Remapping
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It highly depends on [[aligning]], since any alignment change of an image requires a different remapping. Remapping is an inherent part of the [[stitching]] process. | It highly depends on [[aligning]], since any alignment change of an image requires a different remapping. Remapping is an inherent part of the [[stitching]] process. | ||
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| + | Although the software remaps in one single step, one can conceptually identify several logical steps. | ||
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| + | === Camera image to sphere === | ||
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| + | The camera image has to be transformed into angle space, which here is visualised as projecting the image from a virtual camera, reversing the light path, onto a sphere. | ||
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| + | [[Image:Img08232.jpg|300px]] [[Image:Globe05png.svg|230px]] | ||
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| + | === Relative alignment === | ||
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| + | Generally, one is free to choose any orientation of the virtual camera/projector. But for panoramic images, one wants to align these images. The usual software approach is to mark a set of same features in image pairs, and have the distance between such marker pairs minimised in an overall optimisation process. | ||
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| + | [[Image:Img0823xcp3.png|672px]] | ||
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| + | === Screen projection === | ||
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| + | Images in the computer environment are flat, hence one has to remap the spherical geometry. This can be a general mathematical mapping function. Some mappings, as the rectilinear projection below, can be visualised as an optical projection, using a point light source in the centre of the sphere. | ||
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| + | [[Image:Globe08png.svg|240px]][[Image:Img0823xstitch6.jpg|400px]] | ||
Latest revision as of 14:13, 5 May 2008
Contents |
[edit] Definition
Remapping is the process of changing the image geometry in order to fit to the adjacent images that should contribute to a panorama.
It highly depends on aligning, since any alignment change of an image requires a different remapping. Remapping is an inherent part of the stitching process.
Although the software remaps in one single step, one can conceptually identify several logical steps.
[edit] Camera image to sphere
The camera image has to be transformed into angle space, which here is visualised as projecting the image from a virtual camera, reversing the light path, onto a sphere.
[edit] Relative alignment
Generally, one is free to choose any orientation of the virtual camera/projector. But for panoramic images, one wants to align these images. The usual software approach is to mark a set of same features in image pairs, and have the distance between such marker pairs minimised in an overall optimisation process.
[edit] Screen projection
Images in the computer environment are flat, hence one has to remap the spherical geometry. This can be a general mathematical mapping function. Some mappings, as the rectilinear projection below, can be visualised as an optical projection, using a point light source in the centre of the sphere.
