def run_first_stage(image, net, scale, threshold, gpu_id=0):
"""Run P-Net, generate bounding boxes, and do NMS.
Arguments:
image: an instance of PIL.Image.
net: an instance of pytorch's nn.Module, P-Net.
scale: a float number,
scale width and height of the image by this number.
threshold: a float number,
threshold on the probability of a face when generating
bounding boxes from predictions of the net.
Returns:
a float numpy array of shape [n_boxes, 9],
bounding boxes with scores and offsets (4 + 1 + 4).
"""
# scale the image and convert it to a float array
width, height = image.size
sw, sh = math.ceil(width * scale), math.ceil(height * scale)
img = image.resize((sw, sh), Image.BILINEAR)
img = np.asarray(img, 'float32')
img = torch.FloatTensor(_preprocess(img)).to('cuda:%d' % gpu_id)
output = net(img)
probs = output[1].cpu().data.numpy()[0, 1, :, :]
offsets = output[0].cpu().data.numpy()
# probs: probability of a face at each sliding window
# offsets: transformations to true bounding boxes
boxes = _generate_bboxes(probs, offsets, scale, threshold)
if len(boxes) == 0:
return None
keep = nms(boxes[:, 0:5], overlap_threshold=0.5)
return boxes[keep]
def run_first_stage(image, net, scale, threshold):
"""Run P-Net, generate bounding boxes, and do NMS.
Arguments:
image: an instance of PIL.Image.
net: an instance of pytorch's nn.Module, P-Net.
scale: a float number,
scale width and height of the image by this number.
threshold: a float number,
threshold on the probability of a face when generating
bounding boxes from predictions of the net.
Returns:
a float numpy array of shape [n_boxes, 9],
bounding boxes with scores and offsets (4 + 1 + 4).
"""
# scale the image and convert it to a float array
width, height = image.size
sw, sh = math.ceil(width*scale), math.ceil(height*scale)
img = image.resize((sw, sh), Image.BILINEAR)
img = np.asarray(img, 'float32')
img = Variable(torch.FloatTensor(_preprocess(img)), volatile = True)
output = net(img)
probs = output[1].data.numpy()[0, 1, :, :]
offsets = output[0].data.numpy()
# probs: probability of a face at each sliding window
# offsets: transformations to true bounding boxes
boxes = _generate_bboxes(probs, offsets, scale, threshold)
if len(boxes) == 0:
return None
keep = nms(boxes[:, 0:5], overlap_threshold = 0.5)
return boxes[keep]