eKeerar
73 lines
2.5 KiB
Python
73 lines
2.5 KiB
Python
"""
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Make the (opaque, near-white) background of the mascot cutouts transparent,
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WITHOUT punching holes in the character's white clothing.
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Method: flag near-white pixels, then keep only the near-white regions that are
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CONNECTED TO THE IMAGE BORDER (that's the background). Interior whites (hoodie /
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tee), enclosed by the character's outline, are preserved. A tiny alpha blur
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feathers the edge to avoid a white halo.
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Usage:
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python tools/make_transparent.py <file_or_dir> [<file_or_dir> ...]
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Originals are backed up to Characters/_opaque_backup/ (once) before overwrite.
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"""
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import sys, os, glob
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import numpy as np
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from PIL import Image
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from scipy import ndimage
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WHITE_THRESH = 236 # min channel value to be considered "near white"
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FEATHER = 0.8 # gaussian sigma for alpha edge feather (px)
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BACKUP_ROOT = os.path.join("Characters", "_opaque_backup")
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def process(path: str):
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im = Image.open(path).convert("RGBA")
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arr = np.array(im)
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rgb = arr[:, :, :3].astype(np.int16)
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# near-white mask: all channels high AND low chroma (avoids eating pale skin)
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mn = rgb.min(axis=2)
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mx = rgb.max(axis=2)
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near_white = (mn >= WHITE_THRESH) & ((mx - mn) <= 12)
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# connected components of near-white; keep those touching the border = background
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labels, n = ndimage.label(near_white)
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border_labels = set(labels[0, :]) | set(labels[-1, :]) | set(labels[:, 0]) | set(labels[:, -1])
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border_labels.discard(0)
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bg = np.isin(labels, list(border_labels))
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alpha = np.where(bg, 0, 255).astype(np.float32)
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if FEATHER > 0:
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alpha = ndimage.gaussian_filter(alpha, sigma=FEATHER)
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arr[:, :, 3] = np.clip(alpha, 0, 255).astype(np.uint8)
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# backup once
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rel = os.path.relpath(path, "Characters") if path.replace("\\", "/").startswith("Characters") else os.path.basename(path)
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bpath = os.path.join(BACKUP_ROOT, rel)
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os.makedirs(os.path.dirname(bpath), exist_ok=True)
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if not os.path.exists(bpath):
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Image.open(path).save(bpath)
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Image.fromarray(arr, "RGBA").save(path)
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covered = 100.0 * bg.mean()
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print(f" {os.path.basename(path)} bg removed {covered:4.1f}%")
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def collect(target):
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if os.path.isdir(target):
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return sorted(glob.glob(os.path.join(target, "*.png")))
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return [target]
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if __name__ == "__main__":
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targets = sys.argv[1:] or ["Characters/sori", "Characters/dan", "Characters/duo"]
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for t in targets:
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files = collect(t)
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if files:
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print(t)
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for f in files:
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process(f)
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print("done.")
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