In [1]:
import cv2
import keras
from keras.applications.imagenet_utils import preprocess_input
from keras.backend.tensorflow_backend import set_session
from keras.models import Model
from keras.preprocessing import image
import matplotlib.pyplot as plt
import numpy as np
import pickle
from random import shuffle
from scipy.misc import imread
from scipy.misc import imresize
import tensorflow as tf
from ssd import SSD300
from ssd_training import MultiboxLoss
from ssd_utils import BBoxUtility
%matplotlib inline
plt.rcParams['figure.figsize'] = (8, 8)
plt.rcParams['image.interpolation'] = 'nearest'
np.set_printoptions(suppress=True)
# config = tf.ConfigProto()
# config.gpu_options.per_process_gpu_memory_fraction = 0.9
# set_session(tf.Session(config=config))
In [2]:
# some constants
NUM_CLASSES = 4
input_shape = (300, 300, 3)
In [3]:
priors = pickle.load(open('prior_boxes_ssd300.pkl', 'rb'))
bbox_util = BBoxUtility(NUM_CLASSES, priors)
In [4]:
gt = pickle.load(open('gt_pascal.pkl', 'rb'))
keys = sorted(gt.keys())
num_train = int(round(0.8 * len(keys)))
train_keys = keys[:num_train]
val_keys = keys[num_train:]
num_val = len(val_keys)
In [5]:
class Generator(object):
def __init__(self, gt, bbox_util,
batch_size, path_prefix,
train_keys, val_keys, image_size,
saturation_var=0.5,
brightness_var=0.5,
contrast_var=0.5,
lighting_std=0.5,
hflip_prob=0.5,
vflip_prob=0.5,
do_crop=True,
crop_area_range=[0.75, 1.0],
aspect_ratio_range=[3./4., 4./3.]):
self.gt = gt
self.bbox_util = bbox_util
self.batch_size = batch_size
self.path_prefix = path_prefix
self.train_keys = train_keys
self.val_keys = val_keys
self.train_batches = len(train_keys)
self.val_batches = len(val_keys)
self.image_size = image_size
self.color_jitter = []
if saturation_var:
self.saturation_var = saturation_var
self.color_jitter.append(self.saturation)
if brightness_var:
self.brightness_var = brightness_var
self.color_jitter.append(self.brightness)
if contrast_var:
self.contrast_var = contrast_var
self.color_jitter.append(self.contrast)
self.lighting_std = lighting_std
self.hflip_prob = hflip_prob
self.vflip_prob = vflip_prob
self.do_crop = do_crop
self.crop_area_range = crop_area_range
self.aspect_ratio_range = aspect_ratio_range
def grayscale(self, rgb):
return rgb.dot([0.299, 0.587, 0.114])
def saturation(self, rgb):
gs = self.grayscale(rgb)
alpha = 2 * np.random.random() * self.saturation_var
alpha += 1 - self.saturation_var
rgb = rgb * alpha + (1 - alpha) * gs[:, :, None]
return np.clip(rgb, 0, 255)
def brightness(self, rgb):
alpha = 2 * np.random.random() * self.brightness_var
alpha += 1 - self.saturation_var
rgb = rgb * alpha
return np.clip(rgb, 0, 255)
def contrast(self, rgb):
gs = self.grayscale(rgb).mean() * np.ones_like(rgb)
alpha = 2 * np.random.random() * self.contrast_var
alpha += 1 - self.contrast_var
rgb = rgb * alpha + (1 - alpha) * gs
return np.clip(rgb, 0, 255)
def lighting(self, img):
cov = np.cov(img.reshape(-1, 3) / 255.0, rowvar=False)
eigval, eigvec = np.linalg.eigh(cov)
noise = np.random.randn(3) * self.lighting_std
noise = eigvec.dot(eigval * noise) * 255
img += noise
return np.clip(img, 0, 255)
def horizontal_flip(self, img, y):
if np.random.random() < self.hflip_prob:
img = img[:, ::-1]
y[:, [0, 2]] = 1 - y[:, [2, 0]]
return img, y
def vertical_flip(self, img, y):
if np.random.random() < self.vflip_prob:
img = img[::-1]
y[:, [1, 3]] = 1 - y[:, [3, 1]]
return img, y
def random_sized_crop(self, img, targets):
img_w = img.shape[1]
img_h = img.shape[0]
img_area = img_w * img_h
random_scale = np.random.random()
random_scale *= (self.crop_area_range[1] -
self.crop_area_range[0])
random_scale += self.crop_area_range[0]
target_area = random_scale * img_area
random_ratio = np.random.random()
random_ratio *= (self.aspect_ratio_range[1] -
self.aspect_ratio_range[0])
random_ratio += self.aspect_ratio_range[0]
w = np.round(np.sqrt(target_area * random_ratio))
h = np.round(np.sqrt(target_area / random_ratio))
if np.random.random() < 0.5:
w, h = h, w
w = min(w, img_w)
w_rel = w / img_w
w = int(w)
h = min(h, img_h)
h_rel = h / img_h
h = int(h)
x = np.random.random() * (img_w - w)
x_rel = x / img_w
x = int(x)
y = np.random.random() * (img_h - h)
y_rel = y / img_h
y = int(y)
img = img[y:y+h, x:x+w]
new_targets = []
for box in targets:
cx = 0.5 * (box[0] + box[2])
cy = 0.5 * (box[1] + box[3])
if (x_rel < cx < x_rel + w_rel and
y_rel < cy < y_rel + h_rel):
xmin = (box[0] - x_rel) / w_rel
ymin = (box[1] - y_rel) / h_rel
xmax = (box[2] - x_rel) / w_rel
ymax = (box[3] - y_rel) / h_rel
xmin = max(0, xmin)
ymin = max(0, ymin)
xmax = min(1, xmax)
ymax = min(1, ymax)
box[:4] = [xmin, ymin, xmax, ymax]
new_targets.append(box)
new_targets = np.asarray(new_targets).reshape(-1, targets.shape[1])
return img, new_targets
def generate(self, train=True):
while True:
if train:
shuffle(self.train_keys)
keys = self.train_keys
else:
shuffle(self.val_keys)
keys = self.val_keys
inputs = []
targets = []
for key in keys:
img_path = self.path_prefix + key
img = imread(img_path).astype('float32')
y = self.gt[key].copy()
if train and self.do_crop:
img, y = self.random_sized_crop(img, y)
img = imresize(img, self.image_size).astype('float32')
if train:
shuffle(self.color_jitter)
for jitter in self.color_jitter:
img = jitter(img)
if self.lighting_std:
img = self.lighting(img)
if self.hflip_prob > 0:
img, y = self.horizontal_flip(img, y)
if self.vflip_prob > 0:
img, y = self.vertical_flip(img, y)
y = self.bbox_util.assign_boxes(y)
inputs.append(img)
targets.append(y)
if len(targets) == self.batch_size:
tmp_inp = np.array(inputs)
tmp_targets = np.array(targets)
inputs = []
targets = []
yield preprocess_input(tmp_inp), tmp_targets
In [6]:
path_prefix = '../../frames/'
gen = Generator(gt, bbox_util, 16, '../../frames/',
train_keys, val_keys,
(input_shape[0], input_shape[1]), do_crop=False)
In [7]:
model = SSD300(input_shape, num_classes=NUM_CLASSES)
model.load_weights('weights_SSD300.hdf5', by_name=True)
In [8]:
freeze = ['input_1', 'conv1_1', 'conv1_2', 'pool1',
'conv2_1', 'conv2_2', 'pool2',
'conv3_1', 'conv3_2', 'conv3_3', 'pool3']#,
# 'conv4_1', 'conv4_2', 'conv4_3', 'pool4']
for L in model.layers:
if L.name in freeze:
L.trainable = False
In [9]:
def schedule(epoch, decay=0.9):
return base_lr * decay**(epoch)
callbacks = [keras.callbacks.ModelCheckpoint('./checkpoints/weights.{epoch:02d}-{val_loss:.2f}.hdf5',
verbose=1,
save_weights_only=True),
keras.callbacks.LearningRateScheduler(schedule)]
In [10]:
base_lr = 3e-4
optim = keras.optimizers.Adam(lr=base_lr)
# optim = keras.optimizers.RMSprop(lr=base_lr)
# optim = keras.optimizers.SGD(lr=base_lr, momentum=0.9, decay=decay, nesterov=True)
model.compile(optimizer=optim,
loss=MultiboxLoss(NUM_CLASSES, neg_pos_ratio=2.0).compute_loss)
In [11]:
nb_epoch = 30
history = model.fit_generator(gen.generate(True), gen.train_batches,
nb_epoch, verbose=1,
callbacks=callbacks,
validation_data=gen.generate(False),
nb_val_samples=gen.val_batches,
nb_worker=1)
In [12]:
inputs = []
images = []
img_path = path_prefix + sorted(val_keys)[0]
img = image.load_img(img_path, target_size=(300, 300))
img = image.img_to_array(img)
images.append(imread(img_path))
inputs.append(img.copy())
inputs = preprocess_input(np.array(inputs))
In [13]:
preds = model.predict(inputs, batch_size=1, verbose=1)
results = bbox_util.detection_out(preds)
In [14]:
for i, img in enumerate(images):
# Parse the outputs.
det_label = results[i][:, 0]
det_conf = results[i][:, 1]
det_xmin = results[i][:, 2]
det_ymin = results[i][:, 3]
det_xmax = results[i][:, 4]
det_ymax = results[i][:, 5]
# Get detections with confidence higher than 0.6.
top_indices = [i for i, conf in enumerate(det_conf) if conf >= 0.6]
top_conf = det_conf[top_indices]
top_label_indices = det_label[top_indices].tolist()
top_xmin = det_xmin[top_indices]
top_ymin = det_ymin[top_indices]
top_xmax = det_xmax[top_indices]
top_ymax = det_ymax[top_indices]
colors = plt.cm.hsv(np.linspace(0, 1, 4)).tolist()
plt.imshow(img / 255.)
currentAxis = plt.gca()
for i in range(top_conf.shape[0]):
xmin = int(round(top_xmin[i] * img.shape[1]))
ymin = int(round(top_ymin[i] * img.shape[0]))
xmax = int(round(top_xmax[i] * img.shape[1]))
ymax = int(round(top_ymax[i] * img.shape[0]))
score = top_conf[i]
label = int(top_label_indices[i])
# label_name = voc_classes[label - 1]
display_txt = '{:0.2f}, {}'.format(score, label)
coords = (xmin, ymin), xmax-xmin+1, ymax-ymin+1
color = colors[label]
currentAxis.add_patch(plt.Rectangle(*coords, fill=False, edgecolor=color, linewidth=2))
currentAxis.text(xmin, ymin, display_txt, bbox={'facecolor':color, 'alpha':0.5})
plt.show()