％ COMPDIR Computes a search direction in a subspace defined by Z.
％ Helper function for NLCONST.
％ Returns Newton direction if possible.
％ Returns random direction if gradient is small.
％ Otherwise, returns steepest descent direction.
％ If the steepest descent direction is small it computes a negative
％ curvature direction based on the most negative eigenvalue.
％ For singular matrices, returns steepest descent even if small.
％DEFINEV Scaling vector and derivative
％
％ [v,dv]= DEFINEV(g,x,l,u) returns v, distances to the
％ bounds corresponding to the sign of the gradient g, where
％ l is the vector of lower bounds, u is the vector of upper
％ bounds. Vector dv is 0-1 sign vector (See ?? for more detail.)
％
％ Copyright (c) 1990-98 by The MathWorks, Inc.
％ $Revision: 1.2 $ $Date: 1998/03/21 16:29:10 $
Tracking a moving object through several frames, provided changes from frame to frame are on the order of +-(10 + "X Range") pixels in the X direction and +-(10 + "Y Range") in the Y direction is done automatically because of a relatively large area of exploration during the search for an optimal (new) position for a particular control point and a very strong force exerted by large values of the image gradient.
圖像處理的關(guān)于Snakes : Active Contour Models算法和水平集以及GVF的幾篇文章，文章列表為：
[1]Snakes Active Contour Models.pdf
[2]Multiscale Active Contours.pdf
[3]Snakes, shapes, and gradient vector flow.pdf
[4]Motion of level sets by mean curvature I.pdf
[5]Spectral Stability of Local Deformations Spectral Stability of Local Deformations.pdf
[6]An active contour model for object tracking using the previous contour.pdf
[7]Volumetric Segmentation of Brain Images Using Parallel Genetic AlgorithmsI.pdf
[8]Segmentation in echocardiographic sequences using shape-based snake model.pdf
[9]Active Contours Without Edges.pdf
學習圖像處理的人必看的幾篇文章
Hybrid Monte Carlo sampling.SAMPLES = HMC(F, X, OPTIONS, GRADF) uses a hybrid Monte Carlo
algorithm to sample from the distribution P ~ EXP(-F), where F is the
first argument to HMC. The Markov chain starts at the point X, and
the function GRADF is the gradient of the `energy function F.
sfrmat is a Matlab function that provides a spatial frequency response* (SFR) from a digital image file containing a slanted-edge feature. The specific edge-gradient algorithm follows the intent of the standard ISO 12233, developed by Technical Committee ISI/TC 42, for resolution measurements for electronic still pictorial cameras.
用于汽車巡航控制系統(tǒng)的模糊控制算法，以及如何利用梯度下降法和卡爾曼濾波來優(yōu)化模糊控制器的算法。The files illustrate a simple fuzzy control algorithm as applied to an automobile cruise control system. The files also illustrate how gradient descent and Kalman filtering can be used to optimize the fuzzy controller .
General paradigm in solving a computer vision problem is to represent a raw image
using a more informative vector called feature vector and train a classifier on top of
feature vectors collected from training set. From classification perspective, there are
several off-the-shelf methods such as gradient boosting, random forest and support
vector machines that are able to accurately model nonlinear decision boundaries.
Hence, solving a computer vision problem mainly depends on the feature extraction
algorithm
