Files
keys/chromakey.py
2024-08-18 07:11:32 -07:00

125 lines
3.3 KiB
Python

import os
from sklearn.cluster import KMeans
from wand.color import Color
from wand.image import Image
import numpy as np
def chroma_key(img, num_object_colors=1, key_box=((0,0),(100,100)), min_object_pixels=500):
hsv = _hsv_points(img)
hsv_cart = _hsv_to_cartesian(hsv)
labels = _cluster(hsv_cart, num_object_colors+1, img)
key_label = _choose_key(labels, key_box)
mask = _create_mask(labels, key_label)
while True:
ids = _islands(mask)
if not _filter_islands(mask, ids, min_object_pixels):
break
_apply_mask(img, mask)
img.trim()
def _hsv_points(img):
hsv_img = img.clone()
hsv_img.transform_colorspace('hsv')
pixels = list(hsv_img.export_pixels(channel_map='RGB')) # this actually means HSV
return np.array(pixels).reshape(-1, 3)
def _hsv_to_cartesian(hsv):
h = hsv[:, 0]
s = hsv[:, 1]
v = hsv[:, 2]
x = s * np.cos(h * 2 * np.pi / 255)
y = s * np.sin(h * 2 * np.pi / 255)
return np.column_stack((x, y, v))
def _cluster(points, num_clusters, img):
kmeans = KMeans(n_clusters=num_clusters)
kmeans.fit(points)
return kmeans.labels_.reshape(img.height, img.width)
def _choose_key(labels, key_box):
box_labels = labels[key_box[0][0]:key_box[1][0], key_box[0][1]:key_box[1][1]]
values, counts = np.unique(box_labels.flatten(), return_counts=True)
i = np.argmax(counts)
return values[i]
def _islands(mask):
ids = np.zeros_like(mask).astype(np.uint64)
next_id = 1
for (i, j), _ in np.ndenumerate(mask):
_flood_fill(ids, mask, i, j, next_id)
next_id += 1
return ids
def _filter_islands(mask, ids, min_object_pixels):
values, counts = np.unique(ids.flatten(), return_counts=True)
values_rm = values[np.where(counts < min_object_pixels)]
mask_ix = np.isin(ids, values_rm)
mask[mask_ix] = np.where(mask[mask_ix] == 255, 0, 255)
return len(values_rm) > 0
def _flood_fill(ids, mask, i, j, val):
base_val = mask[i, j]
queue = [(i, j)]
while queue:
(i, j) = queue.pop()
if i < 0 or i >= mask.shape[0] or j < 0 or j >= mask.shape[1]:
continue
if mask[i, j] != base_val or ids[i, j] != 0:
continue
ids[i, j] = val
queue.append((i - 1, j))
queue.append((i + 1, j))
queue.append((i - 1, j - 1))
queue.append((i + 1, j - 1))
queue.append((i - 1, j + 1))
queue.append((i + 1, j + 1))
queue.append((i, j - 1))
queue.append((i, j + 1))
def _create_mask(labels, key_label):
return (labels != key_label).astype(np.uint8) * 255
def _apply_mask(img, mask):
with Image.from_array(mask) as mask_img:
img.alpha_channel = 'activate'
img.composite_channel('alpha', mask_img, 'copy_alpha', 0, 0)
img.background_color = Color('transparent')
path = 'data/RAW/SC1/BR1'
for dirpath, dirnames, filenames in os.walk(path):
for filename in filenames:
if not filename.endswith('.orf'):
continue
full_path = os.path.join(dirpath, filename)
print(full_path)
with Image(filename=full_path) as img:
img.crop(left=0, top=0, width=4000, height=3000)
chroma_key(img)
new_path = os.path.join(dirpath, filename.removesuffix('.orf') + '.png')
img.save(filename=new_path)