LA, PA image modes

PIL/PyAccess.py

@@ -86,8 +86,24 @@ class PyAccess(object):
             raise ValueError('pixel location out of range')
         return xy
 
+class _PyAccess32_2(PyAccess):
+    """ PA, LA, stored in first and last bytes of a 32 bit word """
+    def _post_init(self, *args, **kwargs):
+        self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
+        
+    def get_pixel(self, x,y):
+        pixel = self.pixels[y][x]
+        return (pixel.r, pixel.a)
 
+    def set_pixel(self, x,y, color):
+        pixel = self.pixels[y][x]
+        # tuple
+        pixel.r = min(color[0],255)
+        pixel.a = min(color[1],255)
+        
 class _PyAccess32_3(PyAccess):
+    """ RGB and friends, stored in the first three bytes of a 32 bit word """
+    
     def _post_init(self, *args, **kwargs):
         self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
         
@@ -103,6 +119,7 @@ class _PyAccess32_3(PyAccess):
         pixel.b = min(color[2],255)
 
 class _PyAccess32_4(PyAccess):
+    """ RGBA etc, all 4 bytes of a 32 bit word """
     def _post_init(self, *args, **kwargs):
         self.pixels = ffi.cast("struct Pixel_RGBA **", self.image32)
         
@@ -120,6 +137,7 @@ class _PyAccess32_4(PyAccess):
 
             
 class _PyAccess8(PyAccess):
+    """ 1, L, P, 8 bit images stored as uint8 """
     def _post_init(self, *args, **kwargs):
         self.pixels = self.image8
         
@@ -138,6 +156,8 @@ class _PyAccess8(PyAccess):
 mode_map = {'1': _PyAccess8,
             'L': _PyAccess8,
             'P': _PyAccess8,
+            'LA': _PyAccess32_2,
+            'PA': _PyAccess32_2,
             'RGB': _PyAccess32_3,
             'LAB': _PyAccess32_3,
             'YCbCr': _PyAccess32_3,

Tests/test_cffi.py

@@ -37,8 +37,10 @@ def test_get_vs_c():
     _test_get_access(lena('RGB'))
     _test_get_access(lena('RGBA'))
     _test_get_access(lena('L'))
+    _test_get_access(lena('LA'))
     _test_get_access(lena('1'))
     _test_get_access(lena('P'))
+    #_test_get_access(lena('PA')) # PA   -- how do I make a PA image???
 
 
 def _test_set_access(im, color):
@@ -58,7 +60,9 @@ def test_set_vs_c():
     _test_set_access(lena('RGB'), (255, 128,0) )
     _test_set_access(lena('RGBA'), (255, 192, 128, 0))
     _test_set_access(lena('L'), 128)
+    _test_set_access(lena('LA'), (128,128))
     _test_set_access(lena('1'), 255)
     _test_set_access(lena('P') , 128)
+    ##_test_set_access(i, (128,128)) #PA  -- undone how to make