+
−#!/usr/bin/env python
+
−#
+
−# Copyright 2007 Google Inc.
+
−#
+
−# 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.
+
−#
+
−
+
−"""Stub version of the images API."""
+
−
+
−
+
−
+
−import logging
+
−import StringIO
+
−
+
−try:
+
−  import PIL
+
−  from PIL import _imaging
+
−  from PIL import Image
+
−except ImportError:
+
−  import _imaging
+
−  import Image
+
−
+
−from google.appengine.api import apiproxy_stub
+
−from google.appengine.api import images
+
−from google.appengine.api.images import images_service_pb
+
−from google.appengine.runtime import apiproxy_errors
+
−
+
−
+
−def _ArgbToRgbaTuple(argb):
+
−  """Convert from a single ARGB value to a tuple containing RGBA.
+
−
+
−  Args:
+
−    argb: Signed 32 bit integer containing an ARGB value.
+
−
+
−  Returns:
+
−    RGBA tuple.
+
−  """
+
−  unsigned_argb = argb % 0x100000000
+
−  return ((unsigned_argb >> 16) & 0xFF,
+
−          (unsigned_argb >> 8) & 0xFF,
+
−          unsigned_argb & 0xFF,
+
−          (unsigned_argb >> 24) & 0xFF)
+
−
+
−
+
−class ImagesServiceStub(apiproxy_stub.APIProxyStub):
+
−  """Stub version of images API to be used with the dev_appserver."""
+
−
+
−  def __init__(self, service_name='images'):
+
−    """Preloads PIL to load all modules in the unhardened environment.
+
−
+
−    Args:
+
−      service_name: Service name expected for all calls.
+
−    """
+
−    super(ImagesServiceStub, self).__init__(service_name)
+
−    Image.init()
+
−
+
−  def _Dynamic_Composite(self, request, response):
+
−    """Implementation of ImagesService::Composite.
+
−
+
−    Based off documentation of the PIL library at
+
−    http://www.pythonware.com/library/pil/handbook/index.htm
+
−
+
−    Args:
+
−      request: ImagesCompositeRequest, contains image request info.
+
−      response: ImagesCompositeResponse, contains transformed image.
+
−    """
+
−    width = request.canvas().width()
+
−    height = request.canvas().height()
+
−    color = _ArgbToRgbaTuple(request.canvas().color())
+
−    canvas = Image.new("RGBA", (width, height), color)
+
−    sources = []
+
−    if (not request.canvas().width() or request.canvas().width() > 4000 or
+
−        not request.canvas().height() or request.canvas().height() > 4000):
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    if not request.image_size():
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    if not request.options_size():
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    if request.options_size() > images.MAX_COMPOSITES_PER_REQUEST:
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    for image in request.image_list():
+
−      sources.append(self._OpenImage(image.content()))
+
−
+
−    for options in request.options_list():
+
−      if (options.anchor() < images.TOP_LEFT or
+
−          options.anchor() > images.BOTTOM_RIGHT):
+
−        raise apiproxy_errors.ApplicationError(
+
−            images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−      if options.source_index() >= len(sources) or options.source_index() < 0:
+
−        raise apiproxy_errors.ApplicationError(
+
−            images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−      if options.opacity() < 0 or options.opacity() > 1:
+
−        raise apiproxy_errors.ApplicationError(
+
−            images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−      source = sources[options.source_index()]
+
−      x_anchor = (options.anchor() % 3) * 0.5
+
−      y_anchor = (options.anchor() / 3) * 0.5
+
−      x_offset = int(options.x_offset() + x_anchor * (width - source.size[0]))
+
−      y_offset = int(options.y_offset() + y_anchor * (height - source.size[1]))
+
−      alpha = options.opacity() * 255
+
−      mask = Image.new("L", source.size, alpha)
+
−      canvas.paste(source, (x_offset, y_offset), mask)
+
−    response_value = self._EncodeImage(canvas, request.canvas().output())
+
−    response.mutable_image().set_content(response_value)
+
−
+
−  def _Dynamic_Histogram(self, request, response):
+
−    """Trivial implementation of ImagesService::Histogram.
+
−
+
−    Based off documentation of the PIL library at
+
−    http://www.pythonware.com/library/pil/handbook/index.htm
+
−
+
−    Args:
+
−      request: ImagesHistogramRequest, contains the image.
+
−      response: ImagesHistogramResponse, contains histogram of the image.
+
−    """
+
−    image = self._OpenImage(request.image().content())
+
−    img_format = image.format
+
−    if img_format not in ("BMP", "GIF", "ICO", "JPEG", "PNG", "TIFF"):
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.NOT_IMAGE)
+
−    image = image.convert("RGBA")
+
−    red = [0] * 256
+
−    green = [0] * 256
+
−    blue = [0] * 256
+
−    for pixel in image.getdata():
+
−      red[int((pixel[0] * pixel[3]) / 255)] += 1
+
−      green[int((pixel[1] * pixel[3]) / 255)] += 1
+
−      blue[int((pixel[2] * pixel[3]) / 255)] += 1
+
−    histogram = response.mutable_histogram()
+
−    for value in red:
+
−      histogram.add_red(value)
+
−    for value in green:
+
−      histogram.add_green(value)
+
−    for value in blue:
+
−      histogram.add_blue(value)
+
−
+
−  def _Dynamic_Transform(self, request, response):
+
−    """Trivial implementation of ImagesService::Transform.
+
−
+
−    Based off documentation of the PIL library at
+
−    http://www.pythonware.com/library/pil/handbook/index.htm
+
−
+
−    Args:
+
−      request: ImagesTransformRequest, contains image request info.
+
−      response: ImagesTransformResponse, contains transformed image.
+
−    """
+
−    original_image = self._OpenImage(request.image().content())
+
−
+
−    new_image = self._ProcessTransforms(original_image,
+
−                                        request.transform_list())
+
−
+
−    response_value = self._EncodeImage(new_image, request.output())
+
−    response.mutable_image().set_content(response_value)
+
−
+
−  def _EncodeImage(self, image, output_encoding):
+
−    """Encode the given image and return it in string form.
+
−
+
−    Args:
+
−      image: PIL Image object, image to encode.
+
−      output_encoding: ImagesTransformRequest.OutputSettings object.
+
−
+
−    Returns:
+
−      str with encoded image information in given encoding format.
+
−    """
+
−    image_string = StringIO.StringIO()
+
−
+
−    image_encoding = "PNG"
+
−
+
−    if (output_encoding.mime_type() == images_service_pb.OutputSettings.JPEG):
+
−      image_encoding = "JPEG"
+
−
+
−      image = image.convert("RGB")
+
−
+
−    image.save(image_string, image_encoding)
+
−
+
−    return image_string.getvalue()
+
−
+
−  def _OpenImage(self, image):
+
−    """Opens an image provided as a string.
+
−
+
−    Args:
+
−      image: image data to be opened
+
−
+
−    Raises:
+
−      apiproxy_errors.ApplicationError if the image cannot be opened or if it
+
−      is an unsupported format.
+
−
+
−    Returns:
+
−      Image containing the image data passed in.
+
−    """
+
−    if not image:
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.NOT_IMAGE)
+
−
+
−    image = StringIO.StringIO(image)
+
−    try:
+
−      image = Image.open(image)
+
−    except IOError:
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_IMAGE_DATA)
+
−
+
−    img_format = image.format
+
−    if img_format not in ("BMP", "GIF", "ICO", "JPEG", "PNG", "TIFF"):
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.NOT_IMAGE)
+
−    return image
+
−
+
−  def _ValidateCropArg(self, arg):
+
−    """Check an argument for the Crop transform.
+
−
+
−    Args:
+
−      arg: float, argument to Crop transform to check.
+
−
+
−    Raises:
+
−      apiproxy_errors.ApplicationError on problem with argument.
+
−    """
+
−    if not isinstance(arg, float):
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−
+
−    if not (0 <= arg <= 1.0):
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−
+
−  def _CalculateNewDimensions(self,
+
−                              current_width,
+
−                              current_height,
+
−                              req_width,
+
−                              req_height):
+
−    """Get new resize dimensions keeping the current aspect ratio.
+
−
+
−    This uses the more restricting of the two requested values to determine
+
−    the new ratio.
+
−
+
−    Args:
+
−      current_width: int, current width of the image.
+
−      current_height: int, current height of the image.
+
−      req_width: int, requested new width of the image.
+
−      req_height: int, requested new height of the image.
+
−
+
−    Returns:
+
−      tuple (width, height) which are both ints of the new ratio.
+
−    """
+
−
+
−    width_ratio = float(req_width) / current_width
+
−    height_ratio = float(req_height) / current_height
+
−
+
−    if req_width == 0 or (width_ratio > height_ratio and req_height != 0):
+
−      return int(height_ratio * current_width), req_height
+
−    else:
+
−      return req_width, int(width_ratio * current_height)
+
−
+
−  def _Resize(self, image, transform):
+
−    """Use PIL to resize the given image with the given transform.
+
−
+
−    Args:
+
−      image: PIL.Image.Image object to resize.
+
−      transform: images_service_pb.Transform to use when resizing.
+
−
+
−    Returns:
+
−      PIL.Image.Image with transforms performed on it.
+
−
+
−    Raises:
+
−      BadRequestError if the resize data given is bad.
+
−    """
+
−    width = 0
+
−    height = 0
+
−
+
−    if transform.has_width():
+
−      width = transform.width()
+
−      if width < 0 or 4000 < width:
+
−        raise apiproxy_errors.ApplicationError(
+
−            images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−
+
−    if transform.has_height():
+
−      height = transform.height()
+
−      if height < 0 or 4000 < height:
+
−        raise apiproxy_errors.ApplicationError(
+
−            images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−
+
−    current_width, current_height = image.size
+
−    new_width, new_height = self._CalculateNewDimensions(current_width,
+
−                                                         current_height,
+
−                                                         width,
+
−                                                         height)
+
−
+
−    return image.resize((new_width, new_height), Image.ANTIALIAS)
+
−
+
−  def _Rotate(self, image, transform):
+
−    """Use PIL to rotate the given image with the given transform.
+
−
+
−    Args:
+
−      image: PIL.Image.Image object to rotate.
+
−      transform: images_service_pb.Transform to use when rotating.
+
−
+
−    Returns:
+
−      PIL.Image.Image with transforms performed on it.
+
−
+
−    Raises:
+
−      BadRequestError if the rotate data given is bad.
+
−    """
+
−    degrees = transform.rotate()
+
−    if degrees < 0 or degrees % 90 != 0:
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    degrees %= 360
+
−
+
−    degrees = 360 - degrees
+
−    return image.rotate(degrees)
+
−
+
−  def _Crop(self, image, transform):
+
−    """Use PIL to crop the given image with the given transform.
+
−
+
−    Args:
+
−      image: PIL.Image.Image object to crop.
+
−      transform: images_service_pb.Transform to use when cropping.
+
−
+
−    Returns:
+
−      PIL.Image.Image with transforms performed on it.
+
−
+
−    Raises:
+
−      BadRequestError if the crop data given is bad.
+
−    """
+
−    left_x = 0.0
+
−    top_y = 0.0
+
−    right_x = 1.0
+
−    bottom_y = 1.0
+
−
+
−    if transform.has_crop_left_x():
+
−      left_x = transform.crop_left_x()
+
−      self._ValidateCropArg(left_x)
+
−
+
−    if transform.has_crop_top_y():
+
−      top_y = transform.crop_top_y()
+
−      self._ValidateCropArg(top_y)
+
−
+
−    if transform.has_crop_right_x():
+
−      right_x = transform.crop_right_x()
+
−      self._ValidateCropArg(right_x)
+
−
+
−    if transform.has_crop_bottom_y():
+
−      bottom_y = transform.crop_bottom_y()
+
−      self._ValidateCropArg(bottom_y)
+
−
+
−    width, height = image.size
+
−
+
−    box = (int(transform.crop_left_x() * width),
+
−           int(transform.crop_top_y() * height),
+
−           int(transform.crop_right_x() * width),
+
−           int(transform.crop_bottom_y() * height))
+
−
+
−    return image.crop(box)
+
−
+
−  def _ProcessTransforms(self, image, transforms):
+
−    """Execute PIL operations based on transform values.
+
−
+
−    Args:
+
−      image: PIL.Image.Image instance, image to manipulate.
+
−      trasnforms: list of ImagesTransformRequest.Transform objects.
+
−
+
−    Returns:
+
−      PIL.Image.Image with transforms performed on it.
+
−
+
−    Raises:
+
−      BadRequestError if we are passed more than one of the same type of
+
−      transform.
+
−    """
+
−    new_image = image
+
−    if len(transforms) > images.MAX_TRANSFORMS_PER_REQUEST:
+
−      raise apiproxy_errors.ApplicationError(
+
−          images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
+
−    for transform in transforms:
+
−      if transform.has_width() or transform.has_height():
+
−        new_image = self._Resize(new_image, transform)
+
−
+
−      elif transform.has_rotate():
+
−        new_image = self._Rotate(new_image, transform)
+
−
+
−      elif transform.has_horizontal_flip():
+
−        new_image = new_image.transpose(Image.FLIP_LEFT_RIGHT)
+
−
+
−      elif transform.has_vertical_flip():
+
−        new_image = new_image.transpose(Image.FLIP_TOP_BOTTOM)
+
−
+
−      elif (transform.has_crop_left_x() or
+
−          transform.has_crop_top_y() or
+
−          transform.has_crop_right_x() or
+
−          transform.has_crop_bottom_y()):
+
−        new_image = self._Crop(new_image, transform)
+
−
+
−      elif transform.has_autolevels():
+
−        logging.info("I'm Feeling Lucky autolevels will be visible once this "
+
−                     "application is deployed.")
+
−      else:
+
−        logging.warn("Found no transformations found to perform.")
+
−
+
−    return new_image