Converting r g b triplets into a single physical quantity

I used

tst1=imread('tst.png'); 
[x, map]= rgb2ind(tst1,55); 
x2=im2double(x,'indexed');

Thus each element in the matrix x2 contains a value from 0 to 55 which represents the row in the 55 x 3 matrix map and contains the r,g,b triplet value.

My question is how do I now convert x2 into a matrix where the rgb triplet values will represent pressure values ranging from 1500 to 7000 psi? Can't use imadjust as I don't have license for that. Any other workarounds?

Thanks.

Souvik

[Gayatri Menon]

How will the pressure value related to x2 matrix?Are you looking for a linear mapping between x2 and the pressure value?

Answer 1

[Image Analyst]

Doesn't tst1 already have that info? Just do

pressureImage = (7000-1500) * mat2gray(tst1) + 1500;

By the way, if you're using im2double() successfully, then you have the Image Processing Toolbox and could use imadjust() if you want.