python - 如何使用 OpenCV 和 Python 制作矩形图像的正方形？

Question

我有各种各样的矩形图像。我需要将它们修改为统一的方形(不同大小可以)。

为此，我必须将它叠加在较大的方形之上。背景为黑色。

当我需要分层 2 图像时，我想到了这一点:

import cv2
import numpy as np
if 1:
        img = cv2.imread(in_img)
        #get size
        height, width, channels = img.shape
        print (in_img,height, width, channels)
        # Create a black image
        x = height if height > width else width
        y = height if height > width else width
        square= np.zeros((x,y,3), np.uint8)
        cv2.imshow("original", img)
        cv2.imshow("black square", square)
        cv2.waitKey(0)

如何将它们堆叠在一起，使原始图像在黑色形状的顶部垂直和水平居中？

Answer 1

我想通了。你需要“广播成型”:

square[(y-height)/2:y-(y-height)/2, (x-width)/2:x-(x-width)/2] = img

最终草案:

import cv2
import numpy as np
if 1:
        img = cv2.imread(in_img)
        #get size
        height, width, channels = img.shape
        print (in_img,height, width, channels)
        # Create a black image
        x = height if height > width else width
        y = height if height > width else width
        square= np.zeros((x,y,3), np.uint8)
        #
        #This does the job
        #
        square[int((y-height)/2):int(y-(y-height)/2), int((x-width)/2):int(x-(x-width)/2)] = img
        cv2.imwrite(out_img,square)
        cv2.imshow("original", img)
        cv2.imshow("black square", square)
        cv2.waitKey(0)