psnr_denoised_1 =compare_psnr(img, denoised_1)# multi-level case should outperform single level caseassert_(psnr_denoised > psnr_denoised_1 > psnr_noisy)# invalid number of wavelet levels results in a ValueErrormax_level = pywt.dwt_max_level(np.min(img.shape), pywt.Wavelet(wavelet).de...