Python-旋转图像 [英] Python - Rotate Image

问题描述

如何借助OpenCv库在Python中旋转图像，以及如何更改图像的高度和宽度值(不使用OpenCv中内置的旋转方法).它必须实现两个嵌套的for循环.

How can I rotate an image in Python with the help of OpenCv library, and by changing the value of height and width of the image (without using the built-in methods for rotation in OpenCv). It has to implement with two nested for loop.

img=cv2.imread('Images/Screenshot.png',cv2.IMREAD_GRAYSCALE)

height, width = img.shape

# for i in range(0,height):
#     for j in range(0,width):
#         img[i][j]=

# show rotated image
cv2.imshow("image",img)

感谢您抽出宝贵的时间来帮助我！

Thanks for taking your time to help me!

推荐答案

交换索引:

您可以使用np.zeros()创建空白图像，然后将像素从当前图像读取到空白图像.您可以更改读取像素的顺序以执行一些基本旋转.以下示例将有所帮助.

Swap the indexes:

You can create an empty image with np.zeros() and then read the pixels from your current image to the empty image. You can change the order that you read the pixels to perform some basic rotations. The following examples should help.

img = cv2.imread('texas_longhorns_log.png')

h,w,c = img.shape

empty_img = np.zeros([h,w,c], dtype=np.uint8)

for i in range(h):
    for j in range(w):
        empty_img[i,j] = img[j-1,i-1]
        empty_img = empty_img[0:h,0:w]

cv2.imwrite("tester1.png", empty_img)

h,w,c = img.shape

empty_img = np.zeros([h,w,c], dtype=np.uint8)

for i in range(h):
    for j in range(w):
        empty_img[i,j] = img[h-j-1,w-i-1]
        empty_img = empty_img[0:h,0:w]

cv2.imwrite("tester2.png", empty_img)

h,w,c = img.shape

empty_img = np.zeros([h,w,c], dtype=np.uint8)

for i in range(h):
    for j in range(w):
        empty_img[i,j] = img[h-i-1,w-j-1]
        empty_img = empty_img[0:h,0:w]

cv2.imwrite("tester3.png", empty_img)

这篇关于Python-旋转图像的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！