In
computer graphics
Computer graphics deals with generating images with the aid of computers. Today, computer graphics is a core technology in digital photography, film, video games, cell phone and computer displays, and many specialized applications. A great de ...
and
computer vision
Computer vision is an interdisciplinary scientific field that deals with how computers can gain high-level understanding from digital images or videos. From the perspective of engineering, it seeks to understand and automate tasks that the hum ...
, image-based modeling and rendering (IBMR) methods rely on a set of two-dimensional images of a scene to
generate a three-dimensional model and then
render some novel views of this scene.
The traditional approach of computer graphics has been used to create a geometric model in 3D and try to reproject it onto a two-dimensional image. Computer vision, conversely, is mostly focused on detecting, grouping, and extracting features (edges, faces, ''etc.'') present in a given picture and then trying to interpret them as three-dimensional clues. Image-based modeling and rendering allows the use of multiple two-dimensional images in order to generate directly novel two-dimensional images, skipping the manual modeling stage.
Light modeling
Instead of considering only the physical model of a solid, IBMR methods usually focus more on light modeling. The fundamental concept behind IBMR is the
plenoptic illumination function which is a parametrisation of the
light field
The light field is a vector function that describes the amount of light flowing in every direction through every point in space. The space of all possible '' light rays'' is given by the five-dimensional plenoptic function, and the magnitude of e ...
. The plenoptic function describes the light rays contained in a given volume. It can be represented with seven dimensions: a ray is defined by its position
, its orientation
, its wavelength
and its time
:
. IBMR methods try to approximate the plenoptic function to render a novel set of two-dimensional images from another. Given the high dimensionality of this function, practical methods place constraints on the parameters in order to reduce this number (typically to 2 to 4).
IBMR methods and algorithms
*View
morphing
Morphing is a special effect in motion pictures and animations that changes (or morphs) one image or shape into another through a seamless transition. Traditionally such a depiction would be achieved through dissolving techniques on film. Since ...
generates a transition between images
*Panoramic imaging renders panoramas using image mosaics of individual still images
*Lumigraph relies on a dense sampling of a scene
*Space carving generates a 3D model based on a
photo-consistency check
See also
*
View synthesis
*
3D reconstruction
*
Structure from motion
Structure from motion (SfM) is a photogrammetric range imaging technique for estimating three-dimensional structures from two-dimensional image sequences that may be coupled with local motion signals. It is studied in the fields of computer visio ...
References
External links
* Quan, Long. ''Image-based modeling''. Springer Science & Business Media, 2010
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{{Computer graphics
Computer graphics
Applications of computer vision
3D imaging