45 TOP_LEFT = images_service_pb.CompositeImageOptions.TOP_LEFT

    46 TOP_CENTER = images_service_pb.CompositeImageOptions.TOP

    47 TOP_RIGHT = images_service_pb.CompositeImageOptions.TOP_RIGHT

    48 CENTER_LEFT = images_service_pb.CompositeImageOptions.LEFT

    49 CENTER_CENTER = images_service_pb.CompositeImageOptions.CENTER

    50 CENTER_RIGHT = images_service_pb.CompositeImageOptions.RIGHT

    51 BOTTOM_LEFT = images_service_pb.CompositeImageOptions.BOTTOM_LEFT

    52 BOTTOM_CENTER = images_service_pb.CompositeImageOptions.BOTTOM

    53 BOTTOM_RIGHT = images_service_pb.CompositeImageOptions.BOTTOM_RIGHT

    54 

    55 ANCHOR_TYPES = frozenset([TOP_LEFT, TOP_CENTER, TOP_RIGHT, CENTER_LEFT,

    56                           CENTER_CENTER, CENTER_RIGHT, BOTTOM_LEFT,

    57                           BOTTOM_CENTER, BOTTOM_RIGHT])

    58 

    60 

    61 MAX_COMPOSITES_PER_REQUEST = 16

   530   def histogram(self):

   531     """Calculates the histogram of the image.

   532 

   533     Returns: 3 256-element lists containing the number of occurences of each

   534     value of each color in the order RGB. As described at

   535     http://en.wikipedia.org/wiki/Color_histogram for N = 256. i.e. the first

   536     value of the first list contains the number of pixels with a red value of

   537     0, the second the number with a red value of 1.

   538 

   539     Raises:

   540       NotImageError when the image data given is not an image.

   541       BadImageError when the image data given is corrupt.

   542       LargeImageError when the image data given is too large to process.

   543       Error when something unknown, but bad, happens.

   544     """

   545     request = images_service_pb.ImagesHistogramRequest()

   546     response = images_service_pb.ImagesHistogramResponse()

   547 

   548     request.mutable_image().set_content(self._image_data)

   549     try:

   550       apiproxy_stub_map.MakeSyncCall("images",

   551                                      "Histogram",

   552                                      request,

   553                                      response)

   554     except apiproxy_errors.ApplicationError, e:

   555       if (e.application_error ==

   556           images_service_pb.ImagesServiceError.NOT_IMAGE):

   557         raise NotImageError()

   558       elif (e.application_error ==

   559             images_service_pb.ImagesServiceError.BAD_IMAGE_DATA):

   560         raise BadImageError()

   561       elif (e.application_error ==

   562             images_service_pb.ImagesServiceError.IMAGE_TOO_LARGE):

   563         raise LargeImageError()

   564       else:

   565         raise Error()

   566     histogram = response.histogram()

   567     return [histogram.red_list(),

   568             histogram.green_list(),

   569             histogram.blue_list()]

   570 

   691 

   692 def composite(inputs, width, height, color=0, output_encoding=PNG):

   693   """Composite one or more images onto a canvas.

   694 

   695   Args:

   696     inputs: a list of tuples (image_data, x_offset, y_offset, opacity, anchor)

   697     where

   698       image_data: str, source image data.

   699       x_offset: x offset in pixels from the anchor position

   700       y_offset: y offset in piyels from the anchor position

   701       opacity: opacity of the image specified as a float in range [0.0, 1.0]

   702       anchor: anchoring point from ANCHOR_POINTS. The anchor point of the image

   703       is aligned with the same anchor point of the canvas. e.g. TOP_RIGHT would

   704       place the top right corner of the image at the top right corner of the

   705       canvas then apply the x and y offsets.

   706     width: canvas width in pixels.

   707     height: canvas height in pixels.

   708     color: canvas background color encoded as a 32 bit unsigned int where each

   709     color channel is represented by one byte in order ARGB.

   710     output_encoding: a value from OUTPUT_ENCODING_TYPES.

   711 

   712   Returns:

   713       str, image data of the composited image.

   714 

   715   Raises:

   716     TypeError If width, height, color, x_offset or y_offset are not of type

   717     int or long or if opacity is not a float

   718     BadRequestError If more than MAX_TRANSFORMS_PER_REQUEST compositions have

   719     been requested, if the canvas width or height is greater than 4000 or less

   720     than or equal to 0, if the color is invalid or if for any composition

   721     option, the opacity is outside the range [0,1] or the anchor is invalid.

   722   """

   723   if (not isinstance(width, (int, long)) or

   724       not isinstance(height, (int, long)) or

   725       not isinstance(color, (int, long))):

   726     raise TypeError("Width, height and color must be integers.")

   727   if output_encoding not in OUTPUT_ENCODING_TYPES:

   728     raise BadRequestError("Output encoding type '%s' not in recognized set "

   729                           "%s" % (output_encoding, OUTPUT_ENCODING_TYPES))

   730 

   731   if not inputs:

   732     raise BadRequestError("Must provide at least one input")

   733   if len(inputs) > MAX_COMPOSITES_PER_REQUEST:

   734     raise BadRequestError("A maximum of %d composition operations can be"

   735                           "performed in a single request" %

   736                           MAX_COMPOSITES_PER_REQUEST)

   737 

   738   if width <= 0 or height <= 0:

   739     raise BadRequestError("Width and height must be > 0.")

   740   if width > 4000 or height > 4000:

   741     raise BadRequestError("Width and height must be <= 4000.")

   742 

   743   if color > 0xffffffff or color < 0:

   744     raise BadRequestError("Invalid color")

   745   if color >= 0x80000000:

   746     color -= 0x100000000

   747 

   748   image_map = {}

   749 

   750   request = images_service_pb.ImagesCompositeRequest()

   751   response = images_service_pb.ImagesTransformResponse()

   752   for (image, x, y, opacity, anchor) in inputs:

   753     if not image:

   754       raise BadRequestError("Each input must include an image")

   755     if (not isinstance(x, (int, long)) or

   756         not isinstance(y, (int, long)) or

   757         not isinstance(opacity, (float))):

   758       raise TypeError("x_offset, y_offset must be integers and opacity must"

   759                       "be a float")

   760     if x > 4000 or x < -4000:

   761       raise BadRequestError("xOffsets must be in range [-4000, 4000]")

   762     if y > 4000 or y < -4000:

   763       raise BadRequestError("yOffsets must be in range [-4000, 4000]")

   764     if opacity < 0 or opacity > 1:

   765       raise BadRequestError("Opacity must be in the range 0.0 to 1.0")

   766     if anchor not in ANCHOR_TYPES:

   767       raise BadRequestError("Anchor type '%s' not in recognized set %s" %

   768                             (anchor, ANCHOR_TYPES))

   769     if image not in image_map:

   770       image_map[image] = request.image_size()

   771       request.add_image().set_content(image)

   772 

   773     option = request.add_options()

   774     option.set_x_offset(x)

   775     option.set_y_offset(y)

   776     option.set_opacity(opacity)

   777     option.set_anchor(anchor)

   778     option.set_source_index(image_map[image])

   779 

   780   request.mutable_canvas().mutable_output().set_mime_type(output_encoding)

   781   request.mutable_canvas().set_width(width)

   782   request.mutable_canvas().set_height(height)

   783   request.mutable_canvas().set_color(color)

   784 

   785   try:

   786     apiproxy_stub_map.MakeSyncCall("images",

   787                                    "Composite",

   788                                    request,

   789                                    response)

   790   except apiproxy_errors.ApplicationError, e:

   791     if (e.application_error ==

   792         images_service_pb.ImagesServiceError.BAD_TRANSFORM_DATA):

   793       raise BadRequestError()

   794     elif (e.application_error ==

   795           images_service_pb.ImagesServiceError.NOT_IMAGE):

   796       raise NotImageError()

   797     elif (e.application_error ==

   798           images_service_pb.ImagesServiceError.BAD_IMAGE_DATA):

   799       raise BadImageError()

   800     elif (e.application_error ==

   801           images_service_pb.ImagesServiceError.IMAGE_TOO_LARGE):

   802       raise LargeImageError()

   803     elif (e.application_error ==

   804           images_service_pb.ImagesServiceError.UNSPECIFIED_ERROR):

   805       raise TransformationError()

   806     else:

   807       raise Error()

   808 

   809   return response.image().content()

   810 

   811 

   812 def histogram(image_data):

   813   """Calculates the histogram of the given image.

   814 

   815   Args:

   816     image_data: str, source image data.

   817   Returns: 3 256-element lists containing the number of occurences of each

   818   value of each color in the order RGB.

   819 

   820   Raises:

   821     NotImageError when the image data given is not an image.

   822     BadImageError when the image data given is corrupt.

   823     LargeImageError when the image data given is too large to process.

   824     Error when something unknown, but bad, happens.

   825   """

   826   image = Image(image_data)

   827   return image.histogram()