views.py

# Copyright 2014 NeuroData (http://neurodata.io)
# 
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Create your views here.
import numpy as np
import re
from contextlib import closing
import cStringIO
import django.http
from PIL import Image
import base64
from ndproj.ndproject import NDProject
from spdb.spatialdb import SpatialDB
from ndlib.ndctypelib import recolor_ctype
from ndlib.ndtype import DTYPE_uint8, DTYPE_uint16, ANNOTATION_CHANNELS 
from ndlib.windowcutout import windowCutout 

import json

#import synaptogram

"""RESTful interface to a synaptogram.  Rerturn a png file."""

def synaptogram_view (request, webargs):
  """Render a synaptogram as a Web page"""

  try:

    m = re.match ("(?P<token>[\d\w]+)/(?P<channels>[\d\w,]+)/(xy|xz|yz)/(?P<resolution>[\d]+)/(?P<xlow>[\d]+),(?P<xhigh>[\d]+)/(?P<ylow>[\d]+),(?P<yhigh>[\d]+)/(?P<zlow>[\d]+),(?P<zhigh>[\d]+)/", webargs)
    md = m.groupdict()

    token = md['token']
    chanstr = md['channels']
    resolution = int(md['resolution'])
    xlow = int(md['xlow'])
    xhigh = int(md['xhigh'])
    ylow = int(md['ylow'])
    yhigh = int(md['yhigh'])
    zlow = int(md['zlow'])
    zhigh = int(md['zhigh'])

    channels = chanstr.split(',')

    # get the project 
    proj = NDProject.fromTokenName(token)
    
    # and the database and then call the db function
    with closing (SpatialDB(proj)) as db:

      # convert to cutout coordinates
      (xoffset, yoffset, zoffset) = proj.datasetcfg.get_offset(resolution)
      (xlow, xhigh) = (xlow-xoffset, xhigh-xoffset)
      (ylow, yhigh) = (ylow-yoffset, yhigh-yoffset)
      (zlow, zhigh) = (zlow-zoffset, zhigh-zoffset)

      corner = [ xlow, ylow, zlow ]
      dim = [ xhigh-xlow, yhigh-ylow, zhigh-zlow ]

      outputdict = {}

      # get the data region for each channel 
      for chan in channels:
        # data type on a per channel basis
        ch = proj.getChannelObj(chan)
        try: 
          cb = db.cutout ( ch, corner, dim, resolution )
          # apply window for 16 bit projects 
          if ch.getDataType() in DTYPE_uint16:
            [startwindow, endwindow] = window_range = ch.window_range
            if (endwindow != 0):
              cb.data = np.uint8(windowCutout(cb.data, window_range))
          
          outputdict[chan] = []
          for zslice in cb.data:
          
            if ch.getChannelType() in ANNOTATION_CHANNELS:
              # parse annotation project
              imagemap = np.zeros( [ dim[1], dim[0] ], dtype=np.uint32 )
              imagemap = recolor_ctype( zslice, imagemap )
              img = Image.frombuffer( 'RGBA', (dim[0],dim[1]), imagemap, 'raw', 'RGBA', 0, 1 )

            else: 
              # parse image project  
              img = Image.frombuffer( 'L', (dim[0], dim[1]), zslice.flatten(), 'raw', 'L', 0, 1 )
            
            # convert to base64
            fileobj = cStringIO.StringIO()
            img.save(fileobj, "PNG")
            fileobj.seek(0)
            encodedimg = base64.b64encode(fileobj.read())
            outputdict[chan].append(encodedimg)

          #outputdict[chan] = cb.data.tolist()
          outputdict['{}.dtype'.format(chan)] = str(cb.data.dtype)
        except KeyError:
          raise Exception ("Channel %s not found" % ( chan ))

      outputdict['shape'] = cb.data.shape

      jsonstr = json.dumps ( outputdict )

      return django.http.HttpResponse(json.dumps(outputdict), content_type="application/json")


  except:
    raise

def synaptogram_view_old (request, webargs):
  """Render a synaptogram as a Web page"""

  try:

    # token and channels
    token, chanstr, centroidstr, rest = webargs.split('/',3)

    channels = chanstr.split(',')
    centroid =  map(lambda x: int(x),centroidstr.split(','))


    # create the synaptogram object
    sog = synaptogram.Synaptogram ( token, channels, centroid )

    # set options
    # if there is a reference string in the URL
    s = re.search ( 'reference/([\w\-,]+)/', rest )
    if s != None:
      sog.setReference(s.group(1).split(','))

    # tell which channels are EM channels -- no reference
    s = re.search ( 'EM/([\w\-,]+)/', rest )
    if s != None:
      sog.setEM(s.group(1).split(','))

    # if there is a enhance string in the URL
    s = re.search ( 'enhance/([\d.]+)/', rest )
    if s != None:
      sog.setEnhance(float(s.group(1)))
      
    s = re.search ( 'normalize/', rest )
    if s != None:
      sog.setNormalize()

    s = re.search ( 'normalize2/', rest )
    if s != None:
      sog.setNormalize2()

    # resolution
    s = re.search ( 'resolution/([\d]+)/', rest )
    if s != None:
      sog.setResolution(int(s.group(1)))

    # Width of the input data
    s = re.search ( 'width/([\d]+)/', rest )
    if s != None:
      sog.setWidth(int(s.group(1)))

    # Width of the input data
    s = re.search ( 'tile/([\d]+)/', rest )
    if s != None:
      sog.setTileWidth(int(s.group(1)))

    # Width of the input data
    s = re.search ( 'frame/([\d]+)/', rest )
    if s != None:
      sog.setFrameWidth(int(s.group(1)))

    # construct the picture
    sogimg = sog.construct()

    # Draw the image file
    fobj = cStringIO.StringIO() 
    sogimg.save ( fobj, "PNG" )
    fobj.seek(0)
    return django.http.HttpResponse(fobj.read(), content_type="image/png" )

  except Exception, e:
    raise