[2024-09-29 Sun]: Fix rgb in recolor.py
The SuperNote lets me draw with black, dark gray (0x9d), gray
(0xc9), or white. I
wanted to make it easy to recolor them, since a little splash of
colour makes sketches more fun and also makes them easier to pick out
from thumbnails. Here's the Python script I wrote:
Download recolor.py
import numpy as np
import os
import csv
import argparse
from PIL import Image
DARK_GRAY = 0x9d
GRAY = 0xc9
HEADER_GRAY = 0xca
WHITE = 0xfe
color_dict = {}
def color_to_tuple(color_dict, s):
if s in color_dict:
s = color_dict[s]
s = s.lstrip('#')
if (s == '.'):
return (None, None, None)
elif (len(s) == 2):
return (int(s, 16), int(s, 16), int(s, 16))
else:
return tuple(int(s[i:i + 2], 16) for i in (0, 2, 4))
def load_color_dict(filename):
dict = {}
with open(os.path.expanduser(filename), newline='') as csvfile:
reader = csv.reader(csvfile, delimiter=',', quotechar='"')
for row in reader:
dict[row[0]] = row[1]
return dict
def remove_grid(input):
if isinstance(input, str):
im = Image.open(input).convert('RGB')
else:
im = input
data = np.array(im)
freq = get_colors_by_freq(input)
print(freq)
return Image.fromarray(data)
def map_colors(input, color_map):
if isinstance(input, str):
im = Image.open(input).convert('RGB')
else:
im = input
data = np.array(im)
red, green, blue = data[:, :, 0], data[:, :, 1], data[:, :, 2]
for from_c, to_c in color_map.items():
from_r, from_g, from_b = color_to_tuple(color_dict, from_c)
to_r, to_g, to_b = color_to_tuple(color_dict, to_c)
mask = (red == from_r) & (green == from_g) & (blue == from_b)
data[:, :, :3][mask] = [to_r, to_g, to_b]
return Image.fromarray(data)
def set_colors_by_freq(input, color_list):
if isinstance(input, str):
im = Image.open(input).convert('RGB')
else:
im = input
data = np.array(im)
red, green, blue = data[:, :, 0], data[:, :, 1], data[:, :, 2]
sorted_colors = get_colors_by_freq(input)
freq = iter(color_list.split(','))
for i, f in enumerate(freq):
if f != '.':
to_r, to_g, to_b = color_to_tuple(color_dict, f)
by_freq = sorted_colors[i][1]
if isinstance(by_freq, np.uint8):
mask = (red == by_freq) & (green == by_freq) & (blue == by_freq)
else:
mask = (red == by_freq[0]) & (green == by_freq[1]) & (blue == by_freq[2])
data[:, :, :3][mask] = [to_r, to_b, to_g]
return Image.fromarray(data)
def color_string_to_map(s):
color_map = {}
colors = iter(args.colors.split(','))
for from_c in colors:
to_c = next(colors)
color_map[from_c] = to_c
return color_map
def get_colors_by_freq(input):
if isinstance(input, str):
im = Image.open(input).convert('RGB')
else:
im = input
colors = im.getcolors(im.size[0] * im.size[1])
return sorted(colors, key=lambda x: x[0], reverse=True)
def print_colors(input):
sorted_colors = get_colors_by_freq(input)
for x in sorted_colors:
if x[0] > 10:
if isinstance(x[1], np.uint8):
print('%02x %d' % (x[1], x[0]))
else:
print(''.join(['%02x' % c for c in x[1]]) + ' %d' % x[0])
def process_file(input):
print(input)
if args.preview:
output = None
else:
output = args.output if args.output else input
if os.path.isdir(output):
output = os.path.join(output, os.path.basename(input))
im = Image.open(input).convert('RGB')
if args.colors:
im = map_colors(im, color_string_to_map(args.colors))
elif args.freq:
im = set_colors_by_freq(im, args.freq)
else:
print_colors(im)
exit(0)
if args.preview:
im.thumbnail((700, 700))
im.show()
elif output:
im.save(output)
if __name__ == '__main__':
parser = argparse.ArgumentParser(
description='Recolor a PNG.',
formatter_class=argparse.RawTextHelpFormatter,
epilog="If neither --colors nor --freq are specified, "
+ "display the most frequent colours in the image.")
parser.add_argument('--colors', help="""Comma-separated list of RGB hex values in the form of old,new,old,new
Examples:
9d,ffaaaa,c9,ffd2d2 - reddish
c9,ffea96 - yellow highlighter
c9,d2d2ff - light blue
""")
parser.add_argument('--freq', help="Color replacements in order of descending frequency (ex: .,ffea96). .: use original color")
parser.add_argument('--csv', help="CSV of color names to use in the form of colorname,hex")
parser.add_argument('--preview', help="Preview only", action='store_const', const=True)
parser.add_argument('input', nargs="+", help="Input file")
parser.add_argument('--output', help="Output file. If not specified, overwrite input file.")
args = parser.parse_args()
color_dict = load_color_dict(args.csv) if args.csv else {}
for input in args.input:
process_file(os.path.join(os.getcwd(), input))
I don't think in hex colours, so I added a way to refer to colours by
names. I converted this list of Copic CSS colours to a CSV by copying
the text, pasting it into a file, and doing a little replacement. It's
not complete, but I can copy selected colours from this longer list. I
can also add my own. The CSV looks a little like this:
lightgreen,cfe8d3
lightyellow,f6f396
lightblue,b3e3f1
y02,f6f396
w2,ddddd5
b02,b3e3f1
...
It doesn't do any fuzzing or clustering of similar colours, so it
won't work well on antialiased images. For the simple sketches I make
with the SuperNote, though, it seems to work well enough.
I can preview my changes with something like ./recolor.py ~/sketches/"2022-08-02-01 Playing with my drawing workflow #supernote #drawing #workflow #sketching #kaizen.png" --csv colors.csv --freq .,lightyellow --preview , and then I can
take the --preview flag off to overwrite the PNG.
Here's what the output looks like:
