Compress resource image to paper size to reduce file size about cs-unplugged

[JackMorganNZ]

I implemented a basic resize with the Python Pillow library using the following code:

MM_TO_PIXEL_RATIO = 3.78

# Resize image to reduce file size
if paper_size == "a4":
    max_pixel_height = 267 * MM_TO_PIXEL_RATIO
elif paper_size == "letter":
    max_pixel_height = 249 * MM_TO_PIXEL_RATIO
(width, height) = base_image.size
if height > max_pixel_height:
    ratio = height / max_pixel_height
    width *= ratio
    height *= ratio
    base_image = base_image.resize((int(width), int(height)), Image.ANTIALIAS)

However it's very computationally intensive. It would slow down resource generation considerably for small copies and the Django server threw the Killed error at 50 copies.

Amusingly I had implemented the ratio calculation the wrong way around... Silly Jack..

I've noticed a rough ~10% decrease in file size with minimal time delays. It would worth timing the process to see if it's worth the time.

[JackMorganNZ]

Closed in dfab2a2