added simple watermark examples

jdh2358 · jdh2358 · commit 4d11bf46002f · 2008-06-24T18:58:41.000Z
svn path=/trunk/matplotlib/; revision=5669
diff --git a/examples/api/watermark_image.py b/examples/api/watermark_image.py
@@ -0,0 +1,22 @@
+"""
+Use a PNG file as a watermark
+"""
+import numpy as np
+import matplotlib
+matplotlib.use('Agg')
+
+import matplotlib.image as image
+import matplotlib.pyplot as plt
+
+im = image.imread('../data/logo2.png')
+im[:,:,-1] = 0.5  # set the alpha channel
+
+fig = plt.figure()
+ax = fig.add_subplot(111)
+
+ax.plot(np.random.rand(20), '-o', ms=20, lw=2, alpha=0.7, mfc='orange')
+ax.grid()
+fig.figimage(im, 10, 10)
+
+fig.savefig('watermarked', transparent=True)
+
diff --git a/examples/api/watermark_text.py b/examples/api/watermark_text.py
@@ -0,0 +1,34 @@
+"""
+Use a PNG file as a watermark
+"""
+import numpy as np
+import matplotlib
+matplotlib.use('Agg')
+
+import matplotlib.mathtext as mathtext
+import matplotlib.pyplot as plt
+import matplotlib
+matplotlib.rc('image', origin='upper')
+
+dpi = 100   # save dpi
+w, h = 8, 6 # inches
+
+parser = mathtext.MathTextParser("Bitmap")
+
+rgba, depth1 = parser.to_rgba(r'Property of MPL', color='gray',
+                              fontsize=30, dpi=200)
+rgba[:,:,-1] *= 0.5
+fig = plt.figure(figsize=(w,h))
+
+ax = fig.add_subplot(111)
+ax.plot(np.random.rand(20), '-o', ms=20, lw=2, alpha=0.7, mfc='orange')
+ax.grid()
+
+imh, imw, tmp = rgba.shape
+
+# position image at bottom right
+fig.figimage(rgba.astype(float)/255., w*dpi-imw, 0)
+
+
+fig.savefig('watermarked_text', transparent=True, dpi=dpi)
+
diff --git a/examples/data/logo2.png b/examples/data/logo2.png
