How do you read a .bmp file?

[Robert A. Macy]

I have a simple .bmp file, actually in two forms.

Both are 512 by 512 pixels, one is RGB 24 bit format (?)
and the same gray image is in single ?? format.  Of course
the single format is 1/3 the size of the RGB image.

Short of trashing the header, reading the file byte by
byte, is there some easy way to read in the pixel values
for a 512 by 512 image?

I'm using Win98 to run octave 2.1.50a [I have to use 50a to
keep all those plotting functions.]

Robert