware.com /forum2/viewtopic.php?t=2866 (2046 words)

	CineSat Projections
		Cylindrical projections map the earth onto a cylinder which either touches the globe along the equator or intersects it at a given standard parallel.
		Transverse cylindrical projections are often used for areas with a large North-South extent.
		The ellipsoidal shape of the earth is used by the most important azimuthal, cylindrical, and conical projections.
	www.cinesat.com /csprj.htm (1684 words)

	Types of Maps
		Perspective projections are derived directly from the spheroid model and can be simulated using a light source, model globe and projection screen.
		Common perspective projections are the Zenithal gnomonic polar case, Zenithal stereographic polar case, Zenithal orthographic polar case and Equitorial cases, Zenithal appoximated equidistant; Zenithal apporximate equal area, simple perspective cylindrical gnomonic case, Galls projection, Conic perspective gnomonic polar case.
		Derived from simple perspective cylindrical are the Plate Carree, Cassini's projection, Mercator's projection, and Lamberts' Equal Area projection.
	www.fortunecity.com /greenfield/meadow/794/types.htm (692 words)

	Edit Views - Rayfront User Manual
		The graphics area represents the possible image area, or a part of it for perspective and parallel views.
		The perspective view projection comes nearest to what we usually consider a "natural" view, as it most closely reproduces the way that the human eyes perceive reality.
		The cylindrical perspective is also known as "panorama view".
	www.schorsch.com /rayfront/manual/viewedit.html (738 words)

	Elements of Realspace Imaging: A Proposed Taxonomy
		Cylindrical perspective is shot on cylindrically-positioned film and displayed on a cylindrical surface.
		Unlike rectilinear perspective, only one cylindrical perspective image is required for a 360° panorama, and since it is a single image, there are no discontinuities.
		Spherical perspective is shot with spherical optics (such as fisheye lenses) and displayed on a spherical surface.
	www.naimark.net /writing/realspace.html (4770 words)

	Physics of Centrifugal Force "Gravity" - Philosophy Forum (Site not responding. Last check: 2007-10-28)
		The air in the cylinder is moving in a cylindrical direction.
		On earth, gravity is always essentially vertical, so from the observer's perspective, the ball moves with constant horizontal speed, and accelerates "down" towards the ground.
		If the ball has been thrown antispinward sufficiently fast to be motionless from the external perspective, then in the rotating frame, something's got to balance the 'gravitational' force.
	forum.darwinawards.com /index.php?showtopic=2169 (3722 words)

	Mars Exploration Rover Mission: Panoramas: Opportunity
		The great lure of Victoria is an expectation that the thick stack of geological layers exposed in the crater walls could reveal the record of past enviromnental conditions over a much greater span of time than Opportunity has read from rocks examined earlier in the mission.
		Due to a small dune or ripple close to the nearest part of the rim, the scientists and engineers on the rover team planned on sol 951 to drive to the right of the ripple, but not quite all the way to the rim, then to proceed to the rim the following sol.
		The image is presented in cylindrical projection with geometric seam correction.
	origin.mars5.jpl.nasa.gov /gallery/panoramas/opportunity (6782 words)

	GIS Tutorials: Projection System
		The area between two parallels is made equal to the corresponding surface on the sphere at the cost of great distortion in shape towards higher latitudes; this is why it is an equal area projection.
		Cylindricals are true at the equator and the distortion increases as on moves towards the poles.
		Thus the Cylindrical and Zenithal Projections may be regarded as special cases of Conical Projections.
	www.gisdevelopment.net /tutorials/tuman007pf.htm (1330 words)

	Map projection - Wikipedia, the free encyclopedia
		Unavoidably, all cylindrical projections have an east-west stretching away from the equator by a factor equal to the secant of the latitude, compared with the scale at the equator.
		In the second case (central cylindrical), the north-south scale exceeds the east-west scale everywhere away from the equator.
		Cylindrical projections map the whole Earth as a finite rectangle, except in the first two cases, where the rectangle stretches infinitely tall while retaining constant width.
	en.wikipedia.org /wiki/Map_projection (2842 words)

	Panoramic Photography with Fisheye Lenses
		The cylindrical perspective panoramic image is formed by digital image processing of one or more hyperwide fisheye photographs.
		The effect in the cylindrically resampled scene is that the image height of the red, green and blue components are different.
		Ideally, the fisheye lens perspective center (lens entrance pupil) should be at the same location for both the zenith and nadir shots.
	www.nearfield.com /~dan/photo/wide/sphere/sphere1/index.htm (2475 words)

	VripPack User's Guide
		The primary differences among range imaging scanners are the lines of sight of the sensor and the amount of uncertainty and accuracy in the range measurements.
		Cylindrical or line perspective means that the lines of sight are orthographic in one direction and perspective in the others.
		If your sensor obeys a cylindrical perspective, then we assume that it is perspective in the y-z plane and orthographic in the x-direction.
	www-graphics.stanford.edu /software/vrip/guide (2549 words)

	A Panoramic Camera
		In conclusion, linear perspective is useful for narrow fields, while for wide fields it alters the ratio of the sizes of the objects.
		In any case, notice that one of the advantages of this type of perspective is that it respects the ratio among the sizes of the objects.
		As we said, the main disadvantages of cylindrical perspective are to make horizontal lines of close buildings into parabolic lines and to make plane surfaces look cylindrical when they are shot from the front.
	www.funsci.com /fun3_en/panoram2/pan2_en.htm (9980 words)

	Amazon.com: "conformal cylindrical projection": Key Phrase page (Site not responding. Last check: 2007-10-28)
		The projection of a sphere with one standard parallel (the equator) is the sim- plest conformal cylindrical projection, a strictly Mercator projection.
		For the conformal cylindrical projection, this means that the pole cannot be shown on the map.
		available for nearly two decades, using a conformal cylindrical projection, on which graticule and rhumb lines could be coordinated.
	www.amazon.com /phrase/conformal-cylindrical-projection (347 words)

	Room projection using spherical mirror
		Creating a wide field of view perspective projection is likely to be easier for most existing software, however when this is extended to angles greater than 100 degrees the pixel efficiency is rather poor.
		There are other projections in common usage in immersive environments, for example cylindrical projections and cubic maps.
		The wider the FOV the less suitable is a perspective projection as the input image.
	local.wasp.uwa.edu.au /~pbourke/projection/mirrorbox (979 words)

	Glossary for Rendering with Radiance
		A perspective view projection in which the angle from the central view direction is proportional to the distance from the center of the image.
		A viewing projection that maps vertical angles the same way as a linear perspective view, but maps horizontal angles such that horizontal distance from the center of the image is proportional to the angle from the center of view.
		A view type in which the distance from the center of the image is proportional to the distance from the ray starting at the view point and continuing in the view direction.
	radsite.lbl.gov /radiance/book/glossary.html (7098 words)

	Spherecam
		The cylindrical perspective image is then converted into the Apple QTVR file format for viewing with an Apple provided viewer.
		It is compatible with cylindrical and spherical image mappings (as used by the spherecam).
		The basic mathematical concepts behind the conversion of a cylindrical panoramic or spherical image into a view port are well described in books on map making (Snyder 1989, Snyder 1987), 3D computer graphics and spacecraft attitude determination (Wertz 1978).
	www.nearfield.com /sphereca/spherecam.htm (3136 words)

	Basic Photography Course
		photography, perspective is another illusion you use to
		perspective to change the illusion of space and distance
		perspective is produced by a fisheye lens in which all
	www.dofmaster.com /courses/basic/photographycourse-131.html (476 words)

	PerspTut
		We always assume that what we are taught about perspective is the way we actually see.
		Amazingly enough this the only only spherical perspective grid there is, every viewpoint can be found on here somewhere.
		You don't have to use the grid with vertical perspective here's another grid with all the verticals left alone this would be cylindrical perspective with four vanishing points rather than the six you have in spherical perspective.
	www.duggmirror.com /links/Spherical_Perspective_-_a_brief_tutorial_2 (1019 words)

	Spherical Camera & Projection System (Site not responding. Last check: 2007-10-28)
		One, two and three-point perspective systems were well known.
		Cylindrical perspective was heavily promoted at the time by one of the professors, Duncan Stuart; however, had the limitation of not recording the scene above and below.
		Steve and Bob set out to extend the capabilities of perspective systems by developing a camera and projection system which would record and play back the entire surrounding space in front, to the sides, above, below and behind the viewer.
	www.hineslab.com /idSphericalProjection.html (423 words)

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