apply_image_threshold.pro

;----------------------------------------------------------------------------------------
pro apply_image_threshold, raw_arr, noise_threshold, zero_negatives = zero_negatives
;----------------------------------------------------------------------------------------
; apply a treshold to an image
;--(input)-------------------------------------------------------------------------------
; ***  raw_arr           = the array to apply the threshold to. Raw arr is outputted with
; ***                      the threshold applied
; ***  noise_threshold   = the noise threshold to apply in the same units as raw_arr
;--(keywords)----------------------------------------------------------------------------
; ***  zero_negatives    = mask all negative values regardless of noise_threshold
;-----------------------------------------------------------------------------------------
  compile_opt idl2, strictarrsubs

  if n_elements(noise_threshold) eq 1 then begin ; zero values below the noise threshold
    if noise_threshold lt 0.0e0 then f_error, 'iter_image_postprocess: a negative noise_threshold has been supplied for: ' + raw_image_file + '. a positive (or zero) threshold must be suplied'
    zero_list = where(raw_arr lt noise_threshold, zero_count)
    if zero_count ne 0 then raw_arr[zero_list] = 0.0
  endif

  if n_elements(zero_negatives) eq 1 && zero_negatives eq 1 then begin ; zero negative values
    zero_list = where(raw_arr lt 0.0e0, zero_count)
    if zero_count ne 0 then raw_arr[zero_list] = 0.0
  endif



end