thirdparty/google_appengine/google/appengine/api/images/images_stub.py

   1 #!/usr/bin/env python
   2 #
   3 # Copyright 2007 Google Inc.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16 #
  17
  18 """Stub version of the images API."""
  19
  20
  21
  22 import logging
  23 import StringIO
  24
  25 try:
  26   import PIL
  27   from PIL import _imaging
  28   from PIL import Image
  29 except ImportError:
  30   import _imaging
  31   import Image
  32
  33 from google.appengine.api import apiproxy_stub
  34 from google.appengine.api import images
  35 from google.appengine.api.images import images_service_pb
  36 from google.appengine.runtime import apiproxy_errors
  37
  38
  39 def _ArgbToRgbaTuple(argb):
  40   """Convert from a single ARGB value to a tuple containing RGBA.
  41
  42   Args:
  43     argb: Signed 32 bit integer containing an ARGB value.
  44
  45   Returns:
  46     RGBA tuple.
  47   """
  48   unsigned_argb = argb % 0x100000000
  49   return ((unsigned_argb >> 16) & 0xFF,
  50           (unsigned_argb >> 8) & 0xFF,
  51           unsigned_argb & 0xFF,
  52           (unsigned_argb >> 24) & 0xFF)
  53
  54
  55 class ImagesServiceStub(apiproxy_stub.APIProxyStub):
  56   """Stub version of images API to be used with the dev_appserver."""
  57
  58   def __init__(self, service_name='images'):
  59     """Preloads PIL to load all modules in the unhardened environment.
  60
  61     Args:
  62       service_name: Service name expected for all calls.
  63     """
  64     super(ImagesServiceStub, self).__init__(service_name)
  65     Image.init()
  66
  67   def _Dynamic_Composite(self, request, response):
  68     """Implementation of ImagesService::Composite.
  69
  70     Based off documentation of the PIL library at
  71     http://www.pythonware.com/library/pil/handbook/index.htm
  72
  73     Args:
  74       request: ImagesCompositeRequest, contains image request info.
  75       response: ImagesCompositeResponse, contains transformed image.
  76     """
  77     width = request.canvas().width()
  78     height = request.canvas().height()
  79     color = _ArgbToRgbaTuple(request.canvas().color())
  80     canvas = Image.new("RGBA", (width, height), color)
  81     sources = []
  82     if (not request.canvas().width() or request.canvas().width() > 4000 or
  83         not request.canvas().height() or request.canvas().height() > 4000):
  84       raise apiproxy_errors.ApplicationError(
  85           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
  86     if not request.image_size():
  87       raise apiproxy_errors.ApplicationError(
  88           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
  89     if not request.options_size():
  90       raise apiproxy_errors.ApplicationError(
  91           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
  92     if request.options_size() > images.MAX_COMPOSITES_PER_REQUEST:
  93       raise apiproxy_errors.ApplicationError(
  94           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
  95     for image in request.image_list():
  96       sources.append(self._OpenImage(image.content()))
  97
  98     for options in request.options_list():
  99       if (options.anchor() < images.TOP_LEFT or
 100           options.anchor() > images.BOTTOM_RIGHT):
 101         raise apiproxy_errors.ApplicationError(
 102             images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 103       if options.source_index() >= len(sources) or options.source_index() < 0:
 104         raise apiproxy_errors.ApplicationError(
 105             images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 106       if options.opacity() < 0 or options.opacity() > 1:
 107         raise apiproxy_errors.ApplicationError(
 108             images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 109       source = sources[options.source_index()]
 110       x_anchor = (options.anchor() % 3) * 0.5
 111       y_anchor = (options.anchor() / 3) * 0.5
 112       x_offset = int(options.x_offset() + x_anchor * (width - source.size[0]))
 113       y_offset = int(options.y_offset() + y_anchor * (height - source.size[1]))
 114       alpha = options.opacity() * 255
 115       mask = Image.new("L", source.size, alpha)
 116       canvas.paste(source, (x_offset, y_offset), mask)
 117     response_value = self._EncodeImage(canvas, request.canvas().output())
 118     response.mutable_image().set_content(response_value)
 119
 120   def _Dynamic_Histogram(self, request, response):
 121     """Trivial implementation of ImagesService::Histogram.
 122
 123     Based off documentation of the PIL library at
 124     http://www.pythonware.com/library/pil/handbook/index.htm
 125
 126     Args:
 127       request: ImagesHistogramRequest, contains the image.
 128       response: ImagesHistogramResponse, contains histogram of the image.
 129     """
 130     image = self._OpenImage(request.image().content())
 131     img_format = image.format
 132     if img_format not in ("BMP", "GIF", "ICO", "JPEG", "PNG", "TIFF"):
 133       raise apiproxy_errors.ApplicationError(
 134           images_service_pb.ImagesServiceError.NOT_IMAGE)
 135     image = image.convert("RGBA")
 136     red = [0] * 256
 137     green = [0] * 256
 138     blue = [0] * 256
 139     for pixel in image.getdata():
 140       red[int((pixel[0] * pixel[3]) / 255)] += 1
 141       green[int((pixel[1] * pixel[3]) / 255)] += 1
 142       blue[int((pixel[2] * pixel[3]) / 255)] += 1
 143     histogram = response.mutable_histogram()
 144     for value in red:
 145       histogram.add_red(value)
 146     for value in green:
 147       histogram.add_green(value)
 148     for value in blue:
 149       histogram.add_blue(value)
 150
 151   def _Dynamic_Transform(self, request, response):
 152     """Trivial implementation of ImagesService::Transform.
 153
 154     Based off documentation of the PIL library at
 155     http://www.pythonware.com/library/pil/handbook/index.htm
 156
 157     Args:
 158       request: ImagesTransformRequest, contains image request info.
 159       response: ImagesTransformResponse, contains transformed image.
 160     """
 161     original_image = self._OpenImage(request.image().content())
 162
 163     new_image = self._ProcessTransforms(original_image,
 164                                         request.transform_list())
 165
 166     response_value = self._EncodeImage(new_image, request.output())
 167     response.mutable_image().set_content(response_value)
 168
 169   def _EncodeImage(self, image, output_encoding):
 170     """Encode the given image and return it in string form.
 171
 172     Args:
 173       image: PIL Image object, image to encode.
 174       output_encoding: ImagesTransformRequest.OutputSettings object.
 175
 176     Returns:
 177       str with encoded image information in given encoding format.
 178     """
 179     image_string = StringIO.StringIO()
 180
 181     image_encoding = "PNG"
 182
 183     if (output_encoding.mime_type() == images_service_pb.OutputSettings.JPEG):
 184       image_encoding = "JPEG"
 185
 186       image = image.convert("RGB")
 187
 188     image.save(image_string, image_encoding)
 189
 190     return image_string.getvalue()
 191
 192   def _OpenImage(self, image):
 193     """Opens an image provided as a string.
 194
 195     Args:
 196       image: image data to be opened
 197
 198     Raises:
 199       apiproxy_errors.ApplicationError if the image cannot be opened or if it
 200       is an unsupported format.
 201
 202     Returns:
 203       Image containing the image data passed in.
 204     """
 205     if not image:
 206       raise apiproxy_errors.ApplicationError(
 207           images_service_pb.ImagesServiceError.NOT_IMAGE)
 208
 209     image = StringIO.StringIO(image)
 210     try:
 211       image = Image.open(image)
 212     except IOError:
 213       raise apiproxy_errors.ApplicationError(
 214           images_service_pb.ImagesServiceError.BAD_IMAGE_DATA)
 215
 216     img_format = image.format
 217     if img_format not in ("BMP", "GIF", "ICO", "JPEG", "PNG", "TIFF"):
 218       raise apiproxy_errors.ApplicationError(
 219           images_service_pb.ImagesServiceError.NOT_IMAGE)
 220     return image
 221
 222   def _ValidateCropArg(self, arg):
 223     """Check an argument for the Crop transform.
 224
 225     Args:
 226       arg: float, argument to Crop transform to check.
 227
 228     Raises:
 229       apiproxy_errors.ApplicationError on problem with argument.
 230     """
 231     if not isinstance(arg, float):
 232       raise apiproxy_errors.ApplicationError(
 233           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 234
 235     if not (0 <= arg <= 1.0):
 236       raise apiproxy_errors.ApplicationError(
 237           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 238
 239   def _CalculateNewDimensions(self,
 240                               current_width,
 241                               current_height,
 242                               req_width,
 243                               req_height):
 244     """Get new resize dimensions keeping the current aspect ratio.
 245
 246     This uses the more restricting of the two requested values to determine
 247     the new ratio.
 248
 249     Args:
 250       current_width: int, current width of the image.
 251       current_height: int, current height of the image.
 252       req_width: int, requested new width of the image.
 253       req_height: int, requested new height of the image.
 254
 255     Returns:
 256       tuple (width, height) which are both ints of the new ratio.
 257     """
 258
 259     width_ratio = float(req_width) / current_width
 260     height_ratio = float(req_height) / current_height
 261
 262     if req_width == 0 or (width_ratio > height_ratio and req_height != 0):
 263       return int(height_ratio * current_width), req_height
 264     else:
 265       return req_width, int(width_ratio * current_height)
 266
 267   def _Resize(self, image, transform):
 268     """Use PIL to resize the given image with the given transform.
 269
 270     Args:
 271       image: PIL.Image.Image object to resize.
 272       transform: images_service_pb.Transform to use when resizing.
 273
 274     Returns:
 275       PIL.Image.Image with transforms performed on it.
 276
 277     Raises:
 278       BadRequestError if the resize data given is bad.
 279     """
 280     width = 0
 281     height = 0
 282
 283     if transform.has_width():
 284       width = transform.width()
 285       if width < 0 or 4000 < width:
 286         raise apiproxy_errors.ApplicationError(
 287             images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 288
 289     if transform.has_height():
 290       height = transform.height()
 291       if height < 0 or 4000 < height:
 292         raise apiproxy_errors.ApplicationError(
 293             images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 294
 295     current_width, current_height = image.size
 296     new_width, new_height = self._CalculateNewDimensions(current_width,
 297                                                          current_height,
 298                                                          width,
 299                                                          height)
 300
 301     return image.resize((new_width, new_height), Image.ANTIALIAS)
 302
 303   def _Rotate(self, image, transform):
 304     """Use PIL to rotate the given image with the given transform.
 305
 306     Args:
 307       image: PIL.Image.Image object to rotate.
 308       transform: images_service_pb.Transform to use when rotating.
 309
 310     Returns:
 311       PIL.Image.Image with transforms performed on it.
 312
 313     Raises:
 314       BadRequestError if the rotate data given is bad.
 315     """
 316     degrees = transform.rotate()
 317     if degrees < 0 or degrees % 90 != 0:
 318       raise apiproxy_errors.ApplicationError(
 319           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 320     degrees %= 360
 321
 322     degrees = 360 - degrees
 323     return image.rotate(degrees)
 324
 325   def _Crop(self, image, transform):
 326     """Use PIL to crop the given image with the given transform.
 327
 328     Args:
 329       image: PIL.Image.Image object to crop.
 330       transform: images_service_pb.Transform to use when cropping.
 331
 332     Returns:
 333       PIL.Image.Image with transforms performed on it.
 334
 335     Raises:
 336       BadRequestError if the crop data given is bad.
 337     """
 338     left_x = 0.0
 339     top_y = 0.0
 340     right_x = 1.0
 341     bottom_y = 1.0
 342
 343     if transform.has_crop_left_x():
 344       left_x = transform.crop_left_x()
 345       self._ValidateCropArg(left_x)
 346
 347     if transform.has_crop_top_y():
 348       top_y = transform.crop_top_y()
 349       self._ValidateCropArg(top_y)
 350
 351     if transform.has_crop_right_x():
 352       right_x = transform.crop_right_x()
 353       self._ValidateCropArg(right_x)
 354
 355     if transform.has_crop_bottom_y():
 356       bottom_y = transform.crop_bottom_y()
 357       self._ValidateCropArg(bottom_y)
 358
 359     width, height = image.size
 360
 361     box = (int(transform.crop_left_x() * width),
 362            int(transform.crop_top_y() * height),
 363            int(transform.crop_right_x() * width),
 364            int(transform.crop_bottom_y() * height))
 365
 366     return image.crop(box)
 367
 368   def _ProcessTransforms(self, image, transforms):
 369     """Execute PIL operations based on transform values.
 370
 371     Args:
 372       image: PIL.Image.Image instance, image to manipulate.
 373       trasnforms: list of ImagesTransformRequest.Transform objects.
 374
 375     Returns:
 376       PIL.Image.Image with transforms performed on it.
 377
 378     Raises:
 379       BadRequestError if we are passed more than one of the same type of
 380       transform.
 381     """
 382     new_image = image
 383     if len(transforms) > images.MAX_TRANSFORMS_PER_REQUEST:
 384       raise apiproxy_errors.ApplicationError(
 385           images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA)
 386     for transform in transforms:
 387       if transform.has_width() or transform.has_height():
 388         new_image = self._Resize(new_image, transform)
 389
 390       elif transform.has_rotate():
 391         new_image = self._Rotate(new_image, transform)
 392
 393       elif transform.has_horizontal_flip():
 394         new_image = new_image.transpose(Image.FLIP_LEFT_RIGHT)
 395
 396       elif transform.has_vertical_flip():
 397         new_image = new_image.transpose(Image.FLIP_TOP_BOTTOM)
 398
 399       elif (transform.has_crop_left_x() or
 400           transform.has_crop_top_y() or
 401           transform.has_crop_right_x() or
 402           transform.has_crop_bottom_y()):
 403         new_image = self._Crop(new_image, transform)
 404
 405       elif transform.has_autolevels():
 406         logging.info("I'm Feeling Lucky autolevels will be visible once this "
 407                      "application is deployed.")
 408       else:
 409         logging.warn("Found no transformations found to perform.")
 410
 411     return new_image