Patent ID: 11880903
Assignee: TSINGHUA UNIVERSITY
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A Bayesian image denoising method based on a distribution constraint of noiseless images from a distribution of noisy images, comprising:
determining a distribution constraint of noiseless images from a distribution of noisy images; and
performing Bayesian denoising on noisy images based on the distribution constraint of noiseless images,
wherein determining the distribution constraint of noiseless images from the distribution of noisy images comprises:
for images of which the distribution is difficult to be expressed analytically, or for images of which the distribution is too complex, estimating the distribution constraint of noiseless images by:
performing analytical filtering or Bayesian iterative denoising on a group of noisy image samples z1, z2, z3, . . . , zn to obtain initial estimation of corresponding noiseless image samples ŝ1, ŝ2, ŝ3, . . . , ŝn;
estimating a probability density function ƒN of a random vector N for additive noise of the imaging system analytically, in which noise samples n1*, n2*, n3*, . . . , nn* are sampled from the distribution of the random vector N, and the number of the noise samples n1*, n2*, n3*, . . . , nn* is the same as that of the noisy image samples z1, z2, z3, . . . , zn;
adding the noise samples n1*, n2*, n3*, . . . , nn* and the estimated noiseless image samples ŝ1, ŝ2, ŝ3, . . . , ŝn to generate estimated noisy image samples {circumflex over (z)}1, {circumflex over (z)}2, {circumflex over (z)}3, . . . , {circumflex over (z)}n, in which {circumflex over (z)}i=ŝi+ni*, i=1:n;
calculating a distribution distance D({circumflex over (Z)},Z) between a set Z for the estimated noisy image samples {circumflex over (z)}1, {circumflex over (z)}2, {circumflex over (z)}3, . . . , {circumflex over (z)}n and a set Z for the noisy image samples z1, z2, z3, . . . , zn according to a distribution distance function D, and determining the distribution distance D({circumflex over (Z)},Z) as the distribution constraint for noiseless images.