python - 如何在 OpenCV 中进行变形？

Question

我对如何使图像变形感兴趣，例如，有一张 1000x1000 的照片，在 500 400 点，我想在 Photoshop 中用塑料来膨胀它。

我没有代码，因为我没有找到合适的代码。

Answer 1

您可以使用 remapping .这是一个快速演示，但请注意，您必须知道准确的失真函数才能复制 Photoshop 的功能

import cv2 as cv
import numpy as np
from matplotlib import pyplot as plt
import math
img = cv.imread('kit.jpg')

right_eye = (215,105)
radius = 30
power = 1.6 # >1.0 for expansion, <1.0 for shrinkage

height, width, _ = img.shape
map_y = np.zeros((height,width),dtype=np.float32)
map_x = np.zeros((height,width),dtype=np.float32)

# create index map
for i in range(height):
    for j in range(width):
        map_y[i][j]=i
        map_x[i][j]=j

# deform around the right eye
for i in range (-radius, radius):
    for j in range(-radius, radius):
        if (i**2 + j**2 > radius ** 2):
            continue

        if i > 0:
            map_y[right_eye[1] + i][right_eye[0] + j] = right_eye[1] + (i/radius)**power * radius
        if i < 0:
            map_y[right_eye[1] + i][right_eye[0] + j] = right_eye[1] - (-i/radius)**power * radius
        if j > 0:
            map_x[right_eye[1] + i][right_eye[0] + j] = right_eye[0] + (j/radius)**power * radius
        if j < 0:
            map_x[right_eye[1] + i][right_eye[0] + j] = right_eye[0] - (-j/radius)**power * radius

warped=cv.remap(img,map_x,map_y,cv.INTER_LINEAR)
cv.imwrite('warp.jpg', warped)