### 计算机代写|计算机视觉代写Computer Vision代考|CS231

statistics-lab™ 为您的留学生涯保驾护航 在代写计算机视觉Computer Vision方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写计算机视觉Computer Vision方面经验极为丰富，各种代写计算机视觉Computer Vision相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 计算机代写|计算机视觉代写Computer Vision代考|Detection of Translation

Suppose that the position of the pixel at time $t_k$ is $(x, y)$ and the position of the pixel at time $t_{k+1}$ moves to $(x+\mathrm{d} x, y+\mathrm{d} y)$. It is generally assumed that the gray level of the pixel itself remains unchanged during this period of time; then
$$f\left(x+\mathrm{d} x, y+\mathrm{d} y, t_{k+1}\right)=f\left(x, y, t_k\right)$$
According to the properties of Fourier transform, there are
$$\begin{gathered} F_k(u, v)=f\left(x, y, t_k\right) \ F_{k+1}(u, v)=f\left(x+\mathrm{d} x, y+\mathrm{d} y, t_{k+1}\right) \end{gathered}$$
It can be obtained with the help of translation properties:
$$F_{k+1}(u, v)=F_k(u, v) \exp [j 2 \pi(u \mathrm{~d} x+v \mathrm{~d} y)]$$
Equation (4.24) shows that the phase angle difference of the Fourier transform of the two images taken at time $t_k$ and time $t_{k+1}$ is
$$\mathrm{d} \theta(u, v)=2 \pi(u \mathrm{~d} x, v \mathrm{~d} y)$$
Taking into account the separability of Fourier transform, it can be obtained from Eq. (4.25):
\begin{aligned} & \mathrm{d} x=\frac{d \theta_x(u)}{2 \pi u} \ & \mathrm{~d} y=\frac{d \theta_y(v)}{2 \pi v} \end{aligned}
In Eq. (4.26) and (4.27), $\mathrm{d} \theta_x(u)$ and $\mathrm{d} \theta_y(v)$ are the difference between the phase angle of the Fourier transform projected on the $X$ axis and the $Y$ axis by $f\left(x, y, t_k\right)$ and $f\left(x, y, t_k+1\right)$, respectively. Due to the non-uniqueness of the phase angle, the following methods can be used when calculating $\mathrm{d} \theta_x(u)$ and $\mathrm{d} \theta_y(v)$. Suppose the variation range of $\mathrm{d} x$ satisfies
$$\left|\frac{\mathrm{d} x}{L_x}\right|<\frac{1}{2 K}$$

## 计算机代写|计算机视觉代写Computer Vision代考|Detection of Movement Direction

In many applications, certain specific motion patterns need to be determined. In this case, image-based information and motion-based information can be combined. Motion information can be obtained by determining a specific difference between images that are acquired sequentially. Generally, in order to improve the accuracy and use the spatial distribution information, the image is often divided into blocks, and then two moving image blocks with a time difference (one collected at time $t$ and one collected at time $t+\mathrm{d} t$ ) are considered. The direction of motion can use the following four kinds of calculation for difference image:
\begin{aligned} & U=\left|f_t-f_{t+\mathrm{d} t t}\right| \ & D=\left|f_t-f_{t+\mathrm{d} t \mid}\right| \ & L=\left|f_t-f_{t+\mathrm{d} t \leftarrow}\right| \ & R=\left|f_t-f_{t+\mathrm{d} t \rightarrow}\right| \end{aligned}
where the arrow represents the direction of image motion, such as $\downarrow$ represents the image frame $I_{t+\mathrm{d} t}$ moves downward relative to the previous frame $I_t$.

The amplitude of motion can be obtained by summing the area of the image block. This sum can be quickly calculated with the help of the integral image below.
Integral image is a matrix representation method that maintains the global information of the image. In the integral image, the value $I(x, y)$ at the position $(x, y)$ represents the sum of all the pixel values at the upper left of the position in the original image $f(x, y)$ :
$$f(x, y)=\sum_{p \leq x, q \leq y} f(p, q)$$
The construction of the integral image can be carried out by scanning the image only once by means of a loop:

1. Let $s(x, y)$ represent the cumulative sum of a row of pixels, $s(x,-1)=0$.
2. Let $I(x, y)$ be an integral image, $I(-1, y)=0$.

# 计算机视觉代考

## 计算机代写|计算机视觉代写Computer Vision代考|Detection of Translation

$$f\left(x+\mathrm{d} x, y+\mathrm{d} y, t_{k+1}\right)=f\left(x, y, t_k\right)$$

$$F_k(u, v)=f\left(x, y, t_k\right) F_{k+1}(u, v)=f\left(x+\mathrm{d} x, y+\mathrm{d} y, t_{k+1}\right)$$

$$F_{k+1}(u, v)=F_k(u, v) \exp [j 2 \pi(u \mathrm{~d} x+v \mathrm{~d} y)]$$

$$\mathrm{d} \theta(u, v)=2 \pi(u \mathrm{~d} x, v \mathrm{~d} y)$$

$$\mathrm{d} x=\frac{d \theta_x(u)}{2 \pi u} \quad \mathrm{~d} y=\frac{d \theta_y(v)}{2 \pi v}$$

$$\left|\frac{\mathrm{d} x}{L_x}\right|<\frac{1}{2 K}$$

## 计算机代写|计算机视觉代写Computer Vision代考|Detection of Movement Direction

$$U=\left|f_t-f_{t+\mathrm{d} t t}\right| \quad D=\left|f_t-f_{t+\mathrm{d} t \mid}\right| L=\left|f_t-f_{t+\mathrm{d} t \leftarrow}\right| \quad R=\left|f_t-f_{t+\mathrm{d} t \rightarrow}\right|$$

$$f(x, y)=\sum_{p \leq x, q \leq y} f(p, q)$$

1. 让 $s(x, y)$ 表示一行像素的侽加和， $s(x,-1)=0$.
2. 让 $I(x, y)$ 成为一个完整的形象， $I(-1, y)=0$.

## 广义线性模型代考

statistics-lab作为专业的留学生服务机构，多年来已为美国、英国、加拿大、澳洲等留学热门地的学生提供专业的学术服务，包括但不限于Essay代写，Assignment代写，Dissertation代写，Report代写，小组作业代写，Proposal代写，Paper代写，Presentation代写，计算机作业代写，论文修改和润色，网课代做，exam代考等等。写作范围涵盖高中，本科，研究生等海外留学全阶段，辐射金融，经济学，会计学，审计学，管理学等全球99%专业科目。写作团队既有专业英语母语作者，也有海外名校硕博留学生，每位写作老师都拥有过硬的语言能力，专业的学科背景和学术写作经验。我们承诺100%原创，100%专业，100%准时，100%满意。

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。