pgfPlots color plots

Question

So I would like to present data using a color plot subdivided into squares. For a large data set, it is easy to use a 3D plot with surf, however when there is not so much information, this does not work so nicely.

Take for example:

\begin{tikzpicture}
\begin{axis}[view={0}{90}]
    \addplot3 [surf]
        coordinates {
            (0, 0, 1) (1, 0, 9) (2, 0, 3)

            (0, 1, 4) (1, 1, 5) (2, 1, 6)

            (0, 2, 7) (1, 2, 2) (2, 2, 9)};
\end{axis}
\end{tikzpicture}

I have 9 data points, and 4 squares are displayed which reduces greatly the amount of data displayed.

An alternative I thought of was to use square marks

\begin{tikzpicture}
\begin{axis}[view={0}{90}, enlargelimits=.3]
    \addplot3 [scatter, mark=square*, mark size=24pt]
        coordinates {
            (0, 0, 1) (1, 0, 9) (2, 0, 3)

            (0, 1, 4) (1, 1, 5) (2, 1, 6)

            (0, 2, 7) (1, 2, 2) (2, 2, 9)};
\end{axis}
\end{tikzpicture}

but the result is less than pleasing, and would require a lot of mucking around with the size of the marks.

The only "alternative" is to use interpolation so that at the vertices the correct color is displayed

\begin{tikzpicture}
\begin{axis}[view={0}{90}]
    \addplot3 [surf, shader=interp]
        coordinates {
            (0, 0, 1) (1, 0, 9) (2, 0, 3)

            (0, 1, 4) (1, 1, 5) (2, 1, 6)

            (0, 2, 7) (1, 2, 2) (2, 2, 9)};
\end{axis}
\end{tikzpicture}

\begin{tikzpicture}
\begin{axis}[view={0}{90}]
    \addplot3 [surf, shader=interp, patch type=bilinear]
        coordinates {
            (0, 0, 1) (1, 0, 9) (2, 0, 3)

            (0, 1, 4) (1, 1, 5) (2, 1, 6)

            (0, 2, 7) (1, 2, 2) (2, 2, 9)};
\end{axis}
\end{tikzpicture}

But without the correct interpolation, looks ugly. Besides, it doesn't exactly fix the problem of displaying only 9 data points.

So for small data sets, is there a way of plotting exactly the same number of squares as required?