Hello all the general idea is to create a galaxy-like map. I run into problems when I try to display a generated image. I used Python Image library to create the image and store it in the datastore.

when i try to load the image i get no error on the log console and no image on the browser. when i copy/paste the image link (including datastore key) i get a black screen and the following message:

The image “view-source:/localhost:8080/img?img_id=ag5kZXZ-c3BhY2VzaW0xMnINCxIHTWFpbk1hcBgeDA” cannot be displayed because it contains errors.

the firefox error console:

Error: Image corrupt or truncated: /localhost:8080/img?img_id=ag5kZXZ-c3BhY2VzaW0xMnINCxIHTWFpbk1hcBgeDA

import cgi
import datetime
import urllib
import webapp2
import jinja2
import os
import math
import sys



from google.appengine.ext import db
from google.appengine.api import users
from PIL import Image

#SNIP

#class to define the map entity
class MainMap(db.Model):
  defaultmap = db.BlobProperty(default=None)

#SNIP      


class Generator(webapp2.RequestHandler):
  def post(self):

        #SNIP

        test = Image.new("RGBA",(100, 100))
        dMap=MainMap()
        dMap.defaultmap = db.Blob(str(test))
        dMap.put()

        #SNIP

        result = db.GqlQuery("SELECT * FROM MainMap LIMIT 1").fetch(1)

        if result:
          print"item found<br>" #debug info

          if result[0].defaultmap:
              print"defaultmap found<br>" #debug info
              string = "<div><img src='/img?img_id=" + str(result[0].key()) + "' width='100' height='100'></img>"
              print string

        else:
            print"nothing found<br>"

    else:
        self.redirect('/?=error')
    self.redirect('/')


class Image_load(webapp2.RequestHandler):
    def get(self):
        self.response.out.write("started Image load")
        defaultmap = db.get(self.request.get("img_id"))
        if defaultmap.defaultmap:
            try:
              self.response.headers['Content-Type'] = "image/png"
              self.response.out.write(defaultmap.defaultmap)
              self.response.out.write("Image found")
            except:
              print "Unexpected error:", sys.exc_info()[0]
        else:
            self.response.out.write("No image")

#SNIP    



app = webapp2.WSGIApplication([('/', MainPage),
                               ('/generator', Generator),
                               ('/img', Image_load)],
                              debug=True)

the browser shows the "item found" and "defaultmap found" strings and a broken imagelink the exception handling does not catch any errors

Thanks for your help Regards Bert