im.split method

ImagingSplit function without implementation

PIL/Image.py

@@ -1954,9 +1954,7 @@ class Image(object):
         if self.im.bands == 1:
             ims = [self.copy()]
         else:
-            ims = []
+            ims = map(self._new, self.im.split())
-            for i in range(self.im.bands):
-                ims.append(self._new(self.im.getband(i)))
         return tuple(ims)
 
     def tell(self):

_imaging.c

@@ -1905,6 +1905,32 @@ _putband(ImagingObject* self, PyObject* args)
     return Py_None;
 }
 
+static PyObject*
+_split(ImagingObject* self, PyObject* args)
+{
+    int fails = 0;
+    Py_ssize_t i;
+    PyObject* list;
+    PyObject* imaging_object;
+    Imaging bands[4] = {NULL, NULL, NULL, NULL};
+
+    if ( ! ImagingSplit(self->image, bands))
+        return NULL;
+
+    list = PyTuple_New(self->image->bands);
+    for (i = 0; i < self->image->bands; i++) {
+        imaging_object = PyImagingNew(bands[i]);
+        if ( ! imaging_object)
+            fails += 1;
+        PyTuple_SET_ITEM(list, i, imaging_object);
+    }
+    if (fails) {
+        Py_DECREF(list);
+        list = NULL;
+    }
+    return list;
+}
+
 /* -------------------------------------------------------------------- */
 
 #ifdef WITH_IMAGECHOPS
@@ -2972,6 +2998,7 @@ static struct PyMethodDef methods[] = {
 
     {"getband", (PyCFunction)_getband, 1},
     {"putband", (PyCFunction)_putband, 1},
+    {"split", (PyCFunction)_split, 1},
     {"fillband", (PyCFunction)_fillband, 1},
 
     {"setmode", (PyCFunction)im_setmode, 1},

libImaging/Bands.c

@@ -72,6 +72,19 @@ ImagingGetBand(Imaging imIn, int band)
     return imOut;
 }
 
+
+int
+ImagingSplit(Imaging imIn, Imaging bands[4])
+{
+    int i;
+    for (i = 0; i < imIn->bands; i++) {
+        bands[i] = ImagingNew("L", imIn->xsize, imIn->ysize);
+    }
+
+    return imIn->bands;
+}
+
+
 Imaging
 ImagingPutBand(Imaging imOut, Imaging imIn, int band)
 {

libImaging/Imaging.h

@@ -267,6 +267,7 @@ extern Imaging ImagingFlipTopBottom(Imaging imOut, Imaging imIn);
 extern Imaging ImagingGaussianBlur(Imaging imOut, Imaging imIn, float radius,
     int passes);
 extern Imaging ImagingGetBand(Imaging im, int band);
+extern int ImagingSplit(Imaging im, Imaging bands[4]);
 extern int ImagingGetBBox(Imaging im, int bbox[4]);
 typedef struct { int x, y; INT32 count; INT32 pixel; } ImagingColorItem;
 extern ImagingColorItem* ImagingGetColors(Imaging im, int maxcolors,