J. D. Foley, A. Van Dam, S. K. Feiner, and J. F. Hughes, Computer Graphics. Addison-Wesley, 1996.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....as possible so that subsequent image matching can be largely 2D in nature. For this reason, the reference orthoimage is projected into the video frame, since the orthoimage already is coregistered to the elevation map. The projection is accomplished via standard texture map based rendering [8]. The digital elevation map is triangulated to yield a 3D mesh. The orthoimage is regarded as a texture, coregistered to the mesh. The mesh vertices are parametrically mapped to the image plane based on the telemetry implied camera projection matrix. Hidden surfaces are removed via Z buffering. ....

J. Foley, A. van Dam, S. Feiner, J. Highes, Computer Graphics, Addison-Wesley, Reading, MA, 1990.

....reflection coefficient K, controls the overall brighiness of the specular higtdight, independent of the brightness of the light sources and the direction of viewing. 2.2 Light Source attenuation Equaltim 1 does nm take init) account light attenuation. practice a formula that does work well [8] is: 1 A i = rain( Cl C2ds c3ds 2 ;I ) 2) A represents the attenuation factor for the light source c is a user defined constant that keeps the denominator from becoming too small when the light is close, c2 and cs are specific to the light source model. The term d, represents the Euclidean ....

....I, cosY(7) where I. is the intensity of the hypothetical light source, p is the refiector s specular exponent and is the angie between L and L . Note that as the value of p increases more of the light is concentrated along L . This model can be generalized to model different types of spot lights [8]. 4. APPLICATION: STILL PICTURES AND VIDEO 4.1 The museum model Our first model consists of the scene placed on a 2D plane and virtual lights that are placed in the 3D space, illuminating the scene. This is similar to the situation where a photograph hanging on a wall is illuminated with spot ....

Foley etal, "Computer Graphics" Addison Wesley 1997

.... V dir)f Given this origin, focal length, and the viewing direction the image plane is defined. Next is the projection of the 3D points of the model onto the image plane. Given a ray between a 3D point and the CP, any standard ray plane intersection routine may be used (for example Foley, et al.[1] or Glassner[2] For this application, the following was used: t = Ro) Gamma ( O) Rd) where Ro is the ray origin (the current 3D point) and Rd is the ray direction defined as Rd = CP Gamma Ro. The value t is the distance along the ray to the intersection point in k Rdk ....

....(2.000,2.000,3.000) 0.05000,0.05000) 0.00000, 0.05303) 2.000, 2.000,3.000) 0.05000, 0.05000) 0.00000, 0.12374) 2.000, 2.000,7.000) 0.02143, 0.02143) 0.03000, 0.07425) 2.000,2.000,7.000) 0.02143,0.02143) 0.03000, 0.03182) 0] 134.00 359.00 269.00 5.000028 0. 059210 8 [ 1] 359.00 315.00 0.00 5.000029 0.059015 7 [ 2] 180.00 224.00 180.00 5.000027 0.058594 10 [ 3] 314.00 181.00 89.00 5.000027 0.058534 5 [ 0] 134.00 359.00 269.0 5.000028 0.059210 13 [ 1] 359.00 315.00 0.00 5.000029 0.059015 17 left= 2.029475, 2.029475,3.044202 ....

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Foley, J. D., Van Dam, A., Feiner, S. K., and Hughes, J. F. Computer Graphics. Addison-Wesley Publishing Company, 1990.

....into its polyhedral faces which are further decomposed into constituent lines. Given an object viewer relationship, these lines are projected into the screen coordinate system and displayed. A good graphics system makes defining these types of geometric relationships simple and intuitive [15]. X Vision provides this functionality and its converse. In addition to stating how a complex object in a particular pose or configuration is decomposed into a list of primitive features, X Vision describes how the pose or attitude is computed given the locations of those primitives. More ....

....written as a product of an upper triangular matrix U and a rotation matrix R(O) as 0 , sin(O) cos(O) The implementation of image warping mirrors this factorization. First, a rotated rectangular area is acquired using an algorithm closely related to Bresenham algorithms for fast line render ing [15]. The resulting buffer can be subsequently scaled and sheared using an optimized bilinear interpolation algorithm. The former is relatively inexpensive, requiring about 2 additions per pixel to implement. The latter is more expensive, requiring 3 multiplies and 6 additions per pixel in our ....

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J.D. Foley, A. van Dam, S.K. Feiner, and j.F. Hughes. Computer' Graphics. Addison Wesley, 1993.

.... polynomial Q = T C (1) where T = t 1] C = ax ay bx by cx cy dx dy with tangentvector Q (t) Q = T C = 3t 2t 10] C (2) Given hermite parameter matrix i = h i x h i y ] p i;1 ] T (3) the corresponding Hermite coefficient matrix C can be derived as [7] = 2 1 1 ;3 ;2 ;1 0 0 1 0 1 0 0 0 We collect all the hermite parameters in state vector H for later use H = 4) When considering the same criteria of usefulness for the contour finding problem as discussed in previous section for the point , polygon and spline based ....

Foley et al., Computer Graphics, AddisonWesley, 1996.

....which are coplanar are joined in one polygon (for this optimization we use a polygon and not a triangle list) V. Shading The normal at the patch center is obtained by estimating a plane Ax By Cz D = 0 through the patch vertices. We use a robust technique, as described in pp. 476 477 of [3]. The coe#cients A, B and C are proportional to the signed areas of the projections of the patch onto the (x, y) x, z) and (y, z) planes, respectively: A, B, C] # 1 2 n # i=1 (z i z i#1 ) y i#1 y i ) 1 2 n # i=1 (z i z i#1 ) x i#1 x i ) 1 2 n # i=1 (y i ....

J.D. Foley, A. van Dam, S.K. Feiner and J.F. Hughes. Computer Graphics. Addison-Wesley, USA, 1997.

....In these cases, simple algorithms are mandatory, especially for basic primitives like lines, circles or ellipses. The algorithm presented in this paper takes advantage of all the previously ideas introduced by the bibliography: it is an incremental algorithm based on the second order differences [Foley92], it uses an error function based on the middle point [Fellner94] it uses the 4 point symmetry and it uses fixed point arithmetic [Fellner93] It uses 32 and 64 bits mantissas. It works with decimal numbers radii. Although the operations works internally with decimal numbers, they use fixed point ....

....When X 2 surpasses (X 0.5) 2 , X is decreased one unit and (X 1.5) 2 is recalculated. For every step, four points are drawn. 5. COMPUTATIONAL COST The aim in this point is to compare the cost given by this fixed point based algorithm to a paradigm like the Middle Point (MP) algorithm [Foley92]. In order to avoid original the MP implementation penalties, an optimised incremental second order differences version was used. This version used temporal variables to avoid redundant calculations and fixed point arithmetic in order to diminish even more the computational cost and to allow the ....

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Foley JD, van Dam A, Feiner SK, Hughes JF (1992) Computer Graphics, Principles And Practice. Addison-Wesley

....cues, achieving balance in terms of complementary colors, and highlighting in terms of complementary colors. Further, little is said about color systems. Readers wanting more information can refer to the newsletter article on color systems (Eddy 1990) and a host of additional resources such as Foley et al. (1990), Durrett (1987) Friedhoff and Benzon (1989) Tufte (1990) and Mante (1972) Color A physics based description of visible light yields an intensity versus wavelength curve over the spectrum of 400 to 700 nanometers. Figure 1 provides an example for one color. Light consists of photons with ....

....color dimension for representing an ordered variable. The use of gray levels is particularly convenient since it provides a brightness dimension without the risk of suggesting other competing orderings based on hue and saturation. The above physics based description of brightness follows that of Foley et al. (1990). However, luminance as a measure of brightness does not tell the whole story. Murch (1987) uses the word brightness to refer to perceptual color changes that are a function of light intensity or roughly speaking, photon rates. As intensity increases it first becomes possible to see something, ....

Foley, J. D., A. van Dam, S. K. Feiner, and J. F. Hughes. (1990), Computer Graphics, Principles and Practice, Second edition, Addison-Wesley Publishing Co. New Yo r k .

....5 discusses the main results of the thesis and presents some ideas for future research and Chapter 6 concludes and summarizes the thesis. 1 2 Chapter 2 Cloud modeling The purpose of a model of an entity is to allow people to visualize and understand the structure or behaviour of the entity [10]. For clouds and gases the model is often implemented as a density function, #(#x) #x # R 3 that, for each point in space, evaluates to the amount of cloud matter that exists at that point. We shall refer to cloud modeling as the task of de ning such a density function. What should be regarded ....

Foley, J. D., van Dam, A., Feiner, S. K., and Hughes, J. F., 1990, Computer Graphics. Principles and Practice. Second edition. AddisonWesley Publishing Company, 1174 pages. ISBN 0-201-12110-7. 41

....1. It is not clear, however, how a Gaussian model of directions should be constructed. In this section various approaches to that problem are reviewed. First note that there are many colour spaces in which the chromaticity and intensity components are explicitly separated, for examples, see [10]. Many common colour spaces, such as the HSV space, are non linear transformations of the original RGB space. Distributions of data in the RGB cube have different shape in these spaces, which can complicate the form of an appropriate SCM. Such spaces are generally intended for intuitive human ....

J. Foley, A. van Dam, S. Feiner, J. Hughes. "Computer Graphics". Addison Wesley. 1990.

....relative to the feature in the image, the image processing operations can presume a standard pose. This makes them simple (and fast) to implement. Acquiring windows at any position and orientation can be implemented quickly by using ideas for fast drawing of lines and boxes borrowed from graphics [2]. In particular, routines for fast acquisition of oriented and scaled windows are provided in the Framework directory. These routines expect a pointer to a region of memory that is the framebuffer for the digitizer. They deliver the closest approximation possible to the requested rectangular ....

....of the intersection point and the orientations of the two subsidiary lines. GILine is a Positionable. It has four state read functions (the analogous write functions follow the convention outlined above) float x( return state[0] float y( return state[1] float angle1( return state[2]; float angle2( return state[3] Members of the queue of tracked objects can be accessed using the pre defined function BasicFeature child(int n) Note that this function is protected, so it cannot be called outside of a CompFeature or one of its derived classes) Since we know that GILine ....

J. Foley, A. v. Dam, S. Feiner, and J. Hughes. Computer Graphics. Addison Wesley, 1993. 17

....improve the user s understanding. In order to correctly represent the occlusion relationships between real and synthetic objects, an AR application needs to consider the depth of the real imagery in the rendering of the synthetic imagery. Synthetic image generation for AR is the same as for VE [Foley90] Of particular interest in this discussion is the depth buffer, or z buffer. This is a standard way that occlusion relationships are established for objects in VE. The way that AR should differ is that the AR system needs to measure or infer depth for the real imagery and compare this data with ....

....that we must apply to our current estimated orientation. We update this portion of the estimate by computing the rotation matrix determined by the incremental rotation parameters in the state. RWC =RWC Rot##; #; ## where Rot##; #; ## is the 3 # 3 rotation matrix determined by the Euler angles [Foley90] Note that the computation of the Jacobian must account for the current total orientation, and thus must reconstruct RWC with the correct inverse for the chosen definition of Euler angles. After this update, the incremental Euler angles #, #,and# are reset to 0.0. Since we ve updated our ....

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Foley, J. D., van Dam, A., Feiner, S. K., and Hughes, J. F. (1990). Computer Graphics, Principles and Practice, Second Edition. Addison-Wesley.

.... fast search over large scale image collections, Smith and Chang proposed Color Sets as an approximation to the Color Histogram representation [Smith and Chang, 1995a, Smith and Chang, 1995b] They first transformed the (R,G,B) color space into a perceptually uniform space, such as (H,S,V) [Foley et al. 1990], and then quantized the transformed color space into M bins. A Color Set is defined as a selection of the colors from the quantized color space. Because Color Set feature vectors are binary, a binary search tree was constructed to allow fast search. The relationship between the proposed Color ....

Foley, J., van Dam, A., Feiner, S., and Hughes, J. (1990). Computer Graphics. Addison Wesley, 2nd edition. 28

....# ### # ## ## # ## ##### ### # ## # (1) The rotation matrix [R G ] describes the rotation of the object relative to the point G. This notation is impractical especially for several sequential transformations. An alternative notation used here is the introduction of homogenous coordinates [1]. For a given point in homogenous coordinates P hom = P x ,P y ,P z ,1) T the transformation is: # ### # ## #### # # ##### (2) P (k 1) point coordinates at time instance t k 1, P (k) point coordinates at time instance t k, M hom ] homogenous transformation matrix The transformation ....

....in the 3 D model. A possible application of such a label image is the detection of regions in an image that are already covered by the reconstructed 3 D model. The software for image synthesis must be able to cope with object occlusions. The implemented virtual cameras us the z buffer algorithm [1] for this purpose. 3.3 Images and Image Primitives Images are represented as matrices. The image classes are implemented as template classes here. For color images or multispectral images a multi bandimage class was designed (class o CPicture T ) Luminance images, depth maps, label images, and ....

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Foley, J. D., van Dam, A., Feiner, S. K., Hughes J. F., "Computer Graphics", Addison --Wesley Publi. Comp. 1990.

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J. D. Foley, A. Van Dam, S. K. Feiner, and J. F. Hughes, Computer Graphics. Addison-Wesley, 1996.

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FOLEY, J. D., VAN DAM, A., FEINER, S. K., AND HUGHES, J. F. 1996. Computer graphics (2nd ed. in C): principles and practice. AddisonWesley Longman Publishing Co., Inc.

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J. D. Foley, A. Van Dam, S. K. Feiner, and J. F. Hughes. Computer Graphics. Addison-Wesley, 1996.

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J. D. Foley, A. van Dam, S. K. Feiner, and J. F. Hughes. Computer Graphics, chapter 12, pages 550--555. Addison-Wesley, 1996.

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J. Foley, A. van Dam, S. Feiner, J. Hughes, "Computer Graphics", Addison-Wesley Pub. Co., 1990, pp 557-558

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JD Foley, A van Dam, SK Feiner, JF Hughes, Computer Graphics (2nd edition in C). Addison-Wesley, Reading, MA 1996.

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Foley, J. D., van Dam, A., Feiner, S. K., and Hughes, J. F. Computer Graphics:

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J. D. Foley, A. van Dam, S. K. Feiner, and J. F. Hughes, Computer Graphics, Addison-Wesley Publishing Company, 1997.

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J. D. Foley, A. van Dam, S. K. Feiner, and J. F. Hughes. Computer Graphics. Addison-Wesley, 2nd edition, 1990.

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Foley J.D., Van Dam A, Feiner S. K, and Hughes J.F. Computer Graphics. Addison-Wesley, 1990. ( trs complt).

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