Added support for PIL images in imshow(), image.py

astraw · astraw · commit 694f8bd4ef0b · 2004-10-19T17:50:03.000Z
svn path=/trunk/matplotlib/; revision=603
diff --git a/CHANGELOG b/CHANGELOG
@@ -1,6 +1,8 @@
 New entries should be added at the top
 
 ==============================================================
+2004-10-19 Added support for PIL images in imshow(), image.py - ADS
+
 2004-10-19 Re-worked exception handling in _image.py and _transforms.py
            to avoid masking problems with shared libraries.  - JTM
 
diff --git a/examples/data/lena.jpg b/examples/data/lena.jpg
diff --git a/examples/image_demo3.py b/examples/image_demo3.py
@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+from matplotlib.matlab import *
+import Image
+
+lena = Image.open('data/lena.jpg')
+dpi = rcParams['figure.dpi']
+figsize = lena.size[0]/dpi, lena.size[1]/dpi
+
+figure(figsize=figsize)
+
+im = imshow(lena, origin='lower', aspect='preserve')
+
+#savefig('image_demo3')
+show()
+
diff --git a/lib/matplotlib/axes.py b/lib/matplotlib/axes.py
@@ -1251,13 +1251,15 @@ def imshow(self, X,
 IMSHOW(X, cmap=None, norm=None, aspect=None, interpolation=None,
        alpha=1.0, vmin=None, vmax=None, origin=None, extent=None)
                
-IMSHOW(X) - plot image in array X to current axes, resampling to scale
-            to axes size
+IMSHOW(X) - plot image X to current axes, resampling to scale to axes
+            size (X may be numarray/Numeric array or PIL image)
 
 IMSHOW(X, **kwargs) - Use keyword args to control image scaling,
 colormapping etc. See below for details
 
-Display the image in float array X; X can have the following shapes
+
+Display the image in X to current axes.  X may be a float array or a
+PIL image. If X is a float array, X can have the following shapes
 
     MxN    : luminance (grayscale)
 
@@ -1270,7 +1272,7 @@ def imshow(self, X,
 The following kwargs are allowed: 
 
   * cmap is a cm colormap instance, eg cm.jet.  If None, default to rc
-    image.cmap value
+    image.cmap value (Ignored when X has RGB(A) information)
 
   * aspect is one of: free or preserve.  if None, default to rc
     image.aspect value
@@ -1280,7 +1282,8 @@ def imshow(self, X,
     If None, default to rc image.interpolation
 
   * norm is a matplotlib.colors.normalize instance; default is
-    normalization().  This scales luminance -> 0-1. 
+    normalization().  This scales luminance -> 0-1 (Ignored when X is
+    PIL image).
 
   * vmin and vmax are used to scale a luminance image to 0-1.  If
     either is None, the min and max of the luminance values will be
@@ -1308,8 +1311,7 @@ def imshow(self, X,
         if norm is None:            
             im.set_clim(vmin, vmax)
 
-
-        im.set_array(X)
+        im.set_data(X)
         im.set_alpha(alpha)
 
         xmin, xmax, ymin, ymax = im.get_extent()
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -9,6 +9,7 @@
 from artist import Artist
 from colors import normalize, colorConverter
 import cm
+import numerix
 from numerix import arange
 import _image
 
@@ -166,10 +167,16 @@ def write_png(self, fname):
         im.write_png(fname)
         
 
-    def set_array(self, A):
-        'Set the image array from numeric/numarray A'
-        cm.ScalarMappable.set_array(self, A)
+    def set_data(self, A):
+        'Set the image array from numeric/numarray/PIL Image A'
+        # check if data is PIL Image without importing Image
+        if hasattr(A,'getpixel'): X = pil_to_array(A)
+        else: X = A # assume array
+        cm.ScalarMappable.set_array(self, X)
 
+    def set_array(self, A):
+        'retained for backwards compatibility - use set_data instead'
+        self.set_data(A)
 
     def get_aspect(self):
         """
@@ -316,3 +323,26 @@ def imread(fname):
     return handler(fname)
 
     
+
+def pil_to_array( pilImage ):
+    if pilImage.mode == 'P': # convert from paletted
+        im = pilImage.convert('RGBX')
+    else:
+        im = pilImage
+
+    # There's a whole lotta conversion and copying going on
+    # here -- could it be optimized?
+
+    if im.mode in ('RGBA','RGBX'): n_channels = 4
+    elif im.mode == 'RGB': n_channels = 3
+    elif im.mode == 'L': n_channels = 1
+    else: raise RuntimeError('Unknown image mode')
+
+    x_str = im.tostring('raw',im.mode,0,-1)
+    x = numerix.fromstring(x_str,numerix.UInt8)
+    if n_channels == 1:
+        x.shape = im.size[1], im.size[0]
+    else:
+        x.shape = im.size[1], im.size[0], n_channels
+    x=x.astype(numerix.Float32)/255.0
+    return x
