mindspore.dataset.vision.Decode

class mindspore.dataset.vision.Decode(to_pil=False)

Decode the input image in RGB mode. Supported image formats: JPEG, BMP, PNG, TIFF, GIF(need to_pil=True ), WEBP(need to_pil=True ).

Supports Ascend hardware acceleration and can be enabled through the .device(“Ascend”) method.

Parameters

to_pil (bool, optional) – Whether to decode the image to the PIL data type. If True, the image will be decoded to the PIL data type, otherwise it will be decoded to the NumPy data type. Default: False.

Raises

• RuntimeError – If given tensor is not a 1D sequence.

• RuntimeError – If the input is not raw image bytes.

• RuntimeError – If the input image is already decoded.

Supported Platforms:

CPU Ascend

Examples

>>> import os
>>> import numpy as np
>>> from PIL import Image, ImageDraw
>>> import mindspore.dataset as ds
>>> import mindspore.dataset.vision as vision
>>>
>>> # Use the transform in dataset pipeline mode
>>> class MyDataset:
...     def __init__(self):
...         self.data = []
...         img = Image.new("RGB", (300, 300), (255, 255, 255))
...         draw = ImageDraw.Draw(img)
...         draw.ellipse(((0, 0), (100, 100)), fill=(255, 0, 0), outline=(255, 0, 0), width=5)
...         img.save("./1.jpg")
...         data = np.fromfile("./1.jpg", np.uint8)
...         self.data.append(data)
...
...     def __getitem__(self, index):
...         return self.data[0]
...
...     def __len__(self):
...         return 5
>>>
>>> my_dataset = MyDataset()
>>> generator_dataset = ds.GeneratorDataset(my_dataset, column_names="image")
>>> transforms_list = [vision.Decode(), vision.RandomHorizontalFlip()]
>>> generator_dataset = generator_dataset.map(operations=transforms_list, input_columns=["image"])
>>> for item in generator_dataset.create_dict_iterator(num_epochs=1, output_numpy=True):
...     print(item["image"].shape, item["image"].dtype)
...     break
(300, 300, 3) uint8
>>> os.remove("./1.jpg")
>>>
>>> # Use the transform in eager mode
>>> img = Image.new("RGB", (300, 300), (255, 255, 255))
>>> draw = ImageDraw.Draw(img)
>>> draw.polygon([(50, 50), (150, 50), (100, 150)], fill=(0, 255, 0), outline=(0, 255, 0))
>>> img.save("./2.jpg")
>>> data = np.fromfile("./2.jpg", np.uint8)
>>> output = vision.Decode()(data)
>>> print(output.shape, output.dtype)
(300, 300, 3) uint8
>>> os.remove("./2.jpg")

Tutorial Examples:

• Illustration of vision transforms

device(device_target='CPU')

Set the device for the current operator execution.

Parameters

device_target (str, optional) – The operator will be executed on this device. Currently supports CPU and Ascend . Default: CPU .

Raises

• TypeError – If device_target is not of type str.

• ValueError – If device_target is not within the valid set of [‘CPU’, ‘Ascend’].

Supported Platforms:

CPU Ascend

Examples

>>> import os
>>> import numpy as np
>>> from PIL import Image, ImageDraw
>>> import mindspore.dataset as ds
>>> import mindspore.dataset.vision as vision
>>> from mindspore.dataset.vision import Inter
>>>
>>> # Use the transform in dataset pipeline mode
>>> class MyDataset:
...     def __init__(self):
...         self.data = []
...         img = Image.new("RGB", (300, 300), (255, 255, 255))
...         draw = ImageDraw.Draw(img)
...         draw.ellipse(((0, 0), (100, 100)), fill=(255, 0, 0), outline=(255, 0, 0), width=5)
...         img.save("./1.jpg")
...         data = np.fromfile("./1.jpg", np.uint8)
...         self.data.append(data)
...
...     def __getitem__(self, index):
...         return self.data[0]
...
...     def __len__(self):
...         return 5
>>>
>>> my_dataset = MyDataset()
>>> generator_dataset = ds.GeneratorDataset(my_dataset, column_names="image")
>>> decode_op = vision.Decode().device("Ascend")
>>> resize_op = vision.Resize([100, 75], Inter.BICUBIC)
>>> transforms_list = [decode_op, resize_op]
>>> generator_dataset = generator_dataset.map(operations=transforms_list, input_columns=["image"])
>>> for item in generator_dataset.create_dict_iterator(num_epochs=1, output_numpy=True):
...     print(item["image"].shape, item["image"].dtype)
...     break
(100, 75, 3) uint8
>>> os.remove("./1.jpg")
>>>
>>> # Use the transform in eager mode
>>> img = Image.new("RGB", (300, 300), (255, 255, 255))
>>> draw = ImageDraw.Draw(img)
>>> draw.polygon([(50, 50), (150, 50), (100, 150)], fill=(0, 255, 0), outline=(0, 255, 0))
>>> img.save("./2.jpg")
>>> data = np.fromfile("./2.jpg", np.uint8)
>>> output = vision.Decode().device("Ascend")(data)
>>> print(output.shape, output.dtype)
(300, 300, 3) uint8
>>> os.remove("./2.jpg")

Tutorial Examples:

• Illustration of vision transforms