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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 3772.25 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]
2%|β | 3/200 [00:00<00:07, 24.89it/s]
4%|β | 8/200 [00:00<00:05, 36.45it/s]
6%|β | 13/200 [00:00<00:04, 38.73it/s]
9%|β | 18/200 [00:00<00:04, 41.57it/s]
12%|ββ | 23/200 [00:00<00:04, 42.11it/s]
14%|ββ | 28/200 [00:00<00:04, 42.75it/s]
16%|ββ | 33/200 [00:00<00:03, 42.23it/s]
19%|ββ | 38/200 [00:00<00:03, 42.65it/s]
22%|βββ | 43/200 [00:01<00:03, 43.47it/s]
24%|βββ | 48/200 [00:01<00:03, 44.40it/s]
26%|βββ | 53/200 [00:01<00:03, 43.92it/s]
29%|βββ | 58/200 [00:01<00:03, 43.70it/s]
32%|ββββ | 63/200 [00:01<00:03, 44.12it/s]
34%|ββββ | 68/200 [00:01<00:03, 43.39it/s]
36%|ββββ | 73/200 [00:01<00:02, 44.15it/s]
39%|ββββ | 78/200 [00:01<00:02, 43.91it/s]
42%|βββββ | 83/200 [00:01<00:02, 44.89it/s]
44%|βββββ | 88/200 [00:02<00:02, 44.04it/s]
46%|βββββ | 93/200 [00:02<00:02, 44.90it/s]
49%|βββββ | 98/200 [00:02<00:02, 44.56it/s]
52%|ββββββ | 103/200 [00:02<00:02, 43.52it/s]
54%|ββββββ | 108/200 [00:02<00:02, 44.84it/s]
56%|ββββββ | 113/200 [00:02<00:01, 44.04it/s]
59%|ββββββ | 118/200 [00:02<00:01, 43.90it/s]
62%|βββββββ | 123/200 [00:02<00:01, 44.15it/s]
64%|βββββββ | 128/200 [00:02<00:01, 43.70it/s]
66%|βββββββ | 133/200 [00:03<00:01, 44.06it/s]
69%|βββββββ | 138/200 [00:03<00:01, 44.13it/s]
72%|ββββββββ | 143/200 [00:03<00:01, 43.06it/s]
74%|ββββββββ | 148/200 [00:03<00:01, 43.97it/s]
76%|ββββββββ | 153/200 [00:03<00:01, 42.93it/s]
79%|ββββββββ | 158/200 [00:03<00:00, 43.81it/s]
82%|βββββββββ | 163/200 [00:03<00:00, 43.37it/s]
84%|βββββββββ | 168/200 [00:03<00:00, 42.97it/s]
86%|βββββββββ | 173/200 [00:04<00:00, 42.51it/s]
89%|βββββββββ | 178/200 [00:04<00:00, 43.19it/s]
92%|ββββββββββ| 183/200 [00:04<00:00, 44.35it/s]
94%|ββββββββββ| 188/200 [00:04<00:00, 43.98it/s]
96%|ββββββββββ| 193/200 [00:04<00:00, 44.94it/s]
99%|ββββββββββ| 198/200 [00:04<00:00, 44.59it/s]
100%|ββββββββββ| 200/200 [00:04<00:00, 43.49it/s]
Measurement PSNR: 27.5 dB
Poisson2Sparse PSNR: 30.3 dB
- References:
Total running time of the script: (0 minutes 6.482 seconds)