How to resize an image in Python without using Pillow

Question

My Django site is hosted on Azure.

It allows for users to upload photos. I need a way for the system to resize, and possibly rotate photos.

Seems simple, and I tried to use the Pillow library but while it works locally it will not deploy to Azure for a number of reasons. I can be specific if needed but this is well documented like here.

I even tried buiding a wheel of Pillow and deploying that but Azure refuses to load it saying it is the wrong platform (even though I matched the Python 2.7 version - and 32 bit). I tried to upload 64 bit versions as well, and nothing works. So at this point I just want to leave Pillow behind me and ask for another way to achieve this in Python without Pillow. Is there any other way to do this?

Notes of things I tried:

1) Installing Pillow the normal way gives this familiar error message:
ValueError: zlib is required unless explicitly disabled using --disable-zlib, aborting

2) I then created a wheel by doing: pip wheel Pillow --wheel-dir=requirements

This however yields the following error in the pip.log:
Pillow-3.4.2-cp27-cp27m-win32.whl is not a supported wheel on this platform. Pillow-4.1.1-cp27-cp27m-win32.whl is not a supported wheel on this platform.
I am certain that I'm runing Python 2.7 on a 32bit platform so not sure why its complaining.

Answer 1

After days wasted, I've discovered the reason why Pillow isn't installing. It's not because the wheel is incompatible to the platform, but rather that pip is too old.

Azure is using pip version 1.5.6 at the moment - shame on them. This version doesn't recognise wheels.

Here is how I fixed this: Goto the Kudu DebugConsole:
https://[site_name].scm.azurewebsites.net/DebugConsole

Activate your VirtualEnv:
env\Scripts\activate

Note that if you run pip --version how old that version number is. Now upgrade this by running:
python -m pip install -U pip
Note that you cannot upgrade the default pip in D:\Python27 as you don't have access to it but you can upgrade your local pip inside fo the virtual environment. Now run pip --version to ensure you are running the latest version (i.e. >=9.0.1).

Now inside of requirements.txt you can tell pip to look for wheels in specific folders by adding a line at the top such as:
--find-links requirements (which means it will search the requirements folder).
Here is how you create the Pillow wheel. You can run this locally or on the Kudu Console. If you run it locally ensure your python version matches what you use on Azure (2.7 or 3.X) and by default make sure you use a 32bit version.
pip install wheel (Only if you don't have wheel installed)
pip wheel Pillow --wheel-dir=requirements
This will copy two files into your requirements folder: Pillow-X.whl and olefile-X.whl. Ensure these are added to your source control if you are deploying via git push. Push these to the server.

Now in the Kudu DebugConsole you can test the .whl files are there (after deploying) and test the installing by running: pip install --no-index -r requirements.txt
This should now work and install Pillow!

When deploying pay close attention to if it says Found compatible virtual environment. or Creating python 2-7 virtual environment.. The former is what you want. But if you see the latter it means that the deploy has blasted your env folder and reset you back to pip 1.5.6. I don't know why it does this sometimes, but try to make as few changes to the env folder as possible after deploying (i.e. just upgrade pip and thats it) to avoid this.

Answer 2

I can't help you much with installing Pillow on Azure platform. But my days of using manually resizing and other stuff is long gone. I have been using thumbor https://thumbor.org/ for quite some time.

Just setup a secured instance of the same and use it resize, crop and manage your images dynamically.

Hope it helps

Answer 3

There is the other SO thread Microsoft Azure Django Python setup error Pillow, which has the similar issue about installing Pillow on Azure. I think my answer for that is helpful for resolving your issue. Any concern for my solution, please feel free to let me know.