superimposeImage ( grayscaleIm, colormap )

Superimposes a color image (or colormapped image) to a grayscale image for visualization.

Superimposes a color image (or colormapped image) to a grayscale image for visualization of colormaps (density, flow or whatever you are working on) using the grayscale image as a transparency index, for a better visualization.
It works with RGB images (MxNx3 matrices) or with simple grayscale images using a colromap (clasically 'jet', but others can be defined as well).

EXAMPLES:

SUPERIMPOSEIMAGE(im, map) depicts the grayscale image IM fake coloured using the color information in MAP. If MAP is a grayscale image, it uses the 'jet' default colormap. If it is a true color image (a matrix NxMx3), it uses its colour.

SUPERIMPOSEIMAGE(..., 'colormap', cm) uses a user-defined colormap instead of the default 'jet'. E.g. 'bone', 'hot', etc.

SUPERIMPOSEIMAGE(..., 'alpha', alpha) controls the transparency of IM by adjusting its brightness. An alpha > 1 will reduce the transparency of the fake color map, whereas an alpha < 1 will increase the transparency of this maps.

h = SUPERIMPOSEIMAGE(...) returns the handle of the current figure.