clustering example for flickr

code/image_data/cluster_flickr.py

@@ -0,0 +1,89 @@
+#!/usr/bin/env python
+
+import scipy as sp
+import scipy.cluster.vq as spvq
+import matplotlib.image as mpimg
+import matplotlib.pyplot as plt
+import glob
+from math import sqrt, ceil
+
+from imgtools import *
+
+def plot_montage(images, ndx, ncol=None):
+
+    N = len(ndx)
+
+    if not ncol:
+        ncol = int(sqrt(N))
+
+    f = plt.figure(dpi=100)
+
+    row = 0
+    col = 0
+    for i in range(N):
+
+        I = sp.array(images[ndx[i]], dtype='float32')
+        I = I / I.max()
+
+        height = I.shape[0]
+        width = I.shape[1]
+        ax = plt.figimage(I, xo=width*col, yo=height*row, origin='lower')
+
+        col += 1
+        if col % ncol == 0:
+            row += 1
+            col = 0
+
+    f.set_figheight(row*height/100)
+    f.set_figwidth(ncol*width/100)
+
+    return f
+
+if __name__=='__main__':
+
+    directory = 'flickr_vivid'
+    bins = 10
+    K = 3
+
+    pattern = '%s/*.jpg' % directory
+    print pattern
+    fnames = glob.glob(pattern)
+
+    N = len(fnames)
+    print "reading %d image files from %s" % (N, directory)
+    X = sp.zeros( (0,3*bins) )
+    images = []
+    for i, fname in enumerate(fnames):
+        try:
+            I = mpimg.imread(fname)
+
+            X = sp.vstack( (X, rgb_features(I, bins)) )
+            images.append(I)
+
+        except IOError:
+            print "error reading" , fname
+
+        if i % int(N/10) == 0:
+            print "%d/%d images read" % (i,N)
+
+
+    X = spvq.whiten(X)
+
+    sp.random.seed(20110201)
+
+    centers, err = spvq.kmeans(X, K)
+    print err
+
+    assignments, err = spvq.vq(X, centers)
+
+    for k in range(K):
+        ndx = sp.where(assignments == k)
+
+        f = plot_montage(images, ndx[0])
+
+        fname = '%s_cluster_%d.png' % (directory, k)
+        print "saving" , fname
+
+        plt.savefig(fname)
+
+        del(f)

code/image_data/download_flickr.py

@@ -20,9 +20,9 @@ def photo_url(photo, size='s'):
         tags = sys.argv[1]
         n = int(sys.argv[2])
     else:
-        # default to picture of chairs
+        # default to 500 pictures tagged with 'vivid'
         tags = 'vivid'
-        n = 100
+        n = 500
 
     # grab the top-n most interesting photos tagged with 'tags'
     query = '''select * from flickr.photos.search(%d) where

code/image_data/imgtools.py

@@ -26,6 +26,7 @@ def rgb_hist(I, ax, bins=256):
     plt.axis('tight')
     ax.set_aspect(1./ax.get_data_ratio())
 
+
 def imshow_hist(I, bins=256):
 
     f = plt.figure()
@@ -40,6 +41,22 @@ def imshow_hist(I, bins=256):
 
     return f
 
+
+def rgb_features(I, bins=10):
+
+    x = sp.array([])
+
+    # run over red, green, and blue channels
+    channels = ('r','g','b')
+    for i, color in enumerate(channels):
+        # get count pixel intensities for this channel
+        counts, bins = sp.histogram(I[:,:,i].flatten(), bins=bins)
+
+        x = sp.concatenate( (x, counts) )
+
+    return x
+
+
 if __name__=='__main__':
 
     if len(sys.argv) == 3:
@@ -65,4 +82,6 @@ def imshow_hist(I, bins=256):
 
     # save figure
     base, ext = os.path.splitext(fname)
-    plt.savefig('%s_%d.png' % (base, bins))
+    fname = '%s_%d.png' % (base, bins)
+    print "saving" , fname
+    plt.savefig(fname)