Merge branch 'feature/add_3Dcube_export' into develop

Author: mfe

lutLab/README.md

@@ -8,7 +8,7 @@ It uses [OpenColorIO](http://opencolorio.org/) to read and process input LUTs.
 
 Available scripts :   
 
-- **lut_to_lut**: convert a lut into another format. For now, only conversion to 1D/2D cube or 1D/2D csp is supported   
+- **lut_to_lut**: convert a lut into another format. For now, only conversion to 1D/2D/3D cube or 1D/2D csp is supported   
 
 - **ext_1d_lut**: extract the tone mapping curve of a 3D LUT using a bicubic interpolation (or not)   
 

lutLab/lut_to_lut.py

@@ -8,16 +8,19 @@
 import argparse
 from utils.ocio_helper import OCIO_LUTS_FORMATS, create_ocio_processor
 from utils.csp_helper import write_2d_csp_lut
-from utils.cube_helper import write_2d_cube_lut
+from utils.cube_helper import write_2d_cube_lut, write_3d_cube_lut
 from utils.lut_utils import get_default_out_path
+from PyOpenColorIO.Constants import (
+    INTERP_LINEAR, INTERP_TETRAHEDRAL
+)
 
 
 class LutToLutException(Exception):
     pass
 
 
 def lut_to_lut(inlutfile, outlutfile=None, type='1D_CUBE',
-               lutsize=16):
+               lutsize=16, cubesize=17):
     """Extract the tone mapping curve of a 3D LUT
 
     Args:
@@ -27,38 +30,48 @@ def lut_to_lut(inlutfile, outlutfile=None, type='1D_CUBE',
         outlutfile (str): the output 1D LUT. If not define, LUT is written in
         the input LUT directory and post-fixed with "_export"
 
-        type (str): specify output LUT format. For now only 2D csp and 2D cube
-        are available.
+        type (str): specify output LUT format. For now only 2D/3D csp and 2D
+        cube are available.
 
-        lutsize (int): out LUT bit precision. Ex : 16 (bits)
+        lutsize (int): out LUT bit precision for 1D. Ex : 16 (bits)
 
     """
     samples_count = pow(2, lutsize)
     if type == '1D_CUBE':
         ext = ".cube"
         write_function = write_2d_cube_lut
+        interp = INTERP_LINEAR
+    elif type == '3D_CUBE':
+        ext = ".cube"
+        write_function = write_3d_cube_lut
+        interp = INTERP_TETRAHEDRAL
     elif type == '1D_CSP':
         ext = ".csp"
         write_function = write_2d_csp_lut
+        interp = INTERP_LINEAR
     else:
         raise LutToLutException("Unsupported export format!")
     if not outlutfile:
         outlutfile = get_default_out_path(inlutfile, ext)
-    processor = create_ocio_processor(inlutfile)
-        # init vars
+    processor = create_ocio_processor(inlutfile, interpolation=interp)
+    # init vars
     max_value = samples_count - 1.0
     red_values = []
     green_values = []
     blue_values = []
-    # process color values
-    for n in range(0, samples_count):
-        x = n/max_value
-        res = processor.applyRGB([x, x, x])
-        red_values.append(res[0])
-        green_values.append(res[1])
-        blue_values.append(res[2])
-    # write
-    write_function(outlutfile, red_values, green_values, blue_values)
+    if "1D" in type:
+        # process color values
+        for n in range(0, samples_count):
+            x = n/max_value
+            res = processor.applyRGB([x, x, x])
+            red_values.append(res[0])
+            green_values.append(res[1])
+            blue_values.append(res[2])
+        # write
+        write_function(outlutfile, red_values, green_values, blue_values)
+    elif "3D" in type:
+        # write
+        write_function(outlutfile, cubesize, processor)
 
 
 def __get_options():
@@ -83,16 +96,21 @@ def __get_options():
     parser.add_argument("-t", "--out-type",
                         help=("Output LUT type."),
                         type=str,
-                        choices=['1D_CSP', '1D_CUBE'], default='1D_CUBE')
+                        choices=['1D_CSP', '1D_CUBE', '3D_CUBE'],
+                        default='1D_CUBE')
     # out lut size
-    parser.add_argument("-os", "--outlut-size", help=(
+    parser.add_argument("-os", "--out-lut-size", help=(
         "Output lut bit precision. Ex : 10, 16, 32."
     ), default=16, type=int)
+    # out cube size
+    parser.add_argument("-ocs", "--out-cube-size", help=(
+        "Output cube size (3D only). Ex : 17, 32."
+    ), default=17, type=int)
     return parser.parse_args()
 
 if __name__ == '__main__':
     """ Command line interface
     """
     args = __get_options()
     lut_to_lut(args.inlutfile, args.outlutfile, args.out_type,
-               args.outlut_size)
+               args.out_lut_size, args.out_cube_size)

utils/cube_helper.py

@@ -67,5 +67,49 @@ def write_1d_cube_lut(filename, values, comment=None, title="Iridas LUT"):
         comment (str): an optionnal comment
 
         title (str): title of the LUT
+
     """
     write_2d_cube_lut(filename, values, comment, title)
+
+
+def write_3d_cube_lut(filename, cubesize, processor,
+                      comment=None, title="Cube LUT"):
+    """Write a 3D Cube LUT
+
+    Args:
+        filename (str): out LUT path
+
+        cubesize (int): cube size. Ex: 17, 32...
+
+        processor (PyOpenColorIO.config.Processor): an OpenColorIO processor
+
+    Kwargs:
+        comment (str): an optionnal comment
+
+        title (str): title of the LUT
+
+    """
+    f = open(filename, 'w+')
+    # comment
+    if comment:
+        f.write("#{0}\n".format(comment))
+    # title
+    f.write("TITLE {0}\n\n".format(title))
+    # lut size
+    f.write("{0} {1}\n\n".format(CUBE_3D, cubesize))
+    input_range = range(0, cubesize)
+    max_value = cubesize - 1.0
+    # process color values
+    for b in input_range:
+        for g in input_range:
+            for r in input_range:
+                # get a value between [0..1]
+                norm_r = r/max_value
+                norm_g = g/max_value
+                norm_b = b/max_value
+                # apply correction via OCIO
+                res = processor.applyRGB([norm_r, norm_g, norm_b])
+                f.write("{0:.6f} {1:.6f} {2:.6f}\n".format(res[0],
+                                                           res[1],
+                                                           res[2]))
+    f.close()