双三次插值图像超分辨率matlab代码

以下是双三次插值图像超分辨率的MATLAB代码：

clear all; 
clc; 
close all; 

%% Load the low resolution image 
% Replace 'LR_image.png' with the name of your low resolution image 
LR_image = imread('LR_image.png'); 

%% Convert to double precision 
LR_image = im2double(LR_image); 

%% Set the scaling factor 
% Replace 'scale_factor' with the scaling factor you desire 
scale_factor = 2; 

%% Create a bicubic interpolation kernel 
% This will be used to generate the high resolution image 
kernel = 'cubic'; 

%% Upsample the image using bicubic interpolation 
% This will be used as the initial estimate for the high resolution image 
HR_image_bicubic = imresize(LR_image, scale_factor, kernel); 

%% Display the low resolution and initial high resolution images 
figure(); 
subplot(1,2,1); 
imshow(LR_image); 
title('Low Resolution Image'); 
subplot(1,2,2); 
imshow(HR_image_bicubic); 
title('Initial High Resolution Image (Bicubic Interpolation)'); 

%% Set the parameters for the iterative optimization 
num_iterations = 10; % Replace with the number of iterations you desire 
lambda = 0.01; % Replace with the value of lambda you desire 

%% Perform the iterative optimization 
for i = 1:num_iterations
    % Compute the gradient of the objective function 
    grad = compute_gradient(LR_image, HR_image_bicubic, lambda); 
    
    % Update the high resolution image estimate 
    HR_image_bicubic = HR_image_bicubic - grad; 
    
    % Clip the high resolution image estimate to the valid range of intensities 
    HR_image_bicubic(HR_image_bicubic < 0) = 0; 
    HR_image_bicubic(HR_image_bicubic > 1) = 1; 
    
    % Display the current high resolution image estimate 
    figure(); 
    imshow(HR_image_bicubic); 
    title(['High Resolution Image Estimate (Iteration ', num2str(i), ')']); 
end 

%% Display the final high resolution image estimate 
figure(); 
imshow(HR_image_bicubic); 
title('Final High Resolution Image Estimate'); 

%% Compute the gradient of the objective function 
function grad = compute_gradient(LR_image, HR_image, lambda)
    % Compute the Laplacian of the high resolution image 
    laplacian = del2(HR_image); 
    
    % Compute the difference between the low resolution image and the downsampled high resolution image 
    diff = imresize(HR_image, size(LR_image), 'bicubic') - LR_image; 
    
    % Compute the gradient of the objective function 
    grad = lambda * laplacian + 2 * diff; 
end

请注意，这只是一个示例代码，并且可能需要根据您的需求进行修改。此代码使用双三次插值和梯度下降优化来生成高分辨率图像的估计值。