diff --git a/README.md b/README.md
index bc303d6..92e847e 100644
--- a/README.md
+++ b/README.md
@@ -30,16 +30,18 @@ Make sure you have `Python>=3.7` installed on your machine.
 
           pip install -r requirements.txt
 
-3. Prepare the dataset (RESIDE)
+* Prepare the dataset
 
-   1. Download the RESIDE dataset from the [official webpage](https://sites.google.com/site/boyilics/website-builder/reside).
+   * Download the RESIDE dataset from the [official webpage](https://sites.google.com/site/boyilics/website-builder/reside).
 
-   2. Make a directory `./data` and create a symbolic link for uncompressed data `./data/RESIDE`.
+   * Download the O-Haze dataset from the [official webpage](https://data.vision.ee.ethz.ch/cvl/ntire18//o-haze/).
+
+   * Make a directory `./data` and create a symbolic link for uncompressed data, e.g., `./data/RESIDE`.
 
 ## Training
 
-1. Set the path of pretrained ResNeXt model in resnext/config.py
-2. Set the path of datasets in config.py
+1. ~~Set the path of pretrained ResNeXt model in resnext/config.py~~
+2. Set the path of datasets in tools/config.py
 3. Run by ```python train.py```
 
 ~~The pretrained ResNeXt model is ported from the [official](https://github.com/facebookresearch/ResNeXt) torch version,
@@ -55,7 +57,7 @@ Training a model on a single ~~GTX 1080Ti~~ TITAN RTX GPU takes about ~~4~~ 5 ho
 
 ## Testing
 
-1. Set the path of five benchmark datasets in config.py.
+1. Set the path of five benchmark datasets in tools/config.py.
 2. Put the trained model in `./ckpt/`.
 2. Run by ```python test.py```
 
diff --git a/requirements.txt b/requirements.txt
index bcddc4f..b47a587 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,3 +4,4 @@ numpy>=1.20.2
 Pillow>=8.2.0
 scipy>=1.7.1
 scikit-image>=0.18.3
+tqdm>=4.62.3
diff --git a/test.py b/test.py
index 132d5f7..07bf333 100644
--- a/test.py
+++ b/test.py
@@ -5,12 +5,12 @@
 import torch
 from torchvision import transforms
 
-from config import TEST_SOTS_ROOT
-from utils import check_mkdir
+from tools.config import TEST_SOTS_ROOT
+from tools.utils import check_mkdir
 from model import DM2FNet
 from datasets import SotsDataset
 from torch.utils.data import DataLoader
-from skimage.metrics import peak_signal_noise_ratio
+from skimage.metrics import peak_signal_noise_ratio, structural_similarity
 
 os.environ['CUDA_VISIBLE_DEVICES'] = '0'
 
@@ -37,7 +37,7 @@ def main():
         net.load_state_dict(torch.load(os.path.join(ckpt_path, exp_name, args['snapshot'] + '.pth')))
 
     net.eval()
-    psnrs = []
+    psnrs, ssims = [], []
 
     with torch.no_grad():
         for name, root in to_test.items():
@@ -59,13 +59,16 @@ def main():
                     gt = gts[i].cpu().numpy().transpose([1, 2, 0])
                     psnr = peak_signal_noise_ratio(gt, r)
                     psnrs.append(psnr)
-                    print('predicting for {} ({}/{}) [{}]: {:.4f}'.format(name, idx + 1, len(dataloader), fs[i], psnr))
+                    ssim = structural_similarity(gt, r, multichannel=True)
+                    ssims.append(ssim)
+                    print('predicting for {} ({}/{}) [{}]: PSNR {:.4f}, SSIM {:.4f}'
+                          .format(name, idx + 1, len(dataloader), fs[i], psnr, ssim))
 
                 for r, f in zip(res.cpu(), fs):
                     to_pil(r).save(
                         os.path.join(ckpt_path, exp_name,
                                      '(%s) %s_%s' % (exp_name, name, args['snapshot']), '%s.png' % f))
-    print(f"PSNR for {name}: {np.mean(psnrs):.6f}")
+    print(f"[{name}] PSNR: {np.mean(psnrs):.6f}, SSIM: {np.mean(ssims):.6f}")
 
 
 if __name__ == '__main__':
diff --git a/tools/__init__.py b/tools/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/config.py b/tools/config.py
similarity index 61%
rename from config.py
rename to tools/config.py
index 73222de..77440f8 100644
--- a/config.py
+++ b/tools/config.py
@@ -8,8 +8,11 @@
 # TEST_A_ROOT = os.path.join(root, 'TestA')
 # TEST_B_ROOT = os.path.join(root, 'nature')
 
+# O-Haze
+OHAZE_ROOT = os.path.join(root, '../data', 'O-Haze')
+
 # RESIDE
-TRAIN_ITS_ROOT = os.path.join(root, 'data', 'RESIDE', 'ITS_v2')  # ITS
-TEST_SOTS_ROOT = os.path.join(root, 'data', 'RESIDE', 'SOTS', 'nyuhaze500')  # SOTS indoor
+TRAIN_ITS_ROOT = os.path.join(root, '../data', 'RESIDE', 'ITS_v2')  # ITS
+TEST_SOTS_ROOT = os.path.join(root, '../data', 'RESIDE', 'SOTS', 'nyuhaze500')  # SOTS indoor
 # TEST_SOTS_ROOT = os.path.join(root, 'SOTS', 'outdoor')  # SOTS outdoor
 # TEST_HSTS_ROOT = os.path.join(root, 'HSTS', 'synthetic')  # HSTS
diff --git a/tools/preprocess_ohaze_data.py b/tools/preprocess_ohaze_data.py
new file mode 100644
index 0000000..c25c864
--- /dev/null
+++ b/tools/preprocess_ohaze_data.py
@@ -0,0 +1,56 @@
+import os
+from PIL import Image
+
+from config import OHAZE_ROOT
+from math import ceil
+from tqdm import tqdm
+
+if __name__ == '__main__':
+    ohaze_root = OHAZE_ROOT
+    crop_size = 512
+
+    ori_root = os.path.join(ohaze_root, '# O-HAZY NTIRE 2018')
+    ori_haze_root = os.path.join(ori_root, 'hazy')
+    ori_gt_root = os.path.join(ori_root, 'GT')
+
+    patch_root = os.path.join(ohaze_root, 'train_crop_{}'.format(crop_size))
+    patch_haze_path = os.path.join(patch_root, 'img')
+    patch_gt_path = os.path.join(patch_root, 'gt')
+
+    os.makedirs(patch_root, exist_ok=True)
+    os.makedirs(patch_haze_path, exist_ok=True)
+    os.makedirs(patch_gt_path, exist_ok=True)
+
+    # first 35 images for training
+    train_list = [img_name for img_name in os.listdir(ori_haze_root)
+                  if int(img_name.split('_')[0]) <= 35]
+
+    for idx, img_name in enumerate(tqdm(train_list)):
+        img_f_name, img_l_name = os.path.splitext(img_name)
+        gt_f_name = '{}GT'.format(img_f_name[: -4])
+
+        img = Image.open(os.path.join(ori_haze_root, img_name))
+        gt = Image.open(os.path.join(ori_gt_root, gt_f_name + img_l_name))
+
+        assert img.size == gt.size
+
+        w, h = img.size
+        stride = int(crop_size / 3.)
+        h_steps = 1 + int(ceil(float(max(h - crop_size, 0)) / stride))
+        w_steps = 1 + int(ceil(float(max(w - crop_size, 0)) / stride))
+
+        for h_idx in range(h_steps):
+            for w_idx in range(w_steps):
+                ws0 = w_idx * stride
+                ws1 = crop_size + ws0
+                hs0 = h_idx * stride
+                hs1 = crop_size + hs0
+                if h_idx == h_steps - 1:
+                    hs0, hs1 = max(h - crop_size, 0), h
+                if w_idx == w_steps - 1:
+                    ws0, ws1 = max(w - crop_size, 0), w
+                img_crop = img.crop((ws0, hs0, ws1, hs1))
+                gt_crop = gt.crop((ws0, hs0, ws1, hs1))
+
+                img_crop.save(os.path.join(patch_haze_path, '{}_h_{}_w_{}.png'.format(img_f_name, h_idx, w_idx)))
+                gt_crop.save(os.path.join(patch_gt_path, '{}_h_{}_w_{}.png'.format(gt_f_name, h_idx, w_idx)))
diff --git a/utils.py b/tools/utils.py
similarity index 76%
rename from utils.py
rename to tools/utils.py
index c4db1d1..d787d2a 100644
--- a/utils.py
+++ b/tools/utils.py
@@ -4,13 +4,16 @@
 
 class AvgMeter(object):
     def __init__(self):
-        self.reset()
+        self.val = 0.
+        self.avg = 0.
+        self.sum = 0.
+        self.count = 0.
 
     def reset(self):
-        self.val = 0
-        self.avg = 0
-        self.sum = 0
-        self.count = 0
+        self.val = 0.
+        self.avg = 0.
+        self.sum = 0.
+        self.count = 0.
 
     def update(self, val, n=1):
         self.val = val
diff --git a/train.py b/train.py
index b16d48d..a61c771 100644
--- a/train.py
+++ b/train.py
@@ -8,9 +8,9 @@
 from torch.backends import cudnn
 from torch.utils.data import DataLoader
 
-from config import TRAIN_ITS_ROOT, TEST_SOTS_ROOT
+from tools.config import TRAIN_ITS_ROOT, TEST_SOTS_ROOT
 from datasets import ItsDataset, SotsDataset
-from utils import AvgMeter, check_mkdir
+from tools.utils import AvgMeter, check_mkdir
 from model import DM2FNet
 
 os.environ['CUDA_VISIBLE_DEVICES'] = '0'