clothify makes extremely large png files!

[Ofnuts]

No... The compression in PNG is essentially recognizing with very slow changes in color, and clothify does pretty much the opposite, by adding pixel-level detail. So you get no compression, and your final output is roughly the pixel count multiplied by 3,4,6,8, depends on number of channels and channel depth. 10800² × 4 = 466560000 = 445MB so you still get some compression...