mmpretrain/docs/en/api/transforms.rst

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.. role:: hidden
:class: hidden-section
Data Transformations
***********************************
In MMClassification, the data preparation and the dataset is decomposed. The
datasets only define how to get samples' basic information from the file
system. These basic information includes the ground-truth label and raw images
data / the paths of images.
To prepare the inputs data, we need to do some transformations on these basic
information. These transformations includes loading, preprocessing and
formatting. And a series of data transformations makes up a data pipeline.
Therefore, you can find the a ``pipeline`` argument in the configs of dataset,
for example:
.. code:: python
img_norm_cfg = dict(
mean=[123.675, 116.28, 103.53], std=[58.395, 57.12, 57.375], to_rgb=True)
train_pipeline = [
dict(type='LoadImageFromFile'),
dict(type='RandomResizedCrop', size=224),
dict(type='RandomFlip', flip_prob=0.5, direction='horizontal'),
dict(type='Normalize', **img_norm_cfg),
dict(type='ImageToTensor', keys=['img']),
dict(type='ToTensor', keys=['gt_label']),
dict(type='Collect', keys=['img', 'gt_label'])
]
test_pipeline = [
dict(type='LoadImageFromFile'),
dict(type='Resize', size=256),
dict(type='CenterCrop', crop_size=224),
dict(type='Normalize', **img_norm_cfg),
dict(type='ImageToTensor', keys=['img']),
dict(type='Collect', keys=['img'])
]
data = dict(
train=dict(..., pipeline=train_pipeline),
val=dict(..., pipeline=test_pipeline),
test=dict(..., pipeline=test_pipeline),
)
Every item of a pipeline list is one of the following data transformations class. And if you want to add a custom data transformation class, the tutorial :doc:`Custom Data Pipelines </tutorials/data_pipeline>` will help you.
.. contents:: mmcls.datasets.pipelines
:depth: 2
:local:
:backlinks: top
.. currentmodule:: mmcls.datasets.pipelines
Loading
=======
LoadImageFromFile
---------------------
.. autoclass:: LoadImageFromFile
Preprocessing and Augmentation
==============================
CenterCrop
---------------------
.. autoclass:: CenterCrop
Lighting
---------------------
.. autoclass:: Lighting
Normalize
---------------------
.. autoclass:: Normalize
Pad
---------------------
.. autoclass:: Pad
Resize
---------------------
.. autoclass:: Resize
RandomCrop
---------------------
.. autoclass:: RandomCrop
RandomErasing
---------------------
.. autoclass:: RandomErasing
RandomFlip
---------------------
.. autoclass:: RandomFlip
RandomGrayscale
---------------------
.. autoclass:: RandomGrayscale
RandomResizedCrop
---------------------
.. autoclass:: RandomResizedCrop
ColorJitter
---------------------
.. autoclass:: ColorJitter
Composed Augmentation
---------------------
Composed augmentation is a kind of methods which compose a series of data
augmentation transformations, such as ``AutoAugment`` and ``RandAugment``.
.. autoclass:: AutoAugment
.. autoclass:: RandAugment
In composed augmentation, we need to specify several data transformations or
several groups of data transformations (The ``policies`` argument) as the
random sampling space. These data transformations are chosen from the below
table. In addition, we provide some preset policies in `this folder`_.
.. _this folder: https://github.com/open-mmlab/mmclassification/tree/master/configs/_base_/datasets/pipelines
.. autosummary::
:toctree: generated
:nosignatures:
:template: classtemplate.rst
AutoContrast
Brightness
ColorTransform
Contrast
Cutout
Equalize
Invert
Posterize
Rotate
Sharpness
Shear
Solarize
SolarizeAdd
Translate
Formatting
==========
Collect
---------------------
.. autoclass:: Collect
ImageToTensor
---------------------
.. autoclass:: ImageToTensor
ToNumpy
---------------------
.. autoclass:: ToNumpy
ToPIL
---------------------
.. autoclass:: ToPIL
ToTensor
---------------------
.. autoclass:: ToTensor
Transpose
---------------------
.. autoclass:: Transpose