[Radiance-general] converting floating point to RADIANCE HDR format

[Katja Doerschner]

Hi,
 I have an array of M x N x 3 (as in RGB) single precision floating 
point numbers,
 and would like to save it as a RADIANCE hdr format which uses 32 bits 
per pixel,
 i.e. R G B have each 8 bits and they all share one exponent which is 
also 8 bits.( If I understand this correctly)
 I would like to know how exactly the format works. How does one pick 
the common exponent? How does one deal with extrem intensity values in 
the different color channels? 
I am writing the program in C.
 Can anyone help?

THANKS