def init_objects(stream,frames,currsum,denom,seglen,cutoff,frames_offset,SHAPE,size_h,size_bins,fol_h,fol_bins,transform='',outline_engine='homebrew'):
    hsl = seglen/2
    min_arc_score = (2*max(size_h))+max(fol_h) #score of a "perfect" object arc of length 2
    ols = []
    last_frames = []
    ols_offset = frames_offset + hsl
    c = itertools.cycle(['|','/','-','\\'])
    t = time.time()
    print >> sys.stderr, 'analyze %s frames:' % seglen
    for i in xrange(seglen):
        last_frames.append(frames[0])
	frames_offset += 1
	mm = vidtools.shift_frames_return_diff(stream,frames,currsum,denom,seglen,transform=transform)
        if outline_engine == 'homebrew':
            ol = vidtools.chain_outlines_from_mask(mm>cutoff,preshrink=1,debug=False,return_termini=False,order_points=True,sort_outlines=False) #order_points should be True
        elif outline_engine == 'shapely':
            ol = vidtools.chain_outlines_from_mask_shapely(mm>cutoff,preshrink=1)
        else:
            print >> sys.stderr, 'outline_engine must be one of %s' % (['homebrew','shapely'])
            raise ValueError
	ols.append(ol)
	print >> sys.stderr, '\r%s %s ' % (i,c.next()),

    print >> sys.stderr, 'done in', str(datetime.timedelta(seconds=int(time.time() - t)))
    objs = {}
    splits = defaultdict(list)
    objs_sizes = {}
    objs_fols = {}
    
    print >> sys.stderr, '\nperform initial object arc tracking on %s frames' % len(ols)
    #one round of object tracking; assumes next object tracking call will start a single frame from now
    to_retire_objs, to_retire_objs_sizes, to_retire_objs_fols = vidtools.find_objs_progressive(ols, ols_offset, ols_offset, ols_offset+1, SHAPE, objs, splits, \
                                                                                               objs_sizes, objs_fols, size_h,size_bins,fol_h,fol_bins)

    prelast_avg = vidtools.average_frames(last_frames[hsl:])
    prelast_mm = vidtools.mousemask_from_object_arcs(frames_offset-hsl,frames_offset,min_arc_score,ols,ols_offset, \
                                                     Util.merge_dictlist([objs,to_retire_objs]), \
                                                     Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                     Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                     size_h, size_bins, fol_h, fol_bins,SHAPE) 

    print >> sys.stderr, 'object initialization complete in', str(datetime.timedelta(seconds=int(time.time() - t)))
    return ols,ols_offset,frames_offset,objs,splits,objs_sizes,objs_fols,prelast_avg,prelast_mm,to_retire_objs,to_retire_objs_sizes,to_retire_objs_fols
def init_objects(stream,
                 frames,
                 currsum,
                 denom,
                 seglen,
                 cutoff,
                 frames_offset,
                 SHAPE,
                 size_h,
                 size_bins,
                 fol_h,
                 fol_bins,
                 transform='',
                 outline_engine='homebrew'):
    hsl = seglen / 2
    min_arc_score = (2 * max(size_h)) + max(
        fol_h)  #score of a "perfect" object arc of length 2
    ols = []
    last_frames = []
    ols_offset = frames_offset + hsl
    c = itertools.cycle(['|', '/', '-', '\\'])
    t = time.time()
    print >> sys.stderr, 'analyze %s frames:' % seglen
    for i in xrange(seglen):
        last_frames.append(frames[0])
        frames_offset += 1
        mm = vidtools.shift_frames_return_diff(stream,
                                               frames,
                                               currsum,
                                               denom,
                                               seglen,
                                               transform=transform)
        if outline_engine == 'homebrew':
            ol = vidtools.chain_outlines_from_mask(
                mm > cutoff,
                preshrink=1,
                debug=False,
                return_termini=False,
                order_points=True,
                sort_outlines=False)  #order_points should be True
        elif outline_engine == 'shapely':
            ol = vidtools.chain_outlines_from_mask_shapely(mm > cutoff,
                                                           preshrink=1)
        else:
            print >> sys.stderr, 'outline_engine must be one of %s' % (
                ['homebrew', 'shapely'])
            raise ValueError
        ols.append(ol)
        print >> sys.stderr, '\r%s %s ' % (i, c.next()),

    print >> sys.stderr, 'done in', str(
        datetime.timedelta(seconds=int(time.time() - t)))
    objs = {}
    splits = defaultdict(list)
    objs_sizes = {}
    objs_fols = {}

    print >> sys.stderr, '\nperform initial object arc tracking on %s frames' % len(
        ols)
    #one round of object tracking; assumes next object tracking call will start a single frame from now
    to_retire_objs, to_retire_objs_sizes, to_retire_objs_fols = vidtools.find_objs_progressive(ols, ols_offset, ols_offset, ols_offset+1, SHAPE, objs, splits, \
                                                                                               objs_sizes, objs_fols, size_h,size_bins,fol_h,fol_bins)

    prelast_avg = vidtools.average_frames(last_frames[hsl:])
    prelast_mm = vidtools.mousemask_from_object_arcs(frames_offset-hsl,frames_offset,min_arc_score,ols,ols_offset, \
                                                     Util.merge_dictlist([objs,to_retire_objs]), \
                                                     Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                     Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                     size_h, size_bins, fol_h, fol_bins,SHAPE)

    print >> sys.stderr, 'object initialization complete in', str(
        datetime.timedelta(seconds=int(time.time() - t)))
    return ols, ols_offset, frames_offset, objs, splits, objs_sizes, objs_fols, prelast_avg, prelast_mm, to_retire_objs, to_retire_objs_sizes, to_retire_objs_fols
            last_newactols_file = '%07d-%07d-newact_ols.list' % (frames_offset,frames_offset+hsl)
            last_ground_file = '%07d-%07d-ground.list' % (frames_offset,frames_offset+hsl)
            last_digdiff_file = '%07d-%07d-digdiff.mat' % (frames_offset,frames_offset+hsl)

        t = time.time()
        #eventually, choice to reload previous analysis goes here
        last_frames = []
        while len(last_frames) < hsl:
            ols_offset, frames_offset = advance_analysis(ols,ols_offset,objs,splits,objs_sizes,objs_fols, \
                                                         to_retire_objs,to_retire_objs_sizes,to_retire_objs_fols, \
                                                         last_frames,stream,frames,currsum,denom,opts.seglen,cutoff,frames_offset, \
                                                         SHAPE,size_h,size_bins,fol_h,fol_bins,transform=opts.transform,outline_engine=opts.outline_engine)
        last_avg = vidtools.average_frames(last_frames)
        last_mm = vidtools.mousemask_from_object_arcs(frames_offset-len(last_frames),frames_offset,min_arc_score,ols,ols_offset, \
                                                        Util.merge_dictlist([objs,to_retire_objs]), \
                                                        Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                        Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                        size_h, size_bins, fol_h, fol_bins,SHAPE)
        this_avg = vidtools.average_frames(frames[:hsl])
        this_mm = vidtools.mousemask_from_object_arcs(frames_offset,frames_offset+hsl,min_arc_score,ols,ols_offset, \
                                                        Util.merge_dictlist([objs,to_retire_objs]), \
                                                        Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                        Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                        size_h, size_bins, fol_h, fol_bins,SHAPE)
        prelast_masked = prelast_avg.copy()
        prelast_masked[prelast_mm] = numpy.mean(prelast_avg[:50,:50])
        last_masked = last_avg.copy()
        last_masked[last_mm] = numpy.mean(last_avg[:50,:50])
        this_masked = this_avg.copy()
        this_masked[this_mm] = numpy.mean(this_avg[:50,:50])
                                                          frames_offset + hsl)
            last_digdiff_file = '%07d-%07d-digdiff.mat' % (frames_offset,
                                                           frames_offset + hsl)

        t = time.time()
        #eventually, choice to reload previous analysis goes here
        last_frames = []
        while len(last_frames) < hsl:
            ols_offset, frames_offset = advance_analysis(ols,ols_offset,objs,splits,objs_sizes,objs_fols, \
                                                         to_retire_objs,to_retire_objs_sizes,to_retire_objs_fols, \
                                                         last_frames,stream,frames,currsum,denom,opts.seglen,cutoff,frames_offset, \
                                                         SHAPE,size_h,size_bins,fol_h,fol_bins,transform=opts.transform,outline_engine=opts.outline_engine)
        last_avg = vidtools.average_frames(last_frames)
        last_mm = vidtools.mousemask_from_object_arcs(frames_offset-len(last_frames),frames_offset,min_arc_score,ols,ols_offset, \
                                                        Util.merge_dictlist([objs,to_retire_objs]), \
                                                        Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                        Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                        size_h, size_bins, fol_h, fol_bins,SHAPE)
        this_avg = vidtools.average_frames(frames[:hsl])
        this_mm = vidtools.mousemask_from_object_arcs(frames_offset,frames_offset+hsl,min_arc_score,ols,ols_offset, \
                                                        Util.merge_dictlist([objs,to_retire_objs]), \
                                                        Util.merge_dictlist([objs_sizes,to_retire_objs_sizes]), \
                                                        Util.merge_dictlist([objs_fols,to_retire_objs_fols]), \
                                                        size_h, size_bins, fol_h, fol_bins,SHAPE)
        prelast_masked = prelast_avg.copy()
        prelast_masked[prelast_mm] = numpy.mean(prelast_avg[:50, :50])
        last_masked = last_avg.copy()
        last_masked[last_mm] = numpy.mean(last_avg[:50, :50])
        this_masked = this_avg.copy()
        this_masked[this_mm] = numpy.mean(this_avg[:50, :50])