tone curves

[age]

A simply smooth curves adjustement script.
curves.7z

put curves.py in Python/Lib/site-packages.

Usage example:

import vapoursynth as vs
import curves 
core = vs.get_core()
clip = yourclip
clip=curves.ycurve(clip,[(0,0),(16191,13364),(32768,32768),(49087,51400),(65535,65535)])

[age]

Another version of curve,probably better, with spline interpolation(modification of original code in finesharp.py).
Added planes to be processed and changed the way to insert control points (as a string).

import vapoursynth as vs


def spline(x, coordinates):
     def get_matrix(px, py, l):
         matrix = []
         matrix.append([(i == 0) * 1.0 for i in range(l + 1)])
         for i in range(1, l - 1):
             p = [0 for t in range(l + 1)]
             p[i - 1] = px[i] - px[i - 1]
             p[i] = 2 * (px[i + 1] - px[i - 1])
             p[i + 1] = px[i + 1] - px[i]
             p[l] = 6 * (((py[i + 1] - py[i]) / p[i + 1]) - (py[i] - py[i - 1]) / p[i - 1])
             matrix.append(p)
         matrix.append([(i == l - 1) * 1.0 for i in range(l + 1)])
         return matrix

     def equation(matrix, dim):
         for i in range(dim):
             num = matrix[i][i]
             for j in range(dim + 1):
                 matrix[i][j] /= num
             for j in range(dim):
                 if i != j:
                     a = matrix[j][i]
                     for k in range(i, dim + 1):
                         matrix[j][k] -= a * matrix[i][k]

     

     
     if coordinates=="" :   
      s=x
      return s
     else : 
      coordinates=coordinates.replace('-',',').split(",")
      coordinates = [int(i) for i in coordinates]
      length = (len(coordinates))//2
       
      i=0
      px =[]
      py =[]
      while i < ((len(coordinates)-1)) :
          px.append(coordinates[i])
          py.append(coordinates[i+1])
          i=i+2
     
      if  (length == 1) :       
       s=x
       return s 
     
          
     
     
      elif (length == 2) :       
         
       i=0
       x1=px[i]
       y1=py[i] 
       x2=px[i+1] 
       y2=py[i+1]
       s= ((x-x1)*(y2-y1)/(x2-x1))+y1
       return s
      
     
      else :                   
       matrix = get_matrix(px, py, length)
       equation(matrix, length)
       for i in range(length + 1):
           if x >= px[i] and x <= px[i + 1]:
               break
       j = i + 1
       h = px[j] - px[i]
       s = matrix[j][length] * (x - px[i]) ** 3
       s -= matrix[i][length] * (x - px[j]) ** 3
       s /= 6 * h
       s += (py[j] / h - h * matrix[j][length] / 6) * (x - px[i])
       s -= (py[i] / h - h * matrix[i][length] / 6) * (x - px[j])
       return s
     




def curve(c, coordinates="",planes=[] ) :
    core = vs.get_core()  
    lutcurve = []
    h=2**c.format.bits_per_sample
    for x in range(h):
     x=spline(x,coordinates)
     x=int(round(x))
     if (x <= 0) :
      x=0      
     elif (x >= h)  :
      x=h-1      
     else :
      x=x 
     lutcurve.append(x)
    if (len(planes)>0):
     c= core.std.Lut(clip=c,planes=planes, lut=lutcurve)       
    else: 
     c= core.std.Lut(clip=c, lut=lutcurve)    
    return c 


# save this file as curve.py
# usage:
# import curve
# clip = curve.curve(clip, "0-0,128-128,255-255", planes=[0,1,2])