Guided by the haze density, our DADM can handle images with dense haze and complex environments.
- For image dehazing, the haze image can be considered as noisy data, while the clear haze-free image is the target data. By training a diffusion model, we can learn a mapping from haze images to haze-free images. The diffusion model contains a forward diffusion process and a reverse diffusion process.
- In the reverse diffusion process of our DADM, we introduce a density-aware dehazing network (DADNet) to estimate the noise in the input image and recover a haze-free image from a haze image (considered as a noisy state).
The dark channel value of noise areas is also very low, resulting in the inability to extract accurate haze density information. We introduce a cross-feature density extraction module (CDEModule) to optimize the dark channel map and obtain the accurate haze density for the image.
The dehazing results have achieved an optimum at some intermediate time point, while the image quality may instead degrade as the dehazing process continues.
We evaluate all the sampling results at various time steps using the PSNR values against the ground truth. Based on the mean value
$t_2$ and the variance$\sigma$ of the distribution, we can plot the corresponding normal distribution curves$c \sim \mathcal{N}(t_2, \sigma^2)$ . Next, we set a criterion that the area under the corresponding normal distribution curve from$t_1$ to$t=0$ is 90% of the total area.
We use
$t_1$ as the dividing time point. t >$t_1$ is the first stage, while t ≤$t_1$ is the second stage. These two stages use different sampling methods.
We evaluate the PSNR vaules between
$x_t$ and ground-truth for each time step on four datasets.
We compared our methods with IR-SDE.
- OS: Ubuntu 20.04.6
- nvdia: 11.6
- python: 3.7.1
- pytorch: 1.13.0
You can directly configure the hazy and GT paths of the dataset and other parameters in the corresponding files under the Option folder. We have configured four different types of processing methods for different types of data sets hazy image and gt image formats.
- indoor
- outdoor
- NH_Haze
- NH-Haze2
bash train.shbash test.sh






