Padding 붙이기

Opencv 이용

def to_padding(image):
    height = image.shape[0]
    width = image.shape[1]
    top, bottom, left, right = 0, 0, 0, 0

    if height > width:
        left, right = (height - width) // 2, (height - width) // 2
    else:
        top, bottom = (width - height) // 2, (width - height) // 2

    new_image = cv.copyMakeBorder(image, top, bottom, left, right, cv.BORDER_CONSTANT, value=(0, 0, 0))

    # cv.imshow('test', new_image)
    # cv.waitKey(0)

    return new_image

 

Opencv 없이 붙이기

def resize_aspect_ratio(img, final_h, final_w):
    height, width, channel = img.shape
    ratio = 0
    # height = 8914
    # width = 6457
    target_w_size = final_w
    target_h_size = final_h

    h_ratio = target_h_size / height
    target_h, target_w = int(height * h_ratio), int(width * h_ratio)
    diff = target_w_size - target_w
    if diff > 0:
        resized = cv2.resize(img, (target_w, target_h), interpolation=interpolation)
        pad_array = np.ones(shape=(target_h_size, diff, 3), dtype=np.uint8)
        # pad_array = np.full(shape=(target_h_size, diff, 3), 255)
        resized = np.append(resized, pad_array, axis=1)
        ratio = h_ratio
    else:
        w_ratio = target_w_size / width
        target_h, target_w = int(height * w_ratio), int(width * w_ratio)
        diff = target_h_size - target_h
        resized = cv2.resize(img, (target_w, target_h), interpolation=interpolation)
        pad_array = np.ones(shape=(diff, target_w_size, 3), dtype=np.uint8)
        resized = np.append(resized, pad_array, axis=0)
        ratio = w_ratio

    cv2.imshow('test', resized)
    cv2.waitKey(0)

여기서

target_w_size, target_h_size가 원하는 이미지의 크기이고,

이미지가 비율을 일정하게 유지하면서 padding을 붙여서 원하는 크기의 이미지로 resize하는 코드