Example of effect of slice conversion for implementing PS filter effects in Python, python Filter

Example of effect of slice conversion for implementing PS filter effects in Python, python Filter

This article describes how to implement slice-shaped Effect of PS filter effects in Python. We will share this with you for your reference. The details are as follows:

Here, we use Python to implement a special geometric transformation effect in the PS filter, called slice transform, which turns an image into a slice. For detailed algorithm principles and instructions, see the appendix.

import numpy as npfrom skimage import img_as_floatimport matplotlib.pyplot as pltfrom skimage import ioimport mathimport numpy.matlibfile_name2='D:/Visual Effects/PS Algorithm/4.jpg'img=io.imread(file_name2)img = img_as_float(img)# control the radius of the inner circleradius = 150# control the distance between the inner circle and outer circlehigh = 200angle = 0spreadAngle = math.pi# set the center of the circle, proportion of the image sizecenterX = 0.5centerY = 1.0row, col, channel = img.shapeicenterX = col * centerXicenterY = row * centerYimg_out = img * 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 - icenterXyy_dif = y_mask - icenterYtheta = np.arctan2(-yy_dif, -xx_dif+0.0001)r = np.sqrt(xx_dif*xx_dif + yy_dif * yy_dif)theta = np.mod(theta, 2 * math.pi)x1_mask = col * theta/(spreadAngle+0.00001)y1_mask = row * (1-(r-radius)/(high+0.00001))'''mask = x1_mask < 0x1_mask = x1_mask * (1 - mask)mask = x1_mask > (col - 1)x1_mask = x1_mask * (1 - mask) + (x1_mask * 0 + col -2) * maskmask = y1_mask < 0y1_mask = y1_mask * (1 - mask)mask = y1_mask > (row -1)y1_mask = y1_mask * (1 - mask) + (y1_mask * 0 + row -2) * mask'''int_x = np.floor (x1_mask)int_x = int_x.astype(int)int_y = np.floor (y1_mask)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 x1_mask [ii, jj] < 0 or x1_mask [ii, jj] > col -1 :      continue    if y1_mask [ii, jj] < 0 or y1_mask [ii, jj] > row -1 :      continue    img_out[ii, jj, :] = img[new_yy, new_xx, :]plt.figure (1)plt.title('www.jb51.net')plt.imshow (img)plt.axis('off')plt.figure (2)plt.title('www.jb51.net')plt.imshow (img_out)plt.axis('off')plt.show()

Appendix: PS filter--fan-shaped warp

  clc;  clear all;  close all;  addpath('E:\PhotoShop Algortihm\Image Processing\PS Algorithm');  I=imread('4.jpg');  I=double(I);  Image=I/255;  [height, width, depth]=size(Image);  % set the parameters  radius = 150; % control the radius of the inner circle  high = 200;  % control the distance between the inner circle and outer circle  angle = 0;         spreadAngle=pi;    centerX = 0.5; % set the center of the circle, proportion of the image size  centerY = 1.0;  icenterX=width*centerX;  icenterY=height*centerY;  Image_new=Image*0;  for i=1:height    for j=1:width      dx=j-icenterX;      dy=i-icenterY;      theta=atan2(-dy, -dx)+angle;      r=sqrt(dy*dy+dx*dx);      theta=mod(theta, 2*pi);      x=width * theta/(spreadAngle+0.00001);      y=height * (1-(r-radius)/(high+0.00001));  % %     if (x<=1)   x=1; end  % %     if (x>=width)  x=width-1; end;  % %     if (y>=height) y=height-1; end;  % %     if (y<1) y=1;   end;  % %           if (x<=1)   continue; end      if (x>=width)  continue; end;      if (y>=height) continue; end;      if (y<1) continue;   end;      x1=floor(x);      y1=floor(y);      p=x-x1;      q=y-y1;      Image_new(i,j,:)=(1-p)*(1-q)*Image(y1,x1,:)+p*(1-q)*Image(y1,x1+1,:)...        +q*(1-p)*Image(y1+1,x1,:)+p*q*Image(y1+1,x1+1,:);    end  end  imshow(Image_new)  imwrite(Image_new, 'out.jpg');

Reference Source: http://www.jhlabs.com/index.html

In this example, the Python running effect is as follows:

Source image