waterleaf.py

from PIL import Image
from math import sin, cos, pi

r1 = 72
r2 = 97

flag = ''

for j in range(2,1681,4):
    im = Image.open('convert_output_{:05d}.png'.format(j))
    final = 0

    maxi = 0
    maxs = 0
    for i in range(16):
        x, y = 300+r1*sin(pi+i*pi/16), 300+r1*cos(pi+i*pi/16)
        x, y = round(x), round(y)
        s = 0
        for k in [-1,0,1]:
            for l in [-1,0,1]:
                p = im.getpixel((x+k,y+l))
                if type(p) == tuple:
                    p = sum(p)
                s += p
        if s > maxs:
            maxs = s
            maxi = i
    final += 16*maxi

    maxi = 0
    maxs = 0
    for i in range(16):
        x, y = 300+r2*sin(pi+i*pi/16), 300+r2*cos(pi+i*pi/16)
        x, y = round(x), round(y)
        s = 0
        for k in [-1,0,1]:
            for l in [-1,0,1]:
                p = im.getpixel((x+k,y+l))
                if type(p) == tuple:
                    p = sum(p)
                s += p
        if s > maxs:
            maxs = s
            maxi = i
    final += maxi
    flag += chr(final)

print(flag)

waterleaf.sh

#!/bin/bash
ffmpeg -i waterleaf*.avi -an -f image2 "output_%05d.jpg"
for f in output_*.png; do
    convert $f -crop 600x600+0+0 -fft +delete -auto-level -evaluate log 100 convert_$f
done