from matplotlib.pyplot import figure, show, cm
from numpy import arange
from numpy.random import rand

def gbar(ax, x, y, width=0.5, bottom=0):
   X = [[.6, .6],[.7,.7]]
   for left,top in zip(x, y):
       right = left+width
       ax.imshow(X, interpolation='bicubic', cmap=cm.Blues,
                 extent=(left, right, bottom, top), alpha=1)

fig = figure()

xmin, xmax = xlim = 0,10
ymin, ymax = ylim = 0,1
ax = fig.add_subplot(111, xlim=xlim, ylim=ylim,
                    autoscale_on=False)
X = [[.6, .6],[.7,.7]]

ax.imshow(X, interpolation='bicubic', cmap=cm.copper,
         extent=(xmin, xmax, ymin, ymax), alpha=1)

N = 10
x = arange(N)+0.25
y = rand(N)
gbar(ax, x, y, width=0.7)
ax.set_aspect('normal')
show()