How to setup Waifu2x on CentOS7

!! The Python+OpenCL variant used is very slow !!
!! I tested C++, OpenCV+OpenCL variant and it's pretty fast !!
!! Will write the installation guide soon on another post !!

Based on this guide:
https://wiki.tiker.net/OpenCLHowTo

I was having a struggle to get it to work. Especially linking OpenCL.
(No problem with Intel counterpart, but the AMD ones...)

What is Waifu2x?
To sum it simple, it's basically an up-scaller for anime-style image.

Original Waifu2x:
https://github.com/nagadomi/waifu2x (@ultraistter)

Waifu2x I'm using: cl-waifu2x (Waifu2x OpenCL)
https://github.com/marcan/cl-waifu2x (@marcan42)

Reason of using cl-waifu2x:
The original counterpart dependencies requires NVIDIA GPU with CUDA support,
therefore I chose the Python-OpenCL version as it can be done as long as OpenCL is available.

If you do not need OpenCL, you can use this:
https://marcan.st/transf/waifu2x.py
(Same author as cl-waifu2x)

Required:
- Python >= 2.7
- numpy
- scipy
- PIL (or Pillow) < 3.0.0 (3.x above will trigger fromstring() exception)
- OpenCL headers
- OpenCL library (AMD or Intel)
- Boost (Optional)
- OpenCL Test Tool (Optional)
- PyOpenCL

Installation steps:
- Install Python, numpy, scipy, OpenCL headers, Boost
# yum install python numpy scipy opencl-headers boost boost-devel ctags

- Install Pillow (Uses 2.9.0)
# easy_install pillow==2.9.0 

- Install OpenCL Library (Intel OpenCL. the simple way)
* Intel OpenCL requires CPU that supports SSE4.2 and onwards
** Using v16.1 when writing this guide, url might changes.
*** You need redhat-lsb-core for v16.1
**** You can download it here: https://software.intel.com/en-us/articles/opencl-drivers
# yum install redhat-lsb-core
# wget http://registrationcenter-download.intel.com/akdlm/irc_nas/9019/opencl_runtime_16.1_x64_rh_5.2.0.10002.tgz
# tar xzvf opencl_runtime_16.1_x64_rh_5.2.0.10002.tgz
# ./install.sh

Just proceed the installation, nothing much to setting.

- Install OpenCL Library (AMD OpenCL, the hard way)
* AMD OpenCL requires CPU that supports SSE3 and onwards
** The installation is not that hard, but faulty...
*** The real pain lies on linking to AMD OpenCL
**** You can download it here: http://developer.amd.com/tools-and-sdks/opencl-zone/amd-accelerated-parallel-processing-app-sdk/
# tar xjvf AMD-APP-SDKInstaller-v3.0.130.136-GA-linux64.tar.bz2
# ./AMD-APP-SDK-v3.0.130.136-GA-linux64.sh
# vi /etc/ld.so.conf (add /opt/AMDAPPSDK-3.0/lib/x86_64/sdk )
# ln -s /opt/AMDAPPSDK-3.0/lib/x86_64/sdk/libOpenCL.so.1 /usr/lib/libOpenCL.so.1
# ln -s /opt/AMDAPPSDK-3.0/lib/x86_64/sdk/libOpenCL.so.1 /usr/lib64/libOpenCL.so.1

Congrats! You have complete installing OpenCL!
You can test OpenCL by installing the Test Tool.
(You can skip this)
# curl https://codeload.github.com/hpc12/tools/tar.gz/master | tar xvfz -
# cd tools-master

Treaky part-1
Using Intel OpenCL:
# make
Using AMD OpenCL:
# make OPENCL_INC=/opt/AMDAPPSDK-3.0/include OPENCL_LIB=/opt/AMDAPPSDK-3.0/lib/x86_64/sdk

List of Possible OpenCL Device:
# ./print-devices
OpenCL Demo:
# ./cl-demo 1000000 10
If your installation is successful, you should not get no error.
If you installed Intel OpenCL but you get Device Not Available error, it means that your CPU do not support SSE4.2. Use AMD OpenCL instead.

Continue installation.
- Install PyOpenCL.
* Do not install using easy_install or pip, it won't build properly
** 2016.1 was the latest version when writing this guide.
# wget https://pypi.python.org/packages/cb/4e/fcb45db7d3005f5646f28a3de2a2f8e60a6e4b629f02bbb331320778f3a1/pyopencl-2016.1.tar.gz
# tar xzvf pyopencl-2016.1.tar.gz
# cd pyopencl-2016.1

Treaky part-2
Using Intel OpenCL:
# python configure.py

Using AMD OpenCL:
# python configure.py --cl-inc-dir=/opt/AMDAPPSDK-3.0/include --cl-lib-dir=/opt/AMDAPPSDK-3.0/lib/x86_64/sdkintel/opencl/lib64 --cl-libname=OpenCL

Proceed to build:
# make

Treaky part-3 (AMD OpenCL Only)
You might break the make for the last sentence as you get the OpenCL not found error.
It just that the parameter was passed wrongly, you just need to run this once and rerun # make
# g++ -pthread -shared -Wl,-z,relro build/temp.linux-x86_64-2.7/build/temp.linux-x86_64-2.7/pyopencl._cffi.o build/temp.linux-x86_64-2.7/src/c_wrapper/wrap_cl.o build/temp.linux-x86_64-2.7/src/c_wrapper/wrap_constants.o build/temp.linux-x86_64-2.7/src/c_wrapper/bitlog.o build/temp.linux-x86_64-2.7/src/c_wrapper/pyhelper.o build/temp.linux-x86_64-2.7/src/c_wrapper/platform.o build/temp.linux-x86_64-2.7/src/c_wrapper/device.o build/temp.linux-x86_64-2.7/src/c_wrapper/context.o build/temp.linux-x86_64-2.7/src/c_wrapper/command_queue.o build/temp.linux-x86_64-2.7/src/c_wrapper/event.o build/temp.linux-x86_64-2.7/src/c_wrapper/memory_object.o build/temp.linux-x86_64-2.7/src/c_wrapper/image.o build/temp.linux-x86_64-2.7/src/c_wrapper/gl_obj.o build/temp.linux-x86_64-2.7/src/c_wrapper/memory_map.o build/temp.linux-x86_64-2.7/src/c_wrapper/buffer.o build/temp.linux-x86_64-2.7/src/c_wrapper/sampler.o build/temp.linux-x86_64-2.7/src/c_wrapper/program.o build/temp.linux-x86_64-2.7/src/c_wrapper/kernel.o build/temp.linux-x86_64-2.7/src/c_wrapper/debug.o -L/opt/AMDAPPSDK-3.0/lib/x86_64/sdk -L. -lOpenCL -lpython2.7 -o build/lib.linux-x86_64-2.7/pyopencl/_cffi.so

Complete the installation.
# make install

Getting cl-waifu2x
# git clone https://github.com/marcan/cl-waifu2x.git
# cd cl-waifu2x

Test Waifu2x.
# python cl-waifu2x.py image-source.png image-waifu2x.png models/scale2.0x_model.json

That's all!
Have fun with Waifu2x!