utils.py

import colorsys

from PIL import Image, ImageDraw, ImageFont, ImageOps


COCO_CLASSES = [
    "person",
    "bicycle",
    "car",
    "motorcycle",
    "airplane",
    "bus",
    "train",
    "truck",
    "boat",
    "traffic light",
    "fire hydrant",
    "stop sign",
    "parking meter",
    "bench",
    "bird",
    "cat",
    "dog",
    "horse",
    "sheep",
    "cow",
    "elephant",
    "bear",
    "zebra",
    "giraffe",
    "backpack",
    "umbrella",
    "handbag",
    "tie",
    "suitcase",
    "frisbee",
    "skis",
    "snowboard",
    "sports ball",
    "kite",
    "baseball bat",
    "baseball glove",
    "skateboard",
    "surfboard",
    "tennis racket",
    "bottle",
    "wine glass",
    "cup",
    "fork",
    "knife",
    "spoon",
    "bowl",
    "banana",
    "apple",
    "sandwich",
    "orange",
    "broccoli",
    "carrot",
    "hot dog",
    "pizza",
    "donut",
    "cake",
    "chair",
    "couch",
    "potted plant",
    "bed",
    "dining table",
    "toilet",
    "tv",
    "laptop",
    "mouse",
    "remote",
    "keyboard",
    "cell phone",
    "microwave",
    "oven",
    "toaster",
    "sink",
    "refrigerator",
    "book",
    "clock",
    "vase",
    "scissors",
    "teddy bear",
    "hair drier",
    "toothbrush",
]


def draw_overlay(im, threshold, labels, boxes, scores):
    draw = ImageDraw.Draw(im)
    font = ImageFont.load_default()

    for label, box, score in zip(labels[0], boxes[0], scores[0]):
        if score > threshold:
            color = get_color_by_label(label)
            draw.rectangle(box, outline=color, width=2)
            class_name = COCO_CLASSES[label]
            text = f"{class_name}: {score:.2f}"
            draw.text((box[0] + 4, box[1] + 2), text, fill=color, font=font)


def get_color_by_label(label):
    hue = (((label * 17) % len(COCO_CLASSES))) / len(COCO_CLASSES)
    return tuple(round(i * 255) for i in colorsys.hsv_to_rgb(hue, 1.0, 1.0))