[PYPLOT] subplot

여러 subplot그리기

• plt.tight_layout()
• figsize는 하나의 플롯의 크기를 정하는 것
• [i%n_rows][i//(n_cols)]는 행, 열이 같을 때 정상적으로 작동

def get_ann(img_id, coco):
    return coco.getAnnIds(imgIds=img_id)

def get_img(img_id, coco):
    base_path = '/opt/ml/detection/dataset'
    img_path = os.path.join(base_path, coco.loadImgs(img_id)[0]['file_name'])
    image = cv2.imread(img_path)
    return image

def draw_bboxes(img_id, coco, ax):
    anns = get_ann(img_id, coco)
    image = get_img(img_id, coco)
    for ann in anns:
        x, y, w, h = map(int, coco.loadAnns(ann)[0]['bbox'])
        label = coco.loadCats(coco.loadAnns(ann)[0]['category_id'])[0]['name']
        image = cv2.rectangle(image, (x, y), (x + w, y + h), (36,255,12), 3)
        cv2.putText(image, label, (x, y-10), cv2.FONT_HERSHEY_SIMPLEX, 0.9, (255, 0, 0), 4)
    ax.imshow(image)

n_rows, n_cols = 4, 4
fig, ax = plt.subplots(n_rows, n_cols, sharex=True, sharey=True, figsize=(20, 20))

index = list(map(int, np.random.randint(1, len(train_json['images'])-1, size=n_cols*n_rows)))
for i, idx in enumerate(index):
    draw_bboxes(idx, coco, ax[i%n_rows][i//(n_cols)])
    ax[i%n_rows][i//(n_cols)].set_title(idx)
plt.tight_layout()

plt