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random-stuff/steganography.py

63 lines
1.5 KiB
Python

from PIL import Image
import numpy.fft as fft
import numpy as np
import random
import math
with Image.open("/tmp/in.png") as im:
rgb_im = im.convert("RGB")
data = np.asarray(rgb_im, dtype=np.uint8)
out = np.zeros_like(data)
#out2 = np.zeros_like(data)
random.seed(4)
def operate_on_channel(n):
red = data[..., n]
red = fft.fft2(red)
red = fft.fftshift(red)
w, h = red.shape
mask = np.full_like(red, 1)
midx, midy = w // 2, h // 2
print(red.shape)
J = 48
for x in range(midx - J, midx + J + 1):
for y in range(midy - J, midy + J + 1):
mask[x, y] = random.uniform(0.0, 2.0)
"""
for x in range(w):
for y in range(h):
dist = (x - midx) ** 2 + abs(y - midy) ** 2
#if 1024 > dist > 4:
# mask[x, y] = 1
#mask[x, y] = math.sqrt(dist) / 500
if dist < 256: mask[x, y] = 1
"""
"""
for x in range(w):
for y in range(h):
mask[x, y] = random.uniform(0.7, 1)
"""
red = fft.ifftshift(red * mask)
rfft = fft.ifft2(red)
red = np.abs(np.real(rfft))
#red2 = np.abs(np.imag(rfft))
#red = np.log(np.abs(np.real(red)))
#red = np.abs(mask)
red = red * (255 / np.max(red))
#red2 = red2 * (255 / np.max(red2))
out[..., n] = red
#out2[..., n] = red2
for i in range(3):
operate_on_channel(i)
out = Image.fromarray(out, "RGB")
out.save("/tmp/out.png")
#out2 = Image.fromarray(out2, "RGB")
#out2.save("/tmp/out2.png")