Need help to optimize for speed

[From way of Hamid <kohen(at)jpl.nasa.gov>]

Hi,

I have this for loop that searches for a particular pattern (roi).
This search takes for ever.
Does anyone knows how to optimize this code for speed.

Any suggestions ?

Thanks.

Hamid


size1 = size(bscl) ;;; is  1000 x 1000
size2 = size(roi) ;;;;   is about 50 x 50


print, 'Size of bscl is ', size1
print, 'Size of roi is ', size2


a = reform(bscl,size1(4))
b = reform(roi,size2(4))
nmatch = 0

print, 'searching'
for column = 0, size1(1) -1 do begin
 for row = 0, size1(2) -1 do begin  ; num
     print,'row and col', row, col
  sample = reform(extrac(bscl,column,row,size2(1),size2(2)),size2(4))
  IF (array_match(sample,b)) THEN begin
           nmatch = nmatch +1 ;;; length has to match
           print, '-------------------------'
           print,'We have a match at row of', row, ' and colof', column
           print, 'The centriod is at ', row + size2(1)/2 , column +
size2(2)/2
           print, extrac(bscl,column,row,size2(1),size2(2))
           print, '-------------------------'
           print, b
          end
 end
end
print, 'Number of matches', nmatch
print, ' success '