Python实现PS图像调整颜色梯度效果示例

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();

  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');