mmcv 使用

# mmcv 使用

最近发现 open-mmlab 开发的 mmcv 比较好用，故在此记录下使用说明，用的比较多的应该是File IO 和 Image 的相关内容

# 文件读写（file_handlers）

对外提供统一的文件读写API，例如下面的示例

import mmcv

# load data from a file
data = mmcv.load('test.json')
data = mmcv.load('test.yaml')
data = mmcv.load('test.pkl')
# load data from a file-like object
with open('test.json', 'r') as f:
    data = mmcv.load(f, file_format='json')

# dump data to a string
json_str = mmcv.dump(data, file_format='json')

# dump data to a file with a filename (infer format from file extension)
mmcv.dump(data, 'out.pkl')

# dump data to a file with a file-like object
with open('test.yaml', 'w') as f:
    data = mmcv.dump(data, f, file_format='yaml')

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# 图像操作

# 图像的读写和展示

import mmcv

img = mmcv.imread('test.jpg')
img = mmcv.imread('test.jpg', flag='grayscale')
img_ = mmcv.imread(img) # nothing will happen, img_ = img
mmcv.imwrite(img, 'out.jpg')

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mmcv.imshow('tests/data/color.jpg')
# this is equivalent to

for i in range(10):
    img = np.random.randint(256, size=(100, 100, 3), dtype=np.uint8)
    mmcv.imshow(img, win_name='test image', wait_time=200)

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# 图像的 Resize

# resize to a given size
mmcv.imresize(img, (1000, 600), return_scale=True)

# resize to the same size of another image
mmcv.imresize_like(img, dst_img, return_scale=False)

# resize by a ratio
mmcv.imrescale(img, 0.5)

# resize so that the max edge no longer than 1000, short edge no longer than 800
# without changing the aspect ratio
mmcv.imrescale(img, (1000, 800))

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参考资料

https://mmcv.readthedocs.io/en/latest/io.html
https://mmcv.readthedocs.io/en/latest/image.html

上次更新: 2021/08/02, 21:04:52

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