Pixelated

I have these 2 images, can you make a flag out of them? scrambled1.png scrambled2.png

As the images are the same dimensions, it makes sense to consider what could be done with the RBG values. Immediately, XOR springs to mind, and we make a quick script to XOR the pixel data:

from PIL import Image

img1 = Image.open("scrambled1.png")
img2 = Image.open("scrambled2.png")

pixels1 = img1.load()
pixels2 = img2.load()

result_img = Image.new("RGB", img1.size)
result_pixels = result_img.load()

for x in range(img1.width):
    for y in range(img1.height):
        r1, g1, b1 = pixels1[x, y]
        r2, g2, b2 = pixels2[x, y]

        xor_r = r1 ^ r2
        xor_g = g1 ^ g2
        xor_b = b1 ^ b2

        result_pixels[x, y] = (xor_r, xor_g, xor_b)

result_img.save("output.png")

This came up with an interesting output.png, which definitely had the flag in it, but was quite hard to read:

Clearly a flag, but hard to read

After some trial and error and printing of the values, you notice that pretty much everywhere is pure white. To up the contrast a little, we make all the white into black:

if xor_r == xor_g == xor_b == 255:
    xor_r = xor_g = xor_b = 0

And this was enough to spy the flag:

picoCTF{d562333d}