rasterio/tests/test_transform.py

from affine import Affine
import pytest
import rasterio
from rasterio import transform
from rasterio.env import GDALVersion
from rasterio.transform import xy, rowcol
from rasterio.windows import Window


gdal_version = GDALVersion.runtime()


def test_window_transform():
    with rasterio.open('tests/data/RGB.byte.tif') as src:
        assert src.window_transform(((0, None), (0, None))) == src.transform
        assert src.window_transform(((None, None), (None, None))) == src.transform
        assert src.window_transform(
            ((1, None), (1, None))).c == src.bounds.left + src.res[0]
        assert src.window_transform(
            ((1, None), (1, None))).f == src.bounds.top - src.res[1]
        assert src.window_transform(
            ((-1, None), (-1, None))).c == src.bounds.left - src.res[0]
        assert src.window_transform(
            ((-1, None), (-1, None))).f == src.bounds.top + src.res[1]


def test_from_origin():
    with rasterio.open('tests/data/RGB.byte.tif') as src:
        w, n = src.xy(0, 0, offset='ul')
        xs, ys = src.res
        tr = transform.from_origin(w, n, xs, ys)
        assert [round(v, 7) for v in tr] == [round(v, 7) for v in src.transform]


def test_from_bounds():
    with rasterio.open('tests/data/RGB.byte.tif') as src:
        w, s, e, n = src.bounds
        tr = transform.from_bounds(w, s, e, n, src.width, src.height)
        assert [round(v, 7) for v in tr] == [round(v, 7) for v in src.transform]


def test_array_bounds():
    with rasterio.open('tests/data/RGB.byte.tif') as src:
        w, s, e, n = src.bounds
        height = src.height
        width = src.width
        tr = transform.from_bounds(w, s, e, n, src.width, src.height)
    assert (w, s, e, n) == transform.array_bounds(height, width, tr)


def test_window_bounds():
    with rasterio.open('tests/data/RGB.byte.tif') as src:

        rows = src.height
        cols = src.width

        # Test window for entire DS and each window in the DS
        assert src.window_bounds(((0, rows), (0, cols))) == src.bounds
        for _, window in src.block_windows():
            ds_x_min, ds_y_min, ds_x_max, ds_y_max = src.bounds
            w_x_min, w_y_min, w_x_max, w_y_max = src.window_bounds(window)
            assert ds_x_min <= w_x_min <= w_x_max <= ds_x_max
            assert ds_y_min <= w_y_min <= w_y_max <= ds_y_max


def test_affine_roundtrip(tmpdir):
    output = str(tmpdir.join('test.tif'))
    out_affine = Affine(2, 0, 0, 0, -2, 0)

    with rasterio.open(
        output, 'w',
        driver='GTiff',
        count=1,
        dtype=rasterio.uint8,
        width=1,
        height=1,
        transform=out_affine
    ) as out:
        assert out.transform == out_affine

    with rasterio.open(output) as out:
        assert out.transform == out_affine


@pytest.mark.skipif(
    gdal_version.at_least('2.3'),
    reason="Test only applicable to GDAL < 2.3")
def test_affine_identity(tmpdir):
    """
    Setting a transform with absolute values equivalent to Affine.identity()
    should result in a warning (not captured here) and read with
    affine that matches Affine.identity().
    """

    output = str(tmpdir.join('test.tif'))
    out_affine = Affine(1, 0, 0, 0, -1, 0)

    with rasterio.open(
        output, 'w',
        driver='GTiff',
        count=1,
        dtype=rasterio.uint8,
        width=1,
        height=1,
        transform=out_affine
    ) as out:
        assert out.transform == out_affine

    with rasterio.open(output) as out:
        assert out.transform == Affine.identity()


def test_from_bounds_two():
    width = 80
    height = 80
    left = -120
    top = 70
    right = -80.5
    bottom = 30.5
    tr = transform.from_bounds(left, bottom, right, top, width, height)
    # pixelwidth, rotation, ULX, rotation, pixelheight, ULY
    expected = Affine(0.49375, 0.0, -120.0, 0.0, -0.49375, 70.0)
    assert [round(v, 7) for v in tr] == [round(v, 7) for v in expected]

    # Round right and bottom
    right = -80
    bottom = 30
    tr = transform.from_bounds(left, bottom, right, top, width, height)
    # pixelwidth, rotation, ULX, rotation, pixelheight, ULY
    expected = Affine(0.5, 0.0, -120.0, 0.0, -0.5, 70.0)
    assert [round(v, 7) for v in tr] == [round(v, 7) for v in expected]


def test_xy():
    aff = Affine(300.0379266750948, 0.0, 101985.0,
                 0.0, -300.041782729805, 2826915.0)
    ul_x, ul_y = aff * (0, 0)
    xoff = aff.a
    yoff = aff.e
    assert xy(aff, 0, 0, offset='ul') == (ul_x, ul_y)
    assert xy(aff, 0, 0, offset='ur') == (ul_x + xoff, ul_y)
    assert xy(aff, 0, 0, offset='ll') == (ul_x, ul_y + yoff)
    expected = (ul_x + xoff, ul_y + yoff)
    assert xy(aff, 0, 0, offset='lr') == expected
    expected = (ul_x + xoff / 2, ul_y + yoff / 2)
    assert xy(aff, 0, 0, offset='center') == expected
    assert xy(aff, 0, 0, offset='lr') == \
        xy(aff, 0, 1, offset='ll') == \
        xy(aff, 1, 1, offset='ul') == \
        xy(aff, 1, 0, offset='ur')


def test_bogus_offset():
    with pytest.raises(ValueError):
        xy(None, 1, 0, offset='bogus')


def test_guard_transform_gdal_TypeError(path_rgb_byte_tif):
    """As part of the 1.0 migration, guard_transform() should raise a TypeError
    if a GDAL geotransform is encountered"""

    with rasterio.open(path_rgb_byte_tif) as src:
        aff = src.transform

    with pytest.raises(TypeError):
        transform.guard_transform(aff.to_gdal())


def test_tastes_like_gdal_identity():
    aff = Affine.identity()
    assert not transform.tastes_like_gdal(aff)
    assert transform.tastes_like_gdal(aff.to_gdal())


def test_rowcol():
    with rasterio.open("tests/data/RGB.byte.tif", 'r') as src:
        aff = src.transform
        left, bottom, right, top = src.bounds
        assert rowcol(aff, left, top) == (0, 0)
        assert rowcol(aff, right, top) == (0, src.width)
        assert rowcol(aff, right, bottom) == (src.height, src.width)
        assert rowcol(aff, left, bottom) == (src.height, 0)
        assert rowcol(aff, 101985.0, 2826915.0) == (0, 0)
        assert rowcol(aff, 101985.0 + 400.0, 2826915.0) == (0, 1)


def test_xy_rowcol_inverse():
    # TODO this is an ideal candiate for
    # property-based testing with hypothesis
    aff = Affine.identity()
    rows_cols = ([0, 0, 10, 10],
                 [0, 10, 0, 10])
    assert rows_cols == rowcol(aff, *xy(aff, *rows_cols))


def test_from_gcps():
    with rasterio.open("tests/data/white-gemini-iv.vrt", 'r') as src:
        aff = transform.from_gcps(src.gcps[0])
        assert not aff == src.transform
        assert len(aff) == 9
        assert not transform.tastes_like_gdal(aff)