Python深度学习之使用Albumentations对图像做增强

import random
 
import cv2
from matplotlib import pyplot as plt
 
import albumentations as A

BOX_COLOR = (255, 0, 0) # Red
TEXT_COLOR = (255, 255, 255) # White
 
 
def visualize_bbox(img, bbox, class_name, color=BOX_COLOR, thickness=2):
    """Visualizes a single bounding box on the image"""
    x_min, y_min, w, h = bbox
    x_min, x_max, y_min, y_max = int(x_min), int(x_min + w), int(y_min), int(y_min + h)
 
    cv2.rectangle(img, (x_min, y_min), (x_max, y_max), color=color, thickness=thickness)
 
    ((text_width, text_height), _) = cv2.getTextSize(class_name, cv2.FONT_HERSHEY_SIMPLEX, 0.35, 1)    
    cv2.rectangle(img, (x_min, y_min - int(1.3 * text_height)), (x_min + text_width, y_min), BOX_COLOR, -1)
    cv2.putText(
        img,
        text=class_name,
        org=(x_min, y_min - int(0.3 * text_height)),
        fontFace=cv2.FONT_HERSHEY_SIMPLEX,
        fontScale=0.35, 
        color=TEXT_COLOR, 
        lineType=cv2.LINE_AA,
    )
    return img
 
 
def visualize(image, bboxes, category_ids, category_id_to_name):
    img = image.copy()
    for bbox, category_id in zip(bboxes, category_ids):
        class_name = category_id_to_name[category_id]
        img = visualize_bbox(img, bbox, class_name)
    plt.figure(figsize=(12, 12))
    plt.axis('off')
    plt.imshow(img)

image = cv2.imread('images/000000386298.jpg')
image = cv2.cvtColor(image, cv2.COLOR_BGR2RGB)

bboxes = [[5.66, 138.95, 147.09, 164.88], [366.7, 80.84, 132.8, 181.84]]
category_ids = [17, 18]
 
# We will use the mapping from category_id to the class name
# to visualize the class label for the bounding box on the image
category_id_to_name = {17: 'cat', 18: 'dog'}

visualize(image, bboxes, category_ids, category_id_to_name)

transform = A.Compose(
    [A.RandomSizedBBoxSafeCrop(width=448, height=336, erosion_rate=0.2)],
    bbox_params=A.BboxParams(format='coco', label_fields=['category_ids']),
)

random.seed(7)
transformed = transform(image=image, bboxes=bboxes, category_ids=category_ids)
visualize(
    transformed['image'],
    transformed['bboxes'],
    transformed['category_ids'],
    category_id_to_name,
)

random.seed(3)
transformed = transform(image=image, bboxes=bboxes, category_ids=category_ids)
visualize(
    transformed['image'],
    transformed['bboxes'],
    transformed['category_ids'],
    category_id_to_name,
)

random.seed(444)
transformed = transform(image=image, bboxes=bboxes, category_ids=category_ids)
visualize(
    transformed['image'],
    transformed['bboxes'],
    transformed['category_ids'],
    category_id_to_name,
)