File size: 7,825 Bytes
52a9452 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 |
import cv2
import numpy as np
from shapely.geometry import Polygon
import pyclipper
from concern.config import Configurable, State
class SegDetectorRepresenter(Configurable):
thresh = State(default=0.3)
box_thresh = State(default=0.7)
max_candidates = State(default=100)
dest = State(default='binary')
def __init__(self, cmd={}, **kwargs):
self.load_all(**kwargs)
self.min_size = 3
self.scale_ratio = 0.4
if 'debug' in cmd:
self.debug = cmd['debug']
if 'thresh' in cmd:
self.thresh = cmd['thresh']
if 'box_thresh' in cmd:
self.box_thresh = cmd['box_thresh']
if 'dest' in cmd:
self.dest = cmd['dest']
def represent(self, batch, _pred, is_output_polygon=False):
'''
batch: (image, polygons, ignore_tags
batch: a dict produced by dataloaders.
image: tensor of shape (N, C, H, W).
polygons: tensor of shape (N, K, 4, 2), the polygons of objective regions.
ignore_tags: tensor of shape (N, K), indicates whether a region is ignorable or not.
shape: the original shape of images.
filename: the original filenames of images.
pred:
binary: text region segmentation map, with shape (N, 1, H, W)
thresh: [if exists] thresh hold prediction with shape (N, 1, H, W)
thresh_binary: [if exists] binarized with threshhold, (N, 1, H, W)
'''
images = batch['image']
if isinstance(_pred, dict):
pred = _pred[self.dest]
else:
pred = _pred
segmentation = self.binarize(pred)
boxes_batch = []
scores_batch = []
for batch_index in range(images.size(0)):
height, width = batch['shape'][batch_index]
if is_output_polygon:
boxes, scores = self.polygons_from_bitmap(
pred[batch_index],
segmentation[batch_index], width, height)
else:
boxes, scores = self.boxes_from_bitmap(
pred[batch_index],
segmentation[batch_index], width, height)
boxes_batch.append(boxes)
scores_batch.append(scores)
return boxes_batch, scores_batch
def binarize(self, pred):
return pred > self.thresh
def polygons_from_bitmap(self, pred, _bitmap, dest_width, dest_height):
'''
_bitmap: single map with shape (1, H, W),
whose values are binarized as {0, 1}
'''
assert _bitmap.size(0) == 1
bitmap = _bitmap.cpu().numpy()[0] # The first channel
pred = pred.cpu().detach().numpy()[0]
height, width = bitmap.shape
boxes = []
scores = []
contours, _ = cv2.findContours(
(bitmap*255).astype(np.uint8),
cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
for contour in contours[:self.max_candidates]:
epsilon = 0.002 * cv2.arcLength(contour, True)
approx = cv2.approxPolyDP(contour, epsilon, True)
points = approx.reshape((-1, 2))
if points.shape[0] < 4:
continue
# _, sside = self.get_mini_boxes(contour)
# if sside < self.min_size:
# continue
score = self.box_score_fast(pred, points.reshape(-1, 2))
if self.box_thresh > score:
continue
if points.shape[0] > 2:
box = self.unclip(points, unclip_ratio=2.0)
if len(box) > 1:
continue
else:
continue
box = box.reshape(-1, 2)
_, sside = self.get_mini_boxes(box.reshape((-1, 1, 2)))
if sside < self.min_size + 2:
continue
if not isinstance(dest_width, int):
dest_width = dest_width.item()
dest_height = dest_height.item()
box[:, 0] = np.clip(
np.round(box[:, 0] / width * dest_width), 0, dest_width)
box[:, 1] = np.clip(
np.round(box[:, 1] / height * dest_height), 0, dest_height)
boxes.append(box.tolist())
scores.append(score)
return boxes, scores
def boxes_from_bitmap(self, pred, _bitmap, dest_width, dest_height):
'''
_bitmap: single map with shape (1, H, W),
whose values are binarized as {0, 1}
'''
assert _bitmap.size(0) == 1
bitmap = _bitmap.cpu().numpy()[0] # The first channel
pred = pred.cpu().detach().numpy()[0]
height, width = bitmap.shape
contours, _ = cv2.findContours(
(bitmap*255).astype(np.uint8),
cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)
num_contours = min(len(contours), self.max_candidates)
boxes = np.zeros((num_contours, 4, 2), dtype=np.int16)
scores = np.zeros((num_contours,), dtype=np.float32)
for index in range(num_contours):
contour = contours[index]
points, sside = self.get_mini_boxes(contour)
if sside < self.min_size:
continue
points = np.array(points)
score = self.box_score_fast(pred, points.reshape(-1, 2))
if self.box_thresh > score:
continue
box = self.unclip(points).reshape(-1, 1, 2)
box, sside = self.get_mini_boxes(box)
if sside < self.min_size + 2:
continue
box = np.array(box)
if not isinstance(dest_width, int):
dest_width = dest_width.item()
dest_height = dest_height.item()
box[:, 0] = np.clip(
np.round(box[:, 0] / width * dest_width), 0, dest_width)
box[:, 1] = np.clip(
np.round(box[:, 1] / height * dest_height), 0, dest_height)
boxes[index, :, :] = box.astype(np.int16)
scores[index] = score
return boxes, scores
def unclip(self, box, unclip_ratio=1.5):
poly = Polygon(box)
distance = poly.area * unclip_ratio / poly.length
offset = pyclipper.PyclipperOffset()
offset.AddPath(box, pyclipper.JT_ROUND, pyclipper.ET_CLOSEDPOLYGON)
expanded = np.array(offset.Execute(distance))
return expanded
def get_mini_boxes(self, contour):
bounding_box = cv2.minAreaRect(contour)
points = sorted(list(cv2.boxPoints(bounding_box)), key=lambda x: x[0])
index_1, index_2, index_3, index_4 = 0, 1, 2, 3
if points[1][1] > points[0][1]:
index_1 = 0
index_4 = 1
else:
index_1 = 1
index_4 = 0
if points[3][1] > points[2][1]:
index_2 = 2
index_3 = 3
else:
index_2 = 3
index_3 = 2
box = [points[index_1], points[index_2],
points[index_3], points[index_4]]
return box, min(bounding_box[1])
def box_score_fast(self, bitmap, _box):
h, w = bitmap.shape[:2]
box = _box.copy()
xmin = np.clip(np.floor(box[:, 0].min()).astype(np.int32), 0, w - 1)
xmax = np.clip(np.ceil(box[:, 0].max()).astype(np.int32), 0, w - 1)
ymin = np.clip(np.floor(box[:, 1].min()).astype(np.int32), 0, h - 1)
ymax = np.clip(np.ceil(box[:, 1].max()).astype(np.int32), 0, h - 1)
mask = np.zeros((ymax - ymin + 1, xmax - xmin + 1), dtype=np.uint8)
box[:, 0] = box[:, 0] - xmin
box[:, 1] = box[:, 1] - ymin
cv2.fillPoly(mask, box.reshape(1, -1, 2).astype(np.int32), 1)
return cv2.mean(bitmap[ymin:ymax+1, xmin:xmax+1], mask)[0]
|