kwcoco.util.lazy_frame_backends module

Ducktyped interfaces for loading subregions of images with standard slice syntax

class kwcoco.util.lazy_frame_backends.CacheDict(*args, cache_len: int = 10, **kwargs)

Bases: OrderedDict

Dict with a limited length, ejecting LRUs as needed.

Example

>>> c = CacheDict(cache_len=2)
>>> c[1] = 1
>>> c[2] = 2
>>> c[3] = 3
>>> c
CacheDict([(2, 2), (3, 3)])
>>> c[2]
2
>>> c[4] = 4
>>> c
CacheDict([(2, 2), (4, 4)])
>>>

References

https://gist.github.com/davesteele/44793cd0348f59f8fadd49d7799bd306

class kwcoco.util.lazy_frame_backends.LazySpectralFrameFile(fpath)

Bases: NiceRepr

Potentially faster than GDAL for HDR formats.

classmethod available()

Returns True if this backend is available

property ndim

property shape

property dtype

class kwcoco.util.lazy_frame_backends.LazyRasterIOFrameFile(fpath)

Bases: NiceRepr

fpath = ‘/home/joncrall/.cache/kwcoco/demo/large_hyperspectral/big_img_128.bsq’ lazy_rio = LazyRasterIOFrameFile(fpath) ds = lazy_rio._ds

classmethod available()

Returns True if this backend is available

property ndim

property shape

property dtype

class kwcoco.util.lazy_frame_backends.LazyGDalFrameFile(fpath, nodata_method=None, overview=None)

Bases: NiceRepr

Todo

• [ ] Move to its own backend module

• [ ] When used with COCO, allow the image metadata to populate the

  height, width, and channels if possible.

Example

>>> # xdoctest: +REQUIRES(module:osgeo)
>>> self = LazyGDalFrameFile.demo()
>>> print('self = {!r}'.format(self))
>>> self[0:3, 0:3]
>>> self[:, :, 0]
>>> self[0]
>>> self[0, 3]

>>> # import kwplot
>>> # kwplot.imshow(self[:])

Parameters

• fpath (str) – the path to the file to load

• nodata_method (None | int | str) – how to handle nodata

• overview (int) – The overview level to load (zero is no overview)

Example

>>> # See if we can reproduce the INTERLEAVE bug

data = np.random.rand(128, 128, 64) import kwimage import ubelt as ub from os.path import join dpath = ub.ensure_app_cache_dir(‘kwcoco/tests/reader’) fpath = join(dpath, ‘foo.tiff’) kwimage.imwrite(fpath, data, backend=’skimage’) recon1 = kwimage.imread(fpath) recon1.shape

self = LazyGDalFrameFile(fpath) self.shape self[:]

classmethod available()

Returns True if this backend is available

get_overview(overview)

Returns the overview relative to this one.

get_absolute_overview(overview)

Returns the overview relative to the base

classmethod demo(key='astro', dsize=None)

property ndim

property num_overviews

property num_absolute_overviews

property shape

property dtype