fix bad nearest-neighbor scaling and re-scale back up

scalefixer.py

"""
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42 modified):
 * <[email protected]> wrote this file.  As long as you retain this notice and
 * my credit somewhere you can do whatever you want with this stuff.  If we
 * meet some day, and you think this stuff is worth it, you can buy me a beer
 * in return.
 * ----------------------------------------------------------------------------
"""

from PIL import Image
import sys

THRESHOLD = 3
RESCALE_FACTOR = 2

if __name__ == "__main__":
	if len(sys.argv) < 2:
		print("drag and drop a file into me (or pass filename into commandline, optional second argument for output name)")
		sys.exit()
	
	filename, ext = sys.argv[1].split('.')
	
	if len(sys.argv) < 3:
		out_filename = f"{filename}-fixed"
	else:
		out_filename = sys.argv[2]

	# lazy dumb programming mess	
	with Image.open(f"{filename}.{ext}") as im:
		px = im.load()
		width, height = im.size
		newwidth, newheight = width, height

		out = Image.new(im.mode, (width, height))
		px_out = out.load()
		similar = 0

		last = []
		trueN = 0
		for x in range(width):
			col = [px[x, i] for i in range(height)]
			if col != last:
				for y in range(height):
					px_out[trueN, y] = col[y]
				trueN += 1
			else:
				similar += 1
				if similar > THRESHOLD:
					similar = 0
					last = []
			last = col
		newwidth = trueN

		fix1 = out.copy()
		px = fix1.load()
		last = []
		trueN = 0
		for y in range(height):
			row = [px[i, y] for i in range(width)]
			if row != last:
				for x in range(width):
					px_out[x, trueN] = row[x]
				trueN += 1
			else:
				similar += 1
				if similar > THRESHOLD:
					similar = 0
					last = []
			last = row
		newheight = trueN

	out = out.crop((0, 0, newwidth, newheight))
	out = out.resize((newwidth * RESCALE_FACTOR, newheight * RESCALE_FACTOR), Image.Resampling.NEAREST)
	out.save(f"{out_filename}.{ext}")