Student: Xavier Weber
Mentors: Vladimir Tyan & Yida Wang
Student on the same project: Fanny Monori
Link to accomplished work:
- PR in the opencv_contrib repository: opencv_contrib/pull/2231
- EDSR implementation in TensorFlow: EDSR repo
- FSRCNN implementation in TensorFlow: FSRCNN repo
Hello, I am Xavier! I was a student developer for GSoC 2019 with OpenCV (Link to Project).
The main goal of this project was to add a new module to OpenCV: dnn_superres. This module allows for upscaling images via Convolutional Neural Networks. Easy access to popular Super Resolution data was also included.
The module delivers a simple-to-use interface that effectively uses the state-of-the-art super resolution techniques. This enables developers (that have little or no knowledge about deep learning or super resolution) to easily use this tool in his/her project. A developer can input an image or even real-time video, select their desired method and up-scaling factor and get as output their imagery with up-scaled resolution.
During this project I worked closely with Fanny. She worked on the same module but implemented different models: ESPCN [2] and LapSRN [4]. I implemented EDSR [1] and FSRCNN [3]. These are all supported in this module.
In the first month of GSoC I implemented the following:
-
Loading code for three popular SR datasets: Div2k, BSDS and General100.
This allows for easy access to high-quality images inside of the OpenCV environment. -
Creating the 'dnn_superres' module which is the interface that connects users to all the trained models.
This simplifies the use of these trained models by handling all the pre- and post-processing. -
FSRCNN [3]
This is a pretty light-weight network that can upscale images fast and has decent performance.
In the second month of GSoC I implemented the following:
-
EDSR [1]
This is a state-of-the-art high performance neural network, albeit quite slow. -
Updated the 'dnn_superres' module with pre- and post-processing to support this new network.
In the last month of GSoC I implemented the following:
- Finished the models and trained them for scales x2, x3 and x4
- Coordinating with Fanny to complete the module
- Documentation
- Test
- Tutorial
Here I will demonstrate how you can use this module and reveal its POWER!
Make sure you build OpenCV with the contrib-modules, including "dnn_superres".
Now we can upscale any images using state-of-the-art techniques, by only using OpenCV!!
#include <opencv2/dnn_superres.hpp>
using namespace std;
using namespace cv;
using namespace dnn;
using namespace dnn_superres;
//Create the object
DnnSuperResImpl sr;
//Read the desired model - download links below
path = "models/EDSR_x4.pb"
sr.readModel(path);
//Set the desired model and scale to get correct pre- and post-processing
sr.setModel("edsr", 4);
//Upscale
Mat img = cv::imread(img_path);
Mat img_new;
sr.upsample(img, img_new);You can download my models here: EDSR and FSRCNN, and Fanny's models here: ESPCN and LapSRN.
All computations were done on an i7-9700K. Metrics used are PSNR and SSIM.
| Avg inference time in sec (CPU) | Avg PSNR | Avg SSIM | |
|---|---|---|---|
| ESPCN | 0.008795 | 32.7059 | 0.9276 |
| EDSR | 5.923450 | 34.1300 | 0.9447 |
| FSRCNN | 0.021741 | 32.8886 | 0.9301 |
| LapSRN | 0.114812 | 32.2681 | 0.9248 |
| Bicubic | 0.000208 | 32.1638 | 0.9305 |
| Nearest neighbor | 0.000114 | 29.1665 | 0.9049 |
| Lanczos | 0.001094 | 32.4687 | 0.9327 |
| Avg inference time in sec (CPU) | Avg PSNR | Avg SSIM | |
|---|---|---|---|
| ESPCN | 0.004311 | 26.6870 | 0.7891 |
| EDSR | 1.607570 | 28.1552 | 0.8317 |
| FSRCNN | 0.005302 | 26.6088 | 0.7863 |
| LapSRN | 0.121229 | 26.7383 | 0.7896 |
| Bicubic | 0.000311 | 26.0635 | 0.8754 |
| Nearest neighbor | 0.000148 | 23.5628 | 0.8174 |
| Lanczos | 0.001012 | 25.9115 | 0.8706 |
[1] Bee Lim, Sanghyun Son, Heewon Kim, Seungjun Nah, and Kyoung Mu Lee, "Enhanced Deep Residual Networks for Single Image Super-Resolution", 2nd NTIRE: New Trends in Image Restoration and Enhancement workshop and challenge on image super-resolution in conjunction with CVPR 2017. [PDF] [arXiv] [Slide]
[2] Shi, W., Caballero, J., Huszár, F., Totz, J., Aitken, A., Bishop, R., Rueckert, D. and Wang, Z., "Real-Time Single Image and Video Super-Resolution Using an Efficient Sub-Pixel Convolutional Neural Network", Proceedings of the IEEE conference on computer vision and pattern recognition CVPR 2016. [PDF] [arXiv]
[3] Chao Dong, Chen Change Loy, Xiaoou Tang. "Accelerating the Super-Resolution Convolutional Neural Network", in Proceedings of European Conference on Computer Vision ECCV 2016. [PDF] [arXiv] [Project Page]
[4] Lai, W. S., Huang, J. B., Ahuja, N., and Yang, M. H., "Deep laplacian pyramid networks for fast and accurate super-resolution", In Proceedings of the IEEE conference on computer vision and pattern recognition CVPR 2017. [PDF] [arXiv] [Project Page]
Nice write-up and great contribution 🎉 !