edit.py

from PIL import Image, ImageOps, ImageGrab
from matplotlib import pyplot as plt

MAX = 256
HUE_SHIFT_DEG = MAX // 2
BRIGHTNESS_INCR = 30


from_file = False

# Get image
png_image = ImageGrab.grabclipboard()
if png_image is None:
	input("No image in clipboard. Press enter to exit... ")
	exit(1)
elif isinstance(png_image, list):
	from_file = True
	png_image = Image.open(png_image[0])


# Ask whether the image should be hue-shifted
# ... to counteract the inverted colours
response = input("Also shift hue? (y/n) ").strip().lower()
hue_shift = response == "y"


png_image.convert("RGBA") # Not sure if this is useful in any cases

# Preserve alpha, recombined later
png_image_split = png_image.split()
a = png_image_split[3] if len(png_image_split) == 4 else None
if a is None: # Generate alpha
	alpha_opaque = Image.new("RGBA", png_image.size, "black")
	a = alpha_opaque.split()[3]
r, g, b = png_image_split[:3]

rgb_image = Image.merge("RGB", (r, g, b))

inverted_image = ImageOps.invert(rgb_image)
final_image = inverted_image

if hue_shift:
	# Do the hue shift, convert back to RGB
	image_hsv = final_image.convert("HSV")
	h, s, v = image_hsv.split()
	shifted_h = h.point(lambda p: (p + HUE_SHIFT_DEG) % MAX)
	shifted_hsv_image = Image.merge("HSV", (shifted_h, s, v))

	shifted_rgb_image = shifted_hsv_image.convert("RGB")
	final_image = shifted_rgb_image

# Increase brightness by +30
r2, g2, b2 = final_image.split()
add_brightness = lambda p: min(p + BRIGHTNESS_INCR, MAX - 1)
shifted_r2 = r2.point(add_brightness)
shifted_g2 = g2.point(add_brightness)
shifted_b2 = b2.point(add_brightness)

final_png_image = Image.merge("RGBA", \
  (shifted_r2, shifted_g2, shifted_b2, a))


# Display image
# Doesn't copy to clipboard
plt.imshow(final_png_image)
plt.show()
#final_png_image.show() # Windows default image displayer is absurdly faulty

# Close image if opened
if from_file:
	png_image.close()