From 9b44e24f8ed9d711b8127ad8097acb9a0855304d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= <hannesschoenberger@gmail.com>
Date: Thu, 30 Aug 2012 07:33:39 +0200
Subject: [PATCH] Use function pointer for different interpolation methods

---
 skimage/_shared/interpolation.pxd |  6 +++---
 skimage/_shared/interpolation.pyx |  6 +++---
 skimage/feature/_texture.pyx      |  2 +-
 skimage/transform/_warps_cy.pyx   | 15 +++++++++------
 4 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/skimage/_shared/interpolation.pxd b/skimage/_shared/interpolation.pxd
index c883d00d..3e8e74e9 100644
--- a/skimage/_shared/interpolation.pxd
+++ b/skimage/_shared/interpolation.pxd
@@ -1,13 +1,13 @@
 
 cdef inline double nearest_neighbour(double* image, int rows, int cols,
                                      double r, double c, char mode,
-                                     double cval=*)
+                                     double cval)
 
 cdef inline double bilinear_interpolation(double* image, int rows, int cols,
                                           double r, double c, char mode,
-                                          double cval=*)
+                                          double cval)
 
 cdef inline double get_pixel(double* image, int rows, int cols, int r, int c,
-                             char mode, double cval=*)
+                             char mode, double cval)
 
 cdef inline int coord_map(int dim, int coord, char mode)
diff --git a/skimage/_shared/interpolation.pyx b/skimage/_shared/interpolation.pyx
index 83722aba..63f5b70c 100644
--- a/skimage/_shared/interpolation.pyx
+++ b/skimage/_shared/interpolation.pyx
@@ -7,7 +7,7 @@ from libc.math cimport ceil, floor, round
 
 cdef inline double nearest_neighbour(double* image, int rows, int cols,
                                      double r, double c, char mode,
-                                     double cval=0):
+                                     double cval):
     """Nearest neighbour interpolation at a given position in the image.
 
     Parameters
@@ -31,7 +31,7 @@ cdef inline double nearest_neighbour(double* image, int rows, int cols,
 
 cdef inline double bilinear_interpolation(double* image, int rows, int cols,
                                           double r, double c, char mode,
-                                          double cval=0):
+                                          double cval):
     """Bilinear interpolation at a given position in the image.
 
     Parameters
@@ -65,7 +65,7 @@ cdef inline double bilinear_interpolation(double* image, int rows, int cols,
 
 
 cdef inline double get_pixel(double* image, int rows, int cols, int r, int c,
-                             char mode, double cval=0):
+                             char mode, double cval):
     """Get a pixel from the image, taking wrapping mode into consideration.
 
     Parameters
diff --git a/skimage/feature/_texture.pyx b/skimage/feature/_texture.pyx
index 5fb53e90..70a446bb 100644
--- a/skimage/feature/_texture.pyx
+++ b/skimage/feature/_texture.pyx
@@ -132,7 +132,7 @@ def _local_binary_pattern(np.ndarray[double, ndim=2] image,
         for c in range(image.shape[1]):
             for i in range(P):
                 texture[i] = bilinear_interpolation(<double*>image.data,
-                    rows, cols, r + coords[i, 0], c + coords[i, 1], 'C')
+                    rows, cols, r + coords[i, 0], c + coords[i, 1], 'C', 0)
             # signed / thresholded texture
             for i in range(P):
                 if texture[i] - image[r, c] >= 0:
diff --git a/skimage/transform/_warps_cy.pyx b/skimage/transform/_warps_cy.pyx
index 2851a728..5903380e 100644
--- a/skimage/transform/_warps_cy.pyx
+++ b/skimage/transform/_warps_cy.pyx
@@ -111,14 +111,17 @@ def _warp_fast(np.ndarray image, np.ndarray H, output_shape=None, int order=1,
     cdef int rows = img.shape[0]
     cdef int cols = img.shape[1]
 
+    cdef double (*interp_func)(double*, int, int, double, double,
+                               char, double)
+    if order == 0:
+        interp_func = nearest_neighbour
+    elif order == 1:
+        interp_func = bilinear_interpolation
+
     for tfr in range(out_r):
         for tfc in range(out_c):
             _matrix_transform(tfc, tfr, <double*>M.data, &c, &r)
-            if order == 0:
-                out[tfr, tfc] = nearest_neighbour(<double*>img.data, rows,
-                                                  cols, r, c, mode_c, cval)
-            elif order == 1:
-                out[tfr, tfc] = bilinear_interpolation(<double*>img.data, rows,
-                                                       cols, r, c, mode_c, cval)
+            out[tfr, tfc] = interp_func(<double*>img.data, rows, cols, r, c,
+                                        mode_c, cval)
 
     return out