def __call__(self, input_x, t, ignore_t):
if isinstance(input_x, chainer.Variable):
device = cuda.get_device(input_x.data)
else:
device = cuda.get_device(input_x)
xp = self.predictor.xp
with device:
output = self.predictor(input_x)
batch_size, _, grid_h, grid_w = output.shape
self.seen += batch_size
x, y, w, h, conf, prob = F.split_axis(F.reshape(
output, (batch_size, self.predictor.n_boxes,
self.predictor.n_classes + 5, grid_h, grid_w)),
(1, 2, 3, 4, 5),
axis=2)
x = F.sigmoid(x)
y = F.sigmoid(y)
conf = F.sigmoid(conf)
prob = F.transpose(prob, (0, 2, 1, 3, 4))
prob = F.softmax(prob)
# training labels
tw = np.zeros(w.shape, dtype=np.float32)
th = np.zeros(h.shape, dtype=np.float32)
tx = np.tile(0.5, x.shape).astype(np.float32)
ty = np.tile(0.5, y.shape).astype(np.float32)
# set low learning rate for bounding boxes that have no object
if self.seen < self.unstable_seen:
box_learning_scale = np.tile(0.1, x.shape).astype(np.float32)
else:
box_learning_scale = np.tile(0, x.shape).astype(np.float32)
tconf = np.zeros(conf.shape, dtype=np.float32)
conf_learning_scale = np.zeros(conf.shape, dtype=np.float32)
if xp == np:
conf_data = conf.data.copy()
else:
conf_data = cuda.to_cpu(conf.data)
tprob = prob.data.copy()
x_shift = np.broadcast_to(np.arange(grid_w, dtype=np.float32),
x.shape[1:])
y_shift = np.broadcast_to(
np.arange(grid_h, dtype=np.float32).reshape(grid_h, 1),
y.shape[1:])
w_anchor = np.broadcast_to(
np.reshape(
np.array(self.anchors, dtype=np.float32)[:, 0],
(self.predictor.n_boxes, 1, 1, 1)), w.shape[1:])
h_anchor = np.broadcast_to(
np.reshape(
np.array(self.anchors, dtype=np.float32)[:, 1],
(self.predictor.n_boxes, 1, 1, 1)), h.shape[1:])
x_data = cuda.to_cpu(x.data)
y_data = cuda.to_cpu(y.data)
w_data = cuda.to_cpu(w.data)
h_data = cuda.to_cpu(h.data)
best_ious = []
for batch in range(batch_size):
n_truth_boxes = len(t[batch])
box_x = (x_data[batch] + x_shift) / grid_w
box_y = (y_data[batch] + y_shift) / grid_h
box_w = np.exp(w_data[batch]) * w_anchor / grid_w
box_h = np.exp(h_data[batch]) * h_anchor / grid_h
ious = []
for truth_index in range(n_truth_boxes):
truth_box_x = np.broadcast_to(
np.array(t[batch][truth_index]["x"], dtype=np.float32),
box_x.shape)
truth_box_y = np.broadcast_to(
np.array(t[batch][truth_index]["y"], dtype=np.float32),
box_y.shape)
truth_box_w = np.broadcast_to(
np.array(t[batch][truth_index]["w"], dtype=np.float32),
box_w.shape)
truth_box_h = np.broadcast_to(
np.array(t[batch][truth_index]["h"], dtype=np.float32),
box_h.shape)
ious.append(
multi_box_iou(
Box(box_x, box_y, box_w, box_h),
Box(truth_box_x, truth_box_y, truth_box_w,
truth_box_h)))
if len(ious) > 0:
ious = np.asarray(ious)
best_ious.append(np.max(ious, axis=0))
else:
best_ious.append(np.zeros_like(x_data[0]))
best_ious = np.array(best_ious)
# keep confidence of anchor that has more confidence than threshold
tconf[best_ious > self.thresh] = conf.data.get()[
best_ious > self.thresh]
conf_learning_scale[best_ious > self.thresh] = 0
conf_data[best_ious > self.thresh] = 0
# ignored regions are not considered either positive or negative
best_ious = []
for batch in range(batch_size):
n_truth_boxes = len(ignore_t[batch])
box_x = (x_data[batch] + x_shift) / grid_w
box_y = (y_data[batch] + y_shift) / grid_h
box_w = np.exp(w_data[batch]) * w_anchor / grid_w
box_h = np.exp(h_data[batch]) * h_anchor / grid_h
ious = []
for truth_index in range(n_truth_boxes):
truth_box_x = np.broadcast_to(
np.array(ignore_t[batch][truth_index]["x"],
dtype=np.float32), box_x.shape)
truth_box_y = np.broadcast_to(
np.array(ignore_t[batch][truth_index]["y"],
dtype=np.float32), box_y.shape)
truth_box_w = np.broadcast_to(
np.array(ignore_t[batch][truth_index]["w"],
dtype=np.float32), box_w.shape)
truth_box_h = np.broadcast_to(
np.array(ignore_t[batch][truth_index]["h"],
dtype=np.float32), box_h.shape)
ious.append(
multi_box_iou(
Box(box_x, box_y, box_w, box_h),
Box(truth_box_x, truth_box_y, truth_box_w,
truth_box_h)))
if len(ious) > 0:
ious = np.asarray(ious)
best_ious.append(np.max(ious, axis=0))
else:
best_ious.append(np.zeros_like(x_data[0]))
best_ious = np.array(best_ious)
# do not update confidence for ignored regions
tconf[best_ious > self.ignore_thresh] = conf.data.get()[
best_ious > self.ignore_thresh]
conf_learning_scale[best_ious > self.ignore_thresh] = 0
conf_data[best_ious > self.ignore_thresh] = 0
# adjust x, y, w, h, conf, prob of anchor boxes that have objects
abs_anchors = self.anchors / np.array([grid_w, grid_h])
for batch in range(batch_size):
for truth_box in t[batch]:
truth_w = int(float(truth_box["x"]) * grid_w)
truth_h = int(float(truth_box["y"]) * grid_h)
truth_n = 0
best_iou = 0.0
for anchor_index, abs_anchor in enumerate(abs_anchors):
iou = box_iou(
Box(0, 0, float(truth_box["w"]),
float(truth_box["h"])),
Box(0, 0, abs_anchor[0], abs_anchor[1]))
if best_iou < iou:
best_iou = iou
truth_n = anchor_index
box_learning_scale[batch, truth_n, :, truth_h,
truth_w] = 1.0
tx[batch, truth_n, :, truth_h,
truth_w] = float(truth_box["x"]) * grid_w - truth_w
ty[batch, truth_n, :, truth_h,
truth_w] = float(truth_box["y"]) * grid_h - truth_h
tw[batch, truth_n, :, truth_h, truth_w] = np.log(
float(truth_box["w"]) / abs_anchors[truth_n][0])
th[batch, truth_n, :, truth_h, truth_w] = np.log(
float(truth_box["h"]) / abs_anchors[truth_n][1])
tprob[batch, :, truth_n, truth_h, truth_w] = 0
tprob[batch,
int(truth_box["label"]), truth_n, truth_h,
truth_w] = 1
full_truth_box = Box(float(truth_box["x"]),
float(truth_box["y"]),
float(truth_box["w"]),
float(truth_box["h"]))
predicted_box = Box(
(x[batch][truth_n][0][truth_h][truth_w].data.get() +
truth_w) / grid_w,
(y[batch][truth_n][0][truth_h][truth_w].data.get() +
truth_h) / grid_h,
np.exp(
w[batch][truth_n][0][truth_h][truth_w].data.get())
* abs_anchors[truth_n][0],
np.exp(
h[batch][truth_n][0][truth_h][truth_w].data.get())
* abs_anchors[truth_n][1])
predicted_iou = box_iou(full_truth_box, predicted_box)
tconf[batch, truth_n, :, truth_h, truth_w] = predicted_iou
conf_learning_scale[batch, truth_n, :, truth_h,
truth_w] = 10.0
conf_data[batch, truth_n, :, truth_h, truth_w] = 0
n_all = np.prod(conf_learning_scale.shape[1:])
for batch in range(batch_size):
n_truth_boxes = len(t[batch])
n_top = np.maximum(n_truth_boxes * 3, 6)
ids = np.argsort(conf_data[batch].ravel())
flags = np.zeros(n_all, dtype=bool)
flags[ids[-n_top:]] = True
conf_learning_scale[batch][flags.reshape(
conf_learning_scale[batch].shape)] = 10.0
tx = cuda.to_gpu(tx)
ty = cuda.to_gpu(ty)
tw = cuda.to_gpu(tw)
th = cuda.to_gpu(th)
tconf = cuda.to_gpu(tconf)
tprob = cuda.to_gpu(tprob)
box_learning_scale = cuda.to_gpu(box_learning_scale)
conf_learning_scale = cuda.to_gpu(conf_learning_scale)
x_loss = F.sum((tx - x)**2 * box_learning_scale) / 2
y_loss = F.sum((ty - y)**2 * box_learning_scale) / 2
w_loss = F.sum((tw - w)**2 * box_learning_scale) / 2
h_loss = F.sum((th - h)**2 * box_learning_scale) / 2
c_loss = F.sum((tconf - conf)**2 * conf_learning_scale) / 2
p_loss = F.sum((tprob - prob)**2) / 2
return x_loss, y_loss, w_loss, h_loss, c_loss, p_loss
def __call__(self, input_x, t, train=True):
output_fcn, output_yolo = self.predictor(input_x, train=train)
if self.FCN:
if train:
loss_fcn = F.softmax_cross_entropy(output_fcn, t)
reporter.report({'loss': loss_fcn}, self)
return loss_fcn
else:
loss = F.softmax(output_fcn)
return loss
batch_size, _, grid_h, grid_w = output_yolo.shape
self.seen += batch_size
x, y, w, h, conf, prob = F.split_axis(F.reshape(
output_yolo, (batch_size, self.predictor.n_boxes,
self.predictor.n_classes_yolo + 5, grid_h, grid_w)),
(1, 2, 3, 4, 5),
axis=2)
x = F.sigmoid(x)
y = F.sigmoid(y)
conf = F.sigmoid(conf)
prob = F.transpose(prob, (0, 2, 1, 3, 4))
prob = F.softmax(prob)
tw = np.zeros(
w.shape,
dtype=np.float32) # wとhが0になるように学習(e^wとe^hは1に近づく -> 担当するbboxの倍率1)
th = np.zeros(h.shape, dtype=np.float32)
tx = np.tile(0.5, x.shape).astype(np.float32) # 活性化後のxとyが0.5になるように学習()
ty = np.tile(0.5, y.shape).astype(np.float32)
if self.seen < self.unstable_seen:
box_learning_scale = np.tile(0.1, x.shape).astype(np.float32)
else:
box_learning_scale = np.tile(0, x.shape).astype(np.float32)
tconf = np.zeros(
conf.shape, dtype=np.float32
) # confidenceのtruthは基本0、iouがthresh以上のものは学習しない、ただしobjectの存在するgridのbest_boxのみ真のIOUに近づかせる
conf_learning_scale = np.tile(0.1, conf.shape).astype(np.float32)
tprob = prob.data.copy() # best_anchor以外は学習させない(自身との二乗和誤差 = 0)
# 全bboxとtruthのiouを計算(batch単位で計算する)
x_shift = Variable(
np.broadcast_to(np.arange(grid_w, dtype=np.float32), x.shape[1:]))
y_shift = Variable(
np.broadcast_to(
np.arange(grid_h, dtype=np.float32).reshape(grid_h, 1),
y.shape[1:]))
w_anchor = Variable(
np.broadcast_to(
np.reshape(
np.array(self.anchors, dtype=np.float32)[:, 0],
(self.predictor.n_boxes, 1, 1, 1)), w.shape[1:]))
h_anchor = Variable(
np.broadcast_to(
np.reshape(
np.array(self.anchors, dtype=np.float32)[:, 1],
(self.predictor.n_boxes, 1, 1, 1)), h.shape[1:]))
x_shift.to_gpu(), y_shift.to_gpu(), w_anchor.to_gpu(), h_anchor.to_gpu(
)
best_ious = []
for batch in range(batch_size):
#n_truth_boxes = len(t[batch])
n_truth_boxes = int(sum(x[0] != 10.0 for x in t[batch])) # ??
box_x = (x[batch] + x_shift) / grid_w
box_y = (y[batch] + y_shift) / grid_h
box_w = F.exp(w[batch]) * w_anchor / grid_w
box_h = F.exp(h[batch]) * h_anchor / grid_h
ious = []
for truth_index in range(n_truth_boxes):
t = chainer.cuda.to_cpu(t) # ??
truth_box_x = Variable(
np.broadcast_to(
np.array(t[batch][truth_index][1], dtype=np.float32),
box_x.shape))
truth_box_y = Variable(
np.broadcast_to(
np.array(t[batch][truth_index][2], dtype=np.float32),
box_y.shape))
truth_box_w = Variable(
np.broadcast_to(
np.array(t[batch][truth_index][3], dtype=np.float32),
box_w.shape))
truth_box_h = Variable(
np.broadcast_to(
np.array(t[batch][truth_index][4], dtype=np.float32),
box_h.shape))
truth_box_x.to_gpu(), truth_box_y.to_gpu(), truth_box_w.to_gpu(
), truth_box_h.to_gpu()
ious.append(
multi_box_iou(
Box(box_x, box_y, box_w, box_h),
Box(truth_box_x, truth_box_y, truth_box_w,
truth_box_h)).data.get())
if ious:
ious = np.array(ious)
best_ious.append(np.max(ious, axis=0))
else:
best_ious.append(0)
best_ious = np.array(best_ious)
# 一定以上のiouを持つanchorに対しては、confを0に下げないようにする(truthの周りのgridはconfをそのまま維持)。
tconf[best_ious > self.thresh] = conf.data.get()[
best_ious > self.thresh]
conf_learning_scale[best_ious > self.thresh] = 0
# objectの存在するanchor boxのみ、x、y、w、h、conf、probを個別修正
abs_anchors = self.anchors / np.array([grid_w, grid_h])
for batch in range(batch_size):
for truth_box in t[batch]:
if truth_box[0] == 10.0: # ??
continue
truth_w = int(float(truth_box[1]) * grid_w)
truth_h = int(float(truth_box[2]) * grid_h)
truth_n = 0
best_iou = 0.0
for anchor_index, abs_anchor in enumerate(abs_anchors):
iou = box_iou(
Box(0, 0, float(truth_box[3]), float(truth_box[4])),
Box(0, 0, abs_anchor[0], abs_anchor[1]))
if best_iou < iou:
best_iou = iou
truth_n = anchor_index
# objectの存在するanchorについて、centerを0.5ではなく、真の座標に近づかせる。anchorのスケールを1ではなく真のスケールに近づかせる。学習スケールを1にする。
box_learning_scale[batch, truth_n, :, truth_h, truth_w] = 1.0
tx[batch, truth_n, :, truth_h,
truth_w] = float(truth_box[1]) * grid_w - truth_w
ty[batch, truth_n, :, truth_h,
truth_w] = float(truth_box[2]) * grid_h - truth_h
tw[batch, truth_n, :, truth_h, truth_w] = np.log(
float(truth_box[3]) / abs_anchors[truth_n][0])
th[batch, truth_n, :, truth_h, truth_w] = np.log(
float(truth_box[4]) / abs_anchors[truth_n][1])
tprob[batch, :, truth_n, truth_h, truth_w] = 0
tprob[batch, int(truth_box[0]), truth_n, truth_h, truth_w] = 1
# IOUの観測
full_truth_box = Box(float(truth_box[1]), float(truth_box[2]),
float(truth_box[3]), float(truth_box[4]))
predicted_box = Box(
(x[batch][truth_n][0][truth_h][truth_w].data.get() +
truth_w) / grid_w,
(y[batch][truth_n][0][truth_h][truth_w].data.get() +
truth_h) / grid_h,
np.exp(w[batch][truth_n][0][truth_h][truth_w].data.get()) *
abs_anchors[truth_n][0],
np.exp(h[batch][truth_n][0][truth_h][truth_w].data.get()) *
abs_anchors[truth_n][1])
predicted_iou = box_iou(full_truth_box, predicted_box)
tconf[batch, truth_n, :, truth_h, truth_w] = predicted_iou
conf_learning_scale[batch, truth_n, :, truth_h, truth_w] = 10.0
# debug prints
maps = F.transpose(prob[batch], (2, 3, 1, 0)).data
#print("seen = %d" % self.seen)
# loss計算
tx, ty, tw, th, tconf, tprob = Variable(tx), Variable(ty), Variable(
tw), Variable(th), Variable(tconf), Variable(tprob)
box_learning_scale, conf_learning_scale = Variable(
box_learning_scale), Variable(conf_learning_scale)
tx.to_gpu(), ty.to_gpu(), tw.to_gpu(), th.to_gpu(), tconf.to_gpu(
), tprob.to_gpu()
box_learning_scale.to_gpu()
conf_learning_scale.to_gpu()
x_loss = F.sum((tx - x)**2 * box_learning_scale) / 2
y_loss = F.sum((ty - y)**2 * box_learning_scale) / 2
w_loss = F.sum((tw - w)**2 * box_learning_scale) / 2
h_loss = F.sum((th - h)**2 * box_learning_scale) / 2
c_loss = F.sum((tconf - conf)**2 * conf_learning_scale) / 2
p_loss = F.sum((tprob - prob)**2) / 2
#print("x_loss: %f y_loss: %f w_loss: %f h_loss: %f c_loss: %f p_loss: %f" %
# (F.sum(x_loss).data, F.sum(y_loss).data, F.sum(w_loss).data, F.sum(h_loss).data, F.sum(c_loss).data, F.sum(p_loss).data)
#)
reporter.report({'x_loss': F.sum(x_loss).data}, self)
reporter.report({'y_loss': F.sum(y_loss).data}, self)
reporter.report({'w_loss': F.sum(w_loss).data}, self)
reporter.report({'h_loss': F.sum(h_loss).data}, self)
reporter.report({'c_loss': F.sum(c_loss).data}, self)
reporter.report({'p_loss': F.sum(p_loss).data}, self)
loss_yolo = x_loss + y_loss + w_loss + h_loss + c_loss + p_loss
reporter.report({'loss': loss_yolo}, self)
return loss_yolo