This is for IE7 to hold div open
Each element in the image's CData is used to color a rectilinear patch. The data contains the row of the colormap used to color the patch.
pcolor is a surface plot and its CData is scaled into the colormap. Each element of the CData corresponds to a vertex in the plot. Therefore, the number of rectangles in pcolor is always one row and column smaller than the actual data.