SizeMatters (formerly InstaMax)

Maximize Image Size for Instagram

Have you ever wanted to post a portrait-orientation picture to Instagram, but when you go to do so, Instagram forces you to crop it because it is "too tall" for Instagram? For those of us that don't want to crop our image, we usually go and grab an "app" that fits the whole picture into a square and fills in the new space with a background color. This is really silly because we could be getting more pixels for our pictures! Instagram allows a maximum image size of 1080 pixels wide by 1350 pixels tall. This tool gives you the maximum number of pixels allowed by Instagram for your picture.

Requirements

The only requirement of this tool is the Pillow image processing library, which can be found in PyPI. I have included a requirements.txt file if you use pip and a setup.py file, as well. This tool will now only run with Python 3, as it requires the latest version of Pillow which is now only supported on Python 3.

sizematters.py

This script contains a single function to maximize an image based on Instagram's maximum size limitations (although this script can be called from the command line, too). It may be noteworthy that Instagram uses the same image processing library (i.e. Pillow) in their backend to process the images you post.

If you want to import the tool for use with your Python code, here is the docstring for the primary maximize_image function:

Maximize an image to the resolution limits imposed by Instagram.

Note that your image will not be cropped in any way. The new space created
around your image will be whatever color you specify.

Also note that every attempt has been made to keep metadata, etc. intact.
Bicubic interpolation is being used to resize your image. JPEG image
quality is set to a default of 75%. It is not recommended to go above 95%.
Instagram probably uses around 50%.

:Parameters:
    - `input_file`: File name (as a string) or a file object of the input
        image.
    - `output_file`: File name (as a string) or a file object for the output
        image (JPEG).
    - `color`: A standard HTML color to use as the background (as a string).
        Default is 'white'.
    - `quality`: The quality setting for JPEG compression as an integer
        percentage. Default is 75.

:Returns:
    None. A file is written to `output_file`, however. It will be a JPEG
    format image.

:Exceptions:
    None. The PIL library may throw some, depending on what you pass in.

If you just want to run this as a script from the command line, here's the usage:

usage: sizematters.py [-h] [-c COLOR] [-q QUALITY] input_file output_file

SizeMatters: This script will take the input image and maximize it to fit the
maximum dimensions that Instagram allows. Your picture will not be cropped,
but the background will be filled with your choice of color.

positional arguments:
  input_file            Image file to process.
  output_file           File name (with any necessary path information) where
                        the output JPEG will be written.

optional arguments:
  -h, --help            show this help message and exit
  -c COLOR, --color COLOR
                        Common HTML color for background. (Default: white)
  -q QUALITY, --quality QUALITY
                        Output JPEG image quality. (Default: 75)

sizematters_wsgi.py

This script contains a very simple WSGI-compliant web app to wrap the SizeMatters tool. It contains a single function, sizematters_app, which serves as the WSGI-compliant app. Here is the docstring that defines how it is used:

Simple WSGI application for the SizeMatters tool/function.

A WSGI compliant application that only accepts POSTed multipart forms
with `file`, `color`, and `quality`. The returned image will always be in
JPEG format.

:Form Parameters:
    - `file`: Should be a JPEG file (although others may work).
    - `color`: Should be any of the standard HTML color names (string).
        Default is 'white'.
    - `quality`: Should be an integer from 1 to 100 to indicate the quality
        setting for JPEG compression. Default is 75.

:Errors:
    - 400: If the form parameters are bad or the Content-type is not
        multipart/form-data.
    - 405: If the request method is anything other than POST.
    - 500: If anything else raises an exception.

Because this is a WSGI-compliant web app, you can use it with your favorite wrapper, whether that is the reference one provided by Python, or something like uWSGI (which is what I use).

sizematters_lambda.py

This script contains a http-triggered (API Gateway) AWS Lambda handler function that wraps the SizeMatters tool. It contains a single function, sizematters_lambda, which serves as the Lambda handler function. Here is the docstring that defines how it is used:

Simple AWS Lambda handler function for the SizeMatters tool/function.

An http-triggered AWS Lambda handler function that only accepts POSTed
multipart forms with `file`, `color`, and `quality`. The returned image
will always be in JPEG format.

:Form Parameters:
    - `file`: Should be a JPEG file (although others may work).
    - `color`: Should be any of the standard HTML color names (string).
        Default is 'white'.
    - `quality`: Should be an integer from 1 to 100 to indicate the quality
        setting for JPEG compression. Default is 75.

:Errors:
    - 400: If the form parameters are bad or the Content-type is not
        multipart/form-data.
    - 405: If the request method is anything other than POST.
    - 500: If anything else raises an exception.

This should be able to simply be dropped in, and used as is within an AWS Lambda. This will require the Pillow package to be available, though, which means adding a "layer" with the package. This code is in use on the SizeMatters website.

sizematters.html

I have also provided a very basic/stripped-down HTML file that contains a proper form to send requests to the SizeMatters web app. If you make use of this, you'll likely need to tweak it to meet your needs.