PRO image_bp_interp, imdata, bpmdata, status

; Description: This module interpolates over the bad pixels in the image array "imdata", where
;              the bad pixels are flagged in the bad pixel mask "bpmdata". For each bad pixel
;              in "imdata", the module finds the smallest square centred on the bad pixel that 
;              contains at least one good pixel, and then, after growing the square by one
;              pixel in each direction, calculates the mean of all good image pixel values 
;              within the square. This mean value is taken as the replacement pixel value for
;              the current bad pixel. When all bad pixels have been interpolated over, the
;              module sets the value of "status" to "1".
;
; Input Parameters:
;   
;   imdata - FLOAT/DOUBLE ARRAY - An image array for which bad pixels are to be interpolated.
;   bpmdata - BYTE/INTEGER/LONG ARRAY - A bad pixel mask array of the same size as "imdata" 
;                                       which flags bad pixels with a value of "0" and good 
;                                       pixels with a value of "1". If this array does not 
;                                       have the same dimensions as "imdata", then the module 
;                                       does no interpolation on "imdata".
;
; Output Parameters:
;
;   imdata - FLOAT/DOUBLE ARRAY - The image array after interpolating over bad pixels.
;   status - INTEGER - If the bad pixels in "imdata" were interpolated over successfully, then
;                      "status" is set to "1". Otherwise, if "imdata" is not an image, or
;                      "bpmdata" does not have the same dimensions as "imdata", then "status"
;                      is set to "0".
;
; Author: Dan Bramich (dan.bramich@hotmail.co.uk)
;
; History:
;
;   14/08/2008 - Module created (dmb)  

;Check that "imdata" is an image of the correct number type

;Check that "bpmdata" is an image of the correct number type and dimensions

;Determine the total number of good pixels in the image

;If there are no bad pixels in the image, then return with the parameter "status" equal to "1",
;and without doing anything

;If there are no good pixels in the image, then return with the parameter "status" equal to "0",
;and without doing anything

;For each pixel in the input image

    ;If the current pixel is a bad pixel

      ;Find the smallest square centred on the bad pixel that contains at least one good pixel

        ;Define a square

        ;Determine the number of good pixels in the square

        ;Increment the square size

      ;Grow the square by one pixel in each direction on each side

      ;Interpolate the bad pixel value as the mean of the good pixel values within the chosen square

;Set the "status" parameter to "1"