part4_new_functions.py

def randcolorvalue():
    return float(randint(0, 255)) / 255


def randcolor():
    return randcolorvalue(), randcolorvalue(), randcolorvalue()


def draw_boxes(image, boxes):
    image = np.copy(image)

    for box in boxes:
        color = randcolor()

        x_min, x_max, y_min, y_max = box
        cv2.rectangle(image, (x_min, y_min), (x_max, y_max), color, 2)

    return image
  

def sliding_window(
        image,
        x_start=0,
        x_stop=None,
        y_start=0,
        y_stop=None,
        window=None,
        overlap=None
):
    if x_stop is None:
        x_stop = image.shape[1]
    if y_stop is None:
        y_stop = image.shape[0]

    x_span = x_stop - x_start
    y_span = y_stop - y_start
    x_pixel_per_step = np.int(window[0] * (1 - overlap[0]))
    y_pixel_per_step = np.int(window[1] * (1 - overlap[1]))
    x_buffer = np.int(window[0] * overlap[0])
    y_buffer = np.int(window[1] * overlap[1])
    x_window_count = np.int((x_span - x_buffer) / x_pixel_per_step)
    y_window_count = np.int((y_span - y_buffer) / y_pixel_per_step)

    window_list = []
    for y_index in range(y_window_count):
        for x_index in range(x_window_count):
            tmp_start_x = x_index * x_pixel_per_step + x_start # tmp so it is not confused with `x_start`
            tmp_end_x = tmp_start_x + window[0]
            tmp_start_y = y_index * y_pixel_per_step + y_start
            tmp_end_y = tmp_start_y + window[1]

            window_list.append((tmp_start_x, tmp_end_x, tmp_start_y, tmp_end_y))

    return window_list


def predict_windows(image, windows=None, classifier=None):
    positive_windows = []

    for window in windows:
        x_start, x_stop, y_start, y_stop = window
        image_selection = image[y_start:y_stop, x_start:x_stop]
        image_selection = cv2.resize(image_selection, (64, 64))

        features = get_features(image_selection)
        prediction = classifier.predict(features)

        if prediction == 1.:
            positive_windows.append(window)

    return positive_windows