TensorFlow-WESPE (Ongoing as of 2018.10.2)

TensorFlow implementation of "WESPE: Weakly Supervised Photo Enhancer for Digital Cameras" in CVPRW 2018 [1]

How to run the code

• In WESPE-main.ipynb (plan to add main.py soon)
• Model & training code for the previous model, DPED (in ICCV 2017) [2] can be found in DPED.py & DPED-main.ipynb (full version of my implemented DPED can be found in https://github.com/JuheonYi/DPED-Tensorflow/)

TODO list

• [x] Implement WESPE model
• [x] Train WESPE under strong supervision with DPED dataset (WESPE[DPED])
• [x] Implement weakly supervised dataloader for DPED & DIV2K
• [ ] Train WESPE under weak supervision (WESPE[DIV2K]) --> ongoing

Training result

1. Training log
   • Strong supervision: WESPE[DPED]-main.ipynb (test PSNR for iphone is about 17.5 dB, similar to the original paper, 18.11 dB)
   • Weak supervision: WESPE[DIV2K]-main.ipynb
2. Trained model
   • In "./result/" directory
3. Visual result (to be updated soon...)
   • WESPE[DPED]
   • WESPE[DIV2K]

Modifications

1. Model architecture
   • Removed batch normalization layer in generator
   • Replaced the tanh layer to 1x1 convolution
   • (refer to https://github.com/JuheonYi/DPED-Tensorflow/ for reasons)
2. WESPE[DPED] (strong supervision)
   • I used the 'relu_2_2' layer for content loss (using the ealry layers in VGG19 leads to better reconstruction performance)
   • Removed blurring for computing color loss
   • Weights for each losses are configured as (w_content, w_color, w_texture, w_tv) = (0.1, 25, 3, 1/400). w_content should be small enough so that the generator focus more on enhancement rather than reconstruction. w_color seems to be the most important. w_texture also plays an important role in reducing unwanted artifacts in the generated image.
   • Training seems to suffer from mode collapse (when trained wrong, enhanced image looks like negatively processed image). When Enhanced-Original PSNR seems to stay below 10 dB during training, stopped the training and started from beginning again.
3. WESPE[DIV2K] (weak supervision)
   • In process of finding the right weight combinations...

References

• [1] Andrey Ignatov, Nikolay Kobyshev, Radu Timofte, Kenneth Vanhoey and Luc Van Gool. "WESPE: Weakly Supervised Photo Enhancer for Digital Cameras," in IEEE International Conference on Computer Vision and Pattern Recognition Workshop (CVPRW), 2018.
• [2] Andrey Ignatov, Nikolay Kobyshev, Radu Timofte, Kenneth Vanhoey and Luc Van Gool. "DSLR-Quality Photos on Mobile Devices with Deep Convolutional Networks," in IEEE International Conference on Computer Vision (ICCV), 2017.