thông tin trên hình ảnh kỹ thuật số

... regard an image as a sample of a stochastic process. For continuous images, the image function F(x, y, t) is assumed to be a member of a con- tinuous three-dimensional stochastic process with space ... represented as a sum of amplitude- weighted Dirac delta functions by the sifting integral, (1.2-6) where is the weighting factor of the impulse located at coordinates in the x–y plane, as shown ... ω x ω y ,()= Gxy,() 1 4π 2 H ω x ω y ,()F ω x ω y ,()i ω x x ω y y+(){}exp ω x d ω y d ∞ – ∞ ∫ ∞ – ∞ ∫ = 6 CONTINUOUS IMAGE MATHEMATICAL CHARACTERIZATION (1.2-1) In specific cases, the mapping may be many-to-few,...

Ngày tải lên: 24/12/2013, 09:17

... the post-retinal transfer functions of Figure 2.5-3. Undoubtedly, both retinal and post-retinal mechanisms are responsible for the chromatic adaption effect. Further analysis and testing are required ... An observer is shown two sine-wave grating transpar- encies, a reference grating of constant contrast and spatial frequency and a variable- contrast test grating whose spatial frequency is set ... blood capillaries. Inside the choroid is the retina, which is com- posed of two types of receptors: rods and cones. Nerves connecting to the retina leave the eyeball through the optic nerve bundle....

Ngày tải lên: 24/12/2013, 09:17

... , tristimulus units of the primaries as governed by (3.3-13) Integrating each side of Eq. 3.3-13 over and invoking the sifting integral gives the cone signal for the color (C). Thus (3.3-14) By ... T 1 , T 2 , T 3 may be regarded as tristimulus values in a retinal cone color coordinate system. The tristimulus values of the retinal cone color coordinate system are related to the XYZ system ... light. In a subtractive color system, which is the basis of most color photography and color printing, a white light sequentially passes through cyan, magenta, and yellow filters to reproduce a colored...

Ngày tải lên: 24/12/2013, 09:17

... performed by linearly interpo- lating points along separable orthogonal coordinates of the continuous image field. The resultant interpolated surface of Figure 4.3-4b, connecting pixels A, B, C, D, is ... these numbers are then used to reconstruct a con- tinuous image for viewing. Image samples nominally represent some physical mea- surements of a continuous image field, for example, measurements ... ω y d ω ys 2⁄ – ω ys 2⁄ ∫ ω xs 2⁄ – ω xs 2⁄ ∫ = 114 IMAGE SAMPLING AND RECONSTRUCTION where A i , B i , C i , D i are weighting factors. The weighting factors are determined by satisfying two sets of extraneous conditions: 1. at x...

Ngày tải lên: 24/12/2013, 09:17

... CHARACTERIZATION Chapter 1 presented a mathematical characterization of continuous image fields. This chapter develops a vector-space algebra formalism for representing discrete image fields from a deterministic and ... power-spectral density of a discrete image random process may be defined, in analogy with the continuous power spectrum of Eq. 1.4-13, as the two- dimensional discrete Fourier transform of its ... Gaussian density, are rarely found in the literature. Huhns (7) has developed a technique of generating high-order den- sities in terms of specified first-order marginal densities and a specified...

Ngày tải lên: 24/12/2013, 09:17

... which a nonlinear amplification weighting of the continuous signal to be quantized is performed, followed by linear quantization, followed by an inverse weighting of the quantized amplitude. Thus, ... reconstruction level within the range to can be determined by minimization of with respect to . Setting (6.1-6) yields (6.1-7) FIGURE 6.1-2. Quantization decision and reconstruction levels. pr j () E ... are two major forms of numeric representation: real and integer. Real numbers are stored in floating-point form, and typically have a large dynamic range with fine precision. Integer numbers can...

Ngày tải lên: 24/12/2013, 09:17

... applications in image processing require a discretization of the superposition integral relating the input and output continuous fields of a linear system. For exam- ple, image blurring by an optical system, ... general term is described by (7.2-6) where , with and denoting the upper and lower index limits. If the ultimate objective is to estimate the continuous ideal image field by pro- cessing the physical ... AND CONVOLUTION where is a weighting coefficient for the particular quadrature formula employed. Usually, a rectangular quadrature formula is used, and the weighting coefficients are unity. In...

Ngày tải lên: 24/12/2013, 09:17

... based on computational efficiency. In some computing structures, the Hart- ley transform may be more efficiently computed, while in other computing environ- ments, the Fourier transform may be ... cosine transform of a image can be computed by reflecting the image about its edges to obtain a array, taking the FFT of the array and then extracting the real parts of the Fourier transform (15). ... fluctuation vector. This results in (8.4-10) where (8.4-11a) (8.4-11b) are vectors. The process continues until the full transform (8.4-12) is obtained where . It should be noted that the intermediate...

Ngày tải lên: 24/12/2013, 09:17

... obtained by analytically performing the convolution operation of Eq. 9.4-8c and evaluating the resulting continuous function at points . In practice, the analytic convo- lution is often difficult ... one-dimensional continuous signal of wide extent which is bandlimited such that its Fourier transform is zero for greater than a cut- off frequency . This signal is to be convolved with a continuous impulse ... Also, it is often possible to render the filter matrix sparse by setting small-magnitude elements to zero without seriously affecting computational accuracy (1). In subsequent sections, the structure...

Ngày tải lên: 24/12/2013, 09:17

... retention of fine image detail. Several nonlinear techniques are presented below. Mastin (15) has performed subjective testing of several of these operators. FIGURE 10.3-8. Homomorphic filtering on the ... form by replacing the discrete probability distributions of Eq. 10.2-2 by continuous probability densi- ties. The resulting approximation is (10.2-4) g d Tf c {}= f 1 f c f C ≤≤ g 1 g d g D ≤≤ P R g d b d ={} P R f c a c ={} P R f c a c ={} c ... (10.3-2b) Mask 3: (10.3-2c) These arrays, called noise cleaning masks, are normalized to unit weighting so that the noise-cleaning process does not introduce an amplitude bias in the processed image....

Ngày tải lên: 24/12/2013, 09:17

... paper plus any spectral losses resulting from filters or optical elements, and k x is an expo- sure constant that is controllable by an aperture or exposure time setting. Equation 11.3-1 assumes a ... Figure 11.3-1. In this material, silver halide grains are suspended in a transparent layer of gelatin that is deposited on a glass, acetate, or paper backing. If the backing is transparent, a transparency ... then the negative transparency is illuminated to expose negative reflection print paper. The resulting silver density on the developed paper is then proportional to the light intensity that exposed...

Ngày tải lên: 21/01/2014, 15:20

... constraint (12.6-1) where S is a smoothing matrix, M is an error-weighting matrix, and e denotes a residual scalar estimation error. The error-weighting matrix is often chosen to be FIGURE 12.5-3. Wiener image ... RESTORATION 349 extraction operation. Without weighting, errors at the observation boundary completely destroy the estimate in the boundary region, but with weighting the restoration is subjectively satisfying, ... increased by setting b R = 2.0. The higher degree of blur greatly increases the ill-conditioning of the blur matrix, and the residual error in formation of the modified observation after weighting leads...

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20

Ngày tải lên: 21/01/2014, 15:20