visualization_utils.py

# ----------------------------------------------
# --- Author         : Ahmet Ozlu
# --- Mail           : ahmetozlu93@gmail.com
# --- Date           : 27th January 2018
# ----------------------------------------------

"""A set of functions that are used for visualization.

These functions often receive an image, perform some visualization on the image.
The functions do not return a value, instead they modify the image itself.

"""

# Imports
import collections
import functools
import matplotlib.pyplot as plt
import numpy as np
import PIL.Image as Image
import PIL.ImageColor as ImageColor
import PIL.ImageDraw as ImageDraw
import PIL.ImageFont as ImageFont
import six
import tensorflow as tf
import numpy
import os

#  predicted_speed predicted_color module - import
from utils.speed_and_direction_prediction_module import speed_prediction

# color recognition module - import
from utils.color_recognition_module import color_recognition_api

# Variables
is_vehicle_detected = [0]
ROI_POSITION = 200

_TITLE_LEFT_MARGIN = 10
_TITLE_TOP_MARGIN = 10

STANDARD_COLORS = [
    'AliceBlue', 'Chartreuse', 'Aqua', 'Aquamarine', 'Azure', 'Beige', 'Bisque',
    'BlanchedAlmond', 'BlueViolet', 'BurlyWood', 'CadetBlue', 'AntiqueWhite',
    'Chocolate', 'Coral', 'CornflowerBlue', 'Cornsilk', 'Crimson', 'Cyan',
    'DarkCyan', 'DarkGoldenRod', 'DarkGrey', 'DarkKhaki', 'DarkOrange',
    'DarkOrchid', 'DarkSalmon', 'DarkSeaGreen', 'DarkTurquoise', 'DarkViolet',
    'DeepPink', 'DeepSkyBlue', 'DodgerBlue', 'FireBrick', 'FloralWhite',
    'ForestGreen', 'Fuchsia', 'Gainsboro', 'GhostWhite', 'Gold', 'GoldenRod',
    'Salmon', 'Tan', 'HoneyDew', 'HotPink', 'IndianRed', 'Ivory', 'Khaki',
    'Lavender', 'LavenderBlush', 'LawnGreen', 'LemonChiffon', 'LightBlue',
    'LightCoral', 'LightCyan', 'LightGoldenRodYellow', 'LightGray', 'LightGrey',
    'LightGreen', 'LightPink', 'LightSalmon', 'LightSeaGreen', 'LightSkyBlue',
    'LightSlateGray', 'LightSlateGrey', 'LightSteelBlue', 'LightYellow', 'Lime',
    'LimeGreen', 'Linen', 'Magenta', 'MediumAquaMarine', 'MediumOrchid',
    'MediumPurple', 'MediumSeaGreen', 'MediumSlateBlue', 'MediumSpringGreen',
    'MediumTurquoise', 'MediumVioletRed', 'MintCream', 'MistyRose', 'Moccasin',
    'NavajoWhite', 'OldLace', 'Olive', 'OliveDrab', 'Orange', 'OrangeRed',
    'Orchid', 'PaleGoldenRod', 'PaleGreen', 'PaleTurquoise', 'PaleVioletRed',
    'PapayaWhip', 'PeachPuff', 'Peru', 'Pink', 'Plum', 'PowderBlue', 'Purple',
    'Red', 'RosyBrown', 'RoyalBlue', 'SaddleBrown', 'Green', 'SandyBrown',
    'SeaGreen', 'SeaShell', 'Sienna', 'Silver', 'SkyBlue', 'SlateBlue',
    'SlateGray', 'SlateGrey', 'Snow', 'SpringGreen', 'SteelBlue', 'GreenYellow',
    'Teal', 'Thistle', 'Tomato', 'Turquoise', 'Violet', 'Wheat', 'White',
    'WhiteSmoke', 'Yellow', 'YellowGreen'
]

current_path = os.getcwd()


def save_image_array_as_png(image, output_path):
    """Saves an image (represented as a numpy array) to PNG.

    Args:
      image: a numpy array with shape [height, width, 3].
      output_path: path to which image should be written.
    """
    image_pil = Image.fromarray(np.uint8(image)).convert('RGB')
    with tf.gfile.Open(output_path, 'w') as fid:
        image_pil.save(fid, 'PNG')


def encode_image_array_as_png_str(image):
    """Encodes a numpy array into a PNG string.

    Args:
      image: a numpy array with shape [height, width, 3].

    Returns:
      PNG encoded image string.
    """
    image_pil = Image.fromarray(np.uint8(image))
    output = six.BytesIO()
    image_pil.save(output, format='PNG')
    png_string = output.getvalue()
    output.close()
    return png_string


def draw_bounding_box_on_image_array(current_frame_number, image,
                                     ymin,
                                     xmin,
                                     ymax,
                                     xmax,
                                     color='red',
                                     thickness=4,
                                     display_str_list=(),
                                     use_normalized_coordinates=True):
    """Adds a bounding box to an image (numpy array).

    Args:
      image: a numpy array with shape [height, width, 3].
      ymin: ymin of bounding box in normalized coordinates (same below).
      xmin: xmin of bounding box.
      ymax: ymax of bounding box.
      xmax: xmax of bounding box.
      color: color to draw bounding box. Default is red.
      thickness: line thickness. Default value is 4.
      display_str_list: list of strings to display in box
                        (each to be shown on its own line).
      use_normalized_coordinates: If True (default), treat coordinates
        ymin, xmin, ymax, xmax as relative to the image.  Otherwise treat
        coordinates as absolute.
    """
    image_pil = Image.fromarray(np.uint8(image)).convert('RGB')
    is_vehicle_detected, csv_line, update_csv = draw_bounding_box_on_image(current_frame_number, image_pil, ymin, xmin, ymax, xmax, color,
                                                                           thickness, display_str_list,
                                                                           use_normalized_coordinates)
    np.copyto(image, np.array(image_pil))
    return is_vehicle_detected, csv_line, update_csv


def draw_bounding_box_on_image(current_frame_number, image,
                               ymin,
                               xmin,
                               ymax,
                               xmax,
                               color='red',
                               thickness=4,
                               display_str_list=(),
                               use_normalized_coordinates=True):
    """Adds a bounding box to an image.

    Each string in display_str_list is displayed on a separate line above the
    bounding box in black text on a rectangle filled with the input 'color'.
    If the top of the bounding box extends to the edge of the image, the strings
    are displayed below the bounding box.

    Args:
      image: a PIL.Image object.
      ymin: ymin of bounding box.
      xmin: xmin of bounding box.
      ymax: ymax of bounding box.
      xmax: xmax of bounding box.
      color: color to draw bounding box. Default is red.
      thickness: line thickness. Default value is 4.
      display_str_list: list of strings to display in box
                        (each to be shown on its own line).
      use_normalized_coordinates: If True (default), treat coordinates
        ymin, xmin, ymax, xmax as relative to the image.  Otherwise treat
        coordinates as absolute.
    """
    image_temp = numpy.array(image)
    csv_line = ""  # to create new csv line consists of vehicle type, predicted_speed, color and predicted_direction
    # update csv for a new vehicle that are passed from ROI - just one new line for each vehicles
    update_csv = False
    is_vehicle_detected = [0]
    draw = ImageDraw.Draw(image)
    im_width, im_height = image.size
    if use_normalized_coordinates:
        (left, right, top, bottom) = (xmin * im_width, xmax * im_width,
                                      ymin * im_height, ymax * im_height)
    else:
        (left, right, top, bottom) = (xmin, xmax, ymin, ymax)
    draw.line([(left, top), (left, bottom), (right, bottom),
               (right, top), (left, top)], width=thickness, fill=color)

    predicted_speed = "n.a."  # means not available, it is just initialization
    predicted_direction = "n.a."  # means not available, it is just initialization

    detected_vehicle_image = image_temp[int(
        top):int(bottom), int(left):int(right)]

    if(bottom > ROI_POSITION):  # if the vehicle get in ROI area, vehicle predicted_speed predicted_color algorithms are called - 200 is an arbitrary value, for my case it looks very well to set position of ROI line at y pixel 200
        predicted_direction, predicted_speed,  is_vehicle_detected, update_csv = speed_prediction.predict_speed(
            top, bottom, right, left, current_frame_number, detected_vehicle_image, ROI_POSITION)

    predicted_color = color_recognition_api.color_recognition(
        detected_vehicle_image)

    try:
        font = ImageFont.truetype('arial.ttf', 16)
    except IOError:
        font = ImageFont.load_default()

    # If the total height of the display strings added to the top of the bounding
    # box exceeds the top of the image, stack the strings below the bounding box
    # instead of above.
    display_str_list[0] = predicted_color + " " + display_str_list[0]
    csv_line = predicted_color + "," + \
        str(predicted_direction) + "," + \
        str(predicted_speed)  # csv line created
    display_str_heights = [font.getsize(ds)[1] for ds in display_str_list]

    # Each display_str has a top and bottom margin of 0.05x.
    total_display_str_height = (1 + 2 * 0.05) * sum(display_str_heights)

    if top > total_display_str_height:
        text_bottom = top
    else:
        text_bottom = bottom + total_display_str_height

    # Reverse list and print from bottom to top.
    for display_str in display_str_list[::-1]:
        text_width, text_height = font.getsize(display_str)
        margin = np.ceil(0.05 * text_height)
        draw.rectangle(
            [(left, text_bottom - text_height - 2 * margin), (left + text_width,
                                                              text_bottom)],
            fill=color)
        draw.text(
            (left + margin, text_bottom - text_height - margin),
            display_str,
            fill='black',
            font=font)
        text_bottom -= text_height - 2 * margin
        return is_vehicle_detected, csv_line, update_csv


def draw_bounding_boxes_on_image_array(image,
                                       boxes,
                                       color='red',
                                       thickness=4,
                                       display_str_list_list=()):
    """Draws bounding boxes on image (numpy array).

    Args:
      image: a numpy array object.
      boxes: a 2 dimensional numpy array of [N, 4]: (ymin, xmin, ymax, xmax).
             The coordinates are in normalized format between [0, 1].
      color: color to draw bounding box. Default is red.
      thickness: line thickness. Default value is 4.
      display_str_list_list: list of list of strings.
                             a list of strings for each bounding box.
                             The reason to pass a list of strings for a
                             bounding box is that it might contain
                             multiple labels.

    Raises:
      ValueError: if boxes is not a [N, 4] array
    """
    image_pil = Image.fromarray(image)
    draw_bounding_boxes_on_image(
        image_pil, boxes, color, thickness, display_str_list_list)
    np.copyto(image, np.array(image_pil))


def draw_bounding_boxes_on_image(image,
                                 boxes,
                                 color='red',
                                 thickness=4,
                                 display_str_list_list=()):
    """Draws bounding boxes on image.

    Args:
      image: a PIL.Image object.
      boxes: a 2 dimensional numpy array of [N, 4]: (ymin, xmin, ymax, xmax).
             The coordinates are in normalized format between [0, 1].
      color: color to draw bounding box. Default is red.
      thickness: line thickness. Default value is 4.
      display_str_list_list: list of list of strings.
                             a list of strings for each bounding box.
                             The reason to pass a list of strings for a
                             bounding box is that it might contain
                             multiple labels.

    Raises:
      ValueError: if boxes is not a [N, 4] array
    """
    boxes_shape = boxes.shape
    if not boxes_shape:
        return
    if len(boxes_shape) != 2 or boxes_shape[1] != 4:
        raise ValueError('Input must be of size [N, 4]')
    for i in range(boxes_shape[0]):
        display_str_list = ()
        if display_str_list_list:
            display_str_list = display_str_list_list[i]
        draw_bounding_box_on_image(image, boxes[i, 0], boxes[i, 1], boxes[i, 2],
                                   boxes[i, 3], color, thickness, display_str_list)


def draw_bounding_boxes_on_image_tensors(images,
                                         boxes,
                                         classes,
                                         scores,
                                         category_index,
                                         max_boxes_to_draw=20,
                                         min_score_thresh=0.2):
    """Draws bounding boxes on batch of image tensors.

    Args:
      images: A 4D uint8 image tensor of shape [N, H, W, C].
      boxes: [N, max_detections, 4] float32 tensor of detection boxes.
      classes: [N, max_detections] int tensor of detection classes. Note that
        classes are 1-indexed.
      scores: [N, max_detections] float32 tensor of detection scores.
      category_index: a dict that maps integer ids to category dicts. e.g.
        {1: {1: 'dog'}, 2: {2: 'cat'}, ...}
      max_boxes_to_draw: Maximum number of boxes to draw on an image. Default 20.
      min_score_thresh: Minimum score threshold for visualization. Default 0.2.

    Returns:
      4D image tensor of type uint8, with boxes drawn on top.
    """
    visualize_boxes_fn = functools.partial(
        visualize_boxes_and_labels_on_image_array,
        category_index=category_index,
        instance_masks=None,
        keypoints=None,
        use_normalized_coordinates=True,
        max_boxes_to_draw=max_boxes_to_draw,
        min_score_thresh=min_score_thresh,
        agnostic_mode=False,
        line_thickness=4)

    def draw_boxes(image_boxes_classes_scores):
        """Draws boxes on image."""
        (image, boxes, classes, scores) = image_boxes_classes_scores
        image_with_boxes = tf.py_func(visualize_boxes_fn,
                                      [image, boxes, classes, scores], tf.uint8)
        return image_with_boxes

    images = tf.map_fn(
        draw_boxes, (images, boxes, classes, scores),
        dtype=tf.uint8,
        back_prop=False)
    return images


def draw_keypoints_on_image_array(image,
                                  keypoints,
                                  color='red',
                                  radius=2,
                                  use_normalized_coordinates=True):
    """Draws keypoints on an image (numpy array).

    Args:
      image: a numpy array with shape [height, width, 3].
      keypoints: a numpy array with shape [num_keypoints, 2].
      color: color to draw the keypoints with. Default is red.
      radius: keypoint radius. Default value is 2.
      use_normalized_coordinates: if True (default), treat keypoint values as
        relative to the image.  Otherwise treat them as absolute.
    """
    image_pil = Image.fromarray(np.uint8(image)).convert('RGB')
    draw_keypoints_on_image(image_pil, keypoints, color, radius,
                            use_normalized_coordinates)
    np.copyto(image, np.array(image_pil))


def draw_keypoints_on_image(image,
                            keypoints,
                            color='red',
                            radius=2,
                            use_normalized_coordinates=True):
    """Draws keypoints on an image.

    Args:
      image: a PIL.Image object.
      keypoints: a numpy array with shape [num_keypoints, 2].
      color: color to draw the keypoints with. Default is red.
      radius: keypoint radius. Default value is 2.
      use_normalized_coordinates: if True (default), treat keypoint values as
        relative to the image.  Otherwise treat them as absolute.
    """
    draw = ImageDraw.Draw(image)
    im_width, im_height = image.size
    keypoints_x = [k[1] for k in keypoints]
    keypoints_y = [k[0] for k in keypoints]
    if use_normalized_coordinates:
        keypoints_x = tuple([im_width * x for x in keypoints_x])
        keypoints_y = tuple([im_height * y for y in keypoints_y])
    for keypoint_x, keypoint_y in zip(keypoints_x, keypoints_y):
        draw.ellipse([(keypoint_x - radius, keypoint_y - radius),
                      (keypoint_x + radius, keypoint_y + radius)],
                     outline=color, fill=color)


def draw_mask_on_image_array(image, mask, color='red', alpha=0.7):
    """Draws mask on an image.

    Args:
      image: uint8 numpy array with shape (img_height, img_height, 3)
      mask: a uint8 numpy array of shape (img_height, img_height) with
        values between either 0 or 1.
      color: color to draw the keypoints with. Default is red.
      alpha: transparency value between 0 and 1. (default: 0.7)

    Raises:
      ValueError: On incorrect data type for image or masks.
    """
    if image.dtype != np.uint8:
        raise ValueError('`image` not of type np.uint8')
    if mask.dtype != np.uint8:
        raise ValueError('`mask` not of type np.uint8')
    if np.any(np.logical_and(mask != 1, mask != 0)):
        raise ValueError('`mask` elements should be in [0, 1]')
    rgb = ImageColor.getrgb(color)
    pil_image = Image.fromarray(image)

    solid_color = np.expand_dims(
        np.ones_like(mask), axis=2) * np.reshape(list(rgb), [1, 1, 3])
    pil_solid_color = Image.fromarray(np.uint8(solid_color)).convert('RGBA')
    pil_mask = Image.fromarray(np.uint8(255.0*alpha*mask)).convert('L')
    pil_image = Image.composite(pil_solid_color, pil_image, pil_mask)
    np.copyto(image, np.array(pil_image.convert('RGB')))


def visualize_boxes_and_labels_on_image_array(current_frame_number, image,
                                              boxes,
                                              classes,
                                              scores,
                                              category_index,
                                              instance_masks=None,
                                              keypoints=None,
                                              use_normalized_coordinates=False,
                                              max_boxes_to_draw=20,
                                              min_score_thresh=.5,
                                              agnostic_mode=False,
                                              line_thickness=4):
    """Overlay labeled boxes on an image with formatted scores and label names.

    This function groups boxes that correspond to the same location
    and creates a display string for each detection and overlays these
    on the image. Note that this function modifies the image in place, and returns
    that same image.

    Args:
      image: uint8 numpy array with shape (img_height, img_width, 3)
      boxes: a numpy array of shape [N, 4]
      classes: a numpy array of shape [N]. Note that class indices are 1-based,
        and match the keys in the label map.
      scores: a numpy array of shape [N] or None.  If scores=None, then
        this function assumes that the boxes to be plotted are groundtruth
        boxes and plot all boxes as black with no classes or scores.
      category_index: a dict containing category dictionaries (each holding
        category index `id` and category name `name`) keyed by category indices.
      instance_masks: a numpy array of shape [N, image_height, image_width], can
        be None
      keypoints: a numpy array of shape [N, num_keypoints, 2], can
        be None
      use_normalized_coordinates: whether boxes is to be interpreted as
        normalized coordinates or not.
      max_boxes_to_draw: maximum number of boxes to visualize.  If None, draw
        all boxes.
      min_score_thresh: minimum score threshold for a box to be visualized
      agnostic_mode: boolean (default: False) controlling whether to evaluate in
        class-agnostic mode or not.  This mode will display scores but ignore
        classes.
      line_thickness: integer (default: 4) controlling line width of the boxes.

    Returns:
      uint8 numpy array with shape (img_height, img_width, 3) with overlaid boxes.
    """
    # Create a display string (and color) for every box location, group any boxes
    # that correspond to the same location.
    csv_line_util = "not_available"
    counter = 0
    is_vehicle_detected = []
    box_to_display_str_map = collections.defaultdict(list)
    box_to_color_map = collections.defaultdict(str)
    box_to_instance_masks_map = {}
    box_to_keypoints_map = collections.defaultdict(list)
    if not max_boxes_to_draw:
        max_boxes_to_draw = boxes.shape[0]
    for i in range(min(max_boxes_to_draw, boxes.shape[0])):
        if scores is None or scores[i] > min_score_thresh:
            box = tuple(boxes[i].tolist())
            if instance_masks is not None:
                box_to_instance_masks_map[box] = instance_masks[i]
            if keypoints is not None:
                box_to_keypoints_map[box].extend(keypoints[i])
            if scores is None:
                box_to_color_map[box] = 'black'
            else:
                if not agnostic_mode:
                    if classes[i] in category_index.keys():
                        class_name = category_index[classes[i]]['name']
                    else:
                        class_name = 'N/A'
                    display_str = '{}: {}%'.format(
                        class_name, int(100*scores[i]))
                else:
                    display_str = 'score: {}%'.format(int(100 * scores[i]))

                box_to_display_str_map[box].append(display_str)
                if agnostic_mode:
                    box_to_color_map[box] = 'DarkOrange'
                else:
                    box_to_color_map[box] = STANDARD_COLORS[
                        classes[i] % len(STANDARD_COLORS)]

    # Draw all boxes onto image.
    for box, color in box_to_color_map.items():
        ymin, xmin, ymax, xmax = box
        if instance_masks is not None:
            draw_mask_on_image_array(
                image,
                box_to_instance_masks_map[box],
                color=color
            )

        display_str_list = box_to_display_str_map[box]
        # we are interested just vehicles (i.e. cars and trucks)
        if (("car" in display_str_list[0]) or ("truck" in display_str_list[0]) or ("bus" in display_str_list[0])):
            is_vehicle_detected, csv_line, update_csv = draw_bounding_box_on_image_array(current_frame_number,
                                                                                         image,
                                                                                         ymin,
                                                                                         xmin,
                                                                                         ymax,
                                                                                         xmax,
                                                                                         color=color,
                                                                                         thickness=line_thickness,
                                                                                         display_str_list=box_to_display_str_map[
                                                                                             box],
                                                                                         use_normalized_coordinates=use_normalized_coordinates)

            if keypoints is not None:
                draw_keypoints_on_image_array(
                    image,
                    box_to_keypoints_map[box],
                    color=color,
                    radius=line_thickness / 2,
                    use_normalized_coordinates=use_normalized_coordinates)

    if(1 in is_vehicle_detected):
        counter = 1
        del is_vehicle_detected[:]
        is_vehicle_detected = []
        if(class_name == "boat"):
            class_name = "truck"
        csv_line_util = class_name + "," + csv_line

    return counter, csv_line_util


def add_cdf_image_summary(values, name):
    """Adds a tf.summary.image for a CDF plot of the values.

    Normalizes `values` such that they sum to 1, plots the cumulative distribution
    function and creates a tf image summary.

    Args:
      values: a 1-D float32 tensor containing the values.
      name: name for the image summary.
    """
    def cdf_plot(values):
        """Numpy function to plot CDF."""
        normalized_values = values / np.sum(values)
        sorted_values = np.sort(normalized_values)
        cumulative_values = np.cumsum(sorted_values)
        fraction_of_examples = (np.arange(cumulative_values.size, dtype=np.float32)
                                / cumulative_values.size)
        fig = plt.figure(frameon=False)
        ax = fig.add_subplot('111')
        ax.plot(fraction_of_examples, cumulative_values)
        ax.set_ylabel('cumulative normalized values')
        ax.set_xlabel('fraction of examples')
        fig.canvas.draw()
        width, height = fig.get_size_inches() * fig.get_dpi()
        image = np.fromstring(fig.canvas.tostring_rgb(), dtype='uint8').reshape(
            1, height, width, 3)
        return image
    cdf_plot = tf.py_func(cdf_plot, [values], tf.uint8)
    tf.summary.image(name, cdf_plot)