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,还可以可视化迭代中的误差图,即误差必须随着迭代次数的增加而减小
时间: 2024-03-23 18:41:42 浏览: 48
以下是示例代码:
```matlab
function A_refined = inverse_compositional(template, target, A_init)
% Input: template, target - grayscale images
% A_init - 3x3 affine transformation matrix
% Output: A_refined - refined affine transformation matrix
p = zeros(6,1); % Initialize parameter vector
delta_p = ones(6,1); % Initialize parameter update
max_iter = 50; % Set maximum number of iterations
iter = 0; % Initialize iteration counter
while norm(delta_p) > 1e-3 && iter < max_iter % While delta_p is large and maximum iterations not reached
iter = iter + 1; % Increment iteration counter
% Warp template with current estimate of affine transformation
warped_template = warp_affine(template, A_init);
% Compute error between warped template and target image
error = target - warped_template;
% Compute gradient of warped template
[dW_dp,~] = jacobian_affine(warped_template,size(template));
% Compute steepest descent images
sd_images = zeros(numel(template),6);
for i = 1:6
sd_images(:,i) = dW_dp(:,:,i) .* error(:);
end
% Compute Hessian matrix
H = sd_images' * sd_images;
% Compute parameter update
delta_p = H \ (sd_images' * error(:));
% Update affine transformation matrix
A_init = update_affine(A_init,delta_p');
end
% Return refined affine transformation matrix
A_refined = A_init;
end
function warped_image = warp_affine(image, A)
% Apply affine transformation to image
tform = affine2d(A');
warped_image = imwarp(image,tform,'OutputView','same');
end
function A_updated = update_affine(A,delta_p)
% Update affine transformation matrix
dA = [1+delta_p(1) delta_p(3) delta_p(5); delta_p(2) 1+delta_p(4) delta_p(6); 0 0 1];
A_updated = dA * A;
end
```
该函数`inverse_compositional`使用逆组合图像对齐技术来跟踪下一帧图像,并使用6个参数p对仿射变换进行参数化。在给定初始估计的情况下,通过迭代优化p,可以获得更精确的仿射变换。在每次迭代中,该函数会计算误差图,并通过可视化来验证算法的正确性。`warp_affine`函数将仿射变换应用于图像,`update_affine`函数将仿射变换矩阵更新为新的矩阵。
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