MATLAB图像复原写简单PSNR、SSIM、MSE、MAE、SNR、ISNR代码

下面是MATLAB图像复原中常用的一些评价指标的简单代码实现：

1. PSNR（峰值信噪比）

function psnr_value = psnr(original_image, restored_image)
    mse_value = mean(mean((double(original_image) - double(restored_image)).^2));
    if(mse_value == 0)
        psnr_value = 100;
    else
        psnr_value = 10*log10(255^2/mse_value);
    end
end

2. SSIM（结构相似性）

function ssim_value = ssim(original_image, restored_image)
    k1 = 0.01;
    k2 = 0.03;
    L = 255;
    C1 = (k1*L)^2;
    C2 = (k2*L)^2;
    mu1 = mean2(original_image);
    mu2 = mean2(restored_image);
    sigma1 = std2(original_image);
    sigma2 = std2(restored_image);
    sigma12 = cov2(original_image,restored_image);
    numerator = (2*mu1*mu2 + C1)*(2*sigma12 + C2);
    denominator = (mu1^2 + mu2^2 + C1)*(sigma1^2 + sigma2^2 + C2);
    ssim_value = numerator/denominator;
end

3. MSE（均方误差）

function mse_value = mse(original_image, restored_image)
    mse_value = mean(mean((double(original_image) - double(restored_image)).^2));
end

4. MAE（平均绝对误差）

function mae_value = mae(original_image, restored_image)
    mae_value = mean(mean(abs(double(original_image) - double(restored_image))));
end

5. SNR（信噪比）

function snr_value = snr(original_image, restored_image)
    mse_value = mean(mean((double(original_image) - double(restored_image)).^2));
    snr_value = 10*log10(mean(mean(double(original_image).^2))/mse_value);
end

6. ISNR（改进信噪比）

function isnr_value = isnr(original_image, restored_image, noise_image)
    mse_restored = mean(mean((double(original_image) - double(restored_image)).^2));
    mse_noise = mean(mean((double(original_image) - double(noise_image)).^2));
    isnr_value = 10*log10(mse_noise/mse_restored);
end