MATLAB代码在给定的基于特征的图像对齐的仿射变换A的初始估计的情况下,您将使用逆组合方法跟踪下一帧图像。您将使用6个参数p =(p1,p2,p3,p4,p5,p6)对仿射变换进行参数化,输入:灰度模板图像template和目标图像target;3×3仿射变换A的初始化,输出:A_refined是基于逆组合图像对齐的精细化仿射变换。您将使用逆组合图像对齐来精细化仿射变换,即A→A_refined。您可以通过可视化误差图来验证算法
时间: 2024-03-23 13:41:58 浏览: 109
基于仿射变换的数字图象置乱技术 MATLAB源程序代码-综合文档
以下是使用逆组合方法对图像进行对齐并计算精细化仿射变换的MATLAB代码:
```matlab
% Define the template and target images
template = imread('template.jpg');
target = imread('target.jpg');
% Initialize the affine transformation matrix
A = [a11 a12 a13; a21 a22 a23; 0 0 1];
% Define the parameters for the affine transformation
p = [p1; p2; p3; p4; p5; p6];
% Define the inverse affine transformation matrix
A_inv = inv(A);
% Initialize the refined affine transformation matrix
A_refined = A;
% Define the maximum number of iterations and the convergence threshold
max_iter = 100;
thresh = 0.0001;
% Initialize the iteration counter and the error
iter = 0;
err = Inf;
% Loop until the error is below the threshold or the maximum number of iterations is reached
while err > thresh && iter < max_iter
% Compute the affine transformation matrix from the parameters
A_p = [1+p(1) p(3) p(5); p(2) 1+p(4) p(6); 0 0 1];
% Compute the refined affine transformation matrix
A_refined = A_p * A_refined;
% Warp the target image using the refined affine transformation matrix
target_warped = imwarp(target, affine2d(A_refined), 'OutputView', imref2d(size(template)));
% Compute the error between the template and the warped target image
err = sum(sum((template - target_warped).^2));
% Compute the gradient of the error with respect to the parameters
[dEx_dp, dEy_dp] = imgradientxy(target_warped, 'CentralDifference');
dE_dp = zeros(6,1);
for k = 1:6
dE_dp(k) = sum(sum(dEx_dp.*dW_dp(:,:,k))) + sum(sum(dEy_dp.*dW_dp(:,:,k)));
end
% Compute the parameter update
delta_p = (Hessian + lambda*diag(diag(Hessian))) \ dE_dp;
% Update the parameters
p = p + delta_p;
% Increment the iteration counter
iter = iter + 1;
end
% Display the refined affine transformation matrix and the error
disp(A_refined);
disp(err);
% Visualize the error
figure;
imshow(template - target_warped, []);
title('Error image');
```
在这个代码中,我们首先定义了模板图像和目标图像,并初始化了仿射变换矩阵A和参数向量p。然后,我们定义了逆变换矩阵A_inv和精细化仿射变换矩阵A_refined,并初始化了迭代计数器iter和误差err。
在while循环中,我们首先计算了由参数p定义的仿射变换矩阵A_p,然后使用A_p和A_refined计算出精细化仿射变换矩阵A_refined。接下来,我们使用A_refined对目标图像进行变换,并计算模板图像和变换后的目标图像之间的误差。然后,我们计算误差的梯度和参数的更新,并更新参数向量p。最后,我们增加迭代计数器iter并检查是否达到最大迭代次数或误差已经足够小。如果达到任一条件,则退出while循环并输出精细化仿射变换矩阵A_refined和误差err。
最后,我们可视化误差图像以验证算法的有效性。
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