Want to read pixel values of a image

hi to all
i am new to this forum but i know some max scripting,
but i have a problem in reading the pixel value of a image in 32 bit float format
I had used the "getpixels" function also but it doesn't give me the full range.
Is there any other way to try on

any help will be appreciated

thanks in advance

p.s. i am calling the 32 bit image in max by using "Select bitmap function" to a veriable