Generating image thumbnail with PyroCMS - Files Module

gistfile1.txt

image original dimensions (???x???)

files/large/1
files/thumb/1/auto/auto
files/thumb/1/auto/auto/fill
files/thumb/1/auto/auto/fit

max default dimensions (100x100) with aspect ratio

files/thumb/1

exact default dimensions (100x100) without aspect ratio

files/thumb/1/fill

exact default dimensions (100x100) using crop

files/thumb/1/fit

max square dimensions (150x150) with aspect ratio

files/thumb/1/150
files/thumb/1/150/150
files/thumb/1/150x150

files/thumb/1/150/auto or files/thumb/1/auto/150 (if original dimensions not is square)

exact square dimensions (150x150) without aspect ratio

files/thumb/1/150/fill
files/thumb/1/150/150/fill
files/thumb/1/150x150/fill

exact square dimensions (150x150) using crop

files/thumb/1/150/fit
files/thumb/1/150/150/fit
files/thumb/1/150x150/fit

max width (150) with aspect ratio

files/thumb/1/150/auto
files/thumb/1/150/auto/fit
files/thumb/1/150x
files/thumb/1/150x/fit
files/thumb/1/150x0/fit

max height (150) with aspect ratio

files/thumb/1/auto/150
files/thumb/1/auto/150/fit
files/thumb/1/x150
files/thumb/1/x150/fit
files/thumb/1/0x150/fit

exact width and original height (150x???) without aspect ratio

files/thumb/1/150/auto/fill
files/thumb/1/150x0/fill
files/thumb/1/150x0

exact width original and height (???x150) without aspect ratio

files/thumb/1/auto/150/fill
files/thumb/1/0x150/fill
files/thumb/1/0x150

Know if there's anyway to stop the thumbnail generator from generating a thumbnail image larger (dimensions wise) than the original image?