Python numpy.clip() Examples

def augment_hsv(img, hgain=0.5, sgain=0.5, vgain=0.5):
    x = (np.random.uniform(-1, 1, 3) * np.array([hgain, sgain, vgain]) + 1).astype(np.float32)  # random gains
    img_hsv = (cv2.cvtColor(img, cv2.COLOR_BGR2HSV) * x.reshape((1, 1, 3))).clip(None, 255).astype(np.uint8)
    cv2.cvtColor(img_hsv, cv2.COLOR_HSV2BGR, dst=img)  # no return needed


# def augment_hsv(img, hgain=0.5, sgain=0.5, vgain=0.5):  # original version
#     # SV augmentation by 50%
#     img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)  # hue, sat, val
#
#     S = img_hsv[:, :, 1].astype(np.float32)  # saturation
#     V = img_hsv[:, :, 2].astype(np.float32)  # value
#
#     a = random.uniform(-1, 1) * sgain + 1
#     b = random.uniform(-1, 1) * vgain + 1
#     S *= a
#     V *= b
#
#     img_hsv[:, :, 1] = S if a < 1 else S.clip(None, 255)
#     img_hsv[:, :, 2] = V if b < 1 else V.clip(None, 255)
#     cv2.cvtColor(img_hsv, cv2.COLOR_HSV2BGR, dst=img)  # no return needed 

def draw_heatmap(img, heatmap, alpha=0.5):
    """Draw a heatmap overlay over an image."""
    assert len(heatmap.shape) == 2 or \
        (len(heatmap.shape) == 3 and heatmap.shape[2] == 1)
    assert img.dtype in [np.uint8, np.int32, np.int64]
    assert heatmap.dtype in [np.float32, np.float64]

    if img.shape[0:2] != heatmap.shape[0:2]:
        heatmap_rs = np.clip(heatmap * 255, 0, 255).astype(np.uint8)
        heatmap_rs = ia.imresize_single_image(
            heatmap_rs[..., np.newaxis],
            img.shape[0:2],
            interpolation="nearest"
        )
        heatmap = np.squeeze(heatmap_rs) / 255.0

    cmap = plt.get_cmap('jet')
    heatmap_cmapped = cmap(heatmap)
    heatmap_cmapped = np.delete(heatmap_cmapped, 3, 2)
    heatmap_cmapped = heatmap_cmapped * 255
    mix = (1-alpha) * img + alpha * heatmap_cmapped
    mix = np.clip(mix, 0, 255).astype(np.uint8)
    return mix 

def add_image(self, img):
        if self.print_progress and self.cur_images % self.progress_interval == 0:
            print('%d / %d\r' % (self.cur_images, self.expected_images), end='', flush=True)
            sys.stdout.flush()
        if self.shape is None:
            self.shape = img.shape
            self.resolution_log2 = int(np.log2(self.shape[1]))
            assert self.shape[0] in [1, 3]
            assert self.shape[1] == self.shape[2]
            assert self.shape[1] == 2**self.resolution_log2
            tfr_opt = tf.python_io.TFRecordOptions(tf.python_io.TFRecordCompressionType.NONE)
            for lod in range(self.resolution_log2 - 1):
                tfr_file = self.tfr_prefix + '-r%02d.tfrecords' % (self.resolution_log2 - lod)
                self.tfr_writers.append(tf.python_io.TFRecordWriter(tfr_file, tfr_opt))
        assert img.shape == self.shape
        for lod, tfr_writer in enumerate(self.tfr_writers):
            if lod:
                img = img.astype(np.float32)
                img = (img[:, 0::2, 0::2] + img[:, 0::2, 1::2] + img[:, 1::2, 0::2] + img[:, 1::2, 1::2]) * 0.25
            quant = np.rint(img).clip(0, 255).astype(np.uint8)
            ex = tf.train.Example(features=tf.train.Features(feature={
                'shape': tf.train.Feature(int64_list=tf.train.Int64List(value=quant.shape)),
                'data': tf.train.Feature(bytes_list=tf.train.BytesList(value=[quant.tostring()]))}))
            tfr_writer.write(ex.SerializeToString())
        self.cur_images += 1 

def crop(self, bbox):
        """See :func:`BaseInstanceMasks.crop`."""
        assert isinstance(bbox, np.ndarray)
        assert bbox.ndim == 1

        # clip the boundary
        bbox = bbox.copy()
        bbox[0::2] = np.clip(bbox[0::2], 0, self.width)
        bbox[1::2] = np.clip(bbox[1::2], 0, self.height)
        x1, y1, x2, y2 = bbox
        w = np.maximum(x2 - x1, 1)
        h = np.maximum(y2 - y1, 1)

        if len(self.masks) == 0:
            cropped_masks = np.empty((0, h, w), dtype=np.uint8)
        else:
            cropped_masks = self.masks[:, y1:y1 + h, x1:x1 + w]
        return BitmapMasks(cropped_masks, h, w) 

def perturb(self, x_nat, y, sess):
    """Given a set of examples (x_nat, y), returns a set of adversarial
       examples within epsilon of x_nat in l_infinity norm."""
    if self.rand:
      x = x_nat + np.random.uniform(-self.epsilon, self.epsilon, x_nat.shape)
    else:
      x = np.copy(x_nat)

    for i in range(self.k):
      grad = sess.run(self.grad, feed_dict={self.model.x_input: x,
                                            self.model.y_input: y})

      x += self.a * np.sign(grad)

      x = np.clip(x, x_nat - self.epsilon, x_nat + self.epsilon)
      x = np.clip(x, 0, 1) # ensure valid pixel range

    return x 

def perturb(self, x_nat, y, sess):
    """Given a set of examples (x_nat, y), returns a set of adversarial
       examples within epsilon of x_nat in l_infinity norm."""
    if self.rand:
      x = x_nat + np.random.uniform(-self.epsilon, self.epsilon, x_nat.shape)
    else:
      x = np.copy(x_nat)

    for i in range(self.k):
      grad = sess.run(self.grad, feed_dict={self.model.x_input: x,
                                            self.model.y_input: y})

      x += self.a * np.sign(grad)

      x = np.clip(x, x_nat - self.epsilon, x_nat + self.epsilon)
      x = np.clip(x, 0, 1) # ensure valid pixel range

    return x 

def perturb(self, x_nat, y, sess):
    """Given a set of examples (x_nat, y), returns a set of adversarial
       examples within epsilon of x_nat in l_infinity norm."""
    if self.rand:
      x = x_nat + np.random.uniform(-self.epsilon, self.epsilon, x_nat.shape)
    else:
      x = np.copy(x_nat)

    for i in range(self.k):
      grad = sess.run(self.grad, feed_dict={self.model.x_input: x,
                                            self.model.y_input: y})

      x += self.a * np.sign(grad)

      x = np.clip(x, x_nat - self.epsilon, x_nat + self.epsilon)
      x = np.clip(x, 0, 1) # ensure valid pixel range

    return x 

def perturb(self, x_nat, y, sess):
    """Given a set of examples (x_nat, y), returns a set of adversarial
       examples within epsilon of x_nat in l_infinity norm."""
    if self.rand:
      x = x_nat + np.random.uniform(-self.epsilon, self.epsilon, x_nat.shape)
    else:
      x = np.copy(x_nat)

    for i in range(self.k):
      grad = sess.run(self.grad, feed_dict={self.model.x_input: x,
                                            self.model.y_input: y})

      x += self.a * np.sign(grad)

      x = np.clip(x, x_nat - self.epsilon, x_nat + self.epsilon)
      x = np.clip(x, 0, 1) # ensure valid pixel range

    return x 

def perturb(self, x_nat, y, sess):
    """Given a set of examples (x_nat, y), returns a set of adversarial
       examples within epsilon of x_nat in l_infinity norm."""
    if self.rand:
      x = x_nat + np.random.uniform(-self.epsilon, self.epsilon, x_nat.shape)
    else:
      x = np.copy(x_nat)

    for i in range(self.k):
      grad = sess.run(self.grad, feed_dict={self.model.x_input: x,
                                            self.model.y_input: y})

      x += self.a * np.sign(grad)

      x = np.clip(x, x_nat - self.epsilon, x_nat + self.epsilon)
      x = np.clip(x, 0, 1) # ensure valid pixel range

    return x 

def cleverhans_attack_wrapper(cleverhans_attack_fn, reset=True):
    def attack(a):
        session = tf.Session()
        with session.as_default():
            model = RVBCleverhansModel(a)
            adversarial_image = cleverhans_attack_fn(model, session, a)
            adversarial_image = np.squeeze(adversarial_image, axis=0)
            if reset:
                # optionally, reset to ignore other adversarials
                # found during the search
                a._reset()
            # run predictions to make sure the returned adversarial
            # is taken into account
            min_, max_ = a.bounds()
            adversarial_image = np.clip(adversarial_image, min_, max_)
            a.predictions(adversarial_image)
    return attack 

def Chainer2PIL(data, rescale=True):
    data = np.array(data)
    if rescale:
        data *= 256
        # data += 128
    if data.dtype != np.uint8:
        data = np.clip(data, 0, 255)
        data = data.astype(np.uint8)
    if data.shape[0] == 1:
        buf = data.astype(np.uint8).reshape((data.shape[1], data.shape[2]))
    else:
        buf = np.zeros((data.shape[1], data.shape[2], data.shape[0]), dtype=np.uint8)
        for i in range(3):
            a = data[i,:,:]
            buf[:,:,i] = a
    img = Image.fromarray(buf)
    return img 

def wave2input_image(wave, window, pos=0, pad=0):
    wave_image = np.hstack([wave[pos+i*sride:pos+(i+pad*2)*sride+dif].reshape(height+pad*2, sride) for i in range(256//sride)])[:,:254]
    wave_image *= window
    spectrum_image = np.fft.fft(wave_image, axis=1)
    input_image = np.abs(spectrum_image[:,:128].reshape(1, height+pad*2, 128), dtype=np.float32)

    np.clip(input_image, 1000, None, out=input_image)
    np.log(input_image, out=input_image)
    input_image += bias
    input_image /= scale

    if np.max(input_image) > 0.95:
        print('input image max bigger than 0.95', np.max(input_image))
    if np.min(input_image) < 0.05:
        print('input image min smaller than 0.05', np.min(input_image))

    return input_image 

def visual(title, X, activation):
    '''create a grid of images and save it as a final image
    title : grid image name
    X : array of images
    '''
    assert len(X.shape) == 4

    X = X.transpose((0, 2, 3, 1))
    if activation == 'sigmoid':
        X = np.clip((X)*(255.0), 0, 255).astype(np.uint8)
    elif activation == 'tanh':
        X = np.clip((X+1.0)*(255.0/2.0), 0, 255).astype(np.uint8)
    n = np.ceil(np.sqrt(X.shape[0]))
    buff = np.zeros((int(n*X.shape[1]), int(n*X.shape[2]), int(X.shape[3])), dtype=np.uint8)
    for i, img in enumerate(X):
        fill_buf(buff, i, img, X.shape[1:3])
    cv2.imwrite('%s.jpg' % (title), buff) 

def play(self, a):
        assert not self.episode_terminate,\
            "Warning, the episode seems to have terminated. " \
            "We need to call either game.begin_episode(max_episode_step) to continue a new " \
            "episode or game.start() to force restart."
        self.episode_step += 1
        reward = 0.0
        action = self.action_set[a]
        for i in range(self.frame_skip):
            reward += self.ale.act(action)
            self.ale.getScreenGrayscale(self.screen_buffer[i % self.screen_buffer_length, :, :])
        self.total_reward += reward
        self.episode_reward += reward
        ob = self.get_observation()
        terminate_flag = self.episode_terminate
        self.replay_memory.append(ob, a, numpy.clip(reward, -1, 1), terminate_flag)
        return reward, terminate_flag 

def spectrogram2wav(mag):
    '''# Generate wave file from spectrogram'''
    # transpose
    mag = mag.T

    # de-noramlize
    mag = (np.clip(mag, 0, 1) * hp.max_db) - hp.max_db + hp.ref_db

    # to amplitude
    mag = np.power(10.0, mag * 0.05)

    # wav reconstruction
    wav = griffin_lim(mag)

    # de-preemphasis
    wav = signal.lfilter([1], [1, -hp.preemphasis], wav)

    # trim
    wav, _ = librosa.effects.trim(wav)

    return wav.astype(np.float32) 

def convert_to_torque(self, motor_commands, current_motor_angle,
                        current_motor_velocity):
    """Convert the commands (position control or torque control) to torque.

    Args:
      motor_commands: The desired motor angle if the motor is in position
        control mode. The pwm signal if the motor is in torque control mode.
      current_motor_angle: The motor angle at the current time step.
      current_motor_velocity: The motor velocity at the current time step.
    Returns:
      actual_torque: The torque that needs to be applied to the motor.
      observed_torque: The torque observed by the sensor.
    """
    if self._torque_control_enabled:
      pwm = motor_commands
    else:
      pwm = (-self._kp * (current_motor_angle - motor_commands)
             - self._kd * current_motor_velocity)
    pwm = np.clip(pwm, -1.0, 1.0)
    return self._convert_to_torque_from_pwm(pwm, current_motor_velocity) 

def save_wav(audio, output_wav_file):
    wav.write(output_wav_file, 16000, np.array(np.clip(np.round(audio), -2**15, 2**15-1), dtype=np.int16))
    print('output dB', db(audio)) 

def setup_graph(self, input_audio_batch, target_phrase): 
        batch_size = input_audio_batch.shape[0]
        weird = (input_audio_batch.shape[1] - 1) // 320 
        logits_arg2 = np.tile(weird, batch_size)
        dense_arg1 = np.array(np.tile(target_phrase, (batch_size, 1)), dtype=np.int32)
        dense_arg2 = np.array(np.tile(target_phrase.shape[0], batch_size), dtype=np.int32)
        
        pass_in = np.clip(input_audio_batch, -2**15, 2**15-1)
        seq_len = np.tile(weird, batch_size).astype(np.int32)
        
        with tf.variable_scope('', reuse=tf.AUTO_REUSE):
            
            inputs = tf.placeholder(tf.float32, shape=pass_in.shape, name='a')
            len_batch = tf.placeholder(tf.float32, name='b')
            arg2_logits = tf.placeholder(tf.int32, shape=logits_arg2.shape, name='c')
            arg1_dense = tf.placeholder(tf.float32, shape=dense_arg1.shape, name='d')
            arg2_dense = tf.placeholder(tf.int32, shape=dense_arg2.shape, name='e')
            len_seq = tf.placeholder(tf.int32, shape=seq_len.shape, name='f')
            
            logits = get_logits(inputs, arg2_logits)
            target = ctc_label_dense_to_sparse(arg1_dense, arg2_dense, len_batch)
            ctcloss = tf.nn.ctc_loss(labels=tf.cast(target, tf.int32), inputs=logits, sequence_length=len_seq)
            decoded, _ = tf.nn.ctc_greedy_decoder(logits, arg2_logits, merge_repeated=True)
            
            sess = tf.Session()
            saver = tf.train.Saver(tf.global_variables())
            saver.restore(sess, "models/session_dump")
            
        func1 = lambda a, b, c, d, e, f: sess.run(ctcloss, 
            feed_dict={inputs: a, len_batch: b, arg2_logits: c, arg1_dense: d, arg2_dense: e, len_seq: f})
        func2 = lambda a, b, c, d, e, f: sess.run([ctcloss, decoded], 
            feed_dict={inputs: a, len_batch: b, arg2_logits: c, arg1_dense: d, arg2_dense: e, len_seq: f})
        return (func1, func2) 

def getctcloss(self, input_audio_batch, target_phrase, decode=False):
        batch_size = input_audio_batch.shape[0]
        weird = (input_audio_batch.shape[1] - 1) // 320 
        logits_arg2 = np.tile(weird, batch_size)
        dense_arg1 = np.array(np.tile(target_phrase, (batch_size, 1)), dtype=np.int32)
        dense_arg2 = np.array(np.tile(target_phrase.shape[0], batch_size), dtype=np.int32)
        
        pass_in = np.clip(input_audio_batch, -2**15, 2**15-1)
        seq_len = np.tile(weird, batch_size).astype(np.int32)

        if decode:
            return self.funcs[1](pass_in, batch_size, logits_arg2, dense_arg1, dense_arg2, seq_len)
        else:
            return self.funcs[0](pass_in, batch_size, logits_arg2, dense_arg1, dense_arg2, seq_len) 

def iwe_kernel_densities(self, X, Z, clip=1000):
        """
        Estimate importance weights based on kernel density estimation.

        Parameters
        ----------
        X : array
            source data (N samples by D features)
        Z : array
            target data (M samples by D features)
        clip : float
            maximum allowed value for individual weights (def: 1000)

        Returns
        -------
        array
            importance weights (N samples by 1)

        """
        # Data shapes
        N, DX = X.shape
        M, DZ = Z.shape

        # Assert equivalent dimensionalities
        assert DX == DZ

        # Compute probabilities based on source kernel densities
        pT = st.gaussian_kde(Z.T).pdf(X.T)
        pS = st.gaussian_kde(X.T).pdf(X.T)

        # Check for numerics
        assert not np.any(np.isnan(pT)) or np.any(pT == 0)
        assert not np.any(np.isnan(pS)) or np.any(pS == 0)

        # Compute importance weights
        iw = pT / pS

        # Clip importance weights
        return np.minimum(clip, np.maximum(0, iw)) 

def Huber_loss(self, theta, X, y, l2=0.0):
        """
        Huber loss function.

        Reference: Ando & Zhang (2005a). A framework for learning predictive
        structures from multiple tasks and unlabeled data. JMLR.

        Parameters
        ----------
        theta : array
            classifier parameters (D features by 1)
        X : array
            data (N samples by D features)
        y : array
            label vector (N samples by 1)
        l2 : float
            l2-regularization parameter (def= 0.0)

        Returns
        -------
        array
            Objective function value.

        """
        # Precompute terms
        Xy = (X.T*y.T).T
        Xyt = np.dot(Xy, theta)

        # Indices of discontinuity
        ix = (Xyt >= -1)

        # Loss function
        return np.sum(np.clip(1 - Xyt[ix], 0, None)**2, axis=0) \
            + np.sum(-4*Xyt[~ix], axis=0) + l2*np.sum(theta**2, axis=0) 

def Huber_grad(self, theta, X, y, l2=0.0):
        """
        Huber gradient computation.

        Reference: Ando & Zhang (2005a). A framework for learning predictive
        structures from multiple tasks and unlabeled data. JMLR.

        Parameters
        ----------
        theta : array
            classifier parameters (D features by 1)
        X : array
            data (N samples by D features)
        y : array
            label vector (N samples by 1)
        l2 : float
            l2-regularization parameter (def= 0.0)

        Returns
        -------
        array
            Gradient with respect to classifier parameters

        """
        # Precompute terms
        Xy = (X.T*y.T).T
        Xyt = np.dot(Xy, theta)

        # Indices of discontinuity
        ix = (Xyt >= -1)

        # Gradient
        return np.sum(2*np.clip(1-Xyt[ix], 0, None).T * -Xy[ix, :].T,
                      axis=1).T + np.sum(-4*Xy[~ix, :], axis=0) + 2*l2*theta 

def _line_to_xy(self, line_x, line_y, limit_y_min=None, limit_y_max=None):
        point_every = max(1, int(len(line_x) / self.nb_points_max))
        points_x = []
        points_y = []
        curr_sum = 0
        counter = 0
        last_idx = len(line_x) - 1
        for i in range(len(line_x)):
            batch_idx = line_x[i]
            if batch_idx > self.start_batch_idx:
                curr_sum += line_y[i]
                counter += 1
                if counter >= point_every or i == last_idx:
                    points_x.append(batch_idx)
                    y = curr_sum / counter
                    if limit_y_min is not None and limit_y_max is not None:
                        y = np.clip(y, limit_y_min, limit_y_max)
                    elif limit_y_min is not None:
                        y = max(y, limit_y_min)
                    elif limit_y_max is not None:
                        y = min(y, limit_y_max)
                    points_y.append(y)
                    counter = 0
                    curr_sum = 0

        return points_x, points_y 

def fix_by_image_dimensions(self, height, width=None):
        if isinstance(height, (tuple, list)):
            assert width is None
            height, width = height[0], height[1]
        elif isinstance(height, (np.ndarray, np.generic)):
            assert width is None
            height, width = height.shape[0], height.shape[1]
        else:
            assert width is not None
            assert isinstance(height, int)
            assert isinstance(width, int)

        self.x1 = int(np.clip(self.x1, 0, width-1))
        self.x2 = int(np.clip(self.x2, 0, width-1))
        self.y1 = int(np.clip(self.y1, 0, height-1))
        self.y2 = int(np.clip(self.y2, 0, height-1))

        if self.x1 > self.x2:
            self.x1, self.x2 = self.x2, self.x1
        if self.y1 > self.y2:
            self.y1, self.y2 = self.y2, self.y1

        if self.x1 == self.x2:
            if self.x1 > 0:
                self.x1 = self.x1 - 1
            else:
                self.x2 = self.x2 + 1

        if self.y1 == self.y2:
            if self.y1 > 0:
                self.y1 = self.y1 - 1
            else:
                self.y2 = self.y2 + 1

        #self.width = self.x2 - self.x1
        #self.height = self.y2 - self.y1 

def draw_on_image(self, img, color=[0, 255, 0], alpha=1.0, thickness=1, copy=copy):
        assert img.dtype in [np.uint8, np.float32, np.int32, np.int64]

        result = np.copy(img) if copy else img
        for i in range(thickness):
            y = [self.y1-i, self.y1-i, self.y2+i, self.y2+i]
            x = [self.x1-i, self.x2+i, self.x2+i, self.x1-i]
            rr, cc = draw.polygon_perimeter(y, x, shape=img.shape)
            if alpha >= 0.99:
                result[rr, cc, 0] = color[0]
                result[rr, cc, 1] = color[1]
                result[rr, cc, 2] = color[2]
            else:
                if result.dtype == np.float32:
                    result[rr, cc, 0] = (1 - alpha) * result[rr, cc, 0] + alpha * color[0]
                    result[rr, cc, 1] = (1 - alpha) * result[rr, cc, 1] + alpha * color[1]
                    result[rr, cc, 2] = (1 - alpha) * result[rr, cc, 2] + alpha * color[2]
                    result = np.clip(result, 0, 255)
                else:
                    result = result.astype(np.float32)
                    result[rr, cc, 0] = (1 - alpha) * result[rr, cc, 0] + alpha * color[0]
                    result[rr, cc, 1] = (1 - alpha) * result[rr, cc, 1] + alpha * color[1]
                    result[rr, cc, 2] = (1 - alpha) * result[rr, cc, 2] + alpha * color[2]
                    result = np.clip(result, 0, 255).astype(np.uint8)

        return result 

def draw_on_image_filled_binary(self, img, copy=True):
        if copy:
            img = np.copy(img)
        h, w = img.shape[0], img.shape[1]
        x1 = np.clip(self.x1, 0, w-1)
        x2 = np.clip(self.x2, 0, w-1)
        y1 = np.clip(self.y1, 0, h-1)
        y2 = np.clip(self.y2, 0, h-1)
        if x1 < x2 and y1 < y2:
            img[self.y1:self.y2, self.x1:self.x2] = 1
        return img 

def generate_interpolation_video(run_id, snapshot=None, grid_size=[1,1], image_shrink=1, image_zoom=1, duration_sec=60.0, smoothing_sec=1.0, mp4=None, mp4_fps=30, mp4_codec='libx265', mp4_bitrate='16M', random_seed=1000, minibatch_size=8):
    network_pkl = misc.locate_network_pkl(run_id, snapshot)
    if mp4 is None:
        mp4 = misc.get_id_string_for_network_pkl(network_pkl) + '-lerp.mp4'
    num_frames = int(np.rint(duration_sec * mp4_fps))
    random_state = np.random.RandomState(random_seed)

    print('Loading network from "%s"...' % network_pkl)
    G, D, Gs = misc.load_network_pkl(run_id, snapshot)

    print('Generating latent vectors...')
    shape = [num_frames, np.prod(grid_size)] + Gs.input_shape[1:] # [frame, image, channel, component]
    all_latents = random_state.randn(*shape).astype(np.float32)
    all_latents = scipy.ndimage.gaussian_filter(all_latents, [smoothing_sec * mp4_fps] + [0] * len(Gs.input_shape), mode='wrap')
    all_latents /= np.sqrt(np.mean(np.square(all_latents)))

    # Frame generation func for moviepy.
    def make_frame(t):
        frame_idx = int(np.clip(np.round(t * mp4_fps), 0, num_frames - 1))
        latents = all_latents[frame_idx]
        labels = np.zeros([latents.shape[0], 0], np.float32)
        images = Gs.run(latents, labels, minibatch_size=minibatch_size, num_gpus=config.num_gpus, out_mul=127.5, out_add=127.5, out_shrink=image_shrink, out_dtype=np.uint8)
        grid = misc.create_image_grid(images, grid_size).transpose(1, 2, 0) # HWC
        if image_zoom > 1:
            grid = scipy.ndimage.zoom(grid, [image_zoom, image_zoom, 1], order=0)
        if grid.shape[2] == 1:
            grid = grid.repeat(3, 2) # grayscale => RGB
        return grid

    # Generate video.
    import moviepy.editor # pip install moviepy
    result_subdir = misc.create_result_subdir(config.result_dir, config.desc)
    moviepy.editor.VideoClip(make_frame, duration=duration_sec).write_videofile(os.path.join(result_subdir, mp4), fps=mp4_fps, codec='libx264', bitrate=mp4_bitrate)
    open(os.path.join(result_subdir, '_done.txt'), 'wt').close()

#----------------------------------------------------------------------------
# Generate MP4 video of training progress for a previous training run.
# To run, uncomment the appropriate line in config.py and launch train.py. 

def setup_snapshot_image_grid(G, training_set,
    size    = '1080p',      # '1080p' = to be viewed on 1080p display, '4k' = to be viewed on 4k display.
    layout  = 'random'):    # 'random' = grid contents are selected randomly, 'row_per_class' = each row corresponds to one class label.

    # Select size.
    gw = 1; gh = 1
    if size == '1080p':
        gw = np.clip(1920 // G.output_shape[3], 3, 32)
        gh = np.clip(1080 // G.output_shape[2], 2, 32)
    if size == '4k':
        gw = np.clip(3840 // G.output_shape[3], 7, 32)
        gh = np.clip(2160 // G.output_shape[2], 4, 32)

    # Fill in reals and labels.
    reals = np.zeros([gw * gh] + training_set.shape, dtype=training_set.dtype)
    labels = np.zeros([gw * gh, training_set.label_size], dtype=training_set.label_dtype)
    masks = np.zeros([gw * gh] + [1, training_set.shape[-1], training_set.shape[-1]], dtype=training_set.dtype)
    for idx in range(gw * gh):
        x = idx % gw; y = idx // gw
        while True:
            real, label, mask = training_set.get_minibatch_np(1)
            if layout == 'row_per_class' and training_set.label_size > 0:
                if label[0, y % training_set.label_size] == 0.0:
                    continue
            reals[idx] = real[0]
            labels[idx] = label[0]
            masks[idx] = mask[0]
            break

    # Generate latents.
    latents = misc.random_latents(gw * gh, G)
    return (gw, gh), reals, labels, latents, masks

#----------------------------------------------------------------------------
# Just-in-time processing of training images before feeding them to the networks. 

def numpy2pil(a, vmin, vmax):
    a = np.clip((a - vmin) / (vmax - vmin), 0., 1.)
    a = (254.99 * a).astype('u1')
    return PIL.Image.fromarray(a) 

def numpy2pil(a, vmin, vmax, fill=0):
    mask = np.isnan(a)
    a = np.clip((a - vmin) / (vmax - vmin), 0., 1.)
    a = (254.99 * a).astype('u1')
    a[mask] = fill
    return PIL.Image.fromarray(a)