def _transform_image(self, blob_key, options):
"""Construct and execute a transform request using the images stub.
Args:
blob_key: A str containing the blob_key of the image to transform.
options: A str containing the resize and crop options to apply to the
image.
Returns:
A str containing the tranformed (if necessary) image.
"""
resize, crop = self._parse_options(options)
image_data = images_service_pb.ImageData()
image_data.set_blob_key(blob_key)
image = _get_images_stub()._OpenImageData(image_data)
original_mime_type = image.format
width, height = image.size
# Crop to square if necessary
if crop:
crop_xform = None
if width > height:
# landscape: slice the sides
crop_xform = images_service_pb.Transform()
delta = (width - height) / (width * 2.0)
crop_xform.set_crop_left_x(delta)
crop_xform.set_crop_right_x(1.0 - delta)
elif width < height:
# portrait: slice the top and bottom with bias
crop_xform = images_service_pb.Transform()
delta = (height - width) / (height * 2.0)
top_delta = max(0.0, delta - 0.25)
bottom_delta = 1.0 - (2.0 * delta) + top_delta
crop_xform.set_crop_top_y(top_delta)
crop_xform.set_crop_bottom_y(bottom_delta)
if crop_xform:
image = _get_images_stub()._Crop(image, crop_xform)
# Resize
if resize is None:
if width > _DEFAULT_SERVING_SIZE or height > _DEFAULT_SERVING_SIZE:
resize = _DEFAULT_SERVING_SIZE
# resize value of 0 is valid and translates to 'serve at original size'.
if resize:
# Note that resize transform maintains the image aspect ratio.
resize_xform = images_service_pb.Transform()
resize_xform.set_width(resize)
resize_xform.set_height(resize)
image = _get_images_stub()._Resize(image, resize_xform)
output_settings = images_service_pb.OutputSettings()
# EncodeImage only saves out to JPEG or PNG. All image formats other than
# GIF or PNG, will be served as a JPEG.
output_mime_type = images_service_pb.OutputSettings.JPEG
if original_mime_type in ['PNG', 'GIF']:
output_mime_type = images_service_pb.OutputSettings.PNG
output_settings.set_mime_type(output_mime_type)
return (_get_images_stub()._EncodeImage(image, output_settings),
_MIME_TYPE_MAP[output_mime_type])
def expect_encode_image(self, data,
mime_type=images_service_pb.OutputSettings.JPEG):
"""Setup a mox expectation to images_stub._EncodeImage."""
output_settings = images_service_pb.OutputSettings()
output_settings.set_mime_type(mime_type)
self._images_stub._EncodeImage(mox.IsA(MockImage),
output_settings).AndReturn(data)
def _TransformImage(self, blob_key, options):
"""Construct and execute transform request to the images stub.
Args:
blob_key: blob_key to the image to transform.
options: resize and crop option string to apply to the image.
Returns:
The tranformed (if necessary) image bytes.
"""
resize, crop = self._ParseOptions(options)
image_data = images_service_pb.ImageData()
image_data.set_blob_key(blob_key)
image = self._images_stub._OpenImageData(image_data)
original_mime_type = image.format
width, height = image.size
if crop:
crop_xform = None
if width > height:
crop_xform = images_service_pb.Transform()
delta = (width - height) / (width * 2.0)
crop_xform.set_crop_left_x(delta)
crop_xform.set_crop_right_x(1.0 - delta)
elif width < height:
crop_xform = images_service_pb.Transform()
delta = (height - width) / (height * 2.0)
top_delta = max(0.0, delta - 0.25)
bottom_delta = 1.0 - (2.0 * delta) + top_delta
crop_xform.set_crop_top_y(top_delta)
crop_xform.set_crop_bottom_y(bottom_delta)
if crop_xform:
image = self._images_stub._Crop(image, crop_xform)
if resize is None:
if width > DEFAULT_SERVING_SIZE or height > DEFAULT_SERVING_SIZE:
resize = DEFAULT_SERVING_SIZE
if resize:
resize_xform = images_service_pb.Transform()
resize_xform.set_width(resize)
resize_xform.set_height(resize)
image = self._images_stub._Resize(image, resize_xform)
output_settings = images_service_pb.OutputSettings()
output_mime_type = images_service_pb.OutputSettings.JPEG
if original_mime_type in ['PNG', 'GIF']:
output_mime_type = images_service_pb.OutputSettings.PNG
output_settings.set_mime_type(output_mime_type)
return (self._images_stub._EncodeImage(image, output_settings),
self._mime_type_map[output_mime_type])