Example of how to adjust the color gradient of PS Images Using Python, python gradient

Example of how to adjust the color gradient of PS Images Using Python, python gradient

This article describes how to adjust the color gradient of PS Images Using Python. We will share this with you for your reference. The details are as follows:

Here, we use Python to implement a color chart in PS. You can see various gradient colors. For more information about the effects, see the appendix.

Compared with the previous program, the matrix operation is used to replace the for loop, improving the running efficiency.

import numpy as npimport matplotlib.pyplot as pltfrom skimage import ioimport numpy.matlibfrom skimage import img_as_floatfile_name='D:/Visual Effects/PS Algorithm/4.jpg';img=io.imread(file_name)img = img_as_float(img)row, col, channel = img.shaperNW = 0.5rNE = 1.0rSW = 1.0rSE = 0.0gNW = 0.0gNE = 0.5gSW = 0.0gSE = 1.0bNW = 1.0bNE = 0.0bSW = 1.0bSE = 0.0xx = 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)fx = x_mask * 1.0 / colfy = y_mask * 1.0 / rowp = rNW + (rNE - rNW) * fxq = rSW + (rSE - rSW) * fxr = ( p + (q - p) * fy )r[r<0] = 0r[r>1] =1p = gNW + (gNE - gNW) * fxq = gSW + (gSE - gSW) * fxg = ( p + (q - p) * fy )g[g<0] = 0g[g>1] =1p = bNW + (bNE - bNW) * fxq = bSW + (bSE - bSW) * fxb = ( p + (q - p) * fy )b[b<0] = 0.0b[b>1] = 1.0img[:, :, 0] = rimg[:, :, 1] = gimg[:, :, 2] = bplt.figure(1)plt.imshow(img)plt.axis('off');plt.show();

Appendix: PS-color gradient

  clc;  clear all;  close all;  addpath('E:\PhotoShop Algortihm\Image Processing\PS Algorithm');  I=imread('4.jpg');  Image=double(I)/255;  [height, width, depth]=size(Image);  rNW=1.0;   gNW=0.0;  bNW=0.0;  rNE=1.0;   gNE=1.0;  bNE=0.0;  rSW=0.0;   gSW=0;   bSW=1.0;  rSE=0.0;   gSE=1.0;  bSE=0.0;  Img_new=Image;  for ii=1:height    for jj=1:width      fx = jj / width;      fy = ii / height;      p = rNW + (rNE - rNW) * fx;      q = rSW + (rSE - rSW) * fx;      r = ( p + (q - p) * fy );      r = min(max(r, 0), 1);      p = gNW + (gNE - gNW) * fx;      q = gSW + (gSE - gSW) * fx;      g = ( p + (q - p) * fy );      g = min(max(g, 0) ,1);      p = bNW + (bNE - bNW) * fx;      q = bSW + (bSE - bSW) * fx;      b = ( p + (q - p) * fy );      b = min(max(b, 0), 1);      Img_new(ii, jj, 1)=r;      Img_new(ii, jj, 2)=g;      Img_new(ii, jj, 3)=b;    end    end  imshow(Img_new);  imwrite(Img_new, 'out.jpg');

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

In this example, run Python:

Source image:

Running effect: