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Poisson denoising using Poisson2Sparse#
This code shows how to restore a single image corrupted by Poisson noise using Poisson2Sparse, without requiring external training or knowledge of the noise level.
This method is based on the paper βPoisson2Sparseβ Ta et al.[1] and restores an image by learning a sparse non-linear dictionary parametrized by a neural network using a combination of Neighbor2Neighbor Huang et al.[2], of the negative log Poisson likelihood, of the \(\ell^1\) pixel distance and of a sparsity-inducing \(\ell^1\) regularization function on the weights.
import deepinv as dinv
import torch
Load a Poisson corrupted image#
This example uses an image from the microscopy dataset FMD Zhang et al.[3].
# Seed the RNGs for reproducibility
torch.manual_seed(0)
torch.cuda.manual_seed(0)
device = dinv.utils.get_freer_gpu() if torch.cuda.is_available() else "cpu"
physics = dinv.physics.Denoising(dinv.physics.PoissonNoise(gain=0.01, normalize=True))
x = dinv.utils.demo.load_example(
"FMD_TwoPhoton_MICE_R_gt_12_avg50.png", img_size=(256, 256)
).to(device)
x = x[:, 0:1, :64, :64]
x = x.clamp(0, 1)
y = physics(x)
Selected GPU 0 with 4064.25 MiB free memory
Define the Poisson2Sparse model
backbone = dinv.models.ConvLista(
in_channels=1,
out_channels=1,
kernel_size=3,
num_filters=512,
num_iter=10,
stride=2,
threshold=0.01,
)
model = dinv.models.Poisson2Sparse(
backbone=backbone,
lr=1e-4,
num_iter=200,
weight_n2n=2.0,
weight_l1_regularization=1e-5,
verbose=True,
).to(device)
Run the model#
Note that we do not pass in the physics model as Poisson2Sparse assumes a Poisson noise model internally and does not depend on the noise level.
x_hat = model(y)
# Compute and display PSNR values
learning_free_psnr = dinv.metric.PSNR()(y, x).item()
model_psnr = dinv.metric.PSNR()(x_hat, x).item()
print(f"Measurement PSNR: {learning_free_psnr:.1f} dB")
print(f"Poisson2Sparse PSNR: {model_psnr:.1f} dB")
# Plot results
dinv.utils.plot(
[y, x_hat, x],
titles=["Measurement", "Poisson2Sparse", "Ground truth"],
subtitles=[f"{learning_free_psnr:.1f} dB", f"{model_psnr:.1f} dB", ""],
)

0%| | 0/200 [00:00<?, ?it/s]
0%| | 1/200 [00:00<00:22, 8.90it/s]
4%|β | 9/200 [00:00<00:04, 45.53it/s]
8%|β | 15/200 [00:00<00:03, 47.83it/s]
10%|β | 20/200 [00:00<00:03, 46.27it/s]
12%|ββ | 25/200 [00:00<00:03, 44.65it/s]
15%|ββ | 30/200 [00:00<00:03, 43.26it/s]
18%|ββ | 35/200 [00:00<00:03, 42.28it/s]
20%|ββ | 40/200 [00:00<00:03, 41.52it/s]
22%|βββ | 45/200 [00:01<00:03, 41.35it/s]
25%|βββ | 50/200 [00:01<00:03, 41.14it/s]
28%|βββ | 55/200 [00:01<00:03, 41.03it/s]
30%|βββ | 60/200 [00:01<00:03, 40.66it/s]
32%|ββββ | 65/200 [00:01<00:03, 40.67it/s]
35%|ββββ | 70/200 [00:01<00:03, 40.68it/s]
38%|ββββ | 75/200 [00:01<00:03, 40.68it/s]
40%|ββββ | 80/200 [00:01<00:02, 40.29it/s]
42%|βββββ | 85/200 [00:02<00:02, 40.54it/s]
45%|βββββ | 90/200 [00:02<00:02, 40.49it/s]
48%|βββββ | 95/200 [00:02<00:02, 40.63it/s]
50%|βββββ | 100/200 [00:02<00:02, 40.26it/s]
52%|ββββββ | 105/200 [00:02<00:02, 40.27it/s]
55%|ββββββ | 110/200 [00:02<00:02, 40.55it/s]
57%|ββββββ | 115/200 [00:02<00:02, 40.56it/s]
60%|ββββββ | 120/200 [00:02<00:01, 40.59it/s]
62%|βββββββ | 125/200 [00:03<00:01, 40.48it/s]
65%|βββββββ | 130/200 [00:03<00:01, 40.49it/s]
68%|βββββββ | 135/200 [00:03<00:01, 40.15it/s]
70%|βββββββ | 140/200 [00:03<00:01, 40.56it/s]
72%|ββββββββ | 145/200 [00:03<00:01, 40.37it/s]
75%|ββββββββ | 150/200 [00:03<00:01, 40.45it/s]
78%|ββββββββ | 155/200 [00:03<00:01, 40.23it/s]
80%|ββββββββ | 160/200 [00:03<00:00, 40.20it/s]
82%|βββββββββ | 165/200 [00:04<00:00, 39.92it/s]
84%|βββββββββ | 169/200 [00:04<00:00, 39.84it/s]
86%|βββββββββ | 173/200 [00:04<00:00, 39.87it/s]
89%|βββββββββ | 178/200 [00:04<00:00, 40.29it/s]
92%|ββββββββββ| 183/200 [00:04<00:00, 40.52it/s]
94%|ββββββββββ| 188/200 [00:04<00:00, 40.44it/s]
96%|ββββββββββ| 193/200 [00:04<00:00, 40.28it/s]
99%|ββββββββββ| 198/200 [00:04<00:00, 40.43it/s]
100%|ββββββββββ| 200/200 [00:04<00:00, 40.73it/s]
Measurement PSNR: 27.5 dB
Poisson2Sparse PSNR: 30.1 dB
- References:
Total running time of the script: (0 minutes 5.879 seconds)