habana_frameworks.mediapipe.fn.Neg

Class:

• habana_frameworks.mediapipe.fn.Neg(**kwargs)

Define graph call:

• __call__(input)

Parameter:

• input - Input tensor to operator. Supported dimensions: minimum = 1, maximum = 5. Supported data types: INT32, FLOAT16, BFLOAT16, FLOAT32.

Description:

Resultant output tensor has the sign flipped for each element in input, computed as: y = -x.

Supported backend:

• HPU

Keyword Arguments

kwargs	Description
dtype	Ouptput data type. Type: habana_frameworks.mediapipe.media_types.dtype Default: FLOAT32 Optional: yes Supported data types: INT32 BFLOAT16 FLOAT32

Note

1. All input/output tensors must be of the same data type and they must have the same dimensionality.

2. This operator is agnostic to the data layout.

Example: Neg Operator

The following code snippet shows usage of Neg operator:

from habana_frameworks.mediapipe import fn
from habana_frameworks.mediapipe.mediapipe import MediaPipe
from habana_frameworks.mediapipe.media_types import imgtype as it
from habana_frameworks.mediapipe.media_types import dtype as dt

# Create media pipeline derived class
class myMediaPipe(MediaPipe):
    def __init__(self, device, dir, queue_depth, batch_size, img_h, img_w, img_c):
        super(
            myMediaPipe,
            self).__init__(
            device,
            queue_depth,
            batch_size,
            self.__class__.__name__)

        self.input = fn.ReadImageDatasetFromDir(shuffle=False,
                                                dir=dir,
                                                format="jpg")

        self.cast = fn.Cast(dtype=dt.FLOAT32, round_mode=0)

        # WHCN
        self.decode = fn.ImageDecoder(device="hpu",
                                      output_format=it.RGB_P,
                                      resize=[img_w, img_h])

        self.neg = fn.Neg(dtype=dt.FLOAT32)

        # WHCN -> CWHN
        self.transpose = fn.Transpose(permutation=[2, 0, 1, 3],
                                      tensorDim=4,
                                      dtype=dt.FLOAT32)

    def definegraph(self):
        images, labels = self.input()
        images = self.decode(images)
        images = self.cast(images)
        images = self.neg(images)
        images = self.transpose(images)
        return images, labels

def main():
    batch_size = 6
    img_width = 200
    img_height = 200
    img_channel = 3
    img_dir = "/path/to/images"
    queue_depth = 2
    columns = 3

    # Create media pipeline object
    pipe = myMediaPipe('hpu', img_dir, queue_depth, batch_size,
                        img_height, img_width, img_channel)

    # Build media pipeline
    pipe.build()

    # Initialize media pipeline iterator
    pipe.iter_init()

    # Run media pipeline
    images, labels = pipe.run()

    # Copy data to host from device as numpy array
    images = images.as_cpu().as_nparray()
    labels = labels.as_cpu().as_nparray()

    # Display data
    print('data:\n', images)

if __name__ == "__main__":
    main()

The following is the output of Neg operator:

data:
[[[[-122. -113.  -94.]
  [-121. -112.  -93.]
  [-118. -110.  -95.]

  ...

  [ -38.  -49.  -44.]
  [ -42.  -51.  -46.]
  [ -44.  -53.  -48.]]]]