I'm guessing you mean something like : file: 256, 0,0 ,12,25,89.. val_n.. etc...EOF (for a 16X16 image) then the easiest way (C#) is to read the values into program then create a bitmap and read the values into pixels as:
Bitmap.SetPixel(X,Y, Color.FromRGB(val_n,val_n,val_n));
iterate and save bitmap done.