[Matplotlib-users] Facecolor not changing for web service?

[Jeffrey M. <jm...@gm...>]

I'm using Flask to output graphs to a web service, and when I move
from a standalone script to the web service I'm getting weird
behavior.

In gantt_test.py, I do this:

from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure
[...]

canvas = FigureCanvas(fig)
fig.savefig("gantt.png")


And it looks nice.

In the web service, the only difference is:

    canvas = FigureCanvas(fig)

    x = StringIO()

    canvas.print_png(x, facecolor="w", edgecolor="w", dpi=100)

And it has a grey background, weirder margins, and seems to be stuck at dpi=80.

What am I missing? The version of python & matplotlib are the same
between machines.  One is Windows 7, the other 2K3.

-Jeff