本文用 Python 实现 PS 滤镜中的 水波特效

import numpy as npfrom skimage import img_as_floatimport matplotlib.pyplot as pltfrom skimage import ioimport numpy.matlibfile_name2 = 'D:/Visual Effects/PS Algorithm/4.jpg'img=io.imread(file_name2)img = img_as_float(img)row, col, channel = img.shapeimg_out = img * 1.0A = 7.0B = 3.0center_x = (col-1)/2.0center_y = (row-1)/2.0xx = np.arange (col) yy = np.arange (row)x_mask = numpy.matlib.repmat (xx, row, 1)y_mask = numpy.matlib.repmat (yy, col, 1)y_mask = np.transpose(y_mask)xx_dif = x_mask - center_xyy_dif = center_y - y_masktheta = np.arctan2(yy_dif,  xx_dif)r = np.sqrt(xx_dif * xx_dif + yy_dif * yy_dif)r1 = r + A*col*0.01*np.sin(B*0.1*r)x_new = r1 * np.cos(theta) + center_xy_new = center_y - r1 * np.sin(theta) int_x = np.floor (x_new)int_x = int_x.astype(int)int_y = np.floor (y_new)int_y = int_y.astype(int)for ii in range(row):    for jj in range (col):        new_xx = int_x [ii, jj]        new_yy = int_y [ii, jj]        if x_new [ii, jj] < 0 or x_new [ii, jj] > col -1 :            continue        if y_new [ii, jj] < 0 or y_new [ii, jj] > row -1 :            continue        img_out[ii, jj, :] = img[new_yy, new_xx, :]plt.figure (1)plt.imshow (img)plt.axis('off')plt.figure (2)plt.imshow (img_out)plt.axis('off')plt.show()